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  • 1.
    Vagin, Mikhail
    et al.
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering. Linköping University, Department of Physics, Chemistry and Biology.
    Sekretareva, Alina
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, Faculty of Science & Engineering. Stanford Univ, CA 94305 USA; Uppsala Univ, Sweden.
    Håkansson, Anna
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering. Linköping University, Department of Physics, Chemistry and Biology.
    Iakimov, Tihomir
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, Faculty of Science & Engineering. Graphens AB, Teknikringen 1F, SE-58330 Linkoping, Sweden.
    Ivanov, Ivan Gueorguiev
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, Faculty of Science & Engineering.
    Syväjärvi, Mikael
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, Faculty of Science & Engineering. Graphens AB, Teknikringen 1F, SE-58330 Linkoping, Sweden.
    Yakimova, Rositsa
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, Faculty of Science & Engineering. Graphens AB, Teknikringen 1F, SE-58330 Linkoping, Sweden.
    Lundström, Ingemar
    Linköping University, Department of Physics, Chemistry and Biology, Sensor and Actuator Systems. Linköping University, Faculty of Science & Engineering.
    Eriksson, Mats
    Linköping University, Department of Physics, Chemistry and Biology, Sensor and Actuator Systems. Linköping University, Faculty of Science & Engineering.
    Bioelectrocatalysis on Anodized Epitaxial Graphene and Conventional Graphitic Interfaces2019In: CHEMELECTROCHEM, ISSN 2196-0216, Vol. 6, no 14, p. 3791-3796Article in journal (Refereed)
    Abstract [en]

    Graphitic materials exhibit significant anisotropy due to the difference in conductivity in a single layer and between adjacent layers. This anisotropy is manifested on epitaxial graphene (EG), which can be manipulated on the nanoscale in order to provide tailor-made properties. Insertion of defects into the EG lattice was utilized here for controllable surface modification with a model biocatalyst and the properties were quantified by both electrochemical and optical methods. A comparative evaluation of the electrode reaction kinetics on the enzyme-modified 2D material vs conventional carbon electrode materials revealed a significant enhancement of mediated bioelectrocatalysis at the nanoscale.

  • 2.
    Karlsson, Jan Olof
    et al.
    Linköping University, Department of Medical and Health Sciences. Linköping University, Faculty of Medicine and Health Sciences.
    Jynge, Per
    Linköping University, Department of Medical and Health Sciences. Linköping University, Faculty of Medicine and Health Sciences.
    Lundström, Ingemar
    Linköping University, Department of Physics, Chemistry and Biology, Sensor and Actuator Systems. Linköping University, Faculty of Science & Engineering.
    Ignarro, Louis J.
    Linköping University, Department of Medical and Health Sciences, Division of Drug Research. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Diagnostics, Department of Clinical Pharmacology.
    Letter in response to: "Randomised open label exploratory, safety and tolerability study with calmangafodipir in patients treated with the 12-h regimen of N acetylcysteine for paracetamol overdosethe PP100-01 for Overdose of Paracetamol (POP) trial: study protocol for a randomised controlled trial"2019In: Trials, ISSN 1745-6215, E-ISSN 1745-6215, Vol. 20, article id 380Article in journal (Other academic)
    Abstract [en]

    n/a

  • 3.
    Silverå Ejneby, Malin
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Divison of Neurobiology. Linköping University, Faculty of Medicine and Health Sciences.
    Wu, Xiongyu
    Linköping University, Department of Physics, Chemistry and Biology, Chemistry. Linköping University, Faculty of Science & Engineering.
    Ottosson, Nina
    Linköping University, Department of Clinical and Experimental Medicine, Divison of Neurobiology. Linköping University, Faculty of Medicine and Health Sciences.
    Münger, E Peter
    Linköping University, Department of Physics, Chemistry and Biology, Theoretical Physics. Linköping University, Faculty of Science & Engineering.
    Lundström, Ingemar
    Linköping University, Department of Physics, Chemistry and Biology, Sensor and Actuator Systems. Linköping University, Faculty of Science & Engineering.
    Konradsson, Peter
    Linköping University, Department of Physics, Chemistry and Biology, Chemistry. Linköping University, Faculty of Science & Engineering.
    Elinder, Fredrik
    Linköping University, Department of Clinical and Experimental Medicine, Divison of Neurobiology. Linköping University, Faculty of Medicine and Health Sciences.
    Atom-by-atom tuning of the electrostatic potassium-channel modulator dehydroabietic acid2018In: The Journal of General Physiology, ISSN 0022-1295, E-ISSN 1540-7748, Vol. 150, no 5, p. 731-750Article in journal (Refereed)
    Abstract [en]

    Dehydroabietic acid (DHAA) is a naturally occurring component of pine resin that was recently shown to open voltage-gated potassium (KV) channels. The hydrophobic part of DHAA anchors the compound near the channel’s positively charged voltage sensor in a pocket between the channel and the lipid membrane. The negatively charged carboxyl group exerts an electrostatic effect on the channel’s voltage sensor, leading to the channel opening. In this study, we show that the channel-opening effect increases as the length of the carboxyl-group stalk is extended until a critical length of three atoms is reached. Longer stalks render the compounds noneffective. This critical distance is consistent with a simple electrostatic model in which the charge location depends on the stalk length. By combining an effective anchor with the optimal stalk length, we create a compound that opens the human KV7.2/7.3 (M type) potassium channel at a concentration of 1 µM. These results suggest that a stalk between the anchor and the effector group is a powerful way of increasing the potency of a channel-opening drug.

  • 4.
    DAmico, A.
    et al.
    University of Roma Tor Vergata, Italy.
    Di Natale, C.
    University of Roma Tor Vergata, Italy; IDASC CNR, Italy.
    Falconi, C.
    University of Roma Tor Vergata, Italy; IDASC CNR, Italy.
    Pennazza, G.
    University of Campus Biomed Roma, Italy.
    Santonico, M.
    University of Campus Biomed Roma, Italy.
    Lundström, Ingemar
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, Faculty of Science & Engineering.
    Equivalent electric circuits for chemical sensors in the Langmuir regime2017In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 238, p. 214-220Article in journal (Refereed)
    Abstract [en]

    This paper presents an equivalent electric circuit model that describes adsorption-desorption processes occurring on bio and chemical sensor surfaces under the Langmuir hypothesis and considers the following practical case: the pressure or concentration of the particles in the test chamber is not perturbed by these processes and keeps its initial value, as in the cases of relatively high pressure or concentration values with zero molecular flow, or in the presence of a molecular flow at any pressure or concentration value. It is also pointed out that the equivalent circuit for Langmuir adsorption is similar to the circuit proposed for enzymatic reactions. Even if this work essentially covers theoretic aspects, a way is suggested for the possible experimental determination of both adsorption-desorption parameters and adsorption-desorption site density. (C) 2016 Elsevier B.V. All rights reserved.

  • 5.
    Zairov, Rustem
    et al.
    Russian Academic Science, Russia; Kazan Volga Regional Federal University, Russia.
    Mustafina, Asiya
    Russian Academic Science, Russia; Kazan Volga Regional Federal University, Russia.
    Shamsutdinova, Nataliya
    Russian Academic Science, Russia; Kazan Volga Regional Federal University, Russia.
    Nizameev, Irek
    Russian Academic Science, Russia; Kazan National Research Technology University, Russia.
    Moreira, Beatriz
    University of Gothenburg, Sweden.
    Sudakova, Svetlana
    Russian Academic Science, Russia.
    Podyachev, Sergey
    Russian Academic Science, Russia.
    Fattakhova, Alfia
    Kazan Volga Regional Federal University, Russia.
    Safina, Gulnara
    University of Gothenburg, Sweden; Chalmers, Sweden.
    Lundström, Ingemar
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, Faculty of Science & Engineering. Luleå University of Technology, Sweden.
    Gubaidullin, Aidar
    Russian Academic Science, Russia.
    Vomiero, Alberto
    Luleå University of Technology, Sweden.
    High performance magneto-fluorescent nanoparticles assembled from terbium and gadolinium 1,3-diketones2017In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 7, article id 40486Article in journal (Refereed)
    Abstract [en]

    Polyelectrolyte-coated nanoparticles consisting of terbium and gadolinium complexes with calix[ 4] arene tetra-diketone ligand were first synthesized. The antenna effect of the ligand on Tb(III) green luminescence and the presence of water molecules in the coordination sphere of Gd(III) bring strong luminescent and magnetic performance to the core-shell nanoparticles. The size and the core-shell morphology of the colloids were studied using transmission electron microscopy and dynamic light scattering. The correlation between photophysical and magnetic properties of the nanoparticles and their core composition was highlighted. The core composition was optimized for the longitudinal relaxivity to be greater than that of the commercial magnetic resonance imaging (MRI) contrast agents together with high level of Tb(III)-centered luminescence. The tuning of both magnetic and luminescent output of nanoparticles is obtained via the simple variation of lanthanide chelates concentrations in the initial synthetic solution. The exposure of the pheochromocytoma 12 (PC 12) tumor cells and periphery human blood lymphocytes to nanoparticles results in negligible effect on cell viability, decreased platelet aggregation and bright coloring, indicating the nanoparticles as promising candidates for dual magneto-fluorescent bioimaging.

  • 6.
    Vagin, Mikhail
    et al.
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Sekretareva, Alina
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, Faculty of Science & Engineering. Department of Chemistry, Stanford University, Stanford, USA.
    Ivanov, Ivan Gueorguiev
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, Faculty of Science & Engineering.
    Håkansson, Anna
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Iakimov, Tihomir
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, Faculty of Science & Engineering. Graphensic AB, Teknikringen 1F, Linköping, Sweden.
    Syväjärvi, Mikael
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, Faculty of Science & Engineering. Graphensic AB, Teknikringen 1F, Linköping, Sweden.
    Yakimova, Rositsa
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, Faculty of Science & Engineering. Graphensic AB, Teknikringen 1F, Linköping, Sweden.
    Lundström, Ingemar
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, Faculty of Science & Engineering.
    Eriksson, Mats
    Linköping University, Department of Physics, Chemistry and Biology, Chemical and Optical Sensor Systems. Linköping University, Faculty of Science & Engineering.
    Monitoring of epitaxial graphene anodization2017In: Electrochimica Acta, ISSN 0013-4686, E-ISSN 1873-3859, Vol. 238, p. 91-98Article in journal (Refereed)
    Abstract [en]

    Anodization of a graphene monolayer on silicon carbide was monitored with electrochemical impedance spectroscopy. Structural and functional changes of the material were observed by Raman spectroscopy and voltammetry. A 21 fold increase of the specific capacitance of graphene was observed during the anodization. An electrochemical kinetic study of the Fe(CN)(6)(3) (/4) redox couple showed a slow irreversible redox process at the pristine graphene, but after anodization the reaction rate increased by several orders of magnitude. On the other hand, the Ru(NH3) (3+/2+)(6) redox couple proved to be insensitive to the activation process. The results of the electron transfer kinetics correlate well with capacitance measurements. The Raman mapping results suggest that the increased specific capacitance of the anodized sample is likely due to a substantial increase of electron doping, induced by defect formation, in the monolayer upon anodization. The doping concentration increased from less than 1 x 10(13) of the pristine graphene to 4-8 x 10(13) of the anodized graphene. (C) 2017 Elsevier Ltd. All rights reserved.

