liu.seSearch for publications in DiVA
Change search
Refine search result
123 1 - 50 of 124
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • oxford
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 1.
    Wang, Hui
    et al.
    Wannan Med Coll, Peoples R China.
    Cai, Fengze
    Wannan Med Coll, Peoples R China.
    Zhou, Le
    Wannan Med Coll, Peoples R China.
    He, Jing
    Wannan Med Coll, Peoples R China.
    Feng, Dexiang
    Wannan Med Coll, Peoples R China.
    Wei, Yan
    Wannan Med Coll, Peoples R China.
    Feng, Zhijun
    Wannan Med Coll, Peoples R China.
    Gu, Xiaoxia
    Wannan Med Coll, Peoples R China.
    Uvdal, Kajsa
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Hu, Zhang-Jun
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    A red- emissive mitochondrial probe for imaging of the viscosity in living cells2019In: New Journal of Chemistry, ISSN 1144-0546, E-ISSN 1369-9261, Vol. 43, no 22, p. 8811-8815Article in journal (Refereed)
    Abstract [en]

    A novel water- soluble fluorescent probe L based on indole salts has been designed, synthesized and fully characterized. The systematic investigations demonstrated that probe L shows red emission and the fluorescence intensity is linear with the viscosity of the medium. Probe L is able to selectively accumulate in mitochondria within 1 min without any additional reagents for membrane permeabilization. It has been used to distinguish the viscosity differences between mitochondria in normal and nystatin- treated HeLa cells. In addition, due to the good photostability, probe L can be used to monitor the dynamics of mitochondria. These results support that probe L might provide a promising approach for the fluorescence detection of mitochondrial viscosity in living biological systems.

  • 2.
    Rodner, Marius
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Sensor and Actuator Systems. Linköping University, Faculty of Science & Engineering.
    Puglisi, Donatella
    Linköping University, Department of Physics, Chemistry and Biology, Sensor and Actuator Systems. Linköping University, Faculty of Science & Engineering.
    Ekeroth, Sebastian
    Linköping University, Department of Physics, Chemistry and Biology, Plasma and Coating Physics. Linköping University, Faculty of Science & Engineering.
    Helmersson, Ulf
    Linköping University, Department of Physics, Chemistry and Biology, Plasma and Coating Physics. Linköping University, Faculty of Science & Engineering.
    Shtepliuk, Ivan
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, Faculty of Science & Engineering.
    Yakimova, Rositsa
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, Faculty of Science & Engineering.
    Skallberg, Andreas
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Uvdal, Kajsa
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Schutze, Andreas
    Saarland Univ, Germany.
    Eriksson, Jens
    Linköping University, Department of Physics, Chemistry and Biology, Sensor and Actuator Systems. Linköping University, Faculty of Science & Engineering.
    Graphene Decorated with Iron Oxide Nanoparticles for Highly Sensitive Interaction with Volatile Organic Compounds2019In: Sensors, ISSN 1424-8220, E-ISSN 1424-8220, Vol. 19, no 4, article id 918Article in journal (Refereed)
    Abstract [en]

    Gases, such as nitrogen dioxide, formaldehyde and benzene, are toxic even at very low concentrations. However, so far there are no low-cost sensors available with sufficiently low detection limits and desired response times, which are able to detect them in the ranges relevant for air quality control. In this work, we address both, detection of small gas amounts and fast response times, using epitaxially grown graphene decorated with iron oxide nanoparticles. This hybrid surface is used as a sensing layer to detect formaldehyde and benzene at concentrations of relevance (low parts per billion). The performance enhancement was additionally validated using density functional theory calculations to see the effect of decoration on binding energies between the gas molecules and the sensor surface. Moreover, the time constants can be drastically reduced using a derivative sensor signal readout, allowing the sensor to work at detection limits and sampling rates desired for air quality monitoring applications.

  • 3.
    Wang, Xin
    et al.
    Shanghai Univ, Peoples R China.
    Fei, Siming
    Shanghai Univ, Peoples R China.
    Huang, Shoushuang
    Shanghai Univ, Peoples R China.
    Wu, Chenghao
    Shanghai Univ, Peoples R China.
    Zhao, Junru
    Shanghai Univ, Peoples R China.
    Chen, Zhiwen
    Shanghai Univ, Peoples R China.
    Uvdal, Kajsa
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Hu, Zhang-Jun
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering. Shanghai Univ, Peoples R China.
    MoS2 nanosheets inlaid in 3D fibrous N-doped carbon spheres for lithium-ion batteries and electrocatalytic hydrogen evolution reaction2019In: Carbon, ISSN 0008-6223, E-ISSN 1873-3891, Vol. 150, p. 363-370Article in journal (Refereed)
    Abstract [en]

    Molybdenum disulfide (MoS2) has received considerable interests in rechargeable lithium-ion batteries (LIBs) and hydrogen evolution reaction (HER). To overcome the instinct limitations of pristine MoS2, such as low conductivity, poor cyclic stability and rate performance, hybrid carbon-MoS2 composites are often practically applied to improve the electrochemical properties. Herein, a facile, scalable, and durable synthesis method is innovated to inlay MoS2 nanosheets into three-dimensional (3D) fibrous nitrogen-doped carbon spheres (FNCs) for achieving 3D FNC-MoS2 composites. The free-standing 3D FNC-MoS2 nanocomposites can be used as the anode for LIBs. It exhibits a high reversible capacity of similar to 700 mA h g(-1), and nearly no fading of the capacity nearly after 400 cycles at a current density of 1.2 A g(-1). Meanwhile, FNC-MoS2 exhibits superior HER activity accompanied by a small overpotential of around 194 mV in 0.5 M H2SO4. Tafel slopes are estimated to be 54 mV dec(-1), and the current density of FNC-MoS2 decreases very slightly compared to the initial one after 1000 cycles. We are convinced that the enhanced Li+ storage performance and HER activity are attributed to the synergistic effects and structural advantages, such as higher specific surface, larger pore volume, radical fibrous structure, and chemical/mechanical stability, achieved from the unique architectures of the title material. (C) 2019 Elsevier Ltd. All rights reserved.

  • 4.
    Hu, Jiwen
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering. Shanghai Univ, Peoples R China.
    Zhang, Xin
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Liu, Tingting
    Tongji Univ, Peoples R China.
    Gao, Hong-Wen
    Tongji Univ, Peoples R China.
    Lu, Senlin
    Shanghai Univ, Peoples R China.
    Uvdal, Kajsa
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Hu, Zhang-Jun
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering. Shanghai Univ, Peoples R China.
    Ratiometric fluorogenic determination of endogenous hypochlorous acid in living cells2019In: Spectrochimica Acta Part A - Molecular and Biomolecular Spectroscopy, ISSN 1386-1425, E-ISSN 1873-3557, Vol. 219, p. 232-239Article in journal (Refereed)
    Abstract [en]

    Hypochlorous acid (HClO) is one of the most important ROS (reactive oxygen species) and common pollutant in tap-water. However, the determination of HClO with fast response and high sensitivity/selectivity is still an urgent demanding. Here we fabricated a ratiometric fluorescent probe RC based on TBET (through-bond energy transfer) on the platform of coumarin and rhodamine with the thiosemicarbazide group as the linker. This probe could display the characteristic fluorescence emission of coumarin. Upon addition of HClO, the linker was reacted into an oxadiazole, resulting in the opening of spiro-ring of rhodamine. The resultant then gives ratiometric fluorogenic changes. The probe exhibits fast response and high selectivity and sensitivity towards HClO with a low limit of detection (similar to 140 nM). Eventually, RC is successfully applicated for determining spiked HClO in water samples and imaging endogenous HClO in living cells. (C) 2019 Published by Elsevier B.V.

  • 5.
    Xu, Weidong
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering. Key Laboratory of Flexible Electronics (KLOFE) and Institute of Advanced Materials (IAM), Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University (NanjingTech), Nanjing, China.
    Hu, Qi
    Key Laboratory of Flexible Electronics (KLOFE) and Institute of Advanced Materials (IAM), Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University (NanjingTech), Nanjing, China.
    Bai, Sai
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Bao, Chunxiong
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering. International Collaborative Laboratory of 2D Materials for Optoelectronics Science and Technology, Shenzhen University, Shenzhen, China.
    Miao, Yanfeng
    Key Laboratory of Flexible Electronics (KLOFE) and Institute of Advanced Materials (IAM), Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University (NanjingTech), Nanjing, China.
    Yuan, Zhongcheng
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Borzda, Tetiana
    Center for Nano Science and Technology @Polimi, Istituto Italiano di Tecnologia, Milan, Italy.
    Barker, Alex J.
    Center for Nano Science and Technology @Polimi, Istituto Italiano di Tecnologia, Milan, Italy.
    Tyukalova, Elizaveta
    School of Materials Science and Engineering, Nanyang Technological University (NTU), Singapore, Singapore.
    Hu, Zhang-Jun
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Kawecki, Maciej
    Laboratory for Nanoscale Materials Science, Empa, Dubendorf, Switzerland / Department of Physics, University of Basel, Basel, Switzerland.
    Wang, Heyong
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Yan, Zhibo
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering. Laboratory of Solid State Microstructures and Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, P. R. China.
    Liu, Xianjie
    Linköping University, Department of Physics, Chemistry and Biology, Surface Physics and Chemistry. Linköping University, Faculty of Science & Engineering.
    Shi, Xiaobo
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Uvdal, Kajsa
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Fahlman, Mats
    Linköping University, Department of Physics, Chemistry and Biology, Surface Physics and Chemistry. Linköping University, Faculty of Science & Engineering.
    Zhang, Wenjing
    International Collaborative Laboratory of 2D Materials for Optoelectronics Science and Technology, Shenzhen University, Shenzhen, China.
    Duchamp, Martial
    School of Materials Science and Engineering, Nanyang Technological University (NTU), Singapore, Singapore.
    Liu, Jun-Ming
    Laboratory of Solid State Microstructures and Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, P. R. China.
    Petrozza, Annamaria
    Center for Nano Science and Technology @Polimi, Istituto Italiano di Tecnologia, Milan, Italy.
    Wang, Jianpu
    Key Laboratory of Flexible Electronics (KLOFE) and Institute of Advanced Materials (IAM), Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University (NanjingTech), Nanjing, China.
    Liu, Li-Min
    Beijing Computational Science Research Center, Beijing, China / chool of Physics, Beihang University, Beijing, China .
    Huang, Wei
    ey Laboratory of Flexible Electronics (KLOFE) and Institute of Advanced Materials (IAM), Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University (NanjingTech), Nanjing, China / Shaanxi Institute of Flexible Electronics (SIFE), Northwestern Polytechnical University (NPU), Xi’an, China.
    Gao, Feng
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Rational molecular passivation for high-performance perovskite light-emitting diodes2019In: Nature Photonics, ISSN 1749-4885, E-ISSN 1749-4893, Vol. 13, no 6, p. 418-424Article in journal (Refereed)
    Abstract [en]

    A major efficiency limit for solution-processed perovskite optoelectronic devices, for example light-emitting diodes, is trap-mediated non-radiative losses. Defect passivation using organic molecules has been identified as an attractive approach to tackle this issue. However, implementation of this approach has been hindered by a lack of deep understanding of how the molecular structures influence the effectiveness of passivation. We show that the so far largely ignored hydrogen bonds play a critical role in affecting the passivation. By weakening the hydrogen bonding between the passivating functional moieties and the organic cation featuring in the perovskite, we significantly enhance the interaction with defect sites and minimize non-radiative recombination losses. Consequently, we achieve exceptionally high-performance near-infrared perovskite light-emitting diodes with a record external quantum efficiency of 21.6%. In addition, our passivated perovskite light-emitting diodes maintain a high external quantum efficiency of 20.1% and a wall-plug efficiency of 11.0% at a high current density of 200 mA cm−2, making them more attractive than the most efficient organic and quantum-dot light-emitting diodes at high excitations.

