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  • 1.
    Abbasy, Leila
    et al.
    Tabriz University of Medical Sciences, Iran.
    Mohammadzadeh, Arezoo
    Tabriz University of Medical Sciences, Iran.
    Hasanzadeh, Mohammad
    Tabriz University of Medical Sciences, Iran.
    Razmi, Nasrin
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik, elektroteknik och matematik. Linköpings universitet, Tekniska fakulteten.
    Development of a reliable bioanalytical method based on prostate specific antigen trapping on the cavity of molecular imprinted polymer towards sensing of PSA using binding affinity of PSA-MIP receptor: A novel biosensor2020Ingår i: Journal of Pharmaceutical and Biomedical Analysis, ISSN 0731-7085, E-ISSN 1873-264X, Vol. 188, artikel-id 113447Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this study, electrically-conducting poly [Toluidine Blue (PTB)] was applied as artificial receptor. It was organized by molecular imprinting approaches and via electrochemical technique for the sensitive monitoring of prostate-specific antigen (PSA). The protein-imprinted PTB was electropolymerized in a pre-formed glutaraldehyde-cysteamine (GA-Cys A) matrix on the surface of gold electrode, which significantly boosted the stability against degradation of the Molecular Imprinted Polymer (MIP) on the surface of pre-modified gold electrode. Moreover, the MIP bio-receptor ability towards protein recognition was explored by some electrochemical techniques. The binding affinity of MIP system was considerably upper than that of non-imprinted polymer (NIP) system, indicating the success of the method in generating imprinted materials that was specifically use to PSA protein. The incubation of the MIP modified electrode in various concentration of PSA (from 1-60 μg/L) resulted in the increase of the Fe (CN)63-/4- redox peak current. The bio-device also showed linear response from 1-60 μg/L and LLOQ of 1 μg/L by using DPV technique, leading to PSA monitoring in clinical samples. The proposed MIP-based biosensor was satisfactorily applied to the determination of PSA in human plasma samples. Therefore, the developed bio-device provides a new approach for sensitive, simple, rapid, and cost-effective monitoring of 1 μg/L of PSA. Notably, this approach could appear as an appropriate candidate for point-of-care (POC) use in clinical and biomedical analyses.

  • 2.
    Afzali, Maryam
    et al.
    Cardiff Univ, Wales.
    Pieciak, Tomasz
    AGH Univ Sci & Technol, Poland; Univ Valladolid, Spain.
    Newman, Sharlene
    Indiana Univ, IN 47405 USA; Indiana Univ, IN 47405 USA.
    Garyfallidis, Eleftherios
    Indiana Univ, IN 47405 USA; Indiana Univ, IN 47408 USA.
    Özarslan, Evren
    Linköpings universitet, Institutionen för medicinsk teknik, Avdelningen för medicinsk teknik. Linköpings universitet, Tekniska fakulteten. Linköpings universitet, Centrum för medicinsk bildvetenskap och visualisering, CMIV.
    Cheng, Hu
    Indiana Univ, IN 47405 USA; Indiana Univ, IN 47405 USA.
    Jones, Derek K.
    Cardiff Univ, Wales.
    The sensitivity of diffusion MRI to microstructural properties and experimental factors2021Ingår i: Journal of Neuroscience Methods, ISSN 0165-0270, E-ISSN 1872-678X, Vol. 347, artikel-id 108951Artikel, forskningsöversikt (Refereegranskat)
    Abstract [en]

    Diffusion MRI is a non-invasive technique to study brain microstructure. Differences in the microstructural properties of tissue, including size and anisotropy, can be represented in the signal if the appropriate method of acquisition is used. However, to depict the underlying properties, special care must be taken when designing the acquisition protocol as any changes in the procedure might impact on quantitative measurements. This work reviews state-of-the-art methods for studying brain microstructure using diffusion MRI and their sensitivity to microstructural differences and various experimental factors. Microstructural properties of the tissue at a micrometer scale can be linked to the diffusion signal at a millimeter-scale using modeling. In this paper, we first give an introduction to diffusion MRI and different encoding schemes. Then, signal representation-based methods and multi-compartment models are explained briefly. The sensitivity of the diffusion MRI signal to the microstructural components and the effects of curvedness of axonal trajectories on the diffusion signal are reviewed. Factors that impact on the quality (accuracy and precision) of derived metrics are then reviewed, including the impact of random noise, and variations in the acquisition parameters (i.e., number of sampled signals, b-value and number of acquisition shells). Finally, yet importantly, typical approaches to deal with experimental factors are depicted, including unbiased measures and harmonization. We conclude the review with some future directions and recommendations on this topic.

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  • 3.
    Ahlinder, Jon
    et al.
    Totalförsvarets Forskningsinstitut, FOI, Stockholm, Sweden.
    Nordgaard, Anders
    Swedish National Forensic Centre (NFC), Linköping, Sweden.
    Wiklund Lindström, Susanne
    Totalförsvarets Forskningsinstitut, FOI, Stockholm, Sweden.
    Chemometrics comes to court: evidence evaluation of chem–bio threat agent attacks2015Ingår i: Journal of Chemometrics, ISSN 0886-9383, E-ISSN 1099-128X, Vol. 29, nr 5, s. 267-276Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Forensic statistics is a well-established scientific field whose purpose is to statistically analyze evidence in order to support legal decisions. It traditionally relies on methods that assume small numbers of independent variables and multiple samples. Unfortunately, such methods are less applicable when dealing with highly correlated multivariate data sets such as those generated by emerging high throughput analytical technologies. Chemometrics is a field that has a wealth of methods for the analysis of such complex data sets, so it would be desirable to combine the two fields in order to identify best practices for forensic statistics in the future. This paper provides a brief introduction to forensic statistics and describes how chemometrics could be integrated with its established methods to improve the evaluation of evidence in court.

    The paper describes how statistics and chemometrics can be integrated, by analyzing a previous know forensic data set composed of bacterial communities from fingerprints. The presented strategy can be applied in cases where chemical and biological threat agents have been illegally disposed.

  • 4.
    Ahmed Khand, Aftab
    et al.
    Tsinghua Univ Beijing, Peoples R China; Univ Sindh Jamshoro, Pakistan.
    Ahmed Lakho, Saeed
    Univ Karachi, Pakistan.
    Tahira, Aneela
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik, elektroteknik och matematik. Linköpings universitet, Tekniska fakulteten.
    Ahmed, Mansoor
    Univ Karachi, Pakistan.
    Aftab, Umair
    MUET, Pakistan.
    Abro, Muhammad Ishaq
    MUET, Pakistan.
    Juno, Awais Ahmed
    Ziauddin Univ, Pakistan.
    Nafady, Ayman
    King Saud Univ, Saudi Arabia.
    Ibupoto, Zafar Hussain
    Univ Sindh Jamshoro, Pakistan.
    Synthesis of Sheet Like Nanostructures of NiO Using Potassium Dichromate as Surface Modifying Agent for the Sensitive and Selective Determination of Amlodipine Besylate (ADB) Drug2021Ingår i: Electroanalysis, ISSN 1040-0397, E-ISSN 1521-4109, Vol. 33, nr 5, s. 1121-1128Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The monitoring of hypertension drugs is very critical and important to sustain a healthy life. In this study, we have synthesized nickel oxide (NiO) nanostructures using potassium dichromate as surface modifying agent by hydrothermal method. These NiO nanostructures were found highly active for the oxidation of ADB besylate (ADB). The unit cell structure and morphology were investigated by scanning electron microscopy (SEM) and powder X-ray diffraction (XRD) techniques. The SEM study has confirmed the nano sheet like morphology and XRD analysis has described the cubic unit arrays of NiO. After the physical characterization, NiO nanostructures were used to modify the surface of glassy carbon electrode (GCE) by drop casting method. Then cyclic voltammetry (CV) was used to characterize the electrochemical activity of NiO nanostructures in the0.1 M phosphate buffer solution of pH 10.0 and a well resolved oxidation peak was identified at 0.70 V. The linear range for the NiO nanostructures was observed from 20-90 nM with a regression coefficient of 0.99 using CV. The calculated limit of detection (LOD) was 2.125 nM and the limit of quantification (LOQ) was 4.08 nM. Further to validate the CV calibration plot, an amperometry experiment was performed on the NiO nanostructures and sensors exhibited a linear range of 10 nM to 115 nM with LOD of 1.15 nM. The proposed approach was successfully used for the determination of ADB from commercial tablets and it reveals that the sensor could be capitalized to monitor ADB concentrations from pharmaceutical products. The use of potassium dichromate as a surface modifying agent for the metal oxide nanostructures may be of great interest to manipulate their crystal and surface properties for the extended range of biomedical and energy related applications.

  • 5.
    Ali Soomro, Razium
    et al.
    University of Sindh, Pakistan.
    Hallam, Keith Richard
    University of Bristol, UK.
    Hussain Ibupoto, Zafar
    University of Sindh, Pakistan.
    Tahira, Aneela
    University of Sindh, Pakistan.
    Tufail Hussain Sherazi, Syed
    University of Sindh, Pakistan.
    Juddin, Siraj
    University of Sindh, Pakistan.
    Jawaid, Sana
    University of Sindh, Pakistan.
    Willander, Magnus
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska fakulteten.
    Glutaric Acid Assisted Fabrication of CuO Nanostructures and their Application in Development of Highly Sensitive Electrochemical Sensor System for Carbamates2016Ingår i: Electroanalysis, ISSN 1040-0397, E-ISSN 1521-4109, Vol. 28, nr 7, s. 1634-1640Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This work describes the fabrication of unique arrow head shaped CuO nanostructures using simple hydrothermal treatment method. The highly attractive features were obtained by the application of glutaric acid utilised simultaneous as template and functionalising agent. The functionalised nanostructures were known to possess excellent potential towards the electro-catalytic oxidation of carbofuran pesticide. The generated intense electrochemical signal with lower potential value enabled sensitive and selective determination of carbofuran up to 1 x 10(-3) mu M with wide sensing window in range of 0.01 to 0.16 mu M. The feasibility of the developed sensor system for the practical application was also studied by testing its potential in real sample extracts of various vegetables. The excellent recoveries demonstrated the analytical robustness of the developed sensor system. The sensor system utilises a new and simple approach towards sensitive determination of toxic pesticides reflecting its wide spectrum application in various fields.

  • 6.
    Ali Soomro, Razium
    et al.
    University of Bristol, England; University of Sindh, Pakistan.
    Hussain Ibupoto, Zafar
    Dr MA Kazi Institute Chemistry University of Sindh, Pakistan.
    Tufail Hussain Sirajuddin; Sherazi, Syed
    University of Sindh, Pakistan.
    Ishaq Abro, Muhammad
    Mehran University of Engn and Technology, Pakistan.
    Willander, Magnus
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska fakulteten.
    Practice of diclofenac sodium for the hydrothermal growth of NiO nanostructures and their application for enzyme free glucose biosensor2016Ingår i: Microsystem Technologies: Micro- and Nanosystems Information Storage and Processing Systems, ISSN 0946-7076, E-ISSN 1432-1858, Vol. 22, nr 10, s. 2549-2557Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this study diclofenac sodium (DFS), an analgesic drug has been employed as an effective template for the synthesis of NiO nanostructures. The NiO nanostructures were synthesised using low temperature hydrothermal growth method, both in the presence and absence of the DFS drug. The synthesised nanostructures were studied for their structural, compositional and electrochemical properties using scanning electron microscopy, X-ray diffraction and cyclic voltammetry. The synthesised nanostructures were then utilised for the modification of glassy carbon electrode which were then utilised for the electro-catalytic enzyme free glucose sensing in alkaline media. The competitive experiments suggested that although, both nanostructures possess excellent capability of glucose sensing, the NiO nanoflakes modified electrode was found to be twice as much as sensitive (2584 A mu A mM(-1) cm(-2)) as nanoflowers based electrode (1154 A mu A mM(-1) cm(-2)). The NiO nanoflakes based sensor further demonstrated excellent anti-interference potential in the presence of common interferents like uric acid, ascorbic acid and dopamine. In addition, the successful application NiO nanoflakes based sensor to determine real blood glucose concentration further suggest its feasibility for real sample analysis.