  • 7.
    Guanais Goncalves, Carla
    et al.
    University of Roma Tor Vergata, Italy.
    Dini, Francesca
    University of Roma Tor Vergata, Italy.
    Martinelli, Eugenio
    University of Roma Tor Vergata, Italy.
    Catini, Alexandro
    University of Roma Tor Vergata, Italy.
    Lundström, Ingemar
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, Faculty of Science & Engineering.
    Paolesse, Roberto
    University of Roma Tor Vergata, Italy.
    Di Natale, Corrado
    University of Roma Tor Vergata, Italy.
    Detection of diverse potential threats in water with an array of optical sensors2016In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 236, p. 997-1004Article in journal (Refereed)
    Abstract [en]

    Optical sensor arrays are widely used for sensing the evolution and the identification of complex patterns of chemicals either in air or in water. This popularity stems from the fact that low-cost, ready-to-use optical devices, made available by the current commercial development of electronics commodities, are complemented by a number of low-cost chemical indicators, suitable for a wide range of applications. Among them, pH indicators, and metalloporphyrins make a solid library of molecules that can be adequately assembled for many different tasks. Here, such an array is used for the identification of toxic compounds of different origin that may be released in water distribution systems as a consequence of either accidents or deliberated contaminations. The compounds considered are intermediate products of chemical industry (dimethyl methylphosphonate and cyclohexanone), drugs (5-Fluorouracil and piperazine) and pesticides (imidacloprid and paraoxon). Results show that the sensors are sensitive, but with low selectivity, in the interval from 10(-7) mol L-1 to 10(-4) mol L-1. The sensor signals show a linear correlation with the logarithm of the concentration. Although the limited selectivity of individual sensors, the different sensitivity patterns allow for a clear identification of the compounds, independent of their concentration.(C) 2016 Elsevier B.V. All rights reserved.

  • 8.
    Turner, Anthony
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, Faculty of Science & Engineering.
    Gifford, Raeann
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, Faculty of Science & Engineering.
    Holub, Douglas
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, Faculty of Science & Engineering.
    Lundström, Ingemar
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, Faculty of Science & Engineering.
    Method and Device for Measuring EnzymaticActivity of Polysaccharide-Hydrolysing Enzymes.2016Patent (Other (popular science, discussion, etc.))
    Abstract [en]

    A device and method for detecting and/or measuring a polysaccharide-hydrolysing activity of an enzyme and/or quantifying the amount of the enzyme in a sample employs a complex of a polysaccharide that is hydrolysable by the enzyme and an electrically active signal species or progenitor thereof such that action of the enzyme on the complex causes liberation of the signal species or progenitor.  Thus enzyme activity leads to free signal species which can be detected and quantified electrically.

  • 9.
    Karlsson, Jan Olof G
    et al.
    Linköping University, Department of Medical and Health Sciences, Division of Drug Research. Linköping University, Faculty of Medicine and Health Sciences.
    Ignarro, Louis J
    Department of Molecular and Medical Pharmacology, University of California, USA.
    Lundström, Ingemar
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, Faculty of Science & Engineering.
    Jynge, Per
    Linköping University, Department of Medical and Health Sciences, Division of Drug Research. Linköping University, Faculty of Medicine and Health Sciences.
    Almén, Torsten
    Department of Diagnostic Radiology, Lund University.
    Calmangafodipir [Ca4Mn(DPDP)5], mangafodipir (MnDPDP) and MnPLED with special reference to their SOD mimetic and therapeutic properties2015In: Drug Discovery Today, ISSN 1359-6446, E-ISSN 1878-5832, Vol. 20, no 4, p. 411-421Article, review/survey (Refereed)
    Abstract [en]

    Reactive oxygen species (ROS) and reactive nitrogen species (RNS) participate in pathological tissue damage. Mitochondrial manganese superoxide dismutase (MnSOD) normally keeps ROS and RNS in check. During development of mangafodipir (MnDPDP) as a magnetic resonance imaging (MRI) contrast agent, it was discovered that MnDPDP and its metabolite manganese pyridoxyl ethyldiamine (MnPLED) possessed SOD mimetic activity. MnDPDP has been tested as a chemotherapy adjunct in cancer patients and as an adjunct to percutaneous coronary intervention in patients with myocardial infarctions, with promising results. Whereas MRI contrast depends on release of Mn2+, the SOD mimetic activity depends on Mn2+ that remains bound to DPDP or PLED. Calmangafodipir [Ca4Mn(DPDP)5] is stabilized with respect to Mn2+ and has superior therapeutic activity. Ca4Mn(DPDP)5 is presently being explored as a chemotherapy adjunct in a clinical multicenter Phase II study in patients with metastatic colorectal cancer.

  • 10.
    Dini, Francesca
    et al.
    Department of Electronic Engineering, University of Rome, Italy.
    Magna, Gabriele
    Department of Electronic Engineering, University of Rome, Italy.
    Martinelli, Eugenio
    Department of Electronic Engineering, University of Rome, Italy.
    Pomarico, Giuseppe
    Department of Chemical Science and Technologies, University of Rome, Italy.
    Di Natale, Corrado
    Department of Electronic Engineering, University of Rome, Italy.
    Paolesse, Roberto
    Department of Chemical Science and Technologies, University of Rome, Italy.
    Lundström, Ingemar
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, Faculty of Science & Engineering.
    Combining porphyrins and pH indicators for analyte detection2015In: Analytical and Bioanalytical Chemistry, ISSN 1618-2642, E-ISSN 1618-2650, Vol. 407, no 14, p. 3975-3984Article in journal (Refereed)
    Abstract [en]

    High sensitivity and cross-selectivity are mandatory properties for sensor arrays. Although metalloporphyrins and pH indicators are among the most common and appropriate choices for the preparation of optical sensor arrays, the sensitivity spectrum of these dyes is limited to those analytes able to induce an optical response. To extend the receptive field of optical sensors, we explore the design of composite materials, where the molecular interaction among the subunits enriches their sensing working mechanisms. We demonstrate that blends of single metalloporphyrins and pH indicators, tested with a transduction apparatus based on ubiquitous and easily available hardware, can be endowed with sensing properties wider than those of single constituents, enabling the recognition of a broad range of volatiles.

  • 11.
    Vagin, Mikhail Yu
    et al.
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Sekretareva, Alina
    Linköping University, Department of Physics, Chemistry and Biology, Chemical and Optical Sensor Systems. Linköping University, Faculty of Science & Engineering.
    Lindgren, Petter
    Håkansson, Anna
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Eriksson, Mats
    Linköping University, Department of Physics, Chemistry and Biology, Chemical and Optical Sensor Systems. Linköping University, Faculty of Science & Engineering.
    Lundström, Ingemar
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, Faculty of Science & Engineering.
    Syväjärve, Mikael
    Yakimova, Rositsa
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, Faculty of Science & Engineering.
    Direct bioelectrocatalysis on anodized epitaxial graphene2015In: Program of the XXIII International Symposium on Bioelectrochemistry and Bioenergetics of the Bioelectrochemical Society14-18 June, 2015Malmö, Sweden, Lausanne: Bioelectrochemical Society , 2015, p. 170-170Conference paper (Other academic)
    Abstract [en]

    Graphene as a nanomaterial consisting of a single layer sheets of atoms of carbon in hexagonal arrangement is making a significant impact in variety of technologies such as energy storage and chemical analysis. The significant attention paid to this thinnest nanomaterial resulted in thousands of patent applications is due to its staggering properties. Due to the planar conjugation of the sp2bonds in graphene, two-dimensional electrical conduction is highly efficient. On the contrary, the efficiency of electron exchange at the out-of-plane of the graphene sheet is small. The significant difference of the densities of electronic states at in-plane and out-of-plane of graphene sheet determines two distinct structural contributions (basal and edge plane respectively) to the behavior of all graphitic materials yielding the chemical and electrochemical anisotropy. Being the simplest building block of graphitic materials, graphene offers the possibility to study the behavior on the simplest level of structural organization. However, the major effort of the recent electrochemical studies of graphene were done using a bulk materials based on graphene flakes possessing the domination of edges of high reactivity. The planar orientation of graphene sheets with controllable exposure of basal plane is achievable via the growth by chemical vapor deposition or by epitaxial flash annealing on crystalline structures of silicon carbide. The slow growth of graphene onto crystalline support during annealing in the inert atmosphere results in a development of a high quality graphene monolayer attached to the solid insulating support. The creation of sp3-type reactive defects on the basal plane of graphite can be achieved by anodization at high anodic potentials.

    We developed the procedure for the real-time monitoring of epitaxial graphene anodization. The changes of electrochemical properties of graphene monolayer with anodization have been comparatively investigated by electrochemical methods. The estimation of specific capacitance in pure electrolyte and in conditions of Faradaic process has been carried out. Finally, the direct electrocatalysis of laccase (Trametes versicolor) has been used as an electrode reaction to probe the reactivities of anodized epitaxial graphene and conventional carbon materials.

  • 12.
    Lvova, Larisa
    et al.
    University of Roma Tor Vergata, Italy; St Petersburg State University, Russia.
    Pudi, Rajesh
    University of Roma Tor Vergata, Italy.
    Galloni, Pierluca
    University of Roma Tor Vergata, Italy.
    Lippolis, Vito
    University of Cagliari, CA USA.
    Di Natale, Corrado
    University of Roma Tor Vergata, Italy.
    Lundström, Ingemar
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, The Institute of Technology.
    Paolesse, Roberto
    University of Roma Tor Vergata, Italy.
    Multi-transduction sensing films for Electronic Tongue applications2015In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 207, p. 1076-1086Article in journal (Refereed)
    Abstract [en]

    In this paper the use of multi-transduction principle for sensing materials development is reviewed. In particular, the application of porphyrin-based films to a multi-transduction Electronic Tongue system for different analytical tasks is presented. The optical response of sensing films was registered by means of Computer Screen Photoassisted Technology (CSPT) that applies familiar devices, such as computer monitor screen and web-camera, as illumination light source and signal detectors. Simultaneously the electrochemical amperometric or potentiometric response of the same sensing material was measured. Data analysis combining both signals significantly improves the performance of the Electronic Tongue, thus opening new frontiers in application of such a system.