  • 6.
    Wang, Hui
    et al.
    Wannan Med Coll, Peoples R China.
    Fang, Bin
    Anhui Univ, Peoples R China.
    Kong, Lin
    Anhui Univ, Peoples R China.
    Li, Xiangzi
    Wannan Med Coll, Peoples R China.
    Feng, Zhijun
    Wannan Med Coll, Peoples R China.
    Wu, Yunjun
    Wannan Med Coll, Peoples R China.
    Uvdal, Kajsa
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Hu, Zhang-Jun
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    A novel Schiff base derivative: Synthesis, two-photon absorption properties and application for bioimaging2018In: Spectrochimica Acta Part A - Molecular and Biomolecular Spectroscopy, ISSN 1386-1425, E-ISSN 1873-3557, Vol. 198, p. 304-308Article in journal (Refereed)
    Abstract [en]

    A novel donor-pi-acceptor-pi-donor type (D-pi-A-pi-D) Schiff base derivative (L) has been designed and synthesized. The structure of L is confirmed by single-crystal X-ray diffraction analysis as well. The photophysical properties of compound L were comprehensively investigated by using both experimental and theoretical methods. The results indicate that L exhibits large Stokes shift and moderate two-photon action (2PA) cross-section in the near infrared (NIR) region. Furthermore, the confocal microscopy imaging study demonstrates that compound L could penetrate into cells and target the cellular mitochondria compartment. Due to its low cytotoxicity, compound L provides a promising tool for directly lighting up the mitochondria compartment in living HepG2 cells. (C) 2018 Elsevier B.V. All rights reserved.

  • 7.
    Wang, Hui
    et al.
    Wannan Med Coll, Peoples R China.
    Fang, Bin
    Anhui Univ, Peoples R China.
    Zhou, Le
    Wannan Med Coll, Peoples R China.
    Li, Di
    Wannan Med Coll, Peoples R China.
    Kong, Lin
    Anhui Univ, Peoples R China.
    Uvdal, Kajsa
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Hu, Zhang-Jun
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    A reversible and highly selective two-photon fluorescent "on-off-on" probe for biological Cu2+ detection2018In: Organic and biomolecular chemistry, ISSN 1477-0520, E-ISSN 1477-0539, Vol. 16, no 13, p. 2264-2268Article in journal (Refereed)
    Abstract [en]

    A two-photon active probe for physiological copper (Cu2+) detection is expected to play an important role in monitoring biological metabolism. Herein, a novel Schiff base derivative (E)-2,2-((4-((4-(diethylamino)-2-hydroxybenzylidene)amino)phenyl)azanediyl)bis(ethan-1-ol) (L) with remarkable two-photon activity was developed and synthetically investigated. L presents high selectivity and sensitivity for Cu2+ sensing in ethanol/HEPES buffer (v/v, 1:1), which is accompanied by the fluorescence switching off and subsequently on with the addition of EDTA. The mechanism for the detection of Cu2+ is further analyzed using H-1 NMR titration, mass spectra and theoretical calculations. Furthermore, since the probe L possesses good photophysical properties, excellent biocompatibility and low cytotoxicity, it is successfully applied to track Cu2+ in the cellular endoplasmic reticulum by two-photon fluorescence imaging, showing its potential value for practical applications in biological systems.

  • 8.
    Siribbal, Shifaa M.
    et al.
    Univ Cologne, Germany.
    Schlaefer, Johannes
    Univ Cologne, Germany.
    Ilyas, Shaista
    Univ Cologne, Germany.
    Hu, Zhangjun
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Uvdal, Kajsa
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Valldor, Martin
    Max Planck Inst Chem Phys Solids, Germany.
    Mathur, Sanjay
    Univ Cologne, Germany.
    Air-Stable Gadolinium Precursors for the Facile Microwave-Assisted Synthesis of Gd2O3 Nanocontrast Agents for Magnetic Resonance Imaging2018In: Crystal Growth & Design, ISSN 1528-7483, E-ISSN 1528-7505, Vol. 18, no 2, p. 633-641Article in journal (Refereed)
    Abstract [en]

    Using metal organic precursors in materials synthesis remains a challenge due to their high moisture susceptibility. In this work, we describe a facile methodology for the synthesis of Gd2O3-based contrast agents from two new gadolinium-based complexes. [Gd(PyTFP)(4)] (PyH) 1 (PyTFP = C8H5NOF3, Py = C5H5N) and [Gd(DMOTFP)(3)Py] 2 (DMOTFP = C8H7NO2F3) were synthesized via a classical ligand exchange reaction of [Gd{N(SiMe3)(2)}(3)] under inert conditions. As a result, X-ray diffraction analysis revealed a distorted square antiprismatic coordination and an augmented triangular prismatic arrangement of ligands around gadolinium atoms in 1 and 2, respectively. It also showed that 1 is an anionic complex of formula [Gd(PyTFP)(4)](PyH), while a neutral tris-compound, [Gd(DMOTFP)(3)Py], was obtained as a pyridine adduct in 2. Fast and reproducible microwave-assisted decomposition of 1 and 2 provided homogeneous Gd(OH)(3) nanorods at mild temperature without using any surfactant or capping reagent. As-synthesized nanorods were easily transformed into a cubic phase of Gd2O3 nanoparticles by thermal treatment under ambient conditions. The magnetic measurement showed the typical paramagnetic behavior of the Gd2O3 nanoparticles (NPs). The cytotoxicity profile demonstrates the biocompatibility and negligible toxicity of the as-synthesized nanoprobes. The suggested approach provides a new class of gadolinium-based precursors which allows facile synthesis of highly crystalline Gd2O3 NPs.

  • 9.
    Eriksson, Peter
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Tal, Alexey
    Linköping University, Department of Physics, Chemistry and Biology, Theoretical Physics. Linköping University, Faculty of Science & Engineering.
    Skallberg, Andreas
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Brommesson, Caroline
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Hu, Zhang-Jun
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Boyd, Robert
    Linköping University, Department of Physics, Chemistry and Biology, Plasma and Coating Physics. Linköping University, Faculty of Science & Engineering.
    Olovsson, Weine
    Linköping University, Department of Physics, Chemistry and Biology, Theoretical Physics. Linköping University, Faculty of Science & Engineering.
    Fairley, Neal
    Casa Software Ltd, Bay House, Teignmouth, United Kingdom.
    Abrikosov, Igor
    Linköping University, Department of Physics, Chemistry and Biology, Theoretical Physics. Linköping University, Faculty of Science & Engineering. Materials Modeling and Development Laboratory, National University of Science and Technology “MISIS”, Moscow, Russia.
    Zhang, Xuanjun
    Faculty of Health Sciences, University of Macau, Macau, SAR, China.
    Uvdal, Kajsa
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Cerium oxide nanoparticles with antioxidant capabilities and gadolinium integration for MRI contrast enhancement2018In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 8, article id 6999Article in journal (Refereed)
    Abstract [en]

    The chelating gadolinium-complex is routinely used as magnetic resonance imaging (MRI) -contrast enhancer. However, several safety issues have recently been reported by FDA and PRAC. There is an urgent need for the next generation of safer MRI-contrast enhancers, with improved local contrast and targeting capabilities. Cerium oxide nanoparticles (CeNPs) are designed with fractions of up to 50% gadolinium to utilize the superior MRI-contrast properties of gadolinium. CeNPs are well-tolerated in vivo and have redox properties making them suitable for biomedical applications, for example scavenging purposes on the tissue-and cellular level and during tumor treatment to reduce in vivo inflammatory processes. Our near edge X-ray absorption fine structure (NEXAFS) studies show that implementation of gadolinium changes the initial co-existence of oxidation states Ce3+ and Ce4+ of cerium, thereby affecting the scavenging properties of the nanoparticles. Based on ab initio electronic structure calculations, we describe the most prominent spectral features for the respective oxidation states. The as-prepared gadolinium-implemented CeNPs are 3-5 nm in size, have r(1)-relaxivities between 7-13 mM(-1) s(-1) and show clear antioxidative properties, all of which means they are promising theranostic agents for use in future biomedical applications.

  • 10.
    Kilpijarvi, Joni
    et al.
    Univ Oulu, Finland.
    Halonen, Niina
    Univ Oulu, Finland.
    Sobocinski, Maciej
    Univ Oulu, Finland.
    Hassinen, Antti
    Univ Oulu, Finland.
    Senevirathna, Bathiya
    Univ Maryland, MD 20742 USA.
    Uvdal, Kajsa
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Abshire, Pamela
    Univ Maryland, MD 20742 USA.
    Smela, Elisabeth
    Univ Maryland, MD 20742 USA.
    Kellokumpu, Sakari
    Univ Oulu, Finland.
    Juuti, Jari
    Univ Oulu, Finland.
    Lloyd Spetz, Anita
    Linköping University, Department of Physics, Chemistry and Biology, Sensor and Actuator Systems. Linköping University, Faculty of Science & Engineering.
    LTCC Packaged Ring Oscillator Based Sensor for Evaluation of Cell Proliferation2018In: Sensors, ISSN 1424-8220, E-ISSN 1424-8220, Vol. 18, no 10, article id 3346Article in journal (Refereed)
    Abstract [en]

    A complementary metal-oxide-semiconductor (CMOS) chip biosensor was developed for cell viability monitoring based on an array of capacitance sensors utilizing a ring oscillator. The chip was packaged in a low temperature co-fired ceramic (LTCC) module with a flip chip bonding technique. A microcontroller operates the chip, while the whole measurement system was controlled by PC. The developed biosensor was applied for measurement of the proliferation stage of adherent cells where the sensor response depends on the ratio between healthy, viable and multiplying cells, which adhere onto the chip surface, and necrotic or apoptotic cells, which detach from the chip surface. This change in cellular adhesion caused a change in the effective permittivity in the vicinity of the sensor element, which was sensed as a change in oscillation frequency of the ring oscillator. The sensor was tested with human lung epithelial cells (BEAS-2B) during cell addition, proliferation and migration, and finally detachment induced by trypsin protease treatment. The difference in sensor response with and without cells was measured as a frequency shift in the scale of 1.1 MHz from the base frequency of 57.2 MHz. Moreover, the number of cells in the sensor vicinity was directly proportional to the frequency shift.

  • 11.
    Hu, Zhang-Jun
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Yang, Guanqing
    Anhui Univ, Peoples R China.
    Hu, Jiwen
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Wang, Hui
    Anhui Univ, Peoples R China.
    Eriksson, Peter
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Zhang, Ruilong
    Anhui Univ, Peoples R China.
    Zhang, Zhongping
    Anhui Univ, Peoples R China.
    Uvdal, Kajsa
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Real-time visualizing the regulation of reactive oxygen species on Zn2+ release in cellular lysosome by a specific fluorescent probe2018In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 264, p. 419-425Article in journal (Refereed)
    Abstract [en]

    Reactive oxygen species (ROS) regulating the release of free zinc ions (Zn2+) in cellular lysosome is closely related to various pathways of cellular signal transduction, such as inflammation and oxidative stress. Directly visualizing Zn2+ release in lysosome is essential for in-depth understanding these physiological processes, and is still an atelic challenge. In this work, we successfully fabricate a lysosome-specific Zn2+ fluorescent probe and achieve the visualization of ROS-induced Zn2+ release in lysosome of inflammatory cells. The as-prepared probe combines a green fluorophore, an ionophore with five-dentate sites, and a morpholine as the lysosome-specific localization moiety. The fluorescence of the fluorophore in the free probe is suppressed by a photoinduced electron transfer (PET) process from nitrogen atoms in the ionophore. Upon the addition of Zn2+, the fluorescence can be promoted immediately, achieving the real-time detection. Meanwhile, the probe is sensitive and selective to Zn2+, which provides the capability to detect low-concentration of free Zn2+ in lysosomes. Accordingly, the Zn2+ release was clearly observed in lysosome with the increase of ROS levels when the inflammation occurred in living cells. (c) 2018 Published by Elsevier B.V.