  • 7.
    Ali Soomro, Razium
    et al.
    University of Bristol, England; University of Sindh, Pakistan.
    Nafady, Ayman
    King Saud University, Saudi Arabia; Sohag University, Egypt.
    Hallam, Keith Richard
    University of Bristol, England.
    Jawaid, Sana
    University of Sindh, Pakistan.
    Al Enizi, Abdullah
    King Saud University, Saudi Arabia.
    Tufail Hussain Sherazi, Syed
    University of Sindh, Pakistan.
    Sirajuddin,
    Univ Sindh, Natl Ctr Excellence Analyt Chem, Jamshoro 76080, Pakistan.
    Ibupoto, Zafar Hussain
    Univ Sindh, Dr MA Kazi Inst Chem, Jamshoro 76080, Pakistan.
    Willander, Magnus
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska fakulteten.
    Highly sensitive determination of atropine using cobalt oxide nanostructures: Influence of functional groups on the signal sensitivity2016Ingår i: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 948, s. 30-39Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This study describes sensitive determination of atropine using glassy carbon electrodes (GCE) modified with Co3O4 nanostructures. The as-synthesised nanostructures were grown using cysteine (CYS), glutathione (GSH) and histidine (HYS) as effective templates under hydrothermal action. The obtained morphologies revealed interesting structural features, including both cavity-based and flower-shaped structures. The as-synthesised morphologies were noted to actively participate in electro-catalysis of atropine (AT) drug where GSH-assisted structures exhibited the best signal response in terms of current density and over-potential value. The study also discusses the influence of functional groups on the signal sensitivity of atropine electro-oxidation. The functionalisation was carried with the amino acids originally used as effective templates for the growth of Co3O4 nanostructures. The highest increment was obtained when GSH was used as the surface functionalising agent. The GSH-functionalised Co3O4-modified electrode was utilised for the electro-chemical sensing of AT in a concentration range of 0.01 -0.46 mu M. The developed sensor exhibited excellent working linearity (R-2 = 0.999) and signal sensitivity up to 0.001 mu M of AT. The noted high sensitivity of the sensor is associated with the synergy of superb surface architectures and favourable interaction facilitating the electron transfer kinetics for the electro-catalytic oxidation of AT. Significantly, the developed sensor demonstrated excellent working capability when used for AT detection in human urine samples with strong anti-interference potential against common co-existing species, such as glucose, fructose, cysteine, uric acid, dopamine and ascorbic acid. (C) 2016 Elsevier B.V. All rights reserved.

  • 8.
    Alm, Johanna
    Linköpings universitet, Institutionen för fysik, kemi och biologi.
    Method development for identification of N-linked glycans by high performance anion exchange chromatography with pulsed amperometric detection and time of flight mass spectrometry2011Självständigt arbete på grundnivå (högskoleexamen), 10,5 poäng / 16 hpStudentuppsats (Examensarbete)
    Abstract [en]

    In the biopharmaceutical industry, identification of glycans in a glycoprotein is a regulatory requirement and is a part of the characterization of the protein. Glycans are constructed of several monosaccharides linked together. N-linked glycans, which have been studied in this project, are attached to the nitrogen atom in asparagine.

    A method for separating N-linked glycans by high performance anion exchange chromatography had already been developed at the department. To develop a method for identification of the N-glycans by mass spectrometry, a desalting method on porous graphitic carbon (PGC) columns was used and optimized resulting in the eluents A (0,05% TFA in ACN:water 5:95 v/v) and B (0,05% TFA in ACN:water 50:50 v/v). Also the sample introduction on the mass spectrometer was optimized and resulted in a sensitive on-line liquid chromatography mass spectrometry (LC-MS) approach which gave mass spectrometric peaks with high signal to noise ratios and with high mass accuracy.

    The developed procedure was then successfully used on glycans cleaved from a glycoprotein separated by high performance anion exchange chromatography with pulsed amperometric detector.

     

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    FULLTEXT01
  • 9.
    Andersson, Anna
    et al.
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Ashiq, Muhammad Jamshaid
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Shoeb, Mohammad
    Department of Chemistry, University of Dhaka, Dhaka, Bangladesh.
    Karlsson, Susanne
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Bastviken, David
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Kylin, Henrik
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten. Research Unit: Environmental Sciences and Management, North-West University, Potchefstroom, South Africa.
    Evaluating gas chromatography with a halogen-specific detector for the determination of disinfection by-products in drinking water2019Ingår i: Environmental Science and Pollution Research, ISSN 0944-1344, E-ISSN 1614-7499, Vol. 26, s. 7305-7314Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The occurrence of disinfection by-products (DBPs) in drinking water has become an issue of concern during the past decades. The DBPs pose health risks and are suspected to cause various cancer forms, be genotoxic and have negative developmental effects. The vast chemical diversity of DBPs makes comprehensive monitoring challenging. Only few of the DBPs are regulated and included in analytical protocols. In this study, a method for simultaneous measurement of 20 DBPs from five different structural classes (both regulated and non-regulated) was investigated and further developed for 11 DBPs using solid phase extraction and gas chromatography coupled with a halogen specific detector (XSD). The XSD was highly selective towards halogenated DBPs, providing chromatograms with little noise. The method allowed detection down to 0.05 µg/L and showed promising results for the simultaneous determination of a range of neutral DBP classes. Compounds from two classes of emerging DBPs, more cytotoxic than the “traditional” regulated DBPs, were successfully determined using this method. However, haloacetic acids (HAAs) should be analyzed separately as some HAA methyl esters may degrade giving false positives of trihalomethanes (THMs). The method was tested on real water samples from two municipal waterworks where the target DBP concentrations were found below the regulatory limits of Sweden.

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    Evaluating gas chromatography with a halogen-specific detectorfor the determination of disinfection by-products in drinking water
  • 10.
    Andersson, Anna
    et al.
    Linköpings universitet, Filosofiska fakulteten. Linköpings universitet, Institutionen för tema, Tema Miljöförändring.
    Harir, Mourad
    Research Unit Analytical Biogeochemistry, Helmholtz Zentrum München, Ingolstaedter Landstrasse 1, 85764, Neuherberg, Germany ; Analytical Food Chemistry, Technical University Munich, Maximus-von-Imhof-Forum 2, 85354, Freising, Germany.
    Bastviken, David
    Linköpings universitet, Filosofiska fakulteten. Linköpings universitet, Institutionen för tema, Tema Miljöförändring.
    Extending the potential of Fourier transform ion cyclotron resonance massspectrometry for the analysis of disinfection by-products2023Ingår i: TrAC. Trends in analytical chemistry, ISSN 0165-9936, E-ISSN 1879-3142, Vol. 167, artikel-id 117264Artikel, forskningsöversikt (Refereegranskat)
    Abstract [en]

    Potentially harmful disinfection by-products (DBPs) are formed upon drinking water treatment when disinfectantsreact with organic matter in the water. Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS) provides information on the compositions of individual DBPs in the unknown, toxicologically relevantfraction, comprising non-volatile, high-molecular weight DBPs. This review evaluates current applications of FTICR-MS for DBP analysis to assist improved analysis with this technique. Four methodological aspects are infocus, 1) The use of quenching agents, 2) The choice of extraction method 3) The choice of ionization techniques/modes, and 4) Data processing including DBP formula verification and interpretation. Quenching can lead todecomposition or adduct formation and needs to be further evaluated or avoided. There is a large potential toexpand FT-ICR-MS DBP analysis by applying different SPE sorbents and ionization techniques, and improvedsystematic verification procedures are important to ensure reliable non-target analysis.

  • 11.
    Andersson, Anna
    et al.
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Harir, Mourad
    Helmholtz Zentrum München, Germany.
    Gonsior, Michael
    University of Maryland Center for Environmental Science, USA.
    Hertkorn, Norbert
    Helmholtz Zentrum München, Germany.
    Schmitt-Kopplin, Philippe
    Helmholtz Zentrum München, Germany.
    Kylin, Henrik
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Karlsson, Susanne
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Ashiq, Muhammad Jamshaid
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Lavonen, Elin
    Norrvatten, Kvalitet och Utveckling.
    Nilsson, Kerstin
    VA SYD.
    Pettersson, Ämma
    Nodra.
    Stavklint, Helena
    Tekniska verken i Linköping.
    Bastviken, David
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Waterworks-specific composition of drinking water disinfection by-products2019Ingår i: Environmental Science: Water Research & Technology, ISSN 2053-1400, E-ISSN 2053-1419, nr 5, s. 861-872Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Reactions between chemical disinfectants and natural organic matter (NOM) upon drinking water treatment result in formation of potentially harmful disinfection by-products (DBPs). The diversity of DBPs formed is high and a large portion remains unknown. Previous studies have shown that non-volatile DBPs are important, as much of the total toxicity from DBPs has been related to this fraction. To further understand the composition and variation of DBPs associated with this fraction, non-target analysis with ultrahigh resolution Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) was employed to detect DBPs at four Swedish waterworks using different types of raw water and treatments. Samples were collected five times covering a full year. A common group of DBPs formed at all four waterworks was detected, suggesting a similar pool of DBP precursors in all raw waters that might be related to phenolic moieties. However, the largest proportion (64–92%) of the assigned chlorinated and brominated molecular formulae were unique, i.e. were solely found in one of the four waterworks. In contrast, the compositional variations of NOM in the raw waters and samples collected prior to chemical disinfection were rather limited.This indicated that waterworks-specific DBPs presumably originated from matrix effects at the point of disinfection, primarily explained by differences in bromide levels, disinfectants (chlorine versus chloramine) and different relative abundances of isomers among the NOM compositions studied. The large variation of observed DBPs in the toxicologically relevant non-volatile fraction indicates that non-targeted monitoring strategies might be valuable to ensure relevant DBP monitoring in the future.

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    Waterworks-specific composition of drinking water disinfection by-products
  • 12.
    Andersson, Simon
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Sensor- och aktuatorsystem.
    Point-of-care beta-hydroxybutyrate determination for the management of diabetic ketoacidosis based on flexible laser-induced graphene electrode system2021Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [en]

    Diabetic ketoacidosis (DKA) is a life-threatening condition that can appear in patients with diabetes. High ketones in the blood lead to acidity of the blood. For DKA diagnosis and management, ketones such as hydroxybutyrate (HB) can be used to quantify the severity of the disease. The fabrication of electrochemical biosensors for the detection of HB is attractive since their capability to deliver fast response, high sensitivity, good selectivity and potential for miniaturisation. In this thesis, an integrated electrode system was prepared for the detection of HB. Laser-induced graphene (LIG) with a 3D porous structure was used as the flexible platform. Poly (toluidine blue O) (PTB) was electro-deposited on LIG (PTB/LIG) under the optimised conduction (pH of 9.7 and from 0.4 to an upper cyclic potential of 0.8 V). The single PTB/LIG working electrode demonstrated excellent performance towards the detection of NADH with a linear range of 6.7 M to 3 mM using chronoamperometry, high sensitivity of detecting NADH and excellent anti-fouling ability (94 % response current retained after 1500 s). Further integration of the 3-electrode system realised the static amperometric detection of NADH over the range of 78 M to 10 mM. Based on the excellent performance of PTB/LIG to NADH sensing, hydroxybutyrate dehydrogenase was immobilised via encapsulation with chitosan and polyvinyl butyral (PVB) which was used for HB biosensing over the linear range of 0.5 M to 1 mM with NAD+ dissolved in solution. In addition, the co-immobilisation of NAD+ and HBD on PTB/LIG was conducted by optimisation of enzyme and NAD+ amount per electrode, which shows excellent reproducibility and satisfactory HB biosensing performance. Further experiments to improve the long-term stability of the enzyme electrode is expected in the future. The proposed integrated electrode system also possesses the potential to extend to a multichannel sensor array for the detection of multiple biomarkers (e.g. pH and glucose) for diagnosis and management of DKA.