  • 13.
    Vagin, Mikhail
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Chemical and Optical Sensor Systems. Linköping University, The Institute of Technology.
    Sekretareva, Alina
    Linköping University, Department of Physics, Chemistry and Biology, Chemical and Optical Sensor Systems. Linköping University, The Institute of Technology.
    Sanchez, Rafael
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Lundström, Ingemar
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, The Institute of Technology.
    Winquist, Fredrik
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, The Institute of Technology.
    Eriksson, Mats
    Linköping University, Department of Physics, Chemistry and Biology, Chemical and Optical Sensor Systems. Linköping University, The Institute of Technology.
    Arrays of Screen-Printed Graphite Microband Electrodes as a Versatile Electroanalysis Platform2014In: ChemElectroChem, ISSN 2196-0216, Vol. 1, no 4, p. 755-762Article in journal (Refereed)
    Abstract [en]

    Arrays of microband electrodes were developed by screen printing followed by cutting, which enabled the realization of microband arrays at the cut edge. The microband arrays of different designs were characterized by physical and electro-chemical methods. In both cases, the methods showed that the microband width was around 5 mm. Semi-steady-state cyclic voltammetry responses were observed for redox probes, and chronocoulometric measurements showed the establishment of convergent diffusion regimes characterized by current densities similar to those of a single microelectrode. The analytical performance of the electrode system and its versatility were illustrated with two electrochemical assays: detection of ascorbic acid through direct oxidation and a mediated glucose biosensor fabricated by dip coating. Due to convergent mass transport, both systems showed an enhancement in their analytical characteristics. The developed approach can be adapted to automated electrode recovery.

  • 14.
    Vagin, Mikhail Y
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Chemical and Optical Sensor Systems. Linköping University, The Institute of Technology.
    Lundström, Ingemar
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, The Institute of Technology.
    Turner, Anthony
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, The Institute of Technology.
    Beni, Valerio
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, The Institute of Technology.
    Eriksson, Mats
    Linköping University, Department of Physics, Chemistry and Biology, Chemical and Optical Sensor Systems. Linköping University, The Institute of Technology.
    Boron-doped diamond microelectrode arrays for electrochemical monitoring of antibiotics contamination in water2014In: 15th International Conference on Electroanalysis (ESEAC), 2014Conference paper (Other academic)
    Abstract [en]

    The improvement of water management and increasing the access to safe drinking water can develop the quality of life for millions of people world-wide and reduce child mortality due to water-borne diseases [1]. Sweden was recently affected by the lack of appropriate water management which resulted in microbial contamination and tens of thousands of people falling ill [2]. Pollution with chemical compounds is also a waterworks concern. The appearance of pharmaceuticals such as antibiotics in raw water affects the cleaning processes at waterworks [3]. Substances which are not, or are only partly, eliminated in the sewage treatment plant will reach the surface water where they may affect organisms of different trophic levels and cause, for example, the of antibiotics resistance [4]. The inhibition of bacteria of waste water plants by antibiotics may seriously affect organic matter degradation. The efficiency of nitrification as an important step in waste water purification, can be decreased by antibiotics inhibition [5]. Boron-doped diamond (BDD) is an advanced electrode material that possesses the combination of good electrical conductivity achieved via film doping and the extreme chemical inertness of diamond, which gives rise to a number of highly desirable properties of BDD as electrode material: a wide potential window in aqueous media allows electrochemical measurements at both extreme anodic and cathodic potentials, very low capacitive currents leads to a sensitivity increase and extreme chemical and structural inertness prevents electrode fouling [6]. Usage of a microelectrode array as the working electrode offers a variety of benefits for electroanalysis: an improvement of the analytical performance in comparison with macroelectrodes under planar diffusion, higher signal-to-noise ratios due to low capacitive currents at the small surface area, shorter response times and less sensitivity to variations in the water flow rate. The BDD arrays of this work contain 2900 microelectrodes (10 mm diameter each) and have been used for the detection of antibiotics (ofloxacine and canamycin A) in water with high amplitude pulse voltammetry processed by multivariate data analysis. The detection limits observed in monitoring mode were comparable with the characteristics of standard protocols of antibiotics detection, which opens the possibility for continuous monitoring of water.

    [1] The United Nations, World Water Development Report 4, 2012; [2] Lindberg, A. et al.,

    FOI-R--3376--SE, 2011; Dryselius, R.; National Food Agency, Sweden, 2012; [3] Kummerer

    K. Chemosphere, 2009, 75, 417; [4] Kummerer K. Chemosphere, 2009, 75, 435; [5]

    Dokianakis, S.N. et al., Water Sci. Technol. 50, 341; [6] Goeting, C. et al.,

    NewDiam.Front.C.Tech. 1999, 9, 207; Compton, R. et al., Electroanal. 2003, 15, 1349.

     

  • 15.
    Lundström, Ingemar
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, The Institute of Technology.
    From a Laboratory Exercise for Students to a Pioneering Biosensing Technology2014In: PLASMONICS, ISSN 1557-1955, Vol. 9, no 4, p. 741-751Article in journal (Refereed)
    Abstract [en]

    Surface plasmon resonance (SPR) for biosensing was demonstrated 30 years ago. In the present contribution, its general background is described together with the necessary developments both in instrumentation and surface chemistry, leading to the final so-called BIAcore technology. The description is naturally colored by my personal opinion of the developments. SPR for the elucidation of organic mono- and multilayers introduced at the end of the 1970s formed the basis for the first biosensing demonstration of SPR in the beginning of the 1980s. It is pointed out how the need of an up-to-date laboratory exercise for the undergraduate students and the multidisciplinary environment at the Laboratory of Applied Physics at Linkoping University led to this demonstration. The initial experiments are touched upon and the further developments at Pharmacia, which led to the BIAcore technology, are described in some details. Some of the present activities in Linkoping related to optical biosensing with ubiquitous instrumentation are also described, including SPR detection with a computer screen and a web camera and most recently with a cellular phone.

  • 16.
    Holub, Douglas
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, The Institute of Technology.
    Gifford, Raeann
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, The Institute of Technology.
    Lundström, Ingemar
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, The Institute of Technology.
    Turner, Anthony
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, The Institute of Technology.
    PoC Amylase Biosensor2014In: 24th Anniversary World Congress on Biosensors – Biosensors 2014, Elsevier, 2014Conference paper (Other academic)
    Abstract [en]

    A rapid, inexpensive and quantitative biosensor to measure alpha-amylase activity within the relevant clinical range has been developed.  This device is suited for point-of-care (PoC) applications because it is easy to use and disposable.  Salivary α-amylase activity is correlated to stress levels and, therefore, it is a potential monitoring candidate for neurological conditions (e.g. Multiple Sclerosis) for which there are no objective diagnostics available.  The enzyme is also utilized in many industrial processes like fermentation and textile production, where real-time, on-site monitoring can be advantageous for accurate process control.  In contrast to other α-amylase quantitative methods, this biosensor is rapid (results within 10 minutes), it does not require bench-top or specialized equipment (i.e. it is portable and does not need to be sent to a laboratory for results), and the general public can perform the analysis (no specialized training needed).  An electro-active moiety, which is sensitive to α-amylase activity, is incorporated into the biosensor design and generates a signal that is proportional to the alpha-amylase activity in the sample (Figure 1, below).  This new device will allow researchers to better diagnose and monitor neurological conditions and follow treatment effectiveness without relying solely on subjective assessments.  In addition, using this novel biosensor to monitor industrial processes that utilize α-amylase could reduce production costs and waste generation for these industries.

  • 17.
    Cao, Z.
    et al.
    Department of Chemical Science and Technologies, University of Tor Vergata, Rome, Italy, Department of Chemistry and Molecular Engineering, East China University of of Science and Technology, Shanghai, China.
    Lvova, L.
    Department of Chemical Science and Technologies, University of Tor Vergata, Rome, Italy, Faculty of Biology and Soil Science, St. Petersburg State University, St. Petersburg, Russia.
    Paolesse, R.
    Department of Chemical Science and Technologies, University of Tor Vergata, Rome, Italy.
    Di Natale, C
    Department of Electronic Engineering, University of Tor Vergata, Rome, Italy.
    D' Amico, A.
    Department of Electronic Engineering, University of Tor Vergata, Rome, Italy.
    Lundström, Ingemar
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, The Institute of Technology.
    Porphyrin electropolymers as opto-electrochemical probe for the detection of red-ox analytes2014In: Sensors: Proceedings of the First National Conference on Sensors, Rome 15-17 February, 2012, Springer Science Business Media , 2014, Vol. 162 LNEE, p. 49-55Conference paper (Refereed)
    Abstract [en]

    The application of pyrrole-substituted porphyrin electropolymers for simultaneous optical and electrochemical analysis of red-ox active analytes, namely diazo-conjugated dyes of Sudan family, is presented. Sudan colorants are widely used in many fields, but accurate screening of their consumption is required due to their high toxicity. The inherent electrochemical activity of Sudan dyes, as far as their intense coloration, makes possible to find the appropriate conditions of hybrid optical and electrochemical porphyrin electropolymer based sensor array system application. This approach allowed a significant increase in the chemical information, improving the analytical system performance in terms of selectivity and sensitivity, and permitted the fast and simple monitoring of Sudan dye analytes.

  • 18.
    Vagin, Mikhail Y
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Chemical and Optical Sensor Systems. Linköping University, The Institute of Technology.
    Sekretaryova, Alina N
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, The Institute of Technology.
    Reategui, Rafael Sanchez
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics.
    Lundström, Ingemar
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics.
    Turner, Anthony
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, The Institute of Technology.
    Eriksson, Mats
    Linköping University, Department of Physics, Chemistry and Biology, Chemical and Optical Sensor Systems. Linköping University, The Institute of Technology.
    Screen-printed graphite microbands as a versatile biosensor platform2014In: 24th Anniversary World Congress on Biosensors – Biosensors 2014, Elsevier, 2014Conference paper (Other academic)
    Abstract [en]

    The use of extremely small working electrodes offers a variety of benefits for electroanalysis. The enhanced mass transport as a result of convergent diffusion is the most important advantage of microdimensional electrodes and results in improved of analytical performance The low detectable-currents problem can be solved by single microelectrode multiplication into an array, thus combining the advantages of enhanced mass transport and high output signals. The microband is one of the most cost-effective and easy-fabricated geometries for microelectrodes. The microband width is a critical microscopic dimension of the electrode, which maintains the dominance of convergent diffusion, whereas the microband length is macroscopic and ensures registration of high currents.

    Graphite screen-printing on a plastic support is a standard technology for large-scale production of low cost electrochemical devices. This has been combined with simple guillotine cutting to fabricate of microband arrays for autonomous environmental and clinical monitoring.

    Single-layer and multilayer microband arrays of different band lengths were produced and characterised using optical and electrochemical methods. The critical dimension for the microband width to facilitate convergent diffusion was assessed electrochemically and found to be in the order of 5 microns. The developed electrode structures were used as a versatile platform for the manufacture of model electroanalytical systems. Direct oxidation of ascorbic acid was explored at the microband arrays and a glucose biosensor based on mediated and immobilised glucose oxidase was fabricated. Both examples yielded significant enhancement of the analytical performance.