    The full text will be freely available from 2020-03-07 12:11
  • 12.
    Hu, Jiwen
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering. Shanghai Univ, Peoples R China.
    Liu, TingTing
    Tongji Univ, Peoples R China.
    Gao, Hong-Wen
    Tongji Univ, Peoples R China.
    Lu, Senlin
    Shanghai Univ, Peoples R China.
    Uvdal, Kajsa
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Hu, Zhang-Jun
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering. Shanghai Univ, Peoples R China.
    Selective detections of Hg2+ and F- by using tailor-made fluorogenic probes2018In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 269, p. 368-376Article in journal (Refereed)
    Abstract [en]

    By ingeniously using a (imino)coumarin-precursor, three reactive fluorogenic probes of MP, FP, and FMP have been fabricated in a single facile synthetic route. MP and FP are able to respectively act as selective "turn-on" fluorescent probes for detecting Hg2+ and F- in buffer solution via specific analyte-induced reactions. Linear ranges for the detection of Hg2+ and F- are 0-10 mu M and 0-100 mu M with the limits of detection (LODs) of 4.0 x 10(-8) M and 1.14 x 10(-6) M (3 delta/slope), respectively. FMP is able to work as a molecular "AND" logic gate-based fluorogenic probe for monitoring the coexistence of Hg2+ and F- via a multistep reaction cascade. The analytes-induced sensing mechanisms have been determined by using high-performance liquid chromatography analysis (HPLC). In addition, three probes show negligible toxicity under the experimental conditions, and are successfully used for monitoring Hg2+ and F- in living cells with good cell permeability. The success of the work demonstrates that ingenious utility of specific analyte-induced reactions and conventional concepts on the appropriate molecular scaffold can definitely deliver tailor-made probes for various intended sensing purposes. (C) 2018 Published by Elsevier B.V.

    The full text will be freely available from 2020-05-05 01:20
  • 13.
    Skallberg, Andreas
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Brommesson, Caroline
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Uvdal, Kajsa
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Imaging XPS and photoemission electron microscopy; surface chemical mapping and blood cell visualization2017In: Biointerphases, ISSN 1934-8630, E-ISSN 1559-4106, Vol. 12, no 2, article id 02C408Article in journal (Refereed)
    Abstract [en]

    Combined photoemission electron microscopy (PEEM) and imaging x-ray photoelectron spectroscopy (XPS), i.e., electron spectroscopy for chemical analysis in the nanoregion, has been used for surface characterization of bio-relevant and biological samples. In the first example, the authors prepared a gold patterned silicon substrate, stepwise surface modified by self-assembled monolayers followed by quantum dot (QDot) specific linking and investigated by means of work function mapping and elemental imaging in the submicrometer range. Spatially resolved core level images of C1s, V2p, and Y3d are obtained, which verify the selective thiol adsorption on the gold squares and specific binding of europium doped yttrium vanadate QDots on the self-assembled monolayer. The second example is platelet adhesion to Immunoglobulin G modified silicon surfaces, investigated by means of laterally resolved PEEM. Images of platelets clearly show activated cells with a morphology change including an enlarged surface area and elongated pseudopodia, with a lateral resolution of 140 nm. In the last example, neutrophils were allowed to attach to plain silicon surfaces and investigated by means of PEEM and imaging XPS. Here, the cells show a round shaped morphology, as expected. Threshold imaging with work function contrast is used to localize the area of interest, followed by elemental specific mapping on cells in the submicrometer region. Chemical shifts of C1s in photoemission are used to distinguish vital parts of the cell structure. The strong C1s (C-C) signal is achieved from the region of the cell membrane, i.e., high density of phospholipids, while C1s (C-N) and C1s (C-O) signals are obtained from the core of the cell, in good agreement with the presence of cytoplasm and deoxyribonucleic acid containing cell nucleus. The combination of PEEM and imaging XPS is shown here as a tool to deliver new insight into biological samples, i.e., a rapid sample overview is obtained based on low energy secondary electrons with work function contrast, followed by detailed studies in the narrow mode for elemental compositions based on photoemission. This study illustrates the strength of combined PEEM and XPS in the imaging mode on cell studies. (C) 2017 American Vacuum Society.

  • 14.
    Tian, Xiaohe
    et al.
    Anhui University, Peoples R China.
    Zhang, Qian
    Linköping University, Department of Physics, Chemistry and Biology, Surface Physics and Chemistry. Linköping University, Faculty of Science & Engineering. Anhui University, Peoples R China.
    Zhang, Mingzhu
    Anhui University, Peoples R China.
    Uvdal, Kajsa
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Wang, Qin
    Anhui Agriculture University, Peoples R China.
    Chen, Junyang
    Anhui University, Peoples R China.
    Du, Wei
    Anhui University, Peoples R China.
    Huang, Bei
    Anhui University, Peoples R China.
    Wu, Jieying
    Anhui University, Peoples R China.
    Tian, Yupeng
    Anhui University, Peoples R China; Nanjing University, Peoples R China.
    Probe for simultaneous membrane and nucleus labeling in living cells and in vivo bioimaging using a two-photon absorption water-soluble Zn(II) terpyridine complex with a reduced pi-conjugation system2017In: Chemical Science, ISSN 2041-6520, E-ISSN 2041-6539, Vol. 8, no 1, p. 142-149Article in journal (Refereed)
    Abstract [en]

    Small, biocompatible and water-soluble molecules with high two-photon absorption (2PA) cross-section values (delta) are in high demand for specific bioimaging applications. Here, two novel terpyridine derivative ligands with donor-acceptor (D-A) (L1) and donor-pi-acceptor (D-pi-A) (L2) models, and their corresponding Zn(II) complexes are designed and characterized. It was found that the two-photon absorption cross section values (d) in the near-infrared region (NIR, about 800 nm) are significantly enhanced for complexes 1 and 2 compared to their free D-A type ligand L1, while those of complexes 3 and 4 were greatly decreased relative to their free ligand L2, thus confirming that the smaller ligand (D-A type) displays a suitable Turn-ON fluorescence pair for two-photon fluorescence microscopy (2PFM). Firstly, the potential of simultaneously labeling a live cell plasma membrane and nucleus using complex 1 is demonstrated. In addition, live larval and adult zebrafish incubated with an optimal concentration of 1 demonstrated clear brain uptake. Lastly and importantly, using such a probe to visualize the blood-brain- barrier (BBB) capillary endothelial cells and penetrate the BBB into the central nervous system (CNS) intravenously in a mouse model is also explored.

  • 15.
    Hu, Jiwen
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering. Tongji University, Peoples R China.
    Hu, Zhang-Jun
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering. Shanghai University, Peoples R China.
    Chen, Zhiwen
    Shanghai University, Peoples R China.
    Gao, Hong-Wen
    Tongji University, Peoples R China.
    Uvdal, Kajsa
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    A logic gate-based fluorogenic probe for Hg2+ detection and its applications in cellular imaging2016In: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 919, p. 85-93Article in journal (Refereed)
    Abstract [en]

    A new colorimetric and fluorogenic probe (RN3) based on rhodamine-B has been successfully designed and synthesized. It displays a selective response to Hg2+ in the aqueous buffer solution over the other competing metals. Upon addition of Hg2+, the solution of RN3 exhibits a naked eye observable color change from colorless to red and an intensive fluorescence with about 105-fold enhancement. The changes in the color and fluorescence are ascribed to the ring-opening of spirolactam in rhodamine fluorophore, which is induced by a binding of the constructed receptor to Hg2+ with the association and dissociation constants of 0.22 x 10(5) M-1 and 25.2 mM, respectively. The Jobs plot experiment determines a 1: 1 binding stoichiometry between RN3 and Hg2+. The resultant "turn-on" fluorescence in buffer solution, allows the application of a method to determine Hg2+ levels in the range of 4.0-15.0 mu M, with the limit of detection (LOD) calculated at 60.7 nM (3 sigma/slope). In addition, the fluorescence turn-off and color fading-out happen to the mixture of RN3-Hg2+ by further addition of I- or S2-. The reversible switching cycles of fluorescence intensity upon alternate additions of Hg2+ and S2- demonstrate that RN3 can perform as an INHIBIT logic gate. Furthermore, the potential of RN3 as a fluorescent probe has been demonstrated for cellular imaging. (C) 2016 Elsevier B.V. All rights reserved.

  • 16.
    Hu, Jiwen
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering. Tongji University, Peoples R China.
    Hu, Zhang-Jun
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Liu, Sheng
    Huaibei Normal University, Peoples R China.
    Zhang, Qiong
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Gao, Hong-Wen
    Tongji University, Peoples R China.
    Uvdal, Kajsa
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    A new ratiometric fluorescent chemodosimeter based on an ICT modulation for the detection of Hg2+2016In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 230, p. 639-644Article in journal (Refereed)
    Abstract [en]

    We design and synthesize a new ratiometric fluorescent chemodosimeter (S1) for the selective and sensitive detection of Hg2+. Upon addition of Hg2+, the emission of the S1 exhibits a large bathochromic shift from 393 to 515 nm (up to 122 nm) which is ascribed to an intramolecular charge transfer process in the resultant. The Hg2+-induced dethioacetalization for sensing mechanism has been demonstrated by using high-performance liquid chromatography analysis of the sensing process. The interference experiments further demonstrate that S1 exhibits very high selectivity towards Hg2+ over other coexisting cations/anions. Subsequently, a good linearity of the concentrations of Hg2+ (0-15 mu M) vs the ratiometric signals (I-515/I-393) allows a fluorogenic method for the quantitative detection of Hg2+, with the limitation of detection determined to be 5.22 x 10(-7) M. (C) 2016 Elsevier B.V. All rights reserved.

  • 17.
    Hu, Zhang-Jun
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Hu, Jiwen
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, Faculty of Science & Engineering. Tongji University, Peoples R China.
    Wang, Hui
    Anhui University, Peoples R China.
    Zhang, Qiong
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Zhao, Meng
    Anhui University, Peoples R China.
    Brommesson, Caroline
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Tian, Yupeng
    Anhui University, Peoples R China.
    Gao, Hongwen
    Tongji University, Peoples R China.
    Zhang, Xuanjun
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, Faculty of Science & Engineering. University of Macau, Peoples R China.
    Uvdal, Kajsa
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    A TPA-caged precursor of (imino)coumarin for "turn-on" fluorogenic detection of Cu+2016In: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 933, p. 189-195Article in journal (Refereed)
    Abstract [en]

    We strategize to utilize the precursors of (imino) coumarin fluorophores to deliver novel reactive Cu+ probes, where tris[(2-pyridyl)-methyl] amine (TPA) works as a reactive receptor towards Cu+. To verify this strategy, CP1, a representative probe and relevant sensing behaviors towards Cu+ are presented here. CP1 features good solubility and fast response for monitoring labile copper in aqueous solution and live cells. The sensing mechanism of CP1 is determined by HPLC titration and mass spectrometric analysis. The probe CP1 exhibits a 60-fold fluorescence enhancement and a detection limitation of 10.8 nM upon the detection of Cu+. CP1 is further applied for imaging labile copper in live cells. This work provides a starting point for future development of Cu+ probes, based on in situ formation of (imino) coumarin scaffolds, as well as their further investigations of copper signaling and biological events. (C) 2016 Elsevier B.V. All rights reserved.

  • 18.
    Zhang, Qiong
    et al.
    Anhui University, Peoples R China.
    Luo, Lei
    Southwest University, Peoples R China.
    Xu, Hong
    Anhui University, Peoples R China.
    Hu, Zhang-Jun
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Brommesson, Caroline
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Wu, Jieying
    Anhui University, Peoples R China.
    Sun, Zhaoqi
    Anhui University, Peoples R China.
    Tian, Yupeng
    Anhui University, Peoples R China.
    Uvdal, Kajsa
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Design, synthesis, linear and nonlinear photophysical properties of novel pyrimidine-based imidazole derivatives2016In: New Journal of Chemistry, ISSN 1144-0546, E-ISSN 1369-9261, Vol. 40, no 4, p. 3456-3463Article in journal (Refereed)
    Abstract [en]

    Novel donor-pi-acceptor (D-pi-A) and donor-pi-acceptor-pi-donor (D-pi-A-pi-D) type pyrimidine imidazole derivatives with flexible ether chains (L1 and L2) have been efficiently synthesized through improved Knoevenagel condensation and Ullmann reactions with high yields. Based on systematic photophysical investigations and theoretical calculations, the structure-property relationships can be described as follows: (1) the linear and nonlinear optical properties of the target chromophores change regularly with increasing the number of branches and the polarity of the solvents. (2) The single-substituted chromophore L2 exhibited a remarkable negative solvato-kinetic effect, while the double-substituted chromophore L1 showed a positive solvato-kinetic effect. Significant bathochromic shifting of the emission spectra and larger Stokes shifts were observed in polar solvents. (3) The two-photon absorption (TPA) cross-section results further demonstrated that their TPA cross section values (delta) increase notably with increasing branch number, and the presence of high pi-delocalization could induce large size-scalable TPA enhancements. (4) By comprehensively considering the optical performance, cytotoxicity and solubility, L1 was identified as the better candidate for living cell (HepG2) imaging.