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    fulltext
  • 13.
    Anwar Zainuddin, Ahmad
    et al.
    IIUM, Malaysia.
    Nurashikin Nordin, Anis
    IIUM, Malaysia.
    Ab Rahim, Rosminazuin
    IIUM, Malaysia.
    Mak, Wing Cheung
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biosensorer och bioelektronik. Linköpings universitet, Tekniska fakulteten.
    Modeling of a Novel Biosensor with Integrated Mass and Electrochemical Sensing Capabilities2016Ingår i: 2016 IEEE EMBS CONFERENCE ON BIOMEDICAL ENGINEERING AND SCIENCES (IECBES), IEEE , 2016, s. 420-425Konferensbidrag (Refereegranskat)
    Abstract [en]

    Rapid development in technology and society has generated diverse developments in many fields including biosensors in healthcare application. Here, the design of integrated biosensor comprises mass sensing (Quartz Crystal Microbalance) and electrochemistry sensing (Electrochemical Impedance Spectroscopy, EIS and Cyclic Voltammetry, CV) will be presented. The integrated sensor system is developed based on the innovative use of the top electrode of a quartz crystal microbalance (QCM) resonator as a working electrode for the electrochemistry technique. Integration of QCM with the electrochemistry technique is realized by fabricating a semicircular counter electrode near the upper electrode on the same side of the quartz crystal. CV and EIS measurement was conducted using finite element modeling, COMSOL (TM) 5.2 with the probe marker of 1 mmol L-1 of [Fe(CN)(6)](3-/4-). CV test was done to study the effect between increasing scan rate and peak current (anodic and cathodic) in observing the reversible electrochemical process. This observation is crucial in ensuring the electrochemical processes follow the Randles-Sevcik equation in characterizing the platform changes behavior. Later, EIS test was performed in order to measure the radius of the semicircle which reflects the charge transfer resistance (R-CT) of the redox marker. To show the effectiveness of this sensor, gold immobilization surface was electrochemically simulated and reported. Thus, an ultra-sensitive biosensor that capable to produce multi-analysis in the detection of biological targets in terms of electrochemical change of electrode interfaces, which is the crucial step towards the engineering of advanced bioelectronics.

  • 14.
    Arund, Jurgen
    et al.
    Tallinn University of Technology, Estonia.
    Luman, Merike
    North Estonia Medical Centre, Estonia.
    Uhlin, Fredrik
    Region Östergötland, Hjärt- och Medicincentrum, Njurmedicinska kliniken US. Linköpings universitet, Medicinska fakulteten. Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för läkemedelsforskning. Tallinn University of Technology, Estonia.
    Tanner, Risto
    Tallinn University of Technology, Estonia.
    Fridolin, Ivo
    Tallinn University of Technology, Estonia.
    Is Fluorescence Valid to Monitor Removal of Protein Bound Uremic Solutes in Dialysis?2016Ingår i: PLOS ONE, E-ISSN 1932-6203, Vol. 11, nr 5, artikel-id e0156541Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The aim of this study was to evaluate the contribution and removal dynamics of the main fluorophores during dialysis by analyzing the spent dialysate samples to prove the hypothesis whether the fluorescence of spent dialysate can be utilized for monitoring removal of any of the protein bound uremic solute. A high performance liquid chromatography system was used to separate and quantify fluorophoric solutes in the spent dialysate sampled at the start and the end of 99 dialysis sessions, including 57 hemodialysis and 42 hemodiafiltration treatments. Fluorescence was acquired at excitation 280 nm and emission 360 nm. The main fluorophores found in samples were identified as indole derivatives: tryptophan, indoxyl glucuronide, indoxyl sulfate, 5-hydroxy-indoleacetic acid, indoleacetyl glutamine, and indoleacetic acid. The highest contribution (35 +/- 11%) was found to arise from indoxyl sulfate. Strong correlation between contribution values at the start and end of dialysis (R-2 = 0.90) indicated to the stable contribution during the course of the dialysis. The reduction ratio of indoxyl sulfate was very close to the decrease of the total fluorescence signal of the spent dialysate (49 +/- 14% vs 51 +/- 13% respectively, P = 0.30, N = 99) and there was strong correlation between these reduction ratio values (R-2 = 0.86). On-line fluorescence measurements were carried out to illustrate the technological possibility for real-time dialysis fluorescence monitoring reflecting the removal of the main fluorophores from blood into spent dialysate. In summary, since a predominant part of the fluorescence signal at excitation 280 nm and emission 360 nm in the spent dialysate originates from protein bound derivatives of indoles, metabolites of tryptophan and indole, the fluorescence signal at this wavelength region has high potential to be utilized for monitoring the removal of slowly dialyzed uremic toxin indoxyl sulfate.

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  • 15.
    Asri, Mohd Afiq Mohd
    et al.
    Int Islamic Univ Malaysia, Malaysia.
    Mak, Wing Cheung
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Sensor- och aktuatorsystem. Linköpings universitet, Tekniska fakulteten. Chinese Univ Hong Kong, Peoples R China.
    Norazman, Siti Azizah
    Int Islamic Univ Malaysia, Malaysia.
    Nordin, Anis Nurashikin
    Int Islamic Univ Malaysia, Malaysia.
    Low-cost and rapid prototyping of integrated electrochemical microfluidic platforms using consumer-grade off-the-shelf tools and materials2022Ingår i: Lab on a Chip, ISSN 1473-0197, E-ISSN 1473-0189, Vol. 22, nr 9, s. 1779-1792Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We present a low-cost, accessible, and rapid fabrication process for electrochemical microfluidic sensors. This work leverages the accessibility of consumer-grade electronic craft cutters as the primary tool for patterning of sensor electrodes and microfluidic circuits, while commodity materials such as gold leaf, silver ink pen, double-sided tape, plastic transparency films, and fabric adhesives are used as its base structural materials. The device consists of three layers, the silver reference electrode layer at the top, the PET fluidic circuits in the middle and the gold sensing electrodes at the bottom. Separation of the silver reference electrode from the gold sensing electrodes reduces the possibility of cross-contamination during surface modification. A novel approach in mesoscale patterning of gold leaf electrodes can produce generic designs with dimensions as small as 250 mu m. Silver electrodes with dimensions as small as 385 mu m were drawn using a plotter and a silver ink pen, and fluid microchannels as small as 300 mu m were fabricated using a sandwich of iron-on adhesives and PET. Device layers are then fused together using an office laminator. The integrated microfluidic electrochemical platform has electrode kinetics/performance of Delta E-p = 91.3 mV, I-pa/I-pc = 0.905, characterized by cyclic voltammetry using a standard ferrocyanide redox probe, and this was compared against a commercial screen-printed gold electrode (Delta E-p = 68.9 mV, I-pa/I-pc = 0.984). To validate the performance of the integrated microfluidic electrochemical platform, a catalytic hydrogen peroxide sensor and enzyme-coupled glucose biosensors were developed as demonstrators. Hydrogen peroxide quantitation achieves a limit of detection of 0.713 mM and sensitivity of 78.37 mu A mM(-1) cm(-2), while glucose has a limit of detection of 0.111 mM and sensitivity of 12.68 mu A mM(-1) cm(-2). This rapid process allows an iterative design-build-test cycle in under 2 hours. The upfront cost to set up the system is less than USD 520, with each device costing less than USD 0.12, making this manufacturing process suitable for low-resource laboratories or classroom settings.

  • 16.
    Azzouzi, Sawsen
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Sensor- och aktuatorsystem. Linköpings universitet, Tekniska fakulteten. Univ Sousse, Tunisia; Ctr Res Microelect and Nanotechnol Sousse, Tunisia.
    Fredj, Zina
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska fakulteten. Univ Sousse, Tunisia; Ctr Res Microelect and Nanotechnol Sousse, Tunisia.
    Turner, Anthony
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Sensor- och aktuatorsystem. Linköpings universitet, Tekniska fakulteten.
    Ben Ali, Mounir
    Univ Sousse, Tunisia; Ctr Res Microelect and Nanotechnol Sousse, Tunisia.
    Mak, Wing Cheung
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Sensor- och aktuatorsystem. Linköpings universitet, Tekniska fakulteten.
    Generic Neutravidin Biosensor for Simultaneous Multiplex Detection of MicroRNAs via Electrochemically Encoded Responsive Nanolabels2019Ingår i: ACS Sensors, E-ISSN 2379-3694, Vol. 4, nr 2, s. 326-334Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Current electrochemical biosensors for multiple miRNAs require tedious immobilization of various nucleic acid probes. Here, we demonstrate an innovative approach using a generic neutravidin biosensor combined with electrochemically encoded responsive nanolabels for facile and simultaneous multiplexed detection of miRNA-21 and miRNA-141. The selectivity of the biosensor arises from the intrinsic properties of the electrochemically encoded responsive nanolabels, comprising biotinylated molecular beacons (biotin-MB) and metal nanoparticles (metal-NPs). The procedure is a simple one-pot assay, where the targeted miRNA causes the opening of biotin-MB followed by capturing of the biotin-MB-metal-NPs by the neutravidin biosensor and simultaneous detection of the captured metal-NPs by stripping square-wave voltammetry (SSWV). The multiplexed detection of miRNA-21 and miRNA-141 is achieved by differentiation of the electrochemical signature (i.e., the peak current) for the different metal-NP labels. The biosensor delivers simultaneous detection of miRNAs with a linear range of 0.5-1000 pM for miRNA-21 and a limit of detection of 0.3 pM (3 sigma/sensitivity, n = 3), and a range of 50-1000 pM for miRNA-141, with a limit of detection of 10 pM. Furthermore, we demonstrate multiplexed detection of miRNA-21 and miRNA-141 in a spiked serum sample.