    A: the layout of the screen-printed graphite microband array of 5 electrode layers. B: voltammmetric responses obtained at the microband arrays.

    Acknowledgement: Formas and Security Link for financial support; David Nilsson (Acreo) for screen-printing.

  • 19.
    Vagin, Mikhail Y
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Chemical and Optical Sensor Systems. Linköping University, The Institute of Technology.
    Sekretaryova, Alina N
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, The Institute of Technology.
    Reategui, Rafael Sanchez
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, The Institute of Technology.
    Lundström, Ingemar
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, The Institute of Technology.
    Turner, Anthony
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, The Institute of Technology.
    Eriksson, Mats
    Linköping University, Department of Physics, Chemistry and Biology, Chemical and Optical Sensor Systems. Linköping University, The Institute of Technology.
    Screen-printed graphite microbands for electroanalysis2014In: 15th International Conference on Electroanalysis (ESEAC), 2014Conference paper (Other academic)
  • 20.
    Parlak, Onur
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, The Institute of Technology.
    Seshadri, Prethi
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, The Institute of Technology.
    Lundström, Ingemar
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, The Institute of Technology.
    Turner, Anthony P.F.
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, The Institute of Technology.
    Tiwari, Ashutosh
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, The Institute of Technology.
    Two-dimensional gold-tungsten disulphide bio-interface for high-throughput electrocatalytic nano-bioreactors2014In: Advanced Materials Interfaces, ISSN 2196-7350, Vol. 1, no 6, p. 1400136-Article in journal (Refereed)
    Abstract [en]

    A high-throughput electrocatalytic nano-bioreactor on tungsten disulphide nanosheets is demonstrated for the first time. The fundamental goal of this research is to develop a higher surface area, resulting in a greater enzyme loading and thereby increasing bio-catalytic activity within a nano-confined volume. As a result, the nanobio-system is capable of highly specific recognition of target bioanalytes, therefore, showing significant potentials in a range of bioreactor applications.

  • 21.
    Lvova, Larisa
    et al.
    University of Roma Tor Vergata, Italy St Petersburg State University, Russia.
    Galloni, Pierluca
    University of Roma Tor Vergata, Italy.
    Floris, Barbara
    University of Roma Tor Vergata, Italy.
    Lundström, Ingemar
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, The Institute of Technology.
    Paolesse, Roberto
    University of Roma Tor Vergata, Italy.
    Di Natale, Corrado
    University of Roma Tor Vergata, Italy.
    A Ferrocene-Porphyrin Ligand for Multi-Transduction Chemical Sensor Development2013In: Sensors, ISSN 1424-8220, E-ISSN 1424-8220, Vol. 13, no 5, p. 5841-5856Article in journal (Refereed)
    Abstract [en]

    5,10,15,20-Tetraferrocenyl porphyrin, H2TFcP, a simple example of a donor-acceptor system, was tested as ligand for the development of a novel multi-transduction chemical sensors aimed at the determination of transition metal ions. The fluorescence energy transfer between ferrocene donor and porphyrin acceptor sub-units was considered. The simultaneously measured optical and potentiometric responses of solvent polymeric membranes based on H2TFcP permitted the detection of lead ions in sample solutions, in the concentration range from 2.7 × 10−7 to 3.0 × 10−3 M. The detection limit of lead determination was 0.27 μM, low enough to perform the direct analysis of Pb2+ in natural waters.

  • 22.
    Dini, Francesca
    et al.
    University of Roma Tor Vergata, Italy .
    Filippini, Daniel
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Paolesse, Roberto
    University of Roma Tor Vergata, Italy .
    Lundström, Ingemar
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, The Institute of Technology.
    Di Natale, Corrado
    University of Roma Tor Vergata, Italy .
    Computer screen assisted digital photography2013In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 179, no SI, p. 46-53Article in journal (Refereed)
    Abstract [en]

    The computer screen photo-assisted techniques (CSPT) have been developed during the last 10 years through an extensive collaboration between University of Rome "Tor Vergata" and Linkoping University in Sweden. CSPT has thus evolved into a concept we now call computer screen assisted digital photography, yielding detailed information about the interaction between color indicators and (volatile) analytes. In the present paper, we give a brief summary of the CSPT concept and its connection to digital photography. We concentrate, however, on the most recent results, which were obtained by using most of the degrees of freedom offered by a computer screen as a light source and a digital (web) camera as a detector. Thus, we describe in detail recent experiments on cotton yarns impregnated with color indicators for volatile organic molecules. The interaction between the color indicators and molecules, like trimethylamine, was investigated by CSPT in high dynamic imaging together with a background noise limiting algorithm. It is shown that the simultaneous use of the last two additions to the CSPT concept considerably enhances the chemical sensing ability of CSPT. It is concluded that the collaboration between Rome and Linkoping has generated a useful platform for further developments of chemical analysis with a ubiquitous instrumentation, a (computer) screen and a web camera. This technique is aimed at facilitating the assembly of opto-chemical sensors with evident benefits in the reduction of cost of sensor systems and in an increased integrability with the existent telecommunication infrastructures.

  • 23.
    Ericsson, Emma M
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Sensor Science and Molecular Physics. Linköping University, The Institute of Technology.
    Bui, Lan
    Linköping University, Department of Physics, Chemistry and Biology, Chemistry. Linköping University, The Institute of Technology.
    Lundström, Ingemar
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Konradsson, Peter
    Linköping University, Department of Physics, Chemistry and Biology, Chemistry. Linköping University, The Institute of Technology.
    Liedberg, Bo
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Physics. Linköping University, The Institute of Technology.
    Enander, Karin
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Physics. Linköping University, The Institute of Technology.
    Controlled orientation and covalent attachment of proteins on biosensor surfaces by Chelation Assisted Photoimmobilization2013Conference paper (Other academic)
    Abstract [en]

    In the context of surface chemistry for affinity biosensor chips, it is widely accepted that uniform orientation of the immobilized recognition element (ligand) is preferred over random orientation. However, this assumption has often been based on studies where differences in ligand immobilization level have not been taken into account. In this contribution, we present a novel two-step method for homogenous orientation and covalent attachment of proteins to sensing surfaces, called Chelation Assisted Photoimmobilization (CAP). Careful quantification of the effect of ligand orientation on analyte responses was performed by comparing this strategy to immobilization by conventional amine coupling.

     In CAP, the chelation agent is nitrilotriacetic acid (NTA) which chelates Ni2+. A His-tagged ligand forms an oriented assembly when binding Ni2+-NTA and is then covalently bound to the surface via photolabile benzophenone (BP), which attacks C-H bonds upon UV light activation. We relied on a surface chemistry based on self-assembled monolayers (SAMs) of oligo(ethylene glycol) (OEG)-containing alkanethiolates on gold. Alkanethiols terminated with either NTA, BP or OEG were synthesized and mixed SAMs were characterized by infrared reflection absorption spectroscopy (IRAS), ellipsometry and contact angle goniometry. IRAS was also used to quantify ligand immobilization levels obtained either by CAP or by amine coupling via the carboxyl groups of an NTA-presenting surface. The model ligand was human IgG-Fc modified with a C-terminal 6xHis-tag and the analyte was Protein A. The ligand-analyte interaction was quantified by a surface plasmon resonance biosensor.

     Analyte responses were normalized with respect to the ligand amounts obtained by the two immobilization strategies. Interestingly, the normalized analyte response with randomly oriented ligand was >2 times higher than that with ligand immobilized by CAP. This shows that oriented ligand immobilization is not necessarily a means of increasing the sensitivity of a biosensor. Factors that may influence performance include the valency of the ligand and constraints related to the surface chemistry used for orientation.

  • 24.
    Ericsson, Emma
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Sensor Science and Molecular Physics. Linköping University, The Institute of Technology.
    Enander, Karin
    Linköping University, Department of Physics, Chemistry and Biology, Sensor Science and Molecular Physics. Linköping University, The Institute of Technology.
    Bui, Lan
    Institute of Organic Chemistry, RWTH Aachen University, Landoltweg 1, 52074 Aachen, Germany.
    Lundström, Ingemar
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Konradsson, Peter
    Linköping University, Department of Physics, Chemistry and Biology, Organic Chemistry. Linköping University, The Institute of Technology.
    Liedberg, Bo
    Linköping University, Department of Physics, Chemistry and Biology, Sensor Science and Molecular Physics. Linköping University, The Institute of Technology.
    Controlled Orientation and Covalent Attachment of Proteins on Biosensor Surfaces by Chelation Assisted Photoimmobilization2013Manuscript (preprint) (Other academic)
    Abstract [en]

    This report presents a novel method for uniform orientation and covalent attachment of proteins to sensing surfaces, termed Chelation Assisted Photoimmobilization (CAP). Alkanethiols terminated with either nitrilotriacetic acid (NTA), benzophenone (BP) or oligo(ethylene glycol) were synthesized and mixed self-assembled monolayers (SAMs) were prepared on gold and thoroughly characterized by infrared reflection absorption spectroscopy (IRAS), ellipsometry and contact angle goniometry. In the process of CAP, NTA chelates Ni2+ and the complex coordinates a His-tagged ligand in an oriented assembly. The ligand is then photoimmobilized via BP, which forms covalent bonds upon UV light activation. The CAP concept was demonstrated using human IgG-Fc modified with C-terminal hexahistidine tags (His-IgGFc) as the ligand and protein A as the analyte.

    In the development of affinity biosensors, uniform orientation of ligand molecules where all analyte binding sites are accessible is often preferred to random orientation. In order to monitor the effect of ligand orientation on analyte response, the ligand-analyte interaction was quantified by surface plasmon resonance analysis, both in the case of CAP and when the ligand was attached by conventional amine coupling on surfaces presenting NTA. Responses were adjusted for differences in ligand immobilization level using IRAS. The normalized analyte response with randomly oriented ligand was 2.5 times higher than that with ligand immobilized by CAP, probably due to molecular crowding effects on the surface and the fact that His-IgGFc is bivalent for protein A. This is a reminder that many other factors than orientation alone may play a decisive role in analyte binding on biosensor surfaces.