  • 19.
    Eriksson, Jens
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Applied Sensor Science. Linköping University, Faculty of Science & Engineering.
    Puglisi, Donatella
    Linköping University, Department of Physics, Chemistry and Biology, Applied Sensor Science. Linköping University, Faculty of Science & Engineering.
    Strandqvist, Carl
    Linköping University, Department of Physics, Chemistry and Biology, Applied Sensor Science. Linköping University, Faculty of Science & Engineering. Graphensic AB Linköping, Sweden.
    Gunnarsson, Rickard
    Linköping University, Department of Physics, Chemistry and Biology, Plasma and Coating Physics. Linköping University, Faculty of Science & Engineering.
    Ekeroth, Sebastian
    Linköping University, Department of Physics, Chemistry and Biology, Plasma and Coating Physics. Linköping University, Faculty of Science & Engineering.
    Ivanov, Ivan Gueorguiev
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, Faculty of Science & Engineering.
    Helmersson, Ulf
    Linköping University, Department of Physics, Chemistry and Biology, Plasma and Coating Physics. Linköping University, Faculty of Science & Engineering.
    Uvdal, Kajsa
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Yakimova, Rositsa
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, Faculty of Science & Engineering. Graphensic AB Linköping, Sweden.
    Lloyd Spetz, Anita
    Linköping University, Department of Physics, Chemistry and Biology, Applied Sensor Science. Linköping University, Faculty of Science & Engineering.
    Modified Epitaxial Graphene on SiC for Extremely Sensitive andSelective Gas Sensors2016In: Materials Science Forum, ISSN 0255-5476, E-ISSN 1662-9752, Vol. 858, p. 1145-1148Article in journal (Refereed)
    Abstract [en]

    Two-dimensional materials offer a unique platform for sensing where extremely high sensitivity is a priority, since even minimal chemical interaction causes noticeable changes inelectrical conductivity, which can be used for the sensor readout. However, the sensitivity has to becomplemented with selectivity, and, for many applications, improved response- and recovery times are needed. This has been addressed, for example, by combining graphene (for sensitivity) with metal/oxides (for selectivity) nanoparticles (NP). On the other hand, functionalization or modification of the graphene often results in poor reproducibility. In this study, we investigate thegas sensing performance of epitaxial graphene on SiC (EG/SiC) decorated with nanostructured metallic layers as well as metal-oxide nanoparticles deposited using scalable thin-film depositiontechniques, like hollow-cathode pulsed plasma sputtering. Under the right modification conditions the electronic properties of the surface remain those of graphene, while the surface chemistry can betuned to improve sensitivity, selectivity and speed of response to several gases relevant for airquality monitoring and control, such as nitrogen dioxide, benzene, and formaldehyde.

  • 20.
    Zhang, Qiong
    et al.
    Anhui University, Peoples R China; Anhui University, Peoples R China.
    Tian, Xiaohe
    UCL, England.
    Wang, Hui
    Anhui University, Peoples R China.
    Hu, Zhang-Jun
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Wu, Jieying
    Anhui University, Peoples R China.
    Zhou, Hongping
    Anhui University, Peoples R China.
    Zhang, Shengyi
    Anhui University, Peoples R China.
    Yang, Jiaxiang
    Anhui University, Peoples R China.
    Sun, Zhaoqi
    Anhui University, Peoples R China.
    Tian, Yupeng
    Anhui University, Peoples R China; Nanjing University, Peoples R China.
    Uvdal, Kajsa
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    NIR-region two-photon fluorescent probes for Fe3+/Cu2+ ions based on pyrimidine derivatives with different flexible chain2016In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 222, p. 574-578Article in journal (Refereed)
    Abstract [en]

    Two novel NIR-region two-photon fluorescent probes CCP and COP, show strong fluorescence quenching and good ratiometric responses toward Fe3+ and Cu2+, respectively; and their two-photon fluorescence are reversible by the subsequent addition of EDTA. CCP and COP are valuable candidates for two-photon imaging in the biological transparency window. (C) 2015 Elsevier B.V. All rights reserved.

  • 21.
    Zhang, Qiong
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering. Anhui University, Peoples R China.
    Tian, Xiaohe
    UCL, England.
    Hu, Zhang-Jun
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Brommesson, Caroline
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Wu, Jieying
    Anhui University, Peoples R China.
    Zhou, Hongping
    Anhui University, Peoples R China.
    Yang, Jiaxiang
    Anhui University, Peoples R China.
    Sun, Zhaoqi
    Anhui University, Peoples R China.
    Tian, Yupeng
    Anhui University, Peoples R China; Nanjing University, Peoples R China.
    Uvdal, Kajsa
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Nonlinear optical response and two-photon biological applications of a new family of imidazole-pyrimidine derivatives2016In: Dyes and pigments, ISSN 0143-7208, E-ISSN 1873-3743, Vol. 126, p. 286-295Article in journal (Refereed)
    Abstract [en]

    A series of novel D-pi-A type two-photon absorption (2PA) imidazole-pyrimidine derivatives (EX-1 similar to EX-4) have been synthesized and characterized, with EX-1 was crystallography confirmed. Based on systematic photophysical investigations, the structure property relationships can be drawn as follows: (1) Both theoretical and experimental studies indicated that the different donor groups have large influences on the optical properties. (2) The 2PA cross-section values (sigma) were obtained both by Z-Scan and two photon excited fluorescence (2PEF) measurements. 2PA cross sections show an increasing trend with increasing electron-donating strength and the number of branches. (3) Comprehensively considered the optical performance, molecular volume, cytotoxicity and solubility, EX-1 and EX-2 were identified to be the best candidates for living cells (HepG2) imaging. Moreover, the 2PA excitable features of EX-1 and EX-2 are capable of imaging in fresh mouses liver tissues with a depth of ca. 70 mu m. (C) 2015 Elsevier Ltd. All rights reserved.

  • 22.
    Zhang, Qiong
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering. Anhui University, Peoples R China.
    Tian, Xiaohe
    UCL, England.
    Hu, Zhang-Jun
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Brommesson, Caroline
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Wu, Jieying
    Anhui University, Peoples R China.
    Zhou, Hongping
    Anhui University, Peoples R China.
    Li, Shengli
    Anhui University, Peoples R China.
    Yang, Jiaxiang
    Anhui University, Peoples R China.
    Sun, Zhaoqi
    Anhui University, Peoples R China.
    Tian, Yupeng
    Anhui University, Peoples R China; Nanjing University, Peoples R China.
    Uvdal, Kajsa
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    A series of Zn(II) terpyridine complexes with enhanced two-photon-excited fluorescence for in vitro and in vivo bioimaging2015In: Journal of materials chemistry. B, ISSN 2050-750X, E-ISSN 2050-7518, Vol. 3, no 36, p. 7213-7221Article in journal (Refereed)
    Abstract [en]

    It is still a challenge to obtain two-photon excited fluorescent bioimaging probes with intense emission, high photo-stability and low cytotoxicity. In the present work, four Zn(II)-coordinated complexes (1-4) constructed from two novel D-A and D-p-A ligands (L-1 and L-2) are investigated both experimentally and theoretically, aiming to explore efficient two-photon probes for bioimaging. Molecular geometry optimization used for theoretical calculations is achieved using the crystallographic data. Notably, the results indicate that complexes 1 and 2 display enhanced two-photon absorption (2PA) cross sections compared to their corresponding D-A ligand (L1). Furthermore, it was found that complex 1 has the advantages of moderate 2PA cross section in the near-infrared region, longer fluorescence lifetime, higher quantum yield, good biocompatibility and enhanced two-photon excited fluorescence. Therefore, complex 1 is evaluated as a bioimaging probe for in vitro imaging of HepG2 cells, in which it is observed under a two-photon scanning microscope that complex 1 exhibits effective co-staining with endoplasmic reticulum (ER) and nuclear membrane; as well as for in vivo imaging of zebrafish larva, in which it is observed that complex 1 exhibits specificity in the intestinal system.

  • 23.
    Zhang, Xuanjun
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, The Institute of Technology.
    Wang, Wenjing
    Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, China.
    Hu, Zhangjun
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, The Institute of Technology.
    Wang, Guannan
    Liaoning Medical University, China.
    Uvdal, Kajsa
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, The Institute of Technology.
    Coordination polymers for energy transfer: Preparations, properties, sensing applications, and perspectives2015In: Coordination chemistry reviews, ISSN 0010-8545, E-ISSN 1873-3840, Vol. 284, p. 206-235Article, review/survey (Refereed)
    Abstract [en]

    This review highlights the recent progress of bulk and nanoscale coordination polymer (CP) materials forenergy transfer. Artificial light-harvesting materials with efficient energy transfer are practically usefulfor a variety of applications including photovoltaic, white emitting devices, and sensors. In the pastdecades CP (aka Metal-organic framework, MOF) has experienced rapid development due to a multitude of applications, including catalyst, gas storage and separations, non-linear optics, luminescence, and soon. Recent research has shown that CP is a very promising light-harvesting platform because the energytransfers can occur between different ligands, from ligand to metal centers, or from MOF skeleton to guestspecies. This review comprehensively surveyed synthetic approaches to light-harvesting CPs, and postfunctionalization. Sensing applications and achievements in energy-transfer CP nanoparticles and thinfilms were also discussed.

  • 24.
    Larsson, Emanuel
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, The Institute of Technology. Elettra Sincrotrone Trieste, Italy; University of Trieste, Italy.
    Dullin, Christian
    Institute of Diagnostic and Interventional Radiology, University Hospital Goettingen, Germany.
    Abrikossova, Natalia
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Mikac, Urša
    Jožef Stefan Institute, Ljubljana, Slovenia.
    Brommesson, Caroline
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Accardo, Agostino
    Department of Engineering and Architecture, University of Trieste, Italy.
    Tromba, Giuliana
    SYRMEP Beamline, Sincrotrone Trieste S.C.p.A, Italy.
    Uvdal, Kajsa
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Serša, Igor
    Jožef Stefan Institute, Ljubljana, Slovenia.
    Dual-modal CT and MRI functional and anatomical imaging using barium sulphate and gadolinium nanoparticle loaded macrophages in a preclinical asthma mouse model2015Manuscript (preprint) (Other academic)
    Abstract [en]

    Objectives In this study we investigated the potentials of dual-modal CT-MRI macrophage tracking, by a intratracheal instillation of a mixture of either gadolinium nanoparticles or barium sulphate loaded alveolar macrophages into mice of an allergic airway inflammation (asthma) model and their respective healthy control, imaged with Synchrotron X-rays microtomography (SR μCT) and Micro Magnetic Resonance Imaging (μMRI).

    Materials and Methods The mice were scanned ex vivo using SRμCT at 22 keV and with a 9.4 Tesla μMRI scanner. The CT and MRI data sets were registered and fused together, followed by quantitative and statistical analysis.

    Results The asthmatic sample injected with contrast agent loaded macrophages showed high absorbing spots inside the soft-tissue regions of the lung for the CT data set, as well as higher contrast for the soft-tissue in the MRI data set. Furthermore, the correlation analysis showed a perfect negative correlation between the soft tissue mean grey value in CT and the soft tissue mean grey value in MRI.

    Conclusion The dual-modal CT-MRI cell tracking of intratracheally administered macrophages (loaded with contrast agent) in an asthmatic mouse helps to extract synergistic information about the migration  behaviour of macrophages, where clusters of cells were detected in CT, while as a general increase of the soft-tissue contrast could be observed in MRI, due to a homogeneous cell distribution.