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  • 17.
    Azzouzi, Sawsen
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biosensorer och bioelektronik. Linköpings universitet, Tekniska fakulteten. University of Sousse, Tunisia.
    Mak, Wing Cheung
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biosensorer och bioelektronik. Linköpings universitet, Tekniska fakulteten.
    Kor, Kamalodin
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biosensorer och bioelektronik. Linköpings universitet, Tekniska fakulteten. Iranian National Institute Oceanog and Atmospher Science, Iran.
    Turner, Anthony
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biosensorer och bioelektronik. Linköpings universitet, Tekniska fakulteten.
    Ben Ali, Mounir
    University of Sousse, Higher Institute of Applied Sciences and Technology of Sousse, GREENS-ISSAT, Cité Ettafala, 4003 Ibn Khaldoun Sousse, Tunisia.
    Beni, Valerio
    Linköpings universitet, Institutionen för fysik, kemi och biologi. Linköpings universitet, Tekniska fakulteten. ACREO SWEDISH ICE AB, Sweden.
    An integrated dual functional recognition/amplification bio-label for the one-step impedimetric detection of Micro-RNA-212017Ingår i: Biosensors & bioelectronics, ISSN 0956-5663, E-ISSN 1873-4235, Vol. 92, s. 154-161Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Alteration in expression of miRNAs has been correlated with different cancer types, tumour stage and response to treatments. In this context, a structurally responsive oligonucleotide-based electrochemical impedimetric biosensor has been developed for the simple and sensitive detection of miRNA-21. A highly specific biotinylated DNA/LNA molecular beacon (MB) probe was conjugated with gold nanoparticles (AuNPs) to create an integrated, dual function bio-label (biotin-MB-AuNPs) for both biorecognition and signal generation. In the presence of target miRNA-21, hybridisation takes place resulting in the "activation" of the biotin-MB; this event makes the biotin group, which was previously "protected" by the steric hindrance of the MB stem-loop structure, accessible. The activated biotin-MB-AuNPs/miRNA complexes become available for capture, via supramolecular interaction, onto a nentravidin-modified electrode for electrochemical transduction. The binding event results in a decrease of the charge transfer resistance at the working electrode/electrolyte interface. The biosensor responded linearly in the range 1-1000 pM of miRNA-21, with a limit of detection of 0.3 pM, good reproducibility (Relative Standard deviation (RSD) =3.3%) and high selectivity over other miRNAs (i.e. miRNA221 and miRNA-205) sequences. Detection of miRNA-21 in spiked serum samples at clinically relevant levels (low pM range) was also demonstrated, thus illustrating the potential of the biosensor for point-of-care clinical applications. The proposed biosensor design, based on the combination of a neutravidin transducing surface and the dual-function biotin-MB-AuNPs bio-label, provides a simple and robust approach for detection of short-length nucleic acid targets, such as miRNAs.

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  • 18.
    Azzouzi, Sawsen
    et al.
    University of Sousse, Tunisia.
    Patra, Hirak Kumar
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för cellbiologi. Linköpings universitet, Medicinska fakulteten.
    Ben Ali, Mounir
    University of Sousse, Tunisia.
    Nooredeen Abbas, Mohammed
    National Research Centre, Egypt.
    Dridi, Cherif
    Centre Research Microelect and Nanotechnol CRMN Sousse, Tunisia.
    Errachid, Abdelhamid
    University of Lyon 1, France.
    Turner, Anthony
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biosensorer och bioelektronik. Linköpings universitet, Tekniska fakulteten.
    Citrate-selective electrochemical mu-sensor for early stage detection of prostate cancer2016Ingår i: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 228, s. 335-346Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The extremely specialised anatomical function of citrate inside the prostate, make it one of the preferred biomarkers for early stage detection of prostate cancer. However, current detection methods are seriously limited due to the very low citrate concentrations that need to be measured in order to follow disease progression. In the present work, we report a novel citrate-selective-sensor based on iron (III) phthalocyanine chloride-C-monoamido-Poly-n-Butyl Acrylate (Fe(III)MAPcC1 P n BA) modified gold -electrodes for the electrochemical determination and estimation of the pathophysiological range of citrate. The newly synthesised ionophore has been structurally characterised using Fourier transform infrared (FTIR) and UV-vis spectroscopy. Contact angle measurements and atomic force microscopy (AFM) have been used to investigate the adhesion and morphological properties of the membrane. The developed citrate-selective-electrodes had a Nernstian sensitivity of-19.34 +/- 0.83 mV/decade with a detection limit of about 9 x 10-6M and a linear range from 4 x 10(-5)M to 10(-1) M, which covered the pathologically important clinical range. Electrochemical impedance spectroscopy (EIS) showed very high sensitivity with a lower Limit of detection 1.7 x 10(-9) M and linear detection range (10(-8)-10(-1) M), which is very important not only for the early-stage diagnosis and screening procedures, but also in mapping the stage of the cancer too. (C) 2016 Elsevier B.V. All rights reserved.

  • 19.
    Bahavarnia, Farnaz
    et al.
    Tabriz Univ Med Sci, Iran.
    Pashazadeh-Panahi, Paria
    Tabriz Univ Med Sci, Iran.
    Hasanzadeh, Mohammad
    Tabriz Univ Med Sci, Iran.
    Razmi, Nasrin
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik, elektroteknik och matematik. Linköpings universitet, Tekniska fakulteten.
    DNA based biosensing of Acinetobacter baumannii using nanoparticles aggregation method2020Ingår i: Heliyon, E-ISSN 2405-8440, Vol. 6, nr 7, artikel-id e04474Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Acinetobacter baumannii is the main cause of nosocomial infections in blood, urinary tract, wounds and in lungs leading to pneumonia. Apart from its strong predilection to be the cause of serious illnesses in intensive care units. Herein, we present a specific and sensitive approach for the monitoring of Acinetobacter baumannii genome based on citrate capped silver nanoparticles (Cit-AgNPs) using spectroscopic methods. In this study, (5' SH-TTG TGA ACT ATT TAC GTC AGC ATG C3') sequence was used as a probe DNA (pDNA) of Acinetobacter baumannii. Then, complementary DNA (cDNA) was used for hybridization. After the hybridization of pDNA with cDNA, target DNA (5' GCA TGC TGA CGT AAA TAGTTC ACA A 3') was recognized and detected using turn-on fluorescence bioassay. After the hybridization of pDNA with cDNA, the target DNA was successfully measured in optimum time of 2 min by spectrophotometric techniques. Moreover, the selectivity of designed bioassay was evaluated in the presence of two mismatch sequences and excellent differentiation was obtained. 1 Zepto-molar (zM) of low limit of quantification (LLOQ) was achieved by this genosensor. The present study paved the way for quick (2 min) and accurate detection of Acinetobacter baumannii, which can be a good alternative to the traditional methods. Current study proposed a novel and significant diagnostic test towards Acinetobacter baumannii detection based on silver nanoparticles aggregation which has the capability of being a good alternative to the traditional methods. Moreover, the proposed genosensor successfully could be applied for the detection of other pathogens.

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  • 20.
    Baloach, Qurrat-ul-ain
    et al.
    University of Sindh, Pakistan.
    Nafady, Ayman
    King Saud University, Saudi Arabia; Sohag University, Egypt.
    Tahira, Aneela
    University of Sindh, Pakistan.
    Tufail Hussain Sirajuddin; Sherazi, Syed
    University of Sindh, Pakistan.
    Shaikh, Tayyaba
    University of Sindh, Pakistan.
    Arain, Munazza
    University of Sindh, Pakistan.
    Willander, Magnus
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska fakulteten.
    Hussain Ibupoto, Zafar
    University of Sindh, Pakistan.
    An amperometric sensitive dopamine biosensor based on novel copper oxide nanostructures2017Ingår i: Microsystem Technologies: Micro- and Nanosystems Information Storage and Processing Systems, ISSN 0946-7076, E-ISSN 1432-1858, Vol. 23, nr 5, s. 1229-1235Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    It is highly important to explore the influence of counter anions on the morphology in order to have a desired nanostructure with unique properties. Therefore, in this research work the influence of counter anions on the morphology of copper oxide (CuO) nanostructures is presented using copper chloride and copper acetate salts. A significant role of counter anions on the morphology of CuO nanostructures is observed. The hydrothermal method is used to carry out the synthesis of CuO nanomaterial. The prepared CuO nanostructures are characterized by scanning electron microscopy and X-ray diffraction techniques. The prepared CuO nanomaterial exhibits porous nature with thin nanowires and sponge like morphologies. The dopamine sensing application was carried for exploring the electrocatalytic properties of CuO nanostructures. The presented dopamine biosensor exhibited wide linear range for detection of dopamine from 5 to 40 A mu M with sensitivity of 12.8 A mu A mM(-1) cm(-2). The limit of detection and limit of quantification were estimated in order 0.11 and 0.38 A mu M respectively. The developed dopamine biosensor is highly sensitive, selective, stable and reproducible. The common interfering species such as glucose, ascorbic acid and uric acid showed negligible change in the current when same concentration of dopamine and these interfering species was used. The fabricated biosensor could be used for the determination of dopamine from real blood samples.

  • 21.
    Baloach, Qurrat-ul-Ain
    et al.
    University of Sindh, Pakistan.
    Tahira, Aneela
    University of Sindh, Pakistan.
    Begum Mallah, Arfana
    University of Sindh, Pakistan.
    Ishaq Abro, Muhammad
    Mehran University of Engn and Technology, Pakistan.
    Uddin, Siraj
    University of Sindh, Pakistan.
    Willander, Magnus
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska fakulteten.
    Hussain Ibupoto, Zafar
    University of Sindh, Pakistan.
    A Robust, Enzyme-Free Glucose Sensor Based on Lysine-Assisted CuO Nanostructures2016Ingår i: Sensors, E-ISSN 1424-8220, Vol. 16, nr 11, artikel-id 1878Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The production of a nanomaterial with enhanced and desirable electrocatalytic properties is of prime importance, and the commercialization of devices containing these materials is a challenging task. In this study, unique cupric oxide (CuO) nanostructures were synthesized using lysine as a soft template for the evolution of morphology via a rapid and boiled hydrothermal method. The morphology and structure of the synthesized CuO nanomaterial were characterized using scanning electron microscopy (SEM) and X-ray diffraction (XRD), respectively. The prepared CuO nanostructures showed high potential for use in the electrocatalytic oxidation of glucose in an alkaline medium. The proposed enzyme-free glucose sensor demonstrated a robust response to glucose with a wide linear range and high sensitivity, selectivity, stability, and reproducibility. To explore its practical feasibility, the glucose content of serum samples was successfully determined using the enzyme-free sensor. An analytical recovery method was used to measure the actual glucose from the serum samples, and the results were satisfactory. Moreover, the presented glucose sensor has high chemical stability and can be reused for repetitive measurements. This study introduces an enzyme-free glucose sensor as an alternative tool for clinical glucose quantification.

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  • 22.
    Barrirero, J.
    et al.
    Saarland Univ, Germany.
    Engstler, M.
    Saarland Univ, Germany.
    Odén, Magnus
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Nanostrukturerade material. Linköpings universitet, Tekniska fakulteten.
    Muecklich, F.
    Saarland Univ, Germany.
    Phase Selective Sample Preparation of Al-Si alloys for Atom Probe Tomography2019Ingår i: Praktische metallographie, ISSN 0032-678X, E-ISSN 2195-8599, Vol. 56, nr 2, s. 76-90Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We present how the conventional focused ion beam (FIB) lift-out method can be modified to obtain phase selective specimens for atom probe tomography (APT). The modified method combines selective deep etching with site-specific lift-out using a micromanipulator in a FIB/SEM workstation. This method is used for phase-selective sample preparation in alloys with complex microstructures such as the coral- and plate-like silicon structures in the eutectic phase of Al-Si castings. The method proves to be both, practical and robust, with a high success rate of high-quality phase-specific APT specimens.

  • 23. Beställ onlineKöp publikationen >>
    Bengtsson, Katarina
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Ytors Fysik och Kemi. Linköpings universitet, Tekniska fakulteten.
    Electrokinetic devices from polymeric materials2017Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [sv]

    Polymera material finns överallt omkring oss; våra kroppar är uppbyggda av dem,plastpåsarna och burkarna vi förvarar vår mat av består av dem, våra kläder och andra tingsom finns i vår vardag är uppbyggda av olika typer av polymerer. En polymer är uppbyggd aven repetitiv sekvens av identiska grupper, de kan liknas vid en mönsterrapport vilken är denminsta del som man behöver repetera för att få mönstret. Beroende på hur rapporten ser ut såförändras utseendet av mönstret. Hos en polymer påverkar sammansättningen av denrepetitiva gruppen (rapporten) egenskaperna av materialet och polymerer kan vara allt frånhårda och robusta, till flexibla och elektriskt ledande. Arbetet som presenteras i den häravhandlingen berör hur funktionen av olika system påverkas av att man använder sig avpolymerer istället för konventionella material.