  • 25.
    Bazzicalupi, Carla
    et al.
    University of Florence, Italy .
    Caltagirone, Claudia
    University of Cagliari, Italy .
    Cao, Zenfeng
    University of Roma Tor Vergata, Italy E China University of Science and Technology, Peoples R China .
    Chen, Qibin
    E China University of Science and Technology, Peoples R China .
    Di Natale, Corrado
    University of Roma Tor Vergata, Italy .
    Garau, Alessandra
    University of Cagliari, Italy .
    Lippolis, Vito
    University of Cagliari, Italy .
    Lvova, Larisa
    University of Roma Tor Vergata, Italy St Petersburg State University, Russia .
    Liu, Honglai
    E China University of Science and Technology, Peoples R China .
    Lundström, Ingemar
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, The Institute of Technology.
    Mostallino, M. Cristina
    Ist Neurosci CNR Cagliari, Italy .
    Nieddu, Mattia
    University of Cagliari, Italy .
    Paolesse, Roberto
    University of Roma Tor Vergata, Italy .
    Prodi, Luca
    University of Bologna, Italy .
    Sgarzi, Massimo
    University of Bologna, Italy .
    Zaccheroni, Nelsi
    University of Bologna, Italy .
    Multimodal Use of New Coumarin-Based Fluorescent Chemosensors: Towards Highly Selective Optical Sensors for Hg2+ Probing2013In: Chemistry - A European Journal, ISSN 0947-6539, E-ISSN 1521-3765, Vol. 19, no 43, p. 14639-14653Article in journal (Refereed)
    Abstract [en]

    Despite several types of fluorescent sensing molecules have been proposed and examined to signal Hg2+ ion binding, the development of fluorescence-based devices for in-field Hg2+ detection and screening in environmental and industrial samples is still a challenging task. Herein, we report the synthesis and characterization of three new coumarin-based fluorescent chemosensors featuring mixed thia/aza macrocyclic framework as receptors units, that is, ligands L1-L3. These probes revealed an OFF-ON selective response to the presence of Hg2+ ions in MeCN/H2O 4:1 (v/v), which allowed imaging of this metal ion in Cos-7 cells in vitro. Once included in silica core-polyethylene glycol (PEG) shell nanoparticles or supported on polyvinyl chloride (PVC)-based polymeric membranes, ligands L1-L3 can also selectively sense Hg2+ ions in pure water. In particular we have developed an optical sensing array tacking advantage of the fluorescent properties of ligand L3 and based on the computer screen photo assisted technique (CSPT). In the device ligand L3 is dispersed into PVC membranes and it quantitatively responds to Hg2+ ions in natural water samples.

  • 26.
    Polese, D
    et al.
    University of Roma Tor Vergata, Italy .
    Martinelli, E
    University of Roma Tor Vergata, Italy .
    Magna, G
    University of Roma Tor Vergata, Italy .
    Dini, F
    University of Roma Tor Vergata, Italy .
    Catini, A
    University of Roma Tor Vergata, Italy .
    Paolesse, R
    University of Roma Tor Vergata, Italy .
    Lundström, Ingemar
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, The Institute of Technology.
    Di Natale, C
    University of Roma Tor Vergata, Italy .
    Sharing data processing among replicated optical sensor arrays2013In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 179, no SI, p. 252-258Article in journal (Refereed)
    Abstract [en]

    Sensor networks prompt a great deal of research interest within the computer and analytical sciences. To this regard, one of the most important issues is concerned with the interpretation of data that are collected by different sensors. Due to sensors non-reproducibility, this problem may also persist even when many replicas of the same sensors are considered. In this case additional calibrations may be required to use a common knowledge database. Noteworthy, the same problem arises in case of sensors replacement. In this paper we demonstrate that in case of optical chemical sensors drawing inspiration from the connectivity strategy of the olfactory bulb, this problem can find a straightforward solution when an image sensor is used to measure the optical properties of an extended sensing layer. If the sensing layer is formed by a number of spots of different indicators, it is demonstrated that a common data processing can be applied to any replica of the sensing layer even if the indicators are spotted with different geometries and in different quantities.

  • 27.
    Ericsson, Emma
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Physics. Linköping University, Faculty of Science & Engineering.
    Enander, Karin
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Physics. Linköping University, Faculty of Science & Engineering.
    Bui, Lan
    Linköping University, Department of Physics, Chemistry and Biology, Chemistry. Linköping University, Faculty of Science & Engineering.
    Lundström, Ingemar
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, The Institute of Technology.
    Konradsson, Peter
    Linköping University, Department of Physics, Chemistry and Biology, Chemistry. Linköping University, The Institute of Technology.
    Liedberg, Bo
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Physics. Linköping University, Faculty of Science & Engineering.
    Site-Specific and Covalent Attachment of His-Tagged Proteins by Chelation Assisted Photoimmobilization: A Strategy for Microarraying of Protein Ligands2013In: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 29, no 37, p. 11687-11694Article in journal (Refereed)
    Abstract [en]

    A novel strategy for site-specific and covalent attachment of proteins has been developed, intended for robust and controllable immobilization of histidine (His)-tagged ligands in protein microarrays. The method is termed chelation assisted photoimmobilization (CAP) and was demonstrated using human IgG-Fc modified with C-terminal hexahistidines (His-IgGFc) as the ligand and protein A as the analyte. Alkanethiols terminated with either nitrilotriacetic acid (NTA), benzophenone (BP); or oligo(ethylene glycol) were synthesized and mixed self-assembled monolayers (SAMs) were prepared on gold and thoroughly characterized by infrared reflection absorption spectroscopy (IRAS), ellipsometry, and contact angle goniometry. In the process of CAP, NTA chelates Ni2+ and the complex coordinates the His-tagged ligand in an oriented assembly. The ligand is then photoimmobilized via BP, which forms covalent bonds upon UV light activation. In the development of affinity biosensors and protein microarrays, site-specific attachment of ligands in a fashion where analyte binding sites are available is often preferred to random coupling. Analyte binding performance of ligands immobilized either by CAP or by standard amine coupling was characterized by surface plasmon resonance in combination with IRAS. The relative analyte response with randomly coupled ligand was 2.5 times higher than when site-specific attachment was used. This is a reminder that also when immobilizing ligands via residues far from the binding site, there are many other factors influencing availability and activity. Still, CAP provides a valuable expansion of protein immobilization techniques since it offers attractive microarraying possibilities amenable to applications within proteomics.

  • 28.
    Dini, Francesca
    et al.
    Department of Electronic Engineering, University of Rome Tor Vergata, Rome, Italy.
    Capuano, Rosamaria
    Department of Electronic Engineering, University of Rome Tor Vergata, Rome, Italy.
    Strand, Tillan
    Linköping University, Department of Medical and Health Sciences. Linköping University, Faculty of Health Sciences.
    Ek, Anna-Christina
    Linköping University, Department of Medical and Health Sciences, Division of Nursing Science. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Local Health Care Services in Central Östergötland, Department of Acute Health Care in Linköping.
    Lindgren, Margareta
    Linköping University, Department of Medical and Health Sciences, Division of Nursing Science. Linköping University, Faculty of Health Sciences.
    Paolesse, Roberto
    Department of Chemical Science and Technology, University of Rome Tor Vergata, Rome, Italy.
    Di Natale, Corrado
    Department of Electronic Engineering, University of Rome Tor Vergata, Rome, Italy.
    Lundström, Ingemar
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, The Institute of Technology.
    Volatile Emissions from Compressed Tissue2013In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 8, no 7Article in journal (Refereed)
    Abstract [en]

    Since almost every fifth patient treated in hospital care develops pressure ulcers, early identification of risk is important. A non-invasive method for the elucidation of endogenous biomarkers related to pressure ulcers could be an excellent tool for this purpose. We therefore found it of interest to determine if there is a difference in the emissions of volatiles from compressed and uncompressed tissue. The ultimate goal is to find a non-invasive method to obtain an early warning for the risk of developing pressure ulcers for bed-ridden persons. Chemical analysis of the emissions, collected in compresses, was made with gas-chromatography – mass spectrometry and with a chemical sensor array, the so called electronic nose. It was found that the emissions from healthy and hospitalized persons differed significantly irrespective of the site. Within each group there was a clear difference between the compressed and uncompressed site. Peaks that could be certainly deemed as markers of the compression were, however, not identified. Nonetheless, different compounds connected to the application of local mechanical pressure were found. The results obtained with GC-MS reveal the complexity of VOC composition, thus an array of non-selective chemical sensors seems to be a suitable choice for the analysis of skin emission from compressed tissues; it may represent a practical instrument for bed side diagnostics. Results show that the adopted electronic noses are likely sensitive to the total amount of the emission rather than to its composition. The development of a gas sensor-based device requires then the design of sensor receptors adequate to detect the VOCs bouquet typical of pressure. This preliminary experiment evidences the necessity of studies where each given person is followed for a long time in a ward in order to detect the insurgence of specific VOCs pattern changes signalling the occurrence of ulcers.

  • 29.
    Dini, Francesca
    et al.
    University of Roma Tor Vergata.
    Martinelli, Eugenio
    University of Roma Tor Vergata.
    Paolesse, Roberto
    University of Roma Tor Vergata.
    Filippini, Daniel
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Schild, Detlev
    University of Gottingen.
    Lundström, Ingemar
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, The Institute of Technology.
    Di Natale, Corrado
    University of Roma Tor Vergata.
    Data processing for image-based chemical sensors: unsupervised region of interest selection and background noise compensation2012In: Analytical and Bioanalytical Chemistry, ISSN 1618-2642, E-ISSN 1618-2650, Vol. 402, no 2, p. 823-832Article in journal (Refereed)
    Abstract [en]

    Natural olfaction suggests that numerous replicas of small sensors can achieve large sensitivity. This concept of sensor redundancy can be exploited by use of optical chemical sensors whose use of image sensors enables the simultaneous measurement of several spatially distributed indicators. Digital image sensors split the framed scene into hundreds of thousands of pixels each corresponding to a portion of the sensing layer. The signal from each pixel can be regarded as an independent sensor, which leads to a highly redundant sensor array. Such redundancy can eventually be exploited to increase the signal-to-noise ratio. In this paper we report an algorithm for reduction of the noise of pixel signals. For this purpose, the algorithm processes the output of groups of pixels whose signals share the same time behavior, as is the case for signals related to the same indicator. To define these groups of pixels, unsupervised clustering, based on classification of the indicator colors, is proposed here. This approach to signal processing is tested in experiments on the chemical sensitivity of replicas of eight indicators spotted on to a plastic substrate. Results show that the groups of pixels can be defined independently of the geometrical arrangement of the sensing spots, and substantial improvement of the signal-to-noise ratio is obtained, enabling the detection of volatile compounds at any location on the distributed sensing layer.

  • 30.
    Suska, Anke
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Alehagen, Urban
    Linköping University, Department of Medical and Health Sciences, Cardiology. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart and Medicine Centre, Department of Cardiology UHL.
    Lundström, Ingemar
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Dahlström, Ulf
    Linköping University, Department of Medical and Health Sciences, Cardiology. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart and Medicine Centre, Department of Cardiology UHL.
    Salivary Alpha-Amylase Activity, a New Biomarker in Heart Failure?2012In: Journal of Clinical and Experimental Cardiology, ISSN 2155-9880, Vol. S2Article in journal (Refereed)
    Abstract [en]

    Salivary α-amylase activity is an increasingly investigated biomarker for the activation of the autonomic nervous system. Autonomic imbalance is associated to several diseases, one of which is heart failure, and the aim of the present study was to test if salivary α-amylase activity might be a new biomarker in patients with chronic heart failure.