  • 25.
    Wang, Guannan
    et al.
    Liaoning Medical University, Peoples R China; Liaoning Medical University, Peoples R China.
    Zhang, Xuanjun
    University of Macau, Peoples R China.
    Liu, Yaxu
    Liaoning Medical University, Peoples R China; Liaoning Medical University, Peoples R China.
    Hu, Zhang-Jun
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Mei, Xifan
    Liaoning Medical University, Peoples R China; Liaoning Medical University, Peoples R China.
    Uvdal, Kajsa
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Magneto-fluorescent nanoparticles with high-intensity NIR emission, T-1-and T-2-weighted MR for multimodal specific tumor imaging2015In: Journal of materials chemistry. B, ISSN 2050-750X, E-ISSN 2050-7518, Vol. 3, no 15, p. 3072-3080Article in journal (Refereed)
    Abstract [en]

    Nanoparticles exhibiting bright near-infrared (NIR) fluorescence, T-1-and T-2-weighted MR were synthesized for specific tumor imaging. Clinically used Fe3O4 nanoparticles exhibit an intrinsic dark signal (T-2-weighted MRI), which sometimes misleads clinical diagnosis. Here, for the first time we integrated ultrasmall Fe3O4 nanoparticles (2-3 nm) with an NIR emitting semiconducting polymer for both T-1-and T-2-weighted MRI as well as fluorescence imaging of tumors. Bio-functionalized multi-modality fluorescent magnetic nanoparticles (FMNPs) functionalized with folic acid exhibit bright fluorescence and high relaxation (r(1) = 7.008 mM(-1) s(-1), r(2) = 26.788 mM(-1) s(-1), r(2)/r(1) = 3.8). These FMNPs have a small average dynamic size of about 20 nm with low aggregation and long circulation time. In vitro studies revealed that FMNPs can serve as an effective fluorescent probe to achieve targeting images of human A549 lung cancer cells without obvious cytotoxicity. In vivo experimental results show that the FMNPs are able to preferentially accumulate in tumor tissues for specific fluorescence imaging, T-1-and T-2-weighted MRI.

  • 26.
    Larsson, Emanuel
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, The Institute of Technology. Elettra Sincrotrone Trieste, Italy; University of Trieste, Italy.
    Dullin, Christian
    Institute of Diagnostic and Interventional Radiology, University Hospital Goettingen, Germany.
    Abrikossova, Natalia
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Brommesson, Caroline
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Mikac, Urša
    Jožef Stefan Institute, Ljubljana, Slovenia.
    Garrovo, Chiara
    Institute for Maternal and Child Health, IRCCS Burlo Garofolo, Trieste, Italy.
    Accardo, Agostino
    Department of Engineering and Architecture, University of Trieste, Italy.
    Tromba, Giuliana
    SYRMEP Beamline, Sincrotrone Trieste S.C.p.A, Italy.
    Serša, Igor
    Jožef Stefan Institute, Ljubljana, Slovenia.
    Uvdal, Kajsa
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Optimization of the loading efficacy for dual-modal CT/MRI macrophage tracking in lungs of an asthma mouse model2015Manuscript (preprint) (Other academic)
    Abstract [en]

    We present novel cell uptake methodologies related to the usage of MRI/CT contrast agents for the purpose of performing dual-modal cell tracking with macrophages in both MRI and CT. Two different techniques, namely Synchrotron X-rays microtomography and Micro Magnetic Resonance Imaging were used to investigate the contrast  enhancement, as an effect of the MRI/CT contrast agent cell uptake of mouse alveolar macrophages. Macrophages loaded with the  commercial contrast agent Micropaque® CT, containing barium sulphate (BaSO4) immersed in Sorbitol, showed a much higher contrast enhancement in CT, than an MRI/CT contrast agent based on Gadolinium nanoparticles (GdNPs). The CT contrast of GdNPs (at 5 mM of Gd) could be increased, by immersing the GdNPs in Sorbitol, while still maintaining a positive T1-contrast in MRI. The idea of co-loading macrophages with both BaSO4 and GdNP inside the same cells  presented a valid "trade off" between the optimal contrast in CT vs. MRI etc. It was concluded that while optimizing the cell uptake of contrast agent for cell tracking in MRI/CT, it is important to make a "trade off" between the following 3 parameters, 1) optimal contrast in CT, 2) optimal contrast in MRI and 3) metabolic cell activity, depending on the given application. These cell optimization ideas may be of importance to every field aiming to image an inflammatory disease, based on the utilization of contrast agent loaded macrophages.

  • 27.
    Larsson, Emanuel
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering. Elettra Sincrotrone Trieste, Italy; University of Trieste, Italy..
    Tromba, Giuliana
    Elettra Sincrotrone Trieste, Italy.
    Uvdal, Kajsa
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Accardo, Agostino
    University of Trieste, Italy.
    dal Monego, Simeone
    Cluster in Biomedicine s.c.r.l., Trieste, Italy.
    Biffi, Stefania
    Institute for Maternal and Child Health, IRCCS Burlo Garofolo, Trieste, Italy.
    Chiara, Garrovo
    Institute for Maternal and Child Health, IRCCS Burlo Garofolo, Trieste, Italy.
    Lorenzon, Andrea
    Cluster in Biomedicine s.c.r.l., Trieste, Italy.
    Dullin, Christian
    University of Medical Centre Gottingen, Germany.
    Quantification of structural alterations in lung disease—a proposed analysis methodology of CT scans of preclinical mouse models and patients2015In: Biomedical Physics & Engineering Express, ISSN 2057-1976, Vol. 1, no 3, article id 035201Article in journal (Refereed)
    Abstract [en]

    In this paper we have established a general investigative methodology for quantitative computed tomography (CT) lung image analysis in the sagittal, coronal and transversal orientation of lungs with various lung diseases. Mean values were recorded for the two parameters percentage volume and structural thickness based on stripe shaped volumes of interest (VOIs) from the XY (transversal), YZ (sagittal) and ZX (coronal) orientation, placed out in the left and right lung side. A one-way ANOVA with Tukey–Kramer 90% simultaneous confidence intervals for pair wise comparison of means was performed on each considered parameter, in order to detect any statistically significant differences in between the samples. This methodology was first tested on high resolution synchrotron micro-computed tomography images of a preclinical asthma mouse model, injected with barium sulfate filled alveolar macrophages, with the purpose of marking out asthmatic inflammation sites. Preclinical mouse models are today commonly used as artificial models for studying various human diseases, e.g. asthma. Therefore, in order to translate our methodology protocol also to clinical applications the proposed methodology was also tested on lung data sets of patients, with various lung diseases. The presented general methodology was proven to be successful for the quantification of lung structural differences in an asthma mouse model, as well as being applicable also on patient lungs with various lung diseases. The outlined analysis protocol was tested on images obtained only by means of CT, but could also potentially be applied on images of the lung obtained by other 3D-imaging techniques.

  • 28.
    Lindell, Linda
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Surface Physics and Chemistry. Linköping University, The Institute of Technology.
    Vahlberg, Cecilia
    Linköping University, Department of Physics, Chemistry and Biology, Sensor Science and Molecular Physics. Linköping University, The Institute of Technology.
    Uvdal, Kajsa
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Fahlman, Mats
    Linköping University, Department of Physics, Chemistry and Biology, Surface Physics and Chemistry. Linköping University, Faculty of Science & Engineering.
    Braun, Slawomir
    Linköping University, Department of Physics, Chemistry and Biology, Surface Physics and Chemistry. Linköping University, Faculty of Science & Engineering.
    Self-assembled monolayer engineered interfaces: Energy level alignment tuning through chain length and end-group polarity2015In: Journal of Electron Spectroscopy and Related Phenomena, ISSN 0368-2048, E-ISSN 1873-2526, Vol. 204, p. 140-144Article in journal (Refereed)
    Abstract [en]

    We explore the different mechanisms through which self-assembled monolayers can tailor energy level alignment at metal-organic semiconductor interfaces. We show that the large work function variation that can be induced by the self-assembled monolayer on gold has limited ability to tailor the interface energy level alignment of a subsequent organic semiconductor overlayer. (C) 2015 Elsevier B.V. All rights reserved.

  • 29.
    Hu, Zhang-Jun
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, The Institute of Technology. Tongji University, Shanghai, China .
    Hu, Jiwen
    Tongji University, Shanghai, China .
    Cui, Yang
    Tongji University, Shanghai, China .
    Wang, Guannan
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, The Institute of Technology.
    Zhang, Xuanjun
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, The Institute of Technology.
    Uvdal, Kajsa
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, The Institute of Technology.
    Gao, Hong-Wen
    Tongji University, Shanghai, China .
    A facile "click" reaction to fabricate a FRET-based ratiometric fluorescent Cu2+ probe2014In: Journal of materials chemistry. B, ISSN 2050-750X, E-ISSN 2050-7518, Vol. 2, no 28, p. 4467-4472Article in journal (Refereed)
    Abstract [en]

    A facile one-step Cu(I)-catalyzed "click" reaction, between a dansyl-azide and a propargyl-substituted rhodamine B hydrazide, is employed to fabricate a novel FRET ratiometric "off-on" fluorescent probe. The sensitive emission of the donor, a dansyl group, overlaps perfectly with the absorption of the acceptor, xanthene in the open-ring rhodamine. The proposed probe shows high selectivity towards Cu2+. The ratio of emission intensities at 568 and 540 nm (I-568/I-540) exhibits a drastic 28-fold enhancement upon addition of Cu2+. The probe shows an excellent linear relationship between emission ratios and the concentrations of Cu2+ from 10 to 50 mu M, with a detection limit (S/N = 3) of 0.12 mu M. The preliminary cellular studies demonstrated that the probe is cell membrane permeable and could be applied for ratiometric fluorescence imaging of intracellular Cu2+ with almost no cytotoxicity. The ingenuity of the probe design is to construct a FRET donor-acceptor interconnector and a selective receptor simultaneously by "click" reaction. The strategy was verified to have great potential for developing novel FRET probes for Cu2+.

  • 30.
    Hu, Jiwen
    et al.
    Tongji University, Peoples R China.
    Hu, Zhang-Jun
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, The Institute of Technology. Tongji University, Peoples R China.
    Cui, Yang
    Tongji University, Peoples R China.
    Zhang, Xuanjun
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, The Institute of Technology.
    Gao, Hong-Wen
    Tongji University, Peoples R China.
    Uvdal, Kajsa
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, The Institute of Technology.
    A rhodamine-based fluorescent probe for Hg2+ and its application for biological visualization2014In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 203, p. 452-458Article in journal (Refereed)
    Abstract [en]

    A new visible light excitable fluorescent probe (1) is synthesized by appending a hydroxymethyl-pyridine to rhodamine B hydrazide. The probe displays very specific Hg2+-induced colour change and fluorescent enhancement in the aqueous systems. The "turn-on" response of fluorescence is based on a binding-induced ring-opening process from the spirolactam (nonfluorescent) to acyclic xanthene (fluorescent) in rhodamine B. The coordinating atoms O-center dot-N-N-O-center dot from the hydroxymethyl-pyridine and rhodamine B hydrazide play dominant role in the formation of a complex with 1:1 stoichiometry of Hg2+ to 1. It exhibits a linear response in the range of 0.1-5 mu M with the limit of detection (LOD) of 15.7 nM (3 sigma/slope), while the calculated value of the association constant of Hg2+/1 is 0.70 x 10(5) M-1. Furthermore, confocal microscopy imaging experiment demonstrates the probe 1 can be applied as a fluorescent probe for visualization of Hg2+ in living HeLa cells.