    Första delen av avhandlingen handlar om integrering av elektronik i system som innehållervätska. När vätskor, laddade partiklar, molekyler och joner rör på sig på grund av ett yttreelektriskt fält, så kallas detta för elektrokinetik. Detta kan användas för att pumpa vätska ikanaler som är mindre än 0.2 mm, genom så kallad elektroosmos, samtidigt kommermolekyler med olika laddning att börja separera, så kallad elektrofores. Elektroosmos användsinom t.ex. analytisk kemi för injektion och transport av vätskor. Elektrofores används inombl.a. rättsvetenskap och molekylärbiologi för att separera makromolekyler, så som DNA ochproteiner, med avseende på deras storlek och laddning. I dessa system använder man sig oftastav metallelektroder.

    När en spänning läggs till ett par metallelektroder som är i kontakt med vatten kommer denhuvudsakliga reaktionen att vara spjälkning av vatten, så kallad vattenelektrolys. Spjälkningav vatten innebär att det bildas vät-och syrgas samt att pH börjar ändras. Gaserna som bildaskan bryta kopplingen mellan elektroderna och därmed stoppar strömmen, så som sker när mandrar ut sladden för t.ex. en elvisp. Förändringar i pH kan t.ex. påverka biologiska provernegativt, så som proteiners funktion och kan leda till celldöd, men kan också minska flödenaen elektroosmotisk pump kan generera. Det finns flera olika sätt hur man kan hanteravattenelektrolys i system med metallelektroder, så som användning av en pH-buffer. Arbetet iden här avhandlingen visar vad som händer om man ersätter metallelektroder med elektrisktledande plastelektroder. I detta fall har metallelektroderna ersatts av den elektriskt ledandepolymeren PEDOT vilket resulterar i att , där man istället för generera gas och pHviförändringar, så förflyttar man joner mellan elektroden och omgivande lösning. Ledandepolymerer är billiga och enkla att tillverka vilket gör dem lämpliga för engångssystem.

    förändringar, så förflyttar man joner mellan elektroden och omgivande lösning. Ledandepolymerer är billiga och enkla att tillverka vilket gör dem lämpliga för engångssystem.I den här avhandlingen visas följande exempel där metallelektroder ersatts av ledandeplastelektroder: Gelelektrofores (separation av proteiner i en gel), (se papper 1), tyg som kanpumpa vatten (plan elektroosmotisk pump, se papper 2) och en kompakt pump som inte ärstörre än ett kaffemått, som enkelt kan kopplas till befintliga sprutkopplingar och som kananvändas för att kontrollera flödet över t.ex. celler (se papper 3).

    Andra delen av avhandlingen handlar om 3D skrivare och hur materialval påverkarutskriften och designen. 3D skrivare är ett bra alternativ för att snabbt och billigt kunnaproducera prototyper och funktionella individanpassade objekt i varierande storlekar.3D skrivare kan beskrivas som en avancerad spritsmaskin där material läggs lager på lager föratt bygga upp det slutgiltiga objektet utifrån en datorgenererade 3D model. Detta förändrarhelt hur man designar objekt och vilka möjliga strukturer och material man kan använda sigav jämfört än då man till exempel använder sig av svarv eller fräs för tillverkning. Det finnsflera olika typer av 3D skrivare, t.ex. smältplastskrivare (den typ som man kan se i flertaletaffärer idag) och den variant som använts i den här avhandlingen, en sprutbaserad. Ensprutbaserad 3D skrivare kan hantera många olika typer av material så länge dessa kan fyllas ien spruta och tryckas ut genom en nål. Det färdiga resultat kan därmed bli mycket olikaberoende på vilka material som använts.

    Överhängande och utstickande strukturer kan vara komplicerade att skriva ut med en3D skrivare. Utskrift av dessa strukturer kan underlättas genom att man skriver ut en temporärstruktur i ett annat material, ett offermaterial. Offermaterialet fungerar som en mall eller stödtill det slutgiltiga objektet och tas bort (offras) när övriga delar av objektet är klara. I den häravhandlingen beskrivs hur ett offermaterial baserat på polyetylen glykol (PEG, vanligtförekommande i t.ex. schampo och läkemedel) och en mjukgörare kan anpassas för attfungera tillsammans med en sprutbaserad 3D skrivare (se papper 4) för att skriva ut strukturerfrån 0,2 mm och uppåt.

    Arbetet i den här avhandlingen visar användningen av den ledande polymeren PEDOT i ettelektroforessystem och en elektroosmotisk pump. Detta kan förhoppningsvis underlättautvecklingen av dessa system till att bli mindre, smidigare, snabbare och billigare. Den andradelen presenterar ett vattenlösligt, PEG-baserat material som kan användas som stöd till andramaterial i sprutbaserade 3D utskrifter för att underlätta tillverkningen av 3D utskrivna objekt.

    Delarbeten
    1. Conducting Polymer Electrodes for Gel Electrophoresis
    Öppna denna publikation i ny flik eller fönster >>Conducting Polymer Electrodes for Gel Electrophoresis
    2014 (Engelska)Ingår i: PLOS ONE, E-ISSN 1932-6203, Vol. 9, nr 2, s. 0089416-Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    In nearly all cases, electrophoresis in gels is driven via the electrolysis of water at the electrodes, where the process consumes water and produces electrochemical by-products. We have previously demonstrated that p-conjugated polymers such as poly(3,4-ethylenedioxythiophene) (PEDOT) can be placed between traditional metal electrodes and an electrolyte to mitigate electrolysis in liquid (capillary electroosmosis/electrophoresis) systems. In this report, we extend our previous result to gel electrophoresis, and show that electrodes containing PEDOT can be used with a commercial polyacrylamide gel electrophoresis system with minimal impact to the resulting gel image or the ionic transport measured during a separation.

    Ort, förlag, år, upplaga, sidor
    Public Library of Science, 2014
    Nationell ämneskategori
    Teknik och teknologier
    Identifikatorer
    urn:nbn:se:liu:diva-105901 (URN)10.1371/journal.pone.0089416 (DOI)000331711900141 ()
    Tillgänglig från: 2014-04-14 Skapad: 2014-04-12 Senast uppdaterad: 2021-06-14Bibliografiskt granskad
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  • 24.
    Beni, Valerio
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biosensorer och bioelektronik.
    Biosensors for Food and the Environment: Is it all in the DNA?2013Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    Biosensor technology not only holds great promise for the healthcare market but it is also expected to have significant impacts in other areas such as environmental and food analysis. Between the different biosensor formats nucleic acid-based biosensors are gaining increasingly importance allowing the specific identification of DNA/RNA fragments and, more recently, the detection of biological or chemical species. Direct identification of DNA/RNA fragments, via hybridisation assays (genosensors), has been shown to be a very powerful tool for the detection of pathogens in environment and food, in food contamination analysis and food allergens monitoring. Recently the discovery of aptamers, synthetic receptors based on short functional DNA/RNA chains, has opened new opportunities for oligonucleotide based biosensors and more specifically in the detection of biological and/or chemical species, such as proteins and pollutants. In this paper an overview of the most recent advances in the development and applications of nucleic acid-based biosensors for environmental and food safety/quality application will be presented with special emphasis on electrochemical and optical hybridisation genosensors and aptasensors.

  • 25.
    Beni, Valerio
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biosensorer och bioelektronik. Linköpings universitet, Tekniska högskolan.
    Development of an electrochemical genosensors for celiac disease predisposition analysis2013Ingår i: "Biomimetic structures and DNA technology in biosensing" / [ed] Tibor Hianik, 2013, s. 21-Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    Low density DNA arrays are of growing interest in the field of fast clinical/environmental analysis; for example in clinical analysis these can find application in areas as early diagnosis of genetic diseases or as support in the diagnosis of genetically associated diseases. 

    Coeliac disease, a small intestinal inflammation triggered by the intake of gluten, has been shown to affect only genetically predisposed individuals. Relation between Coeliac disease and two Human Leukocyte Antigens (HLA) genes, DQ2 and DQ8, has been reported, with almost 100% of the affected patients carrying at least one of them.

    In this seminar the development of a low density electrochemical genosensor array for medium resolution typing of Coeliac disease associated HLA genes, is presented.                                        

    The proposed array was based on an enzymatic sandwich assay format performed at a photolitographically fabricated electrode array.                                                                            

    The optimisation of different aspects as surface chemistry, assay conditions, probe's design and single stranded DNA generation, together with real sample analysis will be present.

     

  • 26.
    Beni, Valerio
    et al.
    Tyndall National Institute, University College Cork, Ireland.
    Arrigan, Damien
    Tyndall National Institute, University College Cork, Ireland.
    Microelectrode arrays and microfabricated devices in electrochemical stripping analysis2008Ingår i: Current Analytical Chemistry, ISSN 1573-4110, E-ISSN 1875-6727, Vol. 4, nr 3, s. 229-241Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this article a comprehensive overview of the developments in the field of electrochemical stripping analysis with microelectrode arrays and microfabricated devices is presented. Due to the vastness of the topic, this mini-review deals only with the use of regular microelectrode arrays. After the description of the main fabrication methodologies employed, a large part of the review is dedicated to applications, categorised by the electrode material. Microelectrode arrays have found application in several areas of electroanalytical science including clinical and environmental analysis. They have been used for the detection of heavy metals in waters, soil extracts and blood, proving to be reliable analytical devices and bringing the advantages of low-cost, simplicity of use and easy adaptability to field measurement. In many applications, limits of detection are sub-parts per billion. Finally a short section of the review discusses miniaturised potentiostats.

  • 27.
    Beni, Valerio
    et al.
    Tyndall National Institute, University College Cork, Ireland.
    Collins, Gilian
    Tyndall National Institute, University College Cork, Ireland.
    Arrigan, Damien
    Tyndall National Institute, University College Cork, Ireland.
    Investigation into the voltammetric behaviour and detection of selenium(IV) at metal electrodes in diverse electrolyte media2011Ingår i: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 699, nr 2, s. 127-133Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The voltammetric behaviour of selenium(IV) was studied at platinum and gold electrodes in sulphuricacid, perchloric acid and potassium chloride media as a basis for its voltammetric detection. The bestvoltammetric behaviour was recorded at gold electrodes with perchloric acid as the supporting electrolyte.The concomitant presence of metals, such as copper or lead, and of model biomolecules, suchas bovine serum albumin, in the solution resulted in a deterioration of the electrochemical response forselenium(IV). Quantitative detection of selenium(IV) by square wave anodic stripping voltammetry atboth a millimetre-sized gold disc electrode and a microband electrode array revealed linear responsesto selenium concentration in the ranges 5–15 M and 0.1–10 M, respectively, with 60 s preconcentration.The sensitivities were 6.4 A M−1 cm−2 and 100 A M−1 cm−2 at the disc and the microband array,respectively. The detection limit at the microband electrode array was 25 nM, illustrating the potentialityof such microelectrodes for the development of mercury-free analytical methods for the trace detectionof selenium(IV).