    Methods: In this pilot study, 48 elderly men (range 59-89 years), 24 patients with established chronic heart failure in NYHA class I to III, and 24 controls were included. In all participants, saliva was collected for three consecutive days at three time points (at awakening, 30 minutes later and in the late afternoon), and blood was sampled for analysis of NT-proBNP.

    Results: Within the whole group of participants, a statistically significant positive correlation between morning salivary α-amylase activity levels and serum NT-proBNP could be found, which was strongest for the measurement taken 30 minutes after awakening, as well as a significant negative correlation of awakening α-amylase activity levels with arterial blood pressure.

    Within the control group separately, higher daily salivary α-amylase activity output correlated with increasing levels of NT-proBNP, while within the patients, the strongest association of α-amylase activity measures were found to be a negative correlation with blood pressure.

    Conclusions: Our data supports the idea that sAA activity has the potential as a non-invasive index of adrenergic activity in specific pathological conditions, though for heart failure in particular the results were merely modest, which was likely due to the specific intake of beta-receptor blocking drugs by all patients. Due to the large variability of sAA activity levels, we expect a greater potential for monitoring its changes over time, which could prove a valuable surrogate biomarker for cardiovascular diseases, including heart failure.

  • 31.
    Lvova, Larisa
    et al.
    University of Roma Tor Vergata.
    Mastroianni, Marco
    University of Roma Tor Vergata.
    Di Natale, Corrado
    University of Roma Tor Vergata.
    Lundström, Ingemar
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, The Institute of Technology.
    Paolesse, Roberto
    University of Roma Tor Vergata.
    Towards Hyphenated Sensors Development: Design and Application of Porphyrin Electropolymer Materials2012In: Electroanalysis, ISSN 1040-0397, E-ISSN 1521-4109, Vol. 24, no 4, p. 776-789Article in journal (Refereed)
    Abstract [en]

    The peculiar properties of porphyrins allow their exploitation as sensing materials in chemical sensors having different transduction principles, or even the intriguing possibility to develop sensors where two different transduction mechanisms are hyphenated in the same substrate. This approach can allow a significant increase in the chemical information obtained from the device and it can boost the performances in terms of selectivity and sensitivity. Our recent achievements in the field of functionalized porphyrins application for the development of the hyphenated optoelectrochemical sensors will be discussed in this contribution.

  • 32.
    Hammarström, Per
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biochemistry. Linköping University, The Institute of Technology.
    Ali, Malik M
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, The Institute of Technology.
    Mishra, Rajesh
    Linköping University, Department of Physics, Chemistry and Biology, Biochemistry. Linköping University, The Institute of Technology.
    Salagic, Belma
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, The Institute of Technology.
    Svensson, Samuel
    AstraZeneca RandD.
    Tengvall, Pentti
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Lundström, Ingemar
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, The Institute of Technology.
    An Auto-Catalytic Surface for Conformational Replication of Amyloid Fibrils-Genesis of an Amyloid World?2011In: Origins of life and evolution of the biosphere, ISSN 0169-6149, E-ISSN 1573-0875, Vol. 41, no 4, p. 373-383Article in journal (Refereed)
    Abstract [en]

    Amyloid fibrils are composed of self assembled stacked peptide or protein molecules folded and trapped in a stable cross-beta-sheet conformation. The amyloid fibrillation mechanism represents an intriguing self-catalyzed process rendering replication of a molecular conformational memory of interest for prebiotic chemistry. Herein we describe how a solid surface can be rendered auto-catalytic for fibrillation of a protein solution. We have discovered that a hydrophobic silicon or glass surface can be made to continuously fibrillate solutions of insulin monomers under stressed conditions (pH 1.6, 65 degrees C). It was found that the surface acts as a platform for the formation of nascent seeds that induce fibril replication on and at the surface. This autocatalytic effect stems from a layer a few insulin molecules thick representing an oligomeric layer of misfolded, conformationally trapped, insulin molecules that rapidly through epitaxial growth catalyze the rate determining step (nucleation) during fibril replication. This autocatalytic layer is generated by the protein-solid surface interaction and conformational changes of the adsorbed protein during exposure at the air-water interface. The resulting autocatalytic surface thus both initiates local conformational molecular self-replication and acts as a reservoir for fibril seeds budding off into solution spreading fibril replication entities to the surrounding medium. The possibility of catalysis of the conformational replication process by minute amounts of nucleation sites located on a recruiting surface can evade the issue of dramatic concentration dependence of amyloidogenesis.

  • 33.
    Eriksson, Mats
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Chemical and Optical Sensor Systems. Linköping University, Faculty of Science & Engineering.
    Lindgren, David
    Linköping University, Department of Electrical Engineering, Automatic Control. Linköping University, Faculty of Science & Engineering.
    Bjorklund, Robert
    Linköping University, Department of Physics, Chemistry and Biology.
    Winquist, Fredrik
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, Faculty of Science & Engineering.
    Sundgren, Hans
    Linköping University, Department of Physics, Chemistry and Biology, Chemical and Optical Sensor Systems. Linköping University, Faculty of Science & Engineering.
    Lundström, Ingemar
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, Faculty of Science & Engineering.
    Drinking water monitoring with voltammetric sensors2011In: Procedia Engineering, ISSN 1877-7058, E-ISSN 1877-7058, Vol. 25, p. 1165-1168Article in journal (Refereed)
    Abstract [en]

    Pulsed voltammetry has been applied to drinking water monitoring. This non-selective technique facilitates detection of several different threats to the drinking water. A multivariate algorithm shows that anomaly detection is possible with a minimum of false alarms. Multivariate analysis can also be used to classify different types of substances added to the drinking water. Low concentrations of sewage water contaminating the drinking water can be detected. A network of such sensors is envisaged to facilitate real-time and on-line monitoring of drinking water distribution networks.

  • 34.
    Martinelli, E
    et al.
    Electrical Engineering Department, University of Rome Tor Vergata, Italy.
    Polese, D
    Electrical Engineering Department, University of Rome Tor Vergata, Italy.
    Dini, F
    Electrical Engineering Department, University of Rome Tor Vergata, Italy.
    Paolesse, R
    Department of Chemical Science and Technology, University of Rome Tor Vergata, Italy.
    Filippini, Daniel
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology. University Roma Tor Vergata.
    D’Amico, A.
    Electrical Engineering Department, University of Rome Tor Vergata, Italy.
    Schild, D.
    Department of Neurophysiology and Cellular Biophysics, University of Go¨ ttingen, Germany and Bernstein Forum of Neurotechnology, Göttingen, Germany.
    Lundström, Ingemar
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Di Natale, C
    Electrical Engineering Department, University of Rome Tor Vergata, Italy.
    Odor Processing with an experimental model of Olfactory epithelium and bulb2011In: Chemical Senses, ISSN 0379-864X, E-ISSN 1464-3553, Vol. 36, no 1, p. E4-E4Article in journal (Other academic)
    Abstract [en]

    Artificial olfaction  was introduced  as a model tool  to investigateolfaction  properties  [1]. Nonetheless,   the  only  analogy  between the natural and the artificial system lies just in the selectivity proper- ties of the receptors. The implementation of more sophisticated fea- tures such as the large number of receptors and the glomerular layer have been hampered  by technical difficulties related to the manage- ment of large numbers  of simultaneous  signals.As demonstrated in the past, optical imaging is a read-out  tech- nique for sensors development that can provide large sensor arrays [2]. On that basis, we recently introduced  an artificial olfaction sys- tem based on the imaging of a continuous layer of chemical indi- cators [3]. In this situation an image sensor provides a segmentation of the whole sensing layer in a number  of elementary  units corre- sponding to the pixels of the image. Eventually, since it is possible to evaluate the optical properties of every single pixel, each pixel of the image may correspond to an individual sensor. In this regard, even low-resolution  images may easily result in thousands of independ- ent sensing units.In our system a collection of arbitrarily shaped regions of color indicators  is illuminated  by a controlled  light source;  the optical characteristics  of each pixel of the image are measured by a camera yielding the light intensities in the three channels  red, green, and blue.   The  combination  of  illumination   sequence  and   cameraread-out  results  in  a  fingerprint  encoding  the  optical  properties of the sensing layer portioned in image pixels. Even a simple clas- sification of these fingerprints assigns each pixel to a class, and each class contains pixels carrying the same color indicator.  This behav- ior resembles the association between ORNs carrying the same chemical receptors into the same glomerulus [4]. On the basis of this analogy it is straightforward to describe the layer of indicators as an artificial epithelium, pixels of the image as artificial olfactory  neu- rons, and the classes provided  by the classifier as an abstract  rep- resentation of artificial glomeruli.This system thus allows the generation of a complex model of olfaction,  including  glomerular  compartmentalization [5], which is then applied to data generated by the exposure to pure and mixed gases. Results show that such a model enhances the discrimination of pure and mixed odors. Eventually,  such a platform,  apart  from evidencing the similarities between natural and artificial olfactory systems, is also proposed as a practical tool to test olfactory models.

    1. K. Persaud  and G. Dodds,  Nature  299 (1982) 352

    2. Dickinson  et al., Nature  382 (1996) 697

    3. C. Di Natale  et al., PLoS  ONE 3 (2008) 3139

    4. P. Mombaerts, Annu Rev Neurosci 22 (1999) 487

    5. D. Schild and H. Riedel, Biophysical Journal,  61 (1992) 704

  • 35.
    Klingvall, Roger
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Lundström, Ingemar
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, The Institute of Technology.
    Eriksson, Mats
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Robust gas detection at sub ppm concentrations2011In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 160, no 1, p. 571-579Article in journal (Refereed)
    Abstract [en]

    Gas sensors often suffer from signal drift and long response and recovery times, giving rise to problems to evaluate the steady state gas response. It is shown that these problems can be reduced by modulating the test gas concentration and utilizing the change in the slope of the sensor signal as the sensor response feature. The case of low hydrogen concentration detection is studied using a light pulse technique and a PdPt-MIS field-effect device. For the difference in slope method it was possible to reduce the measurement time from hours in the steady state measurements to 1 + 1 min (test gas + reference gas exposure time) and still achieve a detection limit of about 40 ppb for a step change in hydrogen concentration. Such measurements could be made in spite of a drifting baseline caused, e.g. by previous hydrogen exposures. A theoretical model of how a step change in the hydrogen partial pressure affects the difference in slope is given. The model also predicts a non-reactive hydrogen sticking probability (i.e. the probability that an incoming hydrogen molecule from the gas phase will contribute to the response) of about 1 x 10(-8) at 100 ppb H(2), which is about 2 orders of magnitude lower than the reactive sticking coefficient. (C) 2011 Elsevier B.V. All rights reserved.