  • 31.
    Larsson, Emanuel
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, The Institute of Technology. Department of Architecture and Engineering, University of Trieste, Trieste, Italy Sincrotrone Trieste S.C.p.A., Basovizza, Trieste, Italy .
    Brun, F.
    Department of Architecture and Engineering, University of of Trieste, Trieste, Italy, Sincrotrone Trieste S.C.p.A., Basovizza, Trieste, Italy.
    Tromba, G.
    Sincrotrone Trieste S.C.p.A., Basovizza, Trieste, Italy.
    Cataldi, P.
    Department of Pathological Anatomy, Bassa Friulana, Italy.
    Uvdal, Kajsa
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, The Institute of Technology.
    Accardo, A.
    Department of Architecture and Engineering, University of of Trieste, Trieste, Italy.
    Morphological characterization of the human calvarium in relation to the diploic and cranial thickness utilizing X-ray computed microtomography2014In: 13th Mediterranean Conference on Medical and Biological Engineering and Computing 2013, MEDICON 2013; Seville; Spain; 25 September 2013 through 28 September 2013, Springer, 2014, Vol. 41, p. 194-197Conference paper (Refereed)
    Abstract [en]

    When attempting to establish accurate models for the human diploe, micro-scale morphological differences in the four main areas of the calvaria could also be considered. In this study, X-ray computed microtomography (μ-CT) images were analyzed in order to quantitatively characterize the micro-architecture of the human calvarium diploe. A bone specimen from each area of the skull (temporal, frontal, parietal and occipital) was extracted from a set of 5 human donors and each specimen was characterized in terms of density, specific surface area, trabecular thickness, trabecular spacing. The obtained results revealed that subject-individual structural differences could be related with the diploic as well as the total cranial thickness of the human skull bones. Some tendencies of dependency could also be made with respect to the age of the subject. A consideration of these individual variations can improve traditional models that assume equal conditions throughout the skull. 

  • 32.
    Wang, Guannan
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, The Institute of Technology. Liaoning Medical University, Jinzhou, China .
    Zhang, Xuanjun
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Skallberg, Andreas
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Liu, Yaxu
    Liaoning Medical University, Peoples R China Liaoning Medical University, Peoples R China .
    Hu, Zhang-Jun
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Mei, Xifan
    Liaoning Medical University, Peoples R China .
    Uvdal, Kajsa
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    One-step synthesis of water-dispersible ultra-small Fe3O4 nanoparticles as contrast agents for T-1 and T-2 magnetic resonance imaging2014In: Nanoscale, ISSN 2040-3364, E-ISSN 2040-3372, Vol. 6, no 5, p. 2953-2963Article in journal (Refereed)
    Abstract [en]

    Uniform, highly water-dispersible and ultra-small Fe3O4 nanoparticles were synthesized via a modified one-step coprecipitation approach. The prepared Fe3O4 nanoparticles not only show good magnetic properties, long-term stability in a biological environment, but also exhibit good biocompatibility in cell viability and hemolysis assay. Due to the ultra-small sized and highly water-dispersibility, they exhibit excellent relaxivity properties, the 1.7 nm sized Fe3O4 nanoparticles reveal a low r(2)/r(1) ratio of 2.03 (r(1) = 8.20 mM(-1) s(-1), r(2) = 16.67 mM(-1) s(-1)); and the 2.2 nm sized Fe3O4 nanoparticles also appear to have a low r2/r1 ratio of 4.65 (r(1) = 6.15 mM(-1) s(-1), r(2) = 28.62 mM(-1) s(-1)). This demonstrates that the proposed ultra-small Fe3O4 nanoparticles have great potential as a new type of T-1 magnetic resonance imaging contrast agents. Especially, the 2.2 nm sized Fe3O4 nanoparticles, have a competitive r(1) value and r(2) value compared to commercial contrasting agents such as Gd-DTPA (r(1) = 4.8 mM(-1) s(-1)), and SHU-555C (r(2) = 69 mM(-1) s(-1)). In vitro and in vivo imaging experiments, show that the 2.2 nm sized Fe3O4 nanoparticles exhibit great contrast enhancement, long-term circulation, and low toxicity, which enable these ultrasmall sized Fe3O4 nanoparticles to be promising as T-1 and T-2 dual contrast agents in clinical settings.

  • 33.
    Selegård, Linnéa
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Ahrén, Maria
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Brommesson, Caroline
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, The Institute of Technology.
    Söderlind, Fredrik
    Linköping University, Department of Physics, Chemistry and Biology, Nanostructured Materials. Linköping University, The Institute of Technology.
    Persson, Per. O. Å
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, The Institute of Technology.
    Uvdal, Kajsa
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Bifunctional gadolinium decorated ZnO nanocrystals integrating both enhanced MR signal and bright fluorescence2013Manuscript (preprint) (Other academic)
    Abstract [en]

    Gadolinium decorated ZnO nanoparticles simultaneously possess both fluorescent and MR enhancement properties. These ZnO nanoparticles are crystalline and shielded by an amorphous gadolinium acetate matrix. Interestingly, the Gd-acetate decoration enhances the fluorescence emission of the ZnO nanoparticles. The quantum yield does increase for samples with high Gd/Zn relative ratios and these samples do also show a higher colloidal stability.

    In addition, these nanoparticles show an enhanced relaxivity value per Gd atom (r119.9mM1s-1) compared to results earlier reported both on Gd alloyed ZnO nanoparticles and pure Gd2O3 nanoparticles. This improvement is considered to be due to the close proximity of Gd atoms and surrounding water molecules. A comprehensive study of the quantum yield and the relaxivity, as a function of composition, enable us to identify the ultimate design/composition of gadolinium decorated ZnO nanoparticles for optimum fluorescence and MR enhancement properties.

  • 34.
    Zhang, Xuanjun
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, The Institute of Technology.
    Yu, Jiangbo
    Department of Chemistry, University of Washington, Seattle, USA.
    Rong, Yu
    Department of Chemistry, University of Washington, Seattle, USA.
    Ye, Fangmao
    Department of Chemistry, University of Washington, Seattle, USA.
    Chiu, Daniel T
    Department of Chemistry, University of Washington, Seattle, USA.
    Uvdal, Kajsa
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, The Institute of Technology.
    High-intensity near-IR fluorescence in semiconducting polymer dots achieved by cascade FRET strategy2013In: Chemical Science, ISSN 2041-6520, E-ISSN 2041-6539, Vol. 4, no 5, p. 2143-2151Article in journal (Refereed)
    Abstract [en]

    Near-IR (NIR) emitting semiconducting polymer dots (Pdots) with ultrabright fluorescence have been prepared for specific cellular targeting. A series of π-conjugated polymers were synthesized to form water dispersible multicomponent Pdots by an ultrasonication-assisted co-precipitation method. By optimizing cascade energy transfer in Pdots, high-intensity NIR fluorescence (Φ = 0.32) with tunable excitations, large absorption–emission separation (up to 330 nm), and narrow emission bands (FWHM = 44 nm) have been achieved. Single-particle fluorescence imaging show that the as-prepared NIR Pdots were more than three times brighter than the commercially available Qdot705 with comparable sizes under identical conditions of excitation and detection. Because of the covalent introduction of carboxylic acid groups into polymer side chains, the bioconjugation between NIR-emitting Pdots and streptavidins can be readily completed via these functional groups on the surface of Pdots. Furthermore, through flow cytometry and confocal fluorescence microscopy the NIR-emitting Pdot–streptavidin conjugates proved that they could effectively label EpCAM receptors on the surface of MCF-7 cells, via specific binding between streptavidin and biotin.

  • 35.
    Hu, Zhangjun
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Ahrén, Maria
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Selegård, Linnéa
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Skoglund, Caroline
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Söderlind, Fredrik
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Engström, Maria
    Linköping University, Center for Medical Image Science and Visualization (CMIV). Linköping University, Department of Medical and Health Sciences, Division of Radiological Sciences. Linköping University, Faculty of Health Sciences.
    Zhang, Xuanjun
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Uvdal, Kajsa
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Highly Water-Dispersible Surface-Modified Gd2O3 Nanoparticles for Potential Dual-Modal Bioimaging2013In: Chemistry - A European Journal, ISSN 0947-6539, E-ISSN 1521-3765, Vol. 19, no 38, p. 12658-12667Article in journal (Refereed)
    Abstract [en]

    Water-dispersible and luminescent gadolinium oxide (GO) nanoparticles (NPs) were designed and synthesized for potential dual-modal biological imaging. They were obtained by capping gadolinium oxide nanoparticles with a fluorescent glycol-based conjugated carboxylate (HL). The obtained nanoparticles (GO-L) show long-term colloidal stability and intense blue fluorescence. In addition, L can sensitize the luminescence of europium(III) through the so-called antenna effect. Thus, to extend the spectral ranges of emission, europium was introduced into L-modified gadolinium oxide nanoparticles. The obtained Eu-III-doped particles (Eu:GO-L) can provide visible red emission, which is more intensive than that without L capping. The average diameter of the monodisperse modified oxide cores is about 4nm. The average hydrodynamic diameter of the L-modified nanoparticles was estimated to be about 13nm. The nanoparticles show effective longitudinal water proton relaxivity. The relaxivity values obtained for GO-L and Eu:GO-L were r(1)=6.4 and 6.3s(-1)mM(-1) with r(2)/r(1) ratios close to unity at 1.4T. Longitudinal proton relaxivities of these nanoparticles are higher than those of positive contrast agents based on gadolinium complexes such as Gd-DOTA, which are commonly used for clinical magnetic resonance imaging. Moreover, these particles are suitable for cellular imaging and show good biocompatibility.

  • 36.
    Rong, Yu
    et al.
    University of Washington, WA USA .
    Wu, Changfeng
    Jilin University, Peoples R China .
    Yu, Jiangbo
    University of Washington, WA USA .
    Zhang, Xuanjun
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Ye, Fangmao
    University of Washington, WA USA .
    Zeigler, Maxwell
    University of Washington, WA USA .
    Gallina, Maria Elena
    University of Washington, WA USA .
    Wu, I-Che
    University of Washington, WA USA .
    Zhang, Yong
    University of Washington, WA USA .
    Chan, Yang-Hsiang
    University of Washington, WA USA .
    Sun, Wei
    University of Washington, WA USA .
    Uvdal, Kajsa
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Chiu, Daniel T.
    University of Washington, WA USA .
    Multicolor Fluorescent Semiconducting Polymer Dots with Narrow Emissions and High Brightness2013In: ACS Nano, ISSN 1936-0851, E-ISSN 1936-086X, Vol. 7, no 1, p. 376-384Article in journal (Refereed)
    Abstract [en]

    Fluorescent semiconducting polymer dots (Pdots) have attracted great interest because of their superior characteristics as fluorescent probes, such as high fluorescence brightness, fast radiative rates, and excellent photostability. However, currently available Pdots generally exhibit broad emission spectra, which significantly limit their usefulness in many biological applications Involving multiplex detections. Here, we describe the design and development of multicolor narrow emissive Pdots based on different boron dipyrromethene (BODIPY) units. BODIPY-containing semiconducting polymers emitting at multiple wavelengths were synthesized and used as precursors for preparing the Pdots, where intraparticle energy transfer led to highly bright, narrow emissions. The emission full width at half-maximum of the resulting Pdots varies from 40 to 55 nm, which is 15-2 times narrower than those of conventional semiconducting polymer dots. BODIPY 520 Pdots were about an order of magnitude brighter than commercial Qdot 525 under identical laser excitation conditions. Fluorescence imaging and flow cytometry experiments indicate that the narrow emissions from these bright Pdots are promising for multiplexed biological detections.