  • 28.
    Beni, Valerio
    et al.
    Universitat Rovira i Virgili, Tarragona, Spain.
    Gelaw, Tilahun
    Universitat Rovira i Virgili, Tarragona, Spain.
    O´Sullivan, Ciara K.
    Universitat Rovira i Virgili, Tarragona, Spain.
    Study of the combination of the deposition/stripping of sacrificial metal nano-structures and alkanethiol as a route for genosensor surface preparation2011Ingår i: Electrochemistry communications, ISSN 1388-2481, E-ISSN 1873-1902, Vol. 13, nr 4, s. 325-327Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In the reported work the combination of electrodeposition/stripping of copper sacrificial metallic nanostructuresand alkanethiol self-assembling was investigated for the preparation of a randomly nano-patternedorganised monolayer on a gold surface. Electrochemical characterisation of the process demonstrated thepotential of the proposed approach for the random nano-patterning of a chemisorbed monolayer onconductive surfaces with minimal impact on the bulk monolayer. Finally the obtained nano-structuredsurfaces were exploited as a platform for the fabrication of an amperometric genosensor for the detection ofthe DF508 Cystic Fibrosis associated mutation.

  • 29.
    Beni, Valerio
    et al.
    NMRC, University College, Cork, Ireland.
    Ghita, Mihaela
    PSiMedica, Malvern Hills Science Park, UK.
    Arrigan, Damien
    NMRC, University College, Cork, Ireland.
    Cyclic and pulse voltammetric study of dopamine at the interfacebetween two immiscible electrolyte solutions2005Ingår i: Biosensors & bioelectronics, ISSN 0956-5663, E-ISSN 1873-4235, Vol. 20, nr 10, s. 2097-2103Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The detection of dopamine by differential pulse voltammetry (DPV) and square wave voltammetry (SWV) at the interface between twoimmiscible electrolyte solutions (ITIES) has been studied. Voltammetry at the liquid/liquid (water/1,2-dichloroethane) interface provides asimple method for overcoming the major problem associated with dopamine detection by voltammetry at solid electrodes: the co-existenceof ascorbate at higher concentrations. Selectivity for dopamine was achieved by the use of dibenzo-18-crown-6 as an ionophore for thefacilitated transfer voltammetry of protonated dopamine across the ITIES. Under these conditions, ascorbate is not transferred and hence doesnot interfere in the ion transfer current for dopamine. By use of DPV and SWV, the lowest concentration detectable can be lowered from ca.0.1mM (obtained with cyclic voltammetry) to 2 M. Evaluation of the effect of some other physiologically important species (acetylcholine,sodium, potassium and ammonium ions) on the dopamine transfer voltammetry has been studied, indicating the need for improved ionophoredesigns in order to achieve practically useful selectivity.

  • 30.
    Beni, Valerio
    et al.
    Universitat Rovira i Virgili, Tarragona, Spain.
    Hayes, Karen
    Universitat Rovira i Virgili, Tarragona, Spain.
    Mairal Lerga, Teresa
    Universitat Rovira i Virgili, Tarragona, Spain.
    O´Sullivan, Ciara K.
    Universitat Rovira i Virgili, Tarragona, Spain.
    Development of a gold nano-particle-based fluorescent molecular beacon fordetection of cystic fibrosis associated mutation2010Ingår i: Biosensors & bioelectronics, ISSN 0956-5663, E-ISSN 1873-4235, Vol. 26, nr 2, s. 307-313Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Cystic fibrosis is one of the most common genetically inherited diseases in Northern Europe, consistingof an inherited defect of chloride transport in the epithelium. Of the several mutations related to CF, theF508 mutation occurs in ca. 70% of the cases. In this work the use of a gold nano-particle supportedfluorescence molecular beacon was investigated as an optical sensing platform for the detection of theF508 cystic fibrosis associated mutation. Different parameters such as molecular beacon design, Aunano-particle size, molecular beacon–nano-particle conjugation protocol, molecular beacon loading aswell as experimental conditions were evaluated. A 31-base long molecular beacon, containing a 15-baserecognition sequence specific for the mutant target, was linked via a thiol modified poly thymine linker(10 bases long) to a 13 nm gold nano-particle and was exposed to mutant and wild type targets, and aclear differentiation was achieved at target concentrations as low as 1 nM.

  • 31.
    Beni, Valerio
    et al.
    NMRC, University College, Cork, Ireland.
    Newton, Hazel
    NMRC, University College, Cork, Ireland.
    Arrigan, Damien
    NMRC, University College, Cork, Ireland.
    Hill, Martin
    NMRC, University College, Cork, Ireland.
    Lane, William
    NMRC, University College, Cork, Ireland.
    Mathewson, Alan
    NMRC, University College, Cork, Ireland.
    Voltammetric behaviour at gold electrodes immersed in the BCR sequential extraction scheme media: Application of underpotential deposition–stripping voltammetry to determination of copper in soil extracts2004Ingår i: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 502, nr 2, s. 195-206Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The development of mercury-free electroanalytical systems for in-field analysis of pollutants requires a foundation on the electrochemicalbehaviour of the chosen electrode material in the target sample matrices. In this work, the behaviour of gold working electrodes in the mediaemployed in the BCR sequential extraction protocol, for the fractionation of metals in solid environmental matrices, is reported. All three ofthe BCR sequential extraction media are redox active, on the basis of acidity and oxygen content as well as the inherent reducing or oxidisingnature of some of the reagents employed: 0.11M acetic acid, 0.1M hydroxylammonium chloride (adjusted to pH 2) and 1M ammoniumacetate (adjusted to pH 2) with added trace hydrogen peroxide. The available potential ranges together with the demonstrated detection oftarget metals in these media are presented. Stripping voltammetry of copper or lead in the BCR extract media solutions reveal a multi-peakbehaviour due to the stripping of both bulk metal and underpotential metal deposits. A procedure based on underpotential deposition–strippingvoltammetry (UPD-SV) was evaluated for application to determination of copper in 0.11M acetic acid soil extracts. A preliminary screeningstep in which different deposition times are applied to the sample enables a deposition time commensurate with UPD-SV to be selected sothat no bulk deposition or stripping occurs thus simplifying the shape and features of the resulting voltammograms. Choice of the suitabledeposition time is then followed by standards addition calibration. The method was validated by the analysis of a number of BCR 0.11Macetic acid soil extracts. Good agreement was obtained been the UPD-SV method and atomic spectroscopic results.

  • 32.
    Beni, Valerio
    et al.
    Tyndall National Institute, University College, Cork, Ireland.
    Ogurtsov, Vladimir
    Tyndall National Institute, University College, Cork, Ireland.
    Bakunin, Nikolai
    Tyndall National Institute, University College, Cork, Ireland.
    Arrigan, Damien
    Tyndall National Institute, University College, Cork, Ireland.
    Hill, Martin
    Cork Institute of Technology, Bishopstown, Cork, Ireland.
    Development of a portable electroanalytical system for the stripping voltammetry of metals: Determination of copper in acetic acid soil extracts2005Ingår i: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 552, nr 1-2, s. 190-200Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The development, characterisation and evaluation of a prototype portable electrochemical trace metal analyser are presented. The instrumentis a battery-powered microcontroller-based potentiostat, which implements anodic stripping voltammetry (ASV) at suitable sensor electrodes.It is capable of operating away from the laboratory, in the absence of an external power source and is usable by low-skilled personnel. Thedistinguishing feature of the instrument is its custom software, which enables sample pre-screening, data processing and sample dilution andstandard additions calculations to be carried out. The instrument has been evaluated by application of a methodology for the detection ofcopper in acetic acid soil extracts, both in the laboratory and in the field. Underpotential deposition staircase anodic stripping voltammetry(UPD-SCASV) of the copper at gold disk electrodes was used as a test method. There was good agreement between the instrument resultsand those from laboratory-based reference analytical methods for analyses carried out both in the laboratory and in the field.

  • 33.
    Beni, Valerio
    et al.
    Universitat Rovira i Virgili, Spain.
    Zewdu, Taye
    Universitat Rovira i Virgili, Spain.
    Joda, Hamdi
    Universitat Rovira i Virgili, Spain.
    Katakis, Ioanis
    Universitat Rovira i Virgili, Spain.
    O´Sullivan, Ciara K.
    Universitat Rovira i Virgili, Spain.
    Gold nanoparticle fluorescent molecular beacon for low-resolution DQ2 gene HLA typing2012Ingår i: Analytical and Bioanalytical Chemistry, ISSN 1618-2642, E-ISSN 1618-2650, Vol. 402, nr 3, s. 1001-1009Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Coeliac disease is an inflammation of the small intestine triggered by gluten ingestion. We present a fluorescent genosensor, exploiting molecular-beacon-functionalized gold nanoparticles, for the identification of human leukocyte antigen (HLA) DQ2 gene, a key genetic factor in coeliac disease. Optimization of sensor performance was achieved by tuning the composition of the oligonucleotide monolayer immobilized on the gold nanoparticle and the molecular beacon design. Co-immobilization of the molecular beacon with a spacing oligonucleotide (thiolated ten-thymine oligonucleotide) in the presence of ten-adenine oligonucleotides resulted in a significant increase of the sensor response owing to improved spacing of the molecular beacons and extension of the distance from the nanoparticle surface, which renders them more available for recognition. Further increase in the response (approximately 40%) was shown to be achievable when the recognition sequence of the molecular beacon was incorporated in the stem. Improvement of the specificity of the molecular beacons was also achieved by the incorporation within their recognition sequence of a one-base mismatch. Finally, gold nanoparticles functionalized with two molecular beacons targeting the DQA1*05* and DQB1*02* alleles allowed the low-resolution typing of the DQ2 gene at the nanomolar level.

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  • 34.
    Benskin, Jonathan
    et al.
    University of Alberta, Canada.
    Ahrens, Lutz
    Institute for Coastal Research, Geesthacht, Tyskland.
    Muir, Derek
    Environment Canada, Kanada.
    Scott, Brian
    Environment Canada, Kanada.
    Spencer, Christine
    Environment Canada, Kanada.
    Rosenberg, Bruno
    Department of Fisheries and Oceans, Canada.
    Tomy, Gregg
    Department of Fisheries and Oceans, Canada.
    Kylin, Henrik
    Linköpings universitet, Institutionen för tema, Tema vatten i natur och samhälle. Linköpings universitet, Filosofiska fakulteten.
    Lohmann, Rainer
    University of Rhode Island, USA.
    Martin, Jonathan
    University of Alberta, Canada.
    Manufacturing Origin of Perfluorooctanoate (PFOA) in Atlantic and Canadian Arctic Seawater2012Ingår i: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 46, nr 2, s. 677-685Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The extent to which different manufacturing sources and long-range transport pathways contribute to perfluorooctanoate (PFOA) in the world’s oceans, particularly in remote locations, is widely debated. Here, the relative contribution of historic (i.e., electrochemically fluorinated) and contemporary (i.e., telomer) manufacturing sources was assessed for PFOA in various seawater samples by an established isomer profiling technique. The ratios of individual branched PFOA isomers were indistinguishable from those in authentic historic standards in 93% of the samples examined, indicating that marine processes had little influence on isomer profiles, and that isomer profiling is a valid source apportionment tool for seawater. Eastern Atlantic PFOA was largely (83−98%) of historic origin, but this decreased to only 33% close to the Eastern U.S. seaboard. Similarly, PFOA in the Norwegian Sea was near exclusively historic, but the relative contribution decreased to ∼50% near the Baltic Sea. Such observations of contemporary PFOA in coastal source regions coincided with elevated concentrations, suggesting that the continued production and use of PFOA is currently adding to the marine burden of this contaminant. In the Arctic, a spatial trend was observed whereby PFOA in seawater originating from the Atlantic was predominantly historic (up to 99%), whereas water in the Archipelago (i.e., from the Pacific) was predominantly of contemporary origin (as little as 17% historic). These data help to explain reported temporal and spatial trends from Arctic wildlife biomonitoring, and suggest that the dominant PFOA source(s) to the Pacific and Canadian Arctic Archipelago are either (a) from direct emissions of contemporary PFOA via manufacturing or use in Asia, or (b) from atmospheric transport and oxidation of contemporary PFOA-precursors.