  • 36.
    Di Natale, Corrado
    et al.
    University Roma Tor Vergata.
    Santonico, Marco
    University Roma Tor Vergata.
    Paolesse, Roberto
    University Roma Tor Vergata.
    Filippini, Daniel
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics . Linköping University, The Institute of Technology.
    DAmico, Arnaldo
    University Roma Tor Vergata.
    Lundström, Ingemar
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics . Linköping University, The Institute of Technology.
    Evaluation of the performance of sensors based on optical imaging of a chemically sensitive layer2010In: ANALYTICAL AND BIOANALYTICAL CHEMISTRY, ISSN 1618-2642, Vol. 397, no 2, p. 613-621Article in journal (Refereed)
    Abstract [en]

    Interest in the use of the optical properties of chemical indicators is growing steadily. Among the optical methods that can be used to capture changes in sensing layers, those producing images of large-area devices are particularly interesting for chemical sensor array development. Until now, few studies addressed the characterization of image sensors from the point of view of their chemical sensor application. In this paper, a method to evaluate such performance is proposed. It is based on the simultaneous measurement of absorption events in a metalloporphyrin layer with an image sensor and a quartz microbalance (QMB). Exploiting the well-known behaviour of QMB, comparison of signals enables estimation of the minimum amount of absorbed molecules that the image sensor can detect. Results indicate that at the single pixel level a standard image sensor (for example a webcam) can easily detect femtomoles of absorbed molecules. It should therefore be possible to design sensor arrays in which the pixels of images of large-area sensing layers are regarded as individual chemical sensors providing a ready and simple method for large sensor array development.

  • 37.
    Dini, Francesca
    et al.
    University Roma Tor Vergata.
    Filippini, Daniel
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics . Linköping University, The Institute of Technology.
    Paolesse, Roberto
    University Roma Tor Vergata.
    DAmico, Arnaldo
    University Roma Tor Vergata.
    Lundström, Ingemar
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics . Linköping University, The Institute of Technology.
    Di Natale, Corrado
    University Roma Tor Vergata.
    Polymers with embedded chemical indicators as an artificial olfactory mucosa2010In: ANALYST, ISSN 0003-2654, Vol. 135, no 6, p. 1245-1252Article in journal (Refereed)
    Abstract [en]

    Physiological investigations suggest that the olfactory mucosa probably plays an ancillary role in the recognition of odours introducing a sort of chromatographic separation that, together with the zonal distribution of olfactory receptors, gives place to selective spatio-temporal response patterns. It has been recently suggested that this behaviour may be simulated by chemical sensors embedded in continuous polymer layers. In this paper, in analogy to the biology of olfaction, a simple and compact platform able to separate and detect gases and vapours on the basis of their diffusion properties is proposed. In such a system, broadly selective colour indicators, such as metalloporphyrins, are embedded in continuous layers of polymers with different sorption properties. The exposure to various alcohols and amines shows that the porphyrins are mainly responsible for the recognition of the molecular family, while the occurring spatio-temporal signal patterns make possible the identification of the individual chemical species.

  • 38.
    Garvin, Peter
    et al.
    Linköping University, Department of Medical and Health Sciences, Social Medicine and Public Health Science. Linköping University, Faculty of Health Sciences.
    Suska, Anke
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Kristenson, Margareta
    Linköping University, Department of Medical and Health Sciences, Social Medicine and Public Health Science. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Centre for Public Health Sciences.
    Lundström, Ingemar
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Ernerudh, Jan
    Linköping University, Department of Clinical and Experimental Medicine, Clinical Immunology. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Center for Diagnostics, Department of Clinical Immunology and Transfusion Medicine.
    SALIVARY ALPHA-AMYLASE IN A POPULATION BASED SAMPLE. ASSOCIATIONS WITH PSYCHOSOCIAL FACTORS, SELF RATED HEALTH AND INFLAMMATORY MARKERS2010In: International Journal of Behavioral Medicine, ISSN 1070-5503, E-ISSN 1532-7558, Vol. 17, no 1 Supplement, p. S181-S181Article in journal (Other academic)
    Abstract [en]

    Objective: In recent years, salivary alpha-amylase (sAA) has beenproposed as a reliable proxy for sympathetic activity. This study aimed at testing the association between sAA to a broad range of psychosocial factors, self rated health, cardiovascular risk factors and inflammatory markers in a normal population sample.

    Methods: 30 participants, all men between 50 and 54 years old, were randomly selected from a normal population based study. Saliva samples were collected at awakening, 30 minutes after awakening and just before going to bed. sAA was measured by a calorimetric method using Phadebas amylase test. Linear regression models were used to test associations between sAA levels and a broad spectrum of psychosocial factors (e.g. depressive symptamology, vital exhaustion, mastery and sense of coherence) self rated health and inflammatory markers (e.g. C-reactive protein). Adjustments were made for physical exercise, smoking, blood  lipids and  time point  when  sample was collected.

    Results: sAA levels at awakening were positively associated with depressive symptamology (p = 0.046), vital exhaustion (p = 0.025) and negatively associated with sense of coherence (p = 0.034). It was further associated positively associated with levels of C-reactive protein (p = 0.024)  and  negatively associated with  self  reported general health (p = 0.010). Samples taken just before going to bed were showing similar results, whereas samples taken 30 minutes after awakening only showed a few significant associations.

    Conclusions: The associations found give further support for the use of salivary alpha amylase as a psychoneuroendocrinological bio- marker. Assessment just after awakening or just before going to bed seems to be more reliable than samples 30 minutes after awakening.

  • 39.
    Berggren, Karl-Fredrik
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Theoretical Physics . Linköping University, The Institute of Technology.
    Cederwall, Martin
    Chalmers.
    Forssell-Aronsson, Eva
    Sahlgrenska akademin.
    Fredriksson, Billy
    Vetenskapsrådets ämnesråd för naturvetenskap och teknik.
    Goksör, Mattias
    Göteborgs universtitet.
    Häggström, Olle
    Chalmers.
    Lundström, Ingemar
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics . Linköping University, The Institute of Technology.
    Mårtensson, Ann-Sofie
    Högskolan i Borås.
    Sandelius, Anna Stina
    Göteborgs universitet.
    Wennberg, Ann-Marie
    Sahlgrenska universitetssjukhuset.
    Stärk matematiken och naturvetenskapen i nya gymnasiet2010In: NyTeknikArticle in journal (Other (popular science, discussion, etc.))
  • 40.
    Di Natale, C
    et al.
    University Roma Tor Vergata.
    Martinelli, E
    University Roma Tor Vergata.
    Paolesse, R
    University Roma Tor Vergata.
    DAmico, A
    University Roma Tor Vergata.
    Filippini, Daniel
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics . Linköping University, The Institute of Technology.
    Lundström, Ingemar
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics . Linköping University, The Institute of Technology.
    An artificial olfaction system based on the optical imaging of a large array of chemical reporters2009In: SENSORS AND ACTUATORS B-CHEMICAL, ISSN 0925-4005, Vol. 142, no 2, p. 412-417Article in journal (Refereed)
    Abstract [en]

    Electronic noses are object of research since more than two decades; nonetheless. the analogies between natural and olfaction systems are still limited to the selectivity properties of the receptors. The implementation of more sophisticated features such as the large number of receptors and the glomeruli layer have been hampered by technical difficulties related to the management of a large number of contemporaneous signals. As demonstrated in the past, optical imaging is a read-out technique for sensors development that can provide large sensor arrays. In this paper an artificial olfaction system based on the imaging of a continuous layer of chemical indicators is illustrated. The system incorporates an array of thousands of sensors, corresponding to the pixels of the image. The choice of Computer Screen Photoassisted Technology as a platform for optical interrogation of the sensing layer allows for the definition of a strategy for an automatic definition of a glomeruli layer based on the classification of the optical fingerprints of the image pixels. Chemical indicators were dissolved into a polymeric matrix providing the further property of odor diffusion mimicking the functions of the olfactory mucosa. The system has been tested in a simple experiment and data have been treated applying a lateral inhibition to the glomeruli layer resulting in a dynamic pattern resembling that observed in natural olfaction.

  • 41.
    Dini, Francesca
    et al.
    University Roma Tor Vergata.
    Martinelli, Eugenio
    University Roma Tor Vergata.
    Pomarico, Giuseppe
    University Roma Tor Vergata.
    Paolesse, Roberto
    University Roma Tor Vergata.
    Monti, Donato
    University Roma Tor Vergata.
    Filippini, Daniel
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics . Linköping University, The Institute of Technology.
    DAmico, Arnaldo
    University Roma Tor Vergata.
    Lundström, Ingemar
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics . Linköping University, The Institute of Technology.
    Di Natale , Corrado
    University Roma Tor Vergata.
    Chemical sensitivity of self-assembled porphyrin nano-aggregates2009In: NANOTECHNOLOGY, ISSN 0957-4484 , Vol. 20, no 5, p. 055502-Article in journal (Refereed)
    Abstract [en]

    Nanostructured molecular assemblies may provide additional sensing properties not found in other arrangements of the same basic constituents. Among three-dimensional structures, nanotubes are particularly appealing for applications as chemical sensors, because of the potential inclusion of different guests inside the cavity or the induced modification of the skeletal interaction after analyte binding. Porphyrins are a class of compounds characterized by brilliant sensing properties, appearing also in non-ordered solid-state aggregates. In recent years, it was reported that aggregation of oppositely charged porphyrins led to the formation of self-assembled nanotubes and in this paper their sensing properties, both in solution and in the solid state, have been investigated.

    The interactions of porphyrin nanotubes with guest molecules have been monitored by following the changes in their UV-vis spectra. The results obtained have been exploited to build up a sensing platform based on a computer screen as a light source and a digital camera as detector.

    Porphyrin nanostructures exhibited an enhanced sensitivity to different compounds with respect to those shown by single porphyrin subunits. The reason for the increased sensitivity may be likely found in an additional sensing mechanism related to the modulation of the strength of the forces that keep the supramolecular ensemble together.

  • 42.
    Eriksson, Mats
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Winquist, Fredrik
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Bjorklund, Robert
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Lindgren, David
    Linköping University, Department of Electrical Engineering, Automatic Control. Linköping University, The Institute of Technology.
    Sundgren, Hans
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Lundström, Ingemar
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Event Detection in Crisis Management Systems2009In: Procedia Chemistry, ISSN 1876-6196, E-ISSN 1876-6196, Vol. 1, no 1, p. 1055-1058Article in journal (Refereed)
    Abstract [en]

    The EVENT project concerns drinking water surveillance and includes sensors and algorithms that detect anomalies in the drinking water properties, communication of the evaluated sensor data to a crises management system and presentation of information that is relevant for the end users of the crises management system. We have chosen to focus on a sensor technique based on an "electronic tongue", since this robust type of non-selective sensor, can detect a plurality of anomalies without the need of a specific sensor for each type of event. Measurements of natural variations and contamination events are presented and discussed.