  • 37.
    Ahrén, Maria
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Söderlind, Fredrik
    Linköping University, Department of Physics, Chemistry and Biology, Nanostructured Materials. Linköping University, The Institute of Technology.
    Linares, Mathieu
    Linköping University, Department of Physics, Chemistry and Biology, Computational Physics. Linköping University, The Institute of Technology.
    Nordblad, Per
    Division of Solid State Physics, Department of Engineering Sciences, Uppsala University, Uppsala, Sweden.
    Norman, Patrick
    Linköping University, Department of Physics, Chemistry and Biology, Computational Physics. Linköping University, The Institute of Technology.
    Uvdal, Kajsa
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    One-step synthesis of sub 5 nm sized manganese oxide based nanoparticles2013Manuscript (preprint) (Other academic)
    Abstract [en]

    Sub 5 nm sized manganese oxide nanoparticles; MnOx (1 ≤ x ≤ 2), were synthesized via a short time room temperature synthesis route. The nanoparticles are crystalline, spherically shaped and in the size range of 2-4 nm as shown by transmission electron microscopy studies. Selected area electron diffraction patterns were collected and their appearance indicated that the nanoparticle cores are composed of MnO. Also, co-existence of the (II) and (III) oxidation states at the nanoparticle surface was verified by results achieved from infrared spectroscopy and X-ray photoelectron spectroscopy. These measurements also supported presence of a minor amount of acetate groups as well as a negligible fraction of carbonate groups at the nanoparticle surfaces. The interpretation of the IR spectra was confirmed by quantum chemical calculations using the high spin manganese nanoparticle Mn12O12(OAc)16(H2O)4, as a model system for the MnOx nanoparticle surface. Bulk MnO and Mn2O3 are known to be antiferromagnetic. The magnetic properties are however somewhat dependent of the crystallite size and changes when scaling down to the nanoregion. The MnOx (1 ≤ x ≤ 2) nanoparticles investigated in this work show a superparamagnetic behavior with a blocking temperature of approximately 12 K proven by means of SQUID measurements. The relaxivities of the nanoparticles and the Mn(OAc)2 precursors were studied with a bench top NMR analyzer verifying nanoparticle r1 and r2 of 0.5 and 6 mMs-1 respectively. The r1 relaxivity is lower than what is earlier reported for Gd based contrast agent, but improvements are expected by further surface modification, due to increased rotational time and higher water dispersability.

  • 38.
    Selegård, Linnéa
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Zakharov, Alexei
    MAX-lab, Lund University, Lund, Sweden.
    Skallberg, Andréas
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, The Institute of Technology.
    Abrikossova, Natalia
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Uvdal, Kajsa
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    PEEM, LEED and PES temperature study of Eu doped Gd2O3 nanoparticles and their interactions with silicon2013Manuscript (preprint) (Other academic)
    Abstract [en]

    We report the formation of silicate and silicide by annealing of a SiOx surface, with low coverage of Eu doped Gd2O3 nanoparticles. Interestingly, the annealing temperature required for removal of native oxide from the Si substrate decreases with as much as 200 degrees in presence of the nanoparticles. XPEEM, LEEM and MEM are used to monitor the silicide/silicate formation and SiOx removal. Fragmentation of the nanoparticles is observed, and the SiOx layer is gradually removed. Eu is migrating to clean Si areas during the annealing process, while Gd is found in areas where oxide is still present. This annealing process is clearly facilitated in the presence of rare-earth based nanoparticles, where nanoparticles are suggested to function as reaction sites. Reduction of the annealing temperature of SiOx substrates is also observed in presence of pure Eu3+ and Gd3+ ions, but to lesser extent. The significant reduction of the annealing temperature of SiO by several hundred degrees, in presence of Eu doped Gd2O3 nanoparticles, is remarkable. This type of material may find applications both within optoelectronics and processing microelectronic industry.

  • 39.
    Ahrén, Maria
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Selegård, Linnéa
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Söderlind, Fredrik
    Linköping University, Department of Physics, Chemistry and Biology, Nanostructured Materials. Linköping University, The Institute of Technology.
    Linares, Mathieu
    Linköping University, Department of Physics, Chemistry and Biology, Computational Physics. Linköping University, The Institute of Technology.
    Kauczor, Joanna
    Linköping University, Department of Physics, Chemistry and Biology, Computational Physics. Linköping University, The Institute of Technology.
    Norman, Patrick
    Linköping University, Department of Physics, Chemistry and Biology, Computational Physics. Linköping University, The Institute of Technology.
    Käll, Per-Olov
    Linköping University, Department of Physics, Chemistry and Biology, Physical Chemistry. Linköping University, The Institute of Technology.
    Uvdal, Kajsa
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    A simple polyol-free synthesis route to Gd2O3 nanoparticles for MRI applications: an experimental and theoretical study2012In: Journal of nanoparticle research, ISSN 1388-0764, E-ISSN 1572-896X, Vol. 14, no 8Article in journal (Refereed)
    Abstract [en]

    Chelated gadolinium ions, e. g., GdDTPA, are today used clinically as contrast agents for magnetic resonance imaging (MRI). An attractive alternative contrast agent is composed of gadolinium oxide nanoparticles as they have shown to provide enhanced contrast and, in principle, more straightforward molecular capping possibilities. In this study, we report a new, simple, and polyol-free way of synthesizing 4-5-nm-sized Gd2O3 nanoparticles at room temperature, with high stability and water solubility. The nanoparticles induce high-proton relaxivity compared to Gd-DTPA showing r(1) and r(2) values almost as high as those for free Gd3+ ions in water. The Gd2O3 nanoparticles are capped with acetate and carbonate groups, as shown with infrared spectroscopy, near-edge X-ray absorption spectroscopy, X-ray photoelectron spectroscopy and combined thermogravimetric and mass spectroscopy analysis. Interpretation of infrared spectroscopy data is corroborated by extensive quantum chemical calculations. This nanomaterial is easily prepared and has promising properties to function as a core in a future contrast agent for MRI.

  • 40.
    Abrikossova, Natalia
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Skoglund, Caroline
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, The Institute of Technology.
    Ahrén, Maria
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Bengtsson, Torbjorn
    University of Örebro, Sweden .
    Uvdal, Kajsa
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Effects of gadolinium oxide nanoparticles on the oxidative burst from human neutrophil granulocytes2012In: Nanotechnology, ISSN 0957-4484, E-ISSN 1361-6528, Vol. 23, no 27, p. 275101-Article in journal (Refereed)
    Abstract [en]

    We have previously shown that gadolinium oxide (Gd2O3) nanoparticles are promising candidates to be used as contrast agents in magnetic resonance (MR) imaging applications. In this study, these nanoparticles were investigated in a cellular system, as possible probes for visualization and targeting intended for bioimaging applications. We evaluated the impact of the presence of Gd2O3 nanoparticles on the production of reactive oxygen species (ROS) from human neutrophils, by means of luminol-dependent chemiluminescence. Three sets of Gd2O3 nanoparticles were studied, i.e. as synthesized, dialyzed and both PEG-functionalized and dialyzed Gd2O3 nanoparticles. In addition, neutrophil morphology was evaluated by fluorescent staining of the actin cytoskeleton and fluorescence microscopy. We show that surface modification of these nanoparticles with polyethylene glycol (PEG) is essential in order to increase their biocompatibility. We observed that the as synthesized nanoparticles markedly decreased the ROS production from neutrophils challenged with prey (opsonized yeast particles) compared to controls without nanoparticles. After functionalization and dialysis, more moderate inhibitory effects were observed at a corresponding concentration of gadolinium. At lower gadolinium concentration the response was similar to that of the control cells. We suggest that the diethylene glycol (DEG) present in the as synthesized nanoparticle preparation is responsible for the inhibitory effects on the neutrophil oxidative burst. Indeed, in the present study we also show that even a low concentration of DEG, 0.3%, severely inhibits neutrophil function. In summary, the low cellular response upon PEG-functionalized Gd2O3 nanoparticle exposure indicates that these nanoparticles are promising candidates for MR-imaging purposes.

  • 41.
    Wang, Wenjing
    et al.
    Fujian Normal University.
    Chen, Qianhuo
    Fujian Normal University.
    Li, Qing
    Fujian Normal University.
    Sheng, Yu
    Fujian Normal University.
    Zhang, Xuanjun
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science.
    Uvdal, Kajsa
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Ligand-Structure Effect on the Formation of One-Dimensional Nanoscale Cu(II)-Schiff Base Complexes and Solvent-Mediated Shape Transformation2012In: Crystal Growth & Design, ISSN 1528-7483, E-ISSN 1528-7505, Vol. 12, no 5, p. 2707-2713Article in journal (Refereed)
    Abstract [en]

    We report here a Cu(II)-Schiff base complex that can assemble into one-dimensional (1D) nanoscale fibers, belts, and rods under different synthetic conditions. The ligand-structure effect is investigated by modification of the ligand structure. The formation of a ID nanostructure was studied, and the formation of dimers was revealed as a key factor for 1D assembly. In dimethylformamide (DMF) medium, this complex represents one of the rare examples of low-molecular-weight "super-metallogelators" with a critical gelation concentration of 0.3 wt % for DMF. The ligand exhibits good selectivity toward different metal ions in terms of gel formation and only the Cu(II) complex forms gels. It is interesting that this metallogel is a kind of dynamic nanostructure, which can be transformed to rods with different aspect ratios via a solvent-mediated process under stimulation of ultrasound.

  • 42.
    Vahlberg, Cecilia
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Linares, Mathieu
    Linköping University, Department of Physics, Chemistry and Biology, Computational Physics. Linköping University, The Institute of Technology.
    Norman, Patrick
    Linköping University, Department of Physics, Chemistry and Biology, Computational Physics. Linköping University, The Institute of Technology.
    Uvdal, Kajsa
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Phenylboronic Ester- and Phenylboronic Acid-Terminated Alkanethiols on Gold Surfaces2012In: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 116, no 1, p. 796-806Article in journal (Refereed)
    Abstract [en]

    In this work, it is shown that a well-organized monolayer of phenylboronic ester-terminated thiol (BOR-capped) on gold surfaces can be prepared. Our results also show that the BOR-capped molecular system can be cleaved directly on the surface, resulting in an unprotected BOR-uncapped monolayer with the boronic acid functional groups available for coordination to diol molecules in the ambient media. The monolayers of BOR-capped and BOR-uncapped were characterized using infrared spectroscopy, near edge X-ray absorption fine structure spectroscopy, X-ray photoelectron spectroscopy, ellipsometry, and contact angle goniometry. The X-ray photoelectron spectroscopy results showed that both BOR-capped and BOR-uncapped are chemically linked to the gold substrate. According to the infrared spectroscopy results, the main component of the CO vibrational mode present in the amide moiety is perpendicular oriented relative to the gold surface normal for the BOR-capped molecular system. The near edge X-ray absorption fine structure spectroscopy resonance peak located at approximately 285 eV, assigned to pi(1)* transitions, was used to estimate the average tilt angle of the vector parallel to the pi* orbitals of the aromatic ring relative to the gold surface normal. The average tilt angle is estimated to be approximately 63 degrees for the BOR-capped monolayer on gold surfaces. The aromatic ring of the BOR-uncapped molecule has a more tilted orientation compared to the BOR-capped one. The experimental infrared spectroscopy and near edge X-ray absorption fine structure spectroscopy results were supported with theoretical modeling including calculations of vibrational modes and of excitation processes.

  • 43.
    Andersson, Viktor
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Skoglund, Caroline
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, The Institute of Technology.
    Uvdal, Kajsa
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Solin, Niclas
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Preparation of amyloidlike fibrils containing magnetic iron oxide nanoparticles: Effect of protein aggregation on proton relaxivity2012In: Biochemical and Biophysical Research Communications - BBRC, ISSN 0006-291X, E-ISSN 1090-2104, Vol. 419, no 4, p. 682-686Article in journal (Refereed)
    Abstract [en]

    A method to prepare amyloid-like fibrils functionalized with magnetic nanoparticles has been developed. The amyloid-like fibrils are prepared in a two step procedure, where insulin and magnetic nanoparticles are mixed simply by grinding in the solid state, resulting in a water soluble hybrid material. When the hybrid material is heated in aqueous acid, the insulin/nanoparticle hybrid material self assembles to form amyloid-like fibrils incorporating the magnetic nanoparticles. This results in magnetically labeled amyloid-like fibrils which has been characterized by Transmission Electron Microscopy (TEM) and electron tomography. The influence of the aggregation process on proton relaxivity is investigated. The prepared materials have potential uses in a range of bio-imaging applications.