  • 35.
    Benskin, Jonathan P.
    et al.
    University of Alberta, Canada .
    Muir, Derek C. G.
    Environm Canada, Canada .
    Scott, Brian F.
    Environm Canada, Canada .
    Spencer, Christine
    Environm Canada, Canada .
    De Silva, Amila O.
    Environm Canada, Canada .
    Kylin, Henrik
    Linköpings universitet, Institutionen för tema, Tema vatten i natur och samhälle. Linköpings universitet, Filosofiska fakulteten.
    Martin, Jonathan W.
    University of Alberta, Canada .
    Morris, Adam
    University of Guelph, Canada .
    Lohmann, Rainer
    University of Rhode Isl, RI 02882 USA .
    Tomy, Gregg
    Department Fisheries and Oceans Canada, Canada .
    Rosenberg, Bruno
    Department Fisheries and Oceans Canada, Canada .
    Taniyasu, Sachi
    National Institute Adv Ind Science and Technology, Japan .
    Yamashita, Nobuyoshi
    National Institute Adv Ind Science and Technology, Japan .
    Perfluoroalkyl Acids in the Atlantic and Canadian Arctic Oceans2012Ingår i: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 46, nr 11, s. 5815-5823Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We report here on the spatial distribution of C-4, C-6, and C-8 perfluoroalkyl sulfonates, C-6-C-14 perfluoroalkyl carboxylates, and perfluorooctanesulfonamide in the Atlantic and Arctic Oceans, including previously unstudied coastal waters of North and South America, and the Canadian Arctic Archipelago. Perfluorooctanoate (PFOA) and perfluorooctanesulfonate (PFOS) were typically the dominant perfluoroalkyl acids (PFAAs) in Atlantic water. In the midnorthwest Atlantic/Gulf Stream, sum PFAA concentrations (Sigma PFAAs) were low (77-190 pg/L) but increased rapidly upon crossing into U.S. coastal water (up to 5800 pg/L near Rhode Island). Sigma PFAAs in the northeast Atlantic were highest north of the Canary Islands (280-980 pg/L) and decreased with latitude. In the South Atlantic, concentrations increased near Rio de la Plata (Argentina/Uruguay; 350-540 pg/L Sigma PFAAs), possibly attributable to insecticides containing N-ethyl perfluorooctanesulfonamide, or proximity to Montevideo and Buenos Aires. In all other southern hemisphere locations, Sigma PFAAs were less than210 pg/L. PFOA/PFOS ratios were typically greater than= 1 in the northern hemisphere, similar to 1 near the equator, and less than= 1 in the southern hemisphere. In the Canadian Arctic, Sigma PFAAs ranged from 40 to 250 pg/L, with perfluoroheptanoate, PFOA, and PFOS among the PFAAs detected at the highest concentrations. PFOA/PFOS ratios (typically greater thangreater than1) decreased from Baffin Bay to the Amundsen Gulf; possibly attributable to increased atmospheric inputs. These data help validate global emissions models and contribute to understanding of long-range transport pathways and sources of PFAAs to remote regions.

  • 36.
    Berduque, Alfonso
    et al.
    Tyndall National Institute, University College, Cork, Ireland.
    Lanyon, Yvonne
    Tyndall National Institute, University College, Cork, Ireland.
    Beni, Valerio
    Tyndall National Institute, University College, Cork, Ireland.
    Herzog, Gregoire
    Tyndall National Institute, University College, Cork, Ireland.
    Watson, Yvonne
    Tyndall National Institute, University College, Cork, Ireland.
    Rodgers, Kenneth
    Tyndall National Institute, University College, Cork, Ireland.
    Stam, Frank
    Tyndall National Institute, University College, Cork, Ireland.
    Alderman, John
    Tyndall National Institute, University College, Cork, Ireland.
    Arrigan, Damien
    Tyndall National Institute, University College, Cork, Ireland.
    Voltammetric characterisation of silicon-based microelectrode arrays and their application to mercury-free stripping voltammetry of copper ions2007Ingår i: Talanta: The International Journal of Pure and Applied Analytical Chemistry, ISSN 0039-9140, E-ISSN 1873-3573, Vol. 71, nr 3, s. 1022-1030Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This paper describes the electrochemical characterisation of a range of gold and platinum microelectrode arrays (MEAs) fabricated by standardphotolithographic methods. The inter-electrode spacing, geometry, numbers and dimensions of the electrodes in the arrays were found to influencethe voltammetric behaviours obtained. Excellent correlation was found between experimental data and theoretical predictions employing publishedmodels of microelectrode behaviour. Gold MEAs were evaluated for their applicability to copper determination in a soil extract sample, whereagreement was found between the standard analytical method and a method based on underpotential deposition—anodic stripping voltammetry(UPD-ASV) at the MEAs, offering a mercury-free alternative for copper sensing.

  • 37.
    Bergman, Nina
    Linköpings universitet, Institutionen för fysik, kemi och biologi.
    Sample preparation of 8-hydroxy-2’-deoxyguanosine with solid phase extraction methodology based on molecular imprinting polymers and conventional silica based phases2011Självständigt arbete på grundnivå (kandidatexamen), 10,5 poäng / 16 hpStudentuppsats (Examensarbete)
    Abstract [en]

    The aim of this study was to develop methods for sample preparation for 8-OHdG in blood plasma samples with different solid phase extraction techniques using HPLC with an elec- trochemical detector. The solid phase extraction cartridges used were Chromabond® C18, Oasis® MAX, and three types of SupelMIPTM cartridges for chloramphenicol, riboflavin, and nitroimidazoles. The SupelMIPTM cartridges are based on molecularly imprinted polymers- technique. The separation of 8-OHdG in samples extracted from blood plasma was carried out with a Thermo Quest Hypersil Division ODS column (250 mm × 4 mm, 3μm I.D.) and methanol:buffer (10:90, v/v) as mobile phase. Recovery and selectivity was studied for the different solid phase extraction methods. The highest recovery was obtained using the Chromabond C18 cartridge with a recovery of 92%, and CV coefficient 9.5% (n = 4). 8-OHdG could not be extracted on MIP-cartridges for chloramphenicol or riboflavin, but was retained on MIP columns for nitroimidazoles, and the highest recovery was 49%.

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  • 38.
    Berto, Marcello
    et al.
    University of Modena and Reggio Emilia, Italy.
    Casalini, Stefano
    University of Modena and Reggio Emilia, Italy; Institute Ciencia Mat Barcelona ICMAB CSIC, Spain.
    Di Lauro, Michele
    University of Modena and Reggio Emilia, Italy.
    Marasso, Simone L.
    Politecn Torino, Italy; IMEM CNR, Italy.
    Cocuzza, Matteo
    Politecn Torino, Italy; IMEM CNR, Italy.
    Perrone, Denis
    Ist Italiano Tecnol, Italy.
    Pinti, Marcello
    University of Modena and Reggio Emilia, Italy.
    Cossarizza, Andrea
    University of Modena and Reggio Emilia, Italy.
    Pirri, Candido F.
    Politecn Torino, Italy; Ist Italiano Tecnol, Italy.
    Simon, Daniel
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska fakulteten.
    Berggren, Magnus
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska fakulteten.
    Zerbetto, Francesco
    University of Bologna, Italy.
    Bortolotti, Carlo A.
    University of Modena and Reggio Emilia, Italy.
    Biscarini, Fabio
    University of Modena and Reggio Emilia, Italy.
    Biorecognition in Organic Field Effect Transistors Biosensors: The Role of the Density of States of the Organic Semiconductor2016Ingår i: ANALYTICAL CHEMISTRY, ISSN 0003-2700, Vol. 88, nr 24, s. 12330-12338Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Biorecognition is a central event in biological processes in the living systems that is also widely exploited in technological and health applications. We demonstrate that the Electrolyte Gated Organic Field Effect Transistor (EGOFET) is an ultrasensitive and specific device that allows us to quantitatively assess the thermodynamics of biomolecular recognition between a human antibody and its antigen, namely, the inflammatory cytokine TNF alpha at the solid/liquid interface. The EGOFET biosensor exhibits a superexponential response at TNF alpha concentration below 1 nM with a minimum detection level of 100 pM. The sensitivity of the device depends on the analyte concentration, reaching a maximum in the range of clinically relevant TNF alpha concentrations when the EGOFET is operated in the subthreshold regime. At concentrations greater than 1 nM the response scales linearly with the concentration. The sensitivity and the dynamic range are both modulated by the gate voltage. These results are explained by establishing the correlation between the sensitivity and the density of states (DOS) of the organic semiconductor. Then, the superexponential response arises from the energy-dependence of the tail of the DOS of the HOMO level. From the gate voltage-dependent response, we extract the binding constant, as well as the changes of the surface charge and the effective capacitance accompanying biorecognition at the electrode surface. Finally, we demonstrate the detection of TNF alpha in human-plasma derived samples as an example for point-of-care application.

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  • 39.
    Berto, Marcello
    et al.
    Univ Modena and Reggio Emilia, Italy; Univ Ferrara, Italy.
    Diacci, Chiara
    Univ Modena and Reggio Emilia, Italy.
    DAgata, Roberta
    Univ Catania, Italy.
    Pinti, Marcello
    Univ Modena and Reggio Emilia, Italy.
    Bianchini, Elena
    Univ Modena and Reggio Emilia, Italy.
    Di Lauro, Michele
    Univ Modena and Reggio Emilia, Italy.
    Casalini, Stefano
    Univ Modena and Reggio Emilia, Italy; Inst Ciencia Mat Barcelona ICMAB CSIC, Spain.
    Cossarizza, Andrea
    Univ Modena and Reggio Emilia, Italy.
    Berggren, Magnus
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Laboratoriet för organisk elektronik. Linköpings universitet, Tekniska fakulteten.
    Simon, Daniel
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Laboratoriet för organisk elektronik. Linköpings universitet, Tekniska fakulteten.
    Spoto, Giuseppe
    Univ Catania, Italy; Univ Catania, Italy.
    Biscarini, Fabio
    Univ Modena and Reggio Emilia, Italy.
    Bortolotti, Carlo A.
    Univ Modena and Reggio Emilia, Italy.
    EGOFET Peptide Aptasensor for Label-Free Detection of Inflammatory Cytokines in Complex Fluids2018Ingår i: ADVANCED BIOSYSTEMS, ISSN 2366-7478, Vol. 2, nr 2, artikel-id 1700072Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Organic electronic transistors are rapidly emerging as ultrahigh sensitive label-free biosensors suited for point-of-care or in-field deployed applications. Most organic biosensors reported to date are based on immunorecognition between the relevant biomarkers and the immobilized antibodies, whose use is hindered by large dimensions, poor control of sequence, and relative instability. Here, an electrolyte-gated organic field effect transistor (EGOFET) biosensor where the recognition units are surface immobilized peptide aptamers (Affimer proteins) instead of antibodies is reported. Peptide aptasensor for the detection of the pro-inflammatory cytokine tumor necrosis factor alpha (TNF alpha) with a 1 x 10(-12) M limit of detection is demonstrated. Ultralow sensitivity is met even in complex solutions such as cell culture media containing 10% serum, demonstrating the remarkable ligand specificity of the device. The device performances, together with the simple one-step immobilization strategy of the recognition moieties and the low operational voltages, all prompt EGOFET peptide aptasensors as candidates for early diagnostics and monitoring at the point-of-care.

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  • 40.
    Bhatti, Muhammad Ali
    et al.
    Univ Sindh Jamshoro, Pakistan.
    Tahira, Aneela
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik, elektroteknik och matematik. Linköpings universitet, Tekniska fakulteten.
    Chandio, Ali dad
    NED Univ Engn & Technol Karachi, Pakistan.
    Almani, Khalida Faryal
    Univ Sindh Jamshoro, Pakistan.
    Bhatti, Adeel Liaquat
    Univ Sindh Jamshoro, Pakistan.
    Waryani, Baradi
    Univ Sindh Jamshoro, Pakistan.
    Nafady, Ayman
    King Saud Univ, Saudi Arabia.
    Ibupoto, Zafar Hussain
    Univ Sindh Jamshoro, Pakistan.
    Enzymes and phytochemicals from neem extract robustly tuned the photocatalytic activity of ZnO for the degradation of malachite green (MG) in aqueous media2021Ingår i: Research on chemical intermediates (Print), ISSN 0922-6168, E-ISSN 1568-5675, Vol. 47, nr 4, s. 1581-1599Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The malachite green (MG) is very difficult to degrade in water; thus, it needs an efficient photocatalyst. In this study, neem extract was used to tune the surface and crystal properties of ZnO nanostructures for the photodegradation of MG. The biosynthesized ZnO samples were prepared by hydrothermal method in the presence of 5, 10 and 15 mL of neem extract. The structural characterization has shown nanoparticle like morphology of ZnO as revealed by scanning electron microscopy (SEM) and hexagonal phase was confirmed by powder X-ray diffraction (XRD) technique. The XRD analysis has shown a shift in the 2 theta towards lower angle for ZnO with increasing amount of neem extract. Also, the crystallite particle size of ZnO was decreased with increasing neem extract. The UV-visible spectroscopy has shown the decrease in the optical band gap of ZnO, and the lowest band gap is possessed by ZnO sample produced with 15 mL of neem extract. The ZnO sample obtained with 15 mL of neem extract has shown approximately 99% degradation efficiency for MG for 70 min in aqueous solution. The superior photocatalytic activity of ZnO sample with 15 mL of neem extract could be attributed from the decrease in charge recombination rate due to the decreased optical band gap and particle size.

  • 41.
    Bohlin, Nina
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Kemi. Linköpings universitet, Tekniska högskolan.
    Kemiskt försvar mot havstulpanskolonisering i marina svampdjur2013Självständigt arbete på grundnivå (kandidatexamen), 10,5 poäng / 16 hpStudentuppsats (Examensarbete)
    Abstract [en]

    The purpose of this project is to analyze and study the absorption of the substances ivermectin, spinosad and barettin to hydrophobic and hydrophilic surfaces, and to analyze and study if the barnacle larva are effected when they try to settle on the treated surface.

    Incubation tests with barnacle larva in Petri dishes were performed as well as absorption tests on hydrophobic and hydrophilic surfaces which were tested with ellipsometry. To determine the surface thickness.

    The barnacles were placed in hydrophobic as well as hydrophilic Petri dishes that had been incubated with ivermectin, spinosad or barettin. After four to six days the larva was counted to analyze the settling. From the results conclusions could be drawn about the adsorption abilities of the substances to the different surfaces.

    The barnacles were placed in hydrophobic as well as hydrophilic Petri dishes that had been incubated with ivermectin, spinosad or barettin. After four to six days the larva was counted to analyze the settling. From the results conclusions could be drawn about the adsorption abilities of the substances to the different surfaces.

    To analyze the adsorption abilities, pieces of silicon oxide were prepared with hydrophobic and hydrophilic poly dimethyl siloxan groups, and albumine. The pieces were then analyzed with ellipsometry.

    The larva's mortality was very high in the first tests. It can be explained with them being stored too cold the first days, which might have caused their death. It might also be because of contamination from the net used to move the larva, since it was in contact with all the substances concentrations.

    The standard deviations from the ellipsometry tests are very high, most likely due to uneven adsorption of the substances to the surface. With more tests and measurements, more accurate results could have been sustained

    The purpose of this project is to analyze and study the absorption of the substances ivermectin, spinosad and barettin to hydrophobic and hydrophilic surfaces, and to analyze and study if the barnacle larva are effected when they try to settle on the treated surface.

    Incubation tests with barnacle larva in Petri dishes were performed as well as absorption tests on hydrophobic and hydrophilic surfaces which were tested with ellipsometry. To determine the surface thickness.

    The barnacles were placed in hydrophobic as well as hydrophilic Petri dishes that had been incubated with ivermectin, spinosad or barettin. After four to six days the larva was counted to analyze the settling. From the results conclusions could be drawn about the adsorption abilities of the substances to the different surfaces.

    The barnacles were placed in hydrophobic as well as hydrophilic Petri dishes that had been incubated with ivermectin, spinosad or barettin. After four to six days the larva was counted to analyze the settling. From the results conclusions could be drawn about the adsorption abilities of the substances to the different surfaces.

    To analyze the adsorption abilities, pieces of silicon oxide were prepared with hydrophobic and hydrophilic poly dimethyl siloxan groups, and albumine. The pieces were then analyzed with ellipsometry.

    The larva's mortality was very high in the first tests. It can be explained with them being stored too cold the first days, which might have caused their death. It might also be because of contamination from the net used to move the larva, since it was in contact with all the substances concentrations.

    The standard deviations from the ellipsometry tests are very high, most likely due to uneven adsorption of the substances to the surface. With more tests and measurements, more accurate results could have been sustained

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    Kemiskt försvar mot havstulpanslarver i marina svampdjur
  • 42.
    Boiso, Samuel
    et al.
    Swedish National Forensic Centre, Linköping, Sweden.
    Dalin, Erik
    Swedish National Forensic Centre, Linköping, Sweden.
    Seidlitz, Heidi
    Swedish National Forensic Centre, Linköping, Sweden.
    Sidstedt, Maja
    Swedish National Forensic Centre, Linköping, Sweden; Applied Microbiology, Department of Chemistry, Lund University, Lund, Sweden.
    Trygg, Elias
    Swedish National Forensic Centre, Linköping, Sweden.
    Hedman, Johannes
    Swedish National Forensic Centre, Linköping, Sweden; Applied Microbiology, Department of Chemistry, Lund University, Lund, Sweden.
    Ansell, Ricky
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biologi. Linköpings universitet, Tekniska fakulteten. Swedish National Forensic Centre, Linköping, Sweden.
    RapidHIT for the purpose of stain analyses – An interrupted implementation2017Ingår i: Forensic Science International: Genetics Supplement Series, ISSN 1875-1768, E-ISSN 1875-175X, Vol. 6, nr Supplement C, s. e589-e590Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Rapid DNA instruments have in recent years been developed, enabling analysis of forensic samples with a minimum of human intervention. Initially intended for fast handling of reference samples, such as samples from suspects in booking suites, attention shifted to include crime scene samples. The aim of this study was to determine whether or not the RapidHIT System (IntegenX) is fit for crime scene samples. The first runs gave very poor results, which was found to be due to an incorrect firmware setting leading to no or just minute amounts of amplicons being injected for electrophoresis. After solving this problem, 28 full runs (seven samples each) applying NGM SElect Express were performed comprising various amounts of blood on cotton swabs. Six of the runs failed completely, four due to cartridge leakage and in two runs the PCR mix was not injected. For 155 samples with 1–5ÎŒL blood (volumes for which complete DNA profiles are expected), 119 samples (77%) gave complete DNA profiles. Among the most serious failures were incorrect allele calling and leakage of DNA extract or PCR product. Other general issues were failure to export results, anode motor breakdown and broken capillary array. Due to the encountered problems with software, hardware and cartridges, together with the low success rate, it was decided not to continue towards implementation of the RapidHIT System in casework.

  • 43.
    Bojmar, Linda
    et al.
    Linköpings universitet, Institutionen för biomedicinska och kliniska vetenskaper, Avdelningen för kirurgi, ortopedi och onkologi. Linköpings universitet, Medicinska fakulteten. Weill Cornell Med, NY 10065 USA.
    Kim, Han Sang
    Weill Cornell Med, NY 10065 USA; Yonsei Univ, South Korea.
    Sugiura, Kei
    Univ Tokyo, Japan; Tokyo Inst Technol, Japan.
    Heissel, Soren
    Rockefeller Univ, NY USA.
    Lucotti, Serena
    Weill Cornell Med, NY 10065 USA.
    Cioffi, Michele
    Weill Cornell Med, NY 10065 USA.
    Johnson, Kofi Ennu
    Weill Cornell Med, NY 10065 USA; Triinst PhD Program Computat Biol & Med, NY USA.
    Cohen-Gould, Leona
    Weill Cornell Med, NY USA.
    Zhang, Haiying
    Weill Cornell Med, NY 10065 USA.
    Molina, Henrik
    Rockefeller Univ, NY USA.
    Matei, Irina R.
    Weill Cornell Med, NY 10065 USA.
    Lyden, David
    Weill Cornell Med, NY 10065 USA.
    Hoshino, Ayuko
    Weill Cornell Med, NY 10065 USA; Univ Tokyo, Japan; Tokyo Inst Technol, Japan.
    Protocol for cross-platform characterization of human and murine extracellular vesicles and particles2024Ingår i: STAR PROTOCOLS, ISSN 2666-1667, Vol. 5, nr 1, artikel-id 102754Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Characterization of isolated extracellular vesicles and particles (EVPs) is crucial for determining functions and biomarker potential. Here, we present a protocol to analyze size, number, morphology, and EVP protein cargo and to validate EVP proteins in both humans and mice. We describe steps for nanoparticle tracking analysis, transmission electron microscopy, single-EVP immunodetection, EVP proteomic mass spectrometry and bioinformatic analysis, and EVP protein validation by ExoELISA and western blot analysis. This allows for EVP cross -validation across different platforms.For complete details on the use and execution of this protocol, please refer to Hoshino et al.1

  • 44.
    Boknäs, Niklas
    et al.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för klinisk kemi. Linköpings universitet, Medicinska fakulteten. Region Östergötland, Centrum för kirurgi, ortopedi och cancervård, Hematologiska kliniken US. Australian Centre for Blood Diseases, Monash University, Melbourne, Australia.
    Macwan, Ankit
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för klinisk kemi. Linköpings universitet, Medicinska fakulteten.
    Södergren, Anna L.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Medicinska fakulteten.
    Ramström, Sofia
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för klinisk kemi. Linköpings universitet, Medicinska fakulteten. Region Östergötland, Diagnostikcentrum, Klinisk kemi. Örebro University, School of Medical Sciences, Örebro, Sweden.
    Platelet function testing at low platelet counts: When can you trust your analysis?2019Ingår i: RESEARCH AND PRACTICE IN THROMBOSIS AND HAEMOSTASIS, ISSN 2475-0379, Vol. 3, nr 2, s. 285-290Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background: Although flow cytometry is often brought forward as a preferable method in the setting of thrombocytopenia, the relative effects of low sample counts on results from flow cytometry-based platelet function testing (FC-PFT) in comparison with light transmission aggregometry (LTA) and multiple electrode aggregometry (MEA) has not been reported. Objectives: To compare the effects of different sample platelet counts (10, 50, 100, and 200x10(9)L(-1)) on platelet activation measured with FC-PFT