  • 43.
    Suska, Anke
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, Faculty of Science & Engineering.
    Belen Ibanez, Ana
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, Faculty of Science & Engineering.
    Preechaburana, Pakorn
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, Faculty of Science & Engineering.
    Lundström, Ingemar
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Berghard, Anna
    Umeå University.
    G protein-coupled receptor mediated sensing of TMA2009In: PROCEEDINGS OF THE EUROSENSORS XXIII CONFERENCE, ISSN 1876-6196, Vol. 1, no 1, p. 321-324Article in journal (Refereed)
    Abstract [en]

    A new approach for the detection of trimethylamine (TMA) using recombinant Xenopus laevis melanophores was developed. The cells were genetically modified to express the mouse trace amine-associated receptor 5 (mTAAR5), a G protein-coupled receptor from the olfactory epithelium, which conferred high sensitivity to TMA. A focused chemical screen allowed the discovery of additional, previously unknown stimuli of mTAAR5. The cell-based sensor demonstrated no sensitivity to trimethylamine N-oxide (TMAO), making it suitable for a convenient evaluation of TMA levels in fish tissue extracts. The developed gas measurement platform was able to detect TMA from 1 to 100 ppm within thirty-five minutes.

  • 44.
    Suska, Anke
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, Faculty of Science & Engineering.
    Belen Ibanez, Ana
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, Faculty of Science & Engineering.
    Lundström, Ingemar
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Berghard, Anna
    Umea University, Department Mol Biol, SE-90187 Umea, Sweden .
    G protein-coupled receptor mediated trimethylamine sensing2009In: BIOSENSORS and BIOELECTRONICS, ISSN 0956-5663, Vol. 25, no 4, p. 715-720Article in journal (Refereed)
    Abstract [en]

    A new approach for the detection of trimethylamine (TMA) using a recombinant cell line of Xenopus laevis melanophores was developed. The cells were genetically modified to express the mouse trace amine-associated receptor 5 (mTAAR5), a G protein-coupled receptor from the mouse olfactory epithelium, which conferred high sensitivity to TMA. Cellular responses to TMA were analyzed by two different techniques, either by absorbance measurements using a microplate reader or by cellular imaging via an inverted microscope. A focused chemical screen allowed the discovery of additional, previously unknown stimuli of mTAAR5. The developed cell-based sensor demonstrated no sensitivity to trimethylamine N-oxide (TMAO), making it suitable for a straightforward evaluation of TMA levels in fish tissue extracts. For the detection of TMA vapor, the cells were covered with agarose, which allowed for intact cell viability for at least 6 h in air. The developed gas measurement platform was able to detect TMA from I to 100 ppm within 35 min.

  • 45.
    Ali Malik, Muhammad
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, Faculty of Science & Engineering.
    Gatto, Emanuela
    University Roma Tor Vergata.
    Macken, Stephen
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, Faculty of Science & Engineering.
    DiNatale, Corrado
    University Roma Tor Vergata.
    Paolesse, Roberto
    University Roma Tor Vergata.
    DAmico, Arnaldo
    University Roma Tor Vergata.
    Lundström, Ingemar
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Filippini, Daniel
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Imaging fingerprinting of excitation emission matrices2009In: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 635, no 2, p. 196-201Article in journal (Refereed)
    Abstract [en]

    The spectral fingerprinting of the excitation emission matrix (EEM) of fluorescent substances is demonstrated using polychromatic light sources and tri-chromatic image detectors. A model of the measured fingerprints explaining their features and classification performance, based on the polychromatic excitation of the indicators is proposed.

    Substantial amount of spectral information is retained in the fingerprints as corroborated by multivariate analysis and experimental conditions that favor such situation are identified.

    In average, for five different substances, the model shows a fitting goodness measured by the Pearsons r coefficient and the root mean square deviation of 0.8541 and 0.0247 respectively, while principal component classification patterns satisfactorily compare with the EEM spectroscopy classification and respectively explain 96% and 93% of the information in the fist two principal components.

    The measurements can be performed using regular computer screens as illumination and web cameras as detectors, which constitute ubiquitous and affordable platforms compatible with distributed evaluations, in contrast to regular instrumentation for EEM measurements.

  • 46.
    Di Natale, Corrado
    et al.
    University Roma Tor Vergata.
    Buchholt, Kristina
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Martinelli, Eugenio
    University Roma Tor Vergata.
    Paolesse, Roberto
    University Roma Tor Vergata.
    Pomarico, Giuseppe
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    DAmico, Arnaldo
    University Roma Tor Vergata.
    Lundström, Ingemar
    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.
    Investigation of quartz microbalance and ChemFET transduction of molecular recognition events in a metalloporphyrin film2009In: Sensors and actuators. B, Chemical, ISSN 0925-4005, Vol. 135, no 2, p. 560-567Article in journal (Refereed)
    Abstract [en]

    Progresses of synthetic chemistry methodologies have allowed the preparation of a great variety of artificial receptors that are particularly appealing for chemical sensor development. In this paper, we investigate and compare the properties of gas sensors based on two types of devices, quartz microbalances (QMBs) and field effect transistors (FETs), which give the means to exploit the molecular recognition events occurring in non-conductive sensing layers formed by a thiol-modified cobalt tetraphenylporphyrin (CoTPPSH). Since QMB is sensitive to mass and FET is sensitive to electric dipoles, the resulting sensors are expected to exhibit different sensitivities and selectivities, although both based on the same sensing layer. In particular we show that the high sensitivity of CoTPPSH-coated FETs towards CO and NO is a consequence of the significant CoTPPSH electric dipole change after the gas coordination to the metal centre.

  • 47.
    Di Natale, Corrado
    et al.
    Univ Roma Tor Vergata, Dept Elect Engn, I-00133 Rome, Italy.
    Paolesse, Roberto
    Univ Roma Tor Vergata, Dept Chem Sci and Technol, I-00133 Rome, Italy.
    DAmico, Arnaldo
    Univ Roma Tor Vergata, Dept Elect Engn, I-00133 Rome, Italy.
    Lundström, Ingemar
    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.
    Multi-transduction of molecular recognition events in metalloporphyrin layers2009In: Journal of Porphyrins and Phthalocyanines, ISSN 1088-4246, E-ISSN 1099-1409, Vol. 13, no 11, p. 1123-1128Article in journal (Refereed)
    Abstract [en]

    Besides the design and synthesis of appropriate molecular recognition systems, the development of chemical sensors requires a careful selection of the transducer to allow conversion of the chemical interaction into an exploitable electric signal. Metalloporphyrins, which are characterized by manifold of interactions of different strength and selectivity, provide a good example of the complexity of such an issue. In this paper, an example of the different ways to capture interactions occurring in a metalloporphyrin layer is presented. In particular, the properties of mass ( quartz microbalance) and surface potential transducers (field effect transistor) are illustrated. Results suggest that field effect transistors are more suitable to preserve the interactions magnitude scale than to maintain the original selectivity of the molecular recognition system.

  • 48.
    Filippini, Daniel
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Gatto, Emanuela
    University Roma Tor Vergata.
    Alimelli, Adriano
    University Roma Tor Vergata.
    Ali Malik, Muhammad
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Di Natale, Corrado
    University Roma Tor Vergata.
    Paolesse, Roberto
    University Roma Tor Vergata.
    DAmico, Arnaldo
    University Roma Tor Vergata.
    Lundström, Ingemar
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Spectral fingerprinting of porphyrins for distributed chemical sensing2009In: JOURNAL OF PORPHYRINS AND PHTHALOCYANINES, ISSN 1088-4246, Vol. 13, no 1, p. 77-83Article in journal (Refereed)
    Abstract [en]

    Recent progress in spectral fingerprinting of fluorescent indicators using distributed instrumentation based on consumer electronic devices is reviewed. In particular, the evaluation of disposable assays using a computer screen photo-assisted technique (CSPT) is discussed. Sample identification and optimization strategies are analyzed as well as the underlying theoretical background for polychromatic spectral fingerprinting.

  • 49.
    Tortora, Luca
    et al.
    University Roma Tor Vergata.
    Stefanelli, Manuela
    University Roma Tor Vergata.
    Mastroianni, Marco
    University Roma Tor Vergata.
    Lvova, Larisa
    University Roma Tor Vergata.
    Di Natale, Corrado
    University Roma Tor Vergata.
    DAmico, Arnaldo
    University Roma Tor Vergata.
    Filippini, Daniel
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics . Linköping University, The Institute of Technology.
    Lundström, Ingemar
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics . Linköping University, The Institute of Technology.
    Paolesse, Roberto
    University Roma Tor Vergata.
    The hyphenated CSPT-potentiometric analytical system: An application for vegetable oil quality control2009In: SENSORS AND ACTUATORS B-CHEMICAL, ISSN 0925-4005, Vol. 142, no 2, p. 457-463Article in journal (Refereed)
    Abstract [en]

    The computer screen photo assisted technique (CSPT) has been used to develop a hyphenated optical-potentiometric sensing at-ray, based on porphyrinoid materials dispersed into PVC membranes. Sensing layers have been deposited onto indium tin oxide (ITO) glass slides, which were exploited as electrodes, for potentiometric measurements, and chromophore spots, to obtain CSPT data. Both measurements were contemporaneously carried out in the hyphenated sensing platform. The performances of the hyphenated sensing array were first tested for the detection of model analytes, characteristics of vegetable oil matrices, and then evaluated in the discrimination of real samples of olive and seed oils. The results obtained demonstrated that the hyphenated system affords a significant improvement of information and oils classification with respect to the individual potentiometric and optical components.

  • 50.
    Macken, Stephen
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, Faculty of Science & Engineering.
    Di Natale, Corrado
    University Roma Tor Vergata, Italy.
    Paolesse, Roberto
    University Roma Tor Vergata, Italy.
    DAmico, Arnaldo
    University Roma Tor Vergata, Italy.
    Lundström, Ingemar
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Filippini, Daniel
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Towards integrated devices for computer screen photo-assisted multi-parameter sensing2009In: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 632, no 1, p. 143-147Article in journal (Refereed)
    Abstract [en]

    The computer screen photo-assisted technique (CSPT) utilizes consumer electronic devices such as computer screens and web cameras for distributed chemical sensing. Key to this method is the development of small and disposable sensing assays able to aid the CSPT optical detection, and the evaluation of multiple indicators. Here we demonstrate CSPT identification of fluorescent indicators from individual 100 mu m SU-8 (10) pillars covering an area of 4 mm x 4 mm with a density of 47 elements mm-2. The extraction of distinctive spectral fingerprints is aided by the exploitation of a three-band Moire interference that enables the partial Bayer decoding of the CSPT images.

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