  • 44.
    Larsson, E.
    et al.
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, Faculty of Health Sciences.
    Brun, F.
    Sincrotrone Trieste, Italy and University of Trieste, Italy .
    Tromba, G.
    Sincrotrone Trieste, Italy.
    Cataldi, P.
    Azienda per i Servizi Sanitari n. 5 - “Bassa Friulana”, Italy.
    Uvdal, Kajsa
    Linköping University, Department of Physics, Chemistry and Biology, Sensor Science and Molecular Physics. Linköping University, The Institute of Technology.
    Accardo, A.
    University of Trieste, Italy .
    Quantification of Structural Differences in the Human Calvarium Diploe by Means of X-ray Computed Microtomography Image Analysis: A Case Study2012In: 5th European Conference of the International Federation for Medical and Biological Engineering / [ed] Ákos Jobbágy, Springer Berlin/Heidelberg, 2012, Vol. 37, p. 599-602Conference paper (Refereed)
    Abstract [en]

    Accurate models for the human diploe have to take into account any structural differences in the four main areas of the calvaria bones. In this study the technique of X-ray computed microtomography (mu-CT) along with image analysis was used in order to visualize and quantitatively analyze differences in the micro-architecture of the human calvarium diploe. A bone specimen from each area of the skull (temporal, frontal, parietal and occipital) was extracted from a human donor and each specimen was characterized in terms of density, specific surface area, trabecular thickness and anisotropy. The obtained results reveal that in the considered case there are structural differences which therefore can be useful for refining traditional models that assume equal conditions throughout the skull.

  • 45.
    Karlsson, Helen
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Work and Environmental Science. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart and Medicine Center, Occupational and Environmental Medicine Center.
    Ljunggren, Stefan
    Linköping University, Department of Clinical and Experimental Medicine. Linköping University, Faculty of Health Sciences.
    Ahrén, Maria
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Ghafouri, Bijar
    Linköping University, Department of Medical and Health Sciences, Rehabilitation Medicine. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Anaesthetics, Operations and Specialty Surgery Center, Pain and Rehabilitation Center.
    Uvdal, Kajsa
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Lindahl, Mats
    Linköping University, Department of Clinical and Experimental Medicine. Linköping University, Faculty of Health Sciences.
    Ljungman, Anders
    Linköping University, Department of Clinical and Experimental Medicine. Linköping University, Faculty of Health Sciences.
    Two-dimensional gel electrophoresis and mass spectrometry in studies of nanoparticle-protein interactions2012In: Gel electrophoresis-Advanced Techniques / [ed] Sameh Magdeldin, Rijeka, Croatia: In Tech , 2012, p. 1-32Chapter in book (Other academic)
    Abstract [en]

    Over the years a number of epidemiological studies have shown that PM from combustion sources such as motor vehicles contributes to respiratory and cardiovascular morbidity and mortality.Especially so do the ultra-fine particles (UFPs) with a diameter less than 0.1 micrometer.UFPs from combustion engines are capable to translocate over the alveolar–capillary barrier.  When nano-sized PM (nanoparticles, NP), which are small enough to enter the blood stream, do so they are likely to interact with plasma proteins and this protein-NP interaction will probably affect the fate of and the effects caused by the NPs in the human body. Here, by using a proteomic approach, we present results showing that several proteins indeed are associated to NPs that have in vitro been introduced to human blood plasma.

  • 46.
    Yakimova, Rositza
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, The Institute of Technology.
    Selegård, Linnea
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, The Institute of Technology.
    Khranovskyy, Volodymyr
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, The Institute of Technology.
    Pearce, Ruth
    Linköping University, Department of Physics, Chemistry and Biology, Sensor Science and Molecular Physics. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Lloyd Spetz, Anita
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Uvdal, Kajsa
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    ZnO materials and surface tailoring for biosensing2012In: Frontiers in bioscience (Elite edition), ISSN 1945-0508, Vol. 4, no 1, p. 254-278Article in journal (Refereed)
    Abstract [en]

    ZnO nanostructured materials, such as films and nanoparticles, could provide a suitable platform for development of high performance biosensors due to their unique fundamental material properties. This paper reviews different preparation techniques of ZnO nanocrystals and material issues like wettability, biocompatibility and toxicity, which have an important relevance to biosensor functionality. Efforts are made to summarize and analyze existing results regarding surface modification and molecular attachments for successful biofunctionalization and understanding of the mechanisms involved. A section is devoted to implementations of tailored surfaces in biosensors. We end with conclusions on the feasibility of using ZnO nanocrystals for biosensing.

  • 47.
    Hedlund, Anna
    et al.
    Linköping University, Department of Medical and Health Sciences, Radiology. Linköping University, Center for Medical Image Science and Visualization (CMIV). Linköping University, Faculty of Health Sciences.
    Ahrén, Maria
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Gustafsson, Håkan
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medical and Health Sciences, Radiation Physics. Linköping University, Center for Medical Image Science and Visualization (CMIV).
    Abrikossova, Natalia
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Warntjes, Marcel
    Linköping University, Department of Medical and Health Sciences, Clinical Physiology. Linköping University, Faculty of Health Sciences. Linköping University, Center for Medical Image Science and Visualization (CMIV).
    Jönsson, Jan-Ivar
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Clinical and Experimental Medicine, Medical and Physiological Chemistry.
    Uvdal, Kajsa
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Engström, Maria
    Linköping University, Department of Medical and Health Sciences, Radiology. Linköping University, Center for Medical Image Science and Visualization (CMIV). Linköping University, Faculty of Health Sciences.
    Gd2O3 nanoparticles in hematopoietic cells for MRI contrast enhancement2011In: International journal of nano medicine, ISSN 1178-2013, Vol. 6, p. 3233-3240Article in journal (Refereed)
    Abstract [en]

    As the utility of magnetic resonance imaging (MRI) broadens, the importance of having specific and efficient contrast agents increases and in recent time there has been a huge development in the fields of molecular imaging and intracellular markers. Previous studies have shown that gadolinium oxide (Gd2O3) nanoparticles generate higher relaxivity than currently available Gd chelates: In addition, the Gd2O3 nanoparticles have promising properties for MRI cell tracking. The aim of the present work was to study cell labeling with Gd2O3 nanoparticles in hematopoietic cells and to improve techniques for monitoring hematopoietic stem cell migration by MRI. Particle uptake was studied in two cell lines: the hematopoietic progenitor cell line Ba/F3 and the monocytic cell line THP-1. Cells were incubated with Gd2O3 nanoparticles and it was investigated whether the transfection agent protamine sulfate increased the particle uptake. Treated cells were examined by electron microscopy and MRI, and analyzed for particle content by inductively coupled plasma sector field mass spectrometry. Results showed that particles were intracellular, however, sparsely in Ba/F3. The relaxation times were shortened with increasing particle concentration. Relaxivities, r1 and r2 at 1.5 T and 21°C, for Gd2O3 nanoparticles in different cell samples were 3.6–5.3 s-1 mM-1 and 9.6–17.2 s-1 mM-1, respectively. Protamine sulfate treatment increased the uptake in both Ba/F3 cells and THP-1 cells. However, the increased uptake did not increase the relaxation rate for THP-1 as for Ba/F3, probably due to aggregation and/or saturation effects. Viability of treated cells was not significantly decreased and thus, it was concluded that the use of Gd2O3 nanoparticles is suitable for this type of cell labeling by means of detecting and monitoring hematopoietic cells. In conclusion, Gd2O3 nanoparticles are a promising material to achieve positive intracellular MRI contrast; however, further particle development needs to be performed.

  • 48.
    Gustafsson, Håkan
    et al.
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medical and Health Sciences, Radiation Physics. Linköping University, Center for Medical Image Science and Visualization (CMIV).
    Ahrén, Maria
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Söderlind, Fredrik
    Linköping University, Department of Physics, Chemistry and Biology, Chemistry. Linköping University, Faculty of Science & Engineering.
    Córdoba Gallego, José M.
    Linköping University, Department of Physics, Chemistry and Biology, Nanostructured Materials. Linköping University, The Institute of Technology.
    Käll, Per-Olov
    Linköping University, Department of Physics, Chemistry and Biology, Physical Chemistry. Linköping University, Faculty of Science & Engineering.
    Nordblad, Per
    Uppsala Universitet.
    Westlund, Per-Olof
    Umeå Universitet.
    Uvdal, Kajsa
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Engström, Maria
    Linköping University, Department of Medical and Health Sciences, Radiology. Linköping University, Center for Medical Image Science and Visualization (CMIV). Linköping University, Faculty of Health Sciences.
    Magnetic and Electron Spin Relaxation Properties of (GdxY1-x)2O3 (0 ≤ x ≤ 1) Nanoparticles Synthesized by the Combustion Method. Increased Electron Spin Relaxation Times with Increasing Yttrium Content2011In: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 115, no 13, p. 5469-5477Article in journal (Refereed)
    Abstract [en]

    The performance of a magnetic resonance imaging contrast agent (CA) depends on several factors, including the relaxation times of the unpaired electrons in the CA. The electron spin relaxation time may be a key factor for the performance of new CAs, such as nanosized Gd2O3 particles. The aim of this work is, therefore, to study changes in the magnetic susceptibility and the electron spin relaxation time of paramagnetic Gd2O3 nanoparticles diluted with increasing amounts of diamagnetic Y2O3. Nanoparticles of (GdxY1-x)2O3 (0 e x e 1) were prepared by the combustion method and thoroughly characterized (by X-ray di.raction, transmission electron microscopy, thermogravimetry coupled with mass spectroscopy, photoelectron spectroscopy, Fourier transform infrared spectroscopy, and magnetic susceptibility measurements). Changes in the electron spin relaxation time were estimated by observations of the signal line width in electron paramagnetic resonance spectroscopy, and it was found that the line width was dependent on the concentration of yttrium, indicating that diamagnetic Y2O3 may increase the electron spin relaxation time of Gd2O3 nanoparticles.

  • 49.
    Zhang, Xuanjun
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Ballem, Mohamed
    Linköping University, Department of Physics, Chemistry and Biology, Nanostructured Materials. Linköping University, The Institute of Technology.
    Hu, Zhang-Jun
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Bergman, J Peder
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, The Institute of Technology.
    Uvdal, Kajsa
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Nanoscale Light-Harvesting Metal-Organic Frameworks2011In: Angewandte Chemie International Edition, ISSN 1433-7851, E-ISSN 1521-3773, Vol. 50, no 25, p. 5728-5732Article in journal (Refereed)
    Abstract [en]

    n/a

  • 50.
    Vahlberg, Cecilia
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Linares, Mathieu
    Linköping University, Department of Physics, Chemistry and Biology, Computational Physics. Linköping University, The Institute of Technology.
    Villaume, Sebastien
    Linköping University, Department of Physics, Chemistry and Biology, Computational Physics. Linköping University, The Institute of Technology.
    Norman, Patrick
    Linköping University, Department of Physics, Chemistry and Biology, Computational Physics. Linköping University, The Institute of Technology.
    Uvdal, Kajsa
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, The Institute of Technology.
    Noradrenaline and a Thiol Analogue on Gold Surfaces: An Infrared Reflection-Absorption Spectroscopy, X-ray Photoelectron Spectroscopy, and Near-Edge X-ray Absorption Fine Structure Spectroscopy Study2011In: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 115, no 1, p. 165-175Article in journal (Refereed)
    Abstract [en]

    Self-assembled monolayers and multilayers of a noradrenaline analogue (Nor-Pt) on gold substrates as well as multilayers of noradrenaline have been investigated by means of the molecular orientation, the molecule surface interaction, the molecular composition and the functional group availability for further biointeraction processes, using X-ray photoelectron spectroscopy (XPS), infrared reflection absorption spectroscopy (IRAS), and near-edge X-ray absorption fine structure (NEXAFS) spectroscopy. A chemical shift (1.7 eV) of the S 2p peak to lower binding energies is observed, in the XPS spectrum, indicating that the Nor-Pt molecules are chemisorbed onto the gold substrate. The IR results show that Nor-Pt adsorbate has the C=O stretching vibration modes parallel oriented relative to the gold substrate. The average tilt angle of the aromatic ring relative to the gold surface normal is determined to be approximately 51 degrees, based on the NEXAFS measurements on Nor-Pt monolayers. The experimental results and assignments are supported with theoretical studies where we use the building block principle in the spectral analysis and compare with the measurements of noradrenaline and Nor-Pt. The theoretical calculations are shown to be useful; for angle dependence NEXAFS studies as resonances with fully pi* or sigma* character are preferred for correct analysis.

123 1 - 50 of 124
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • oxford
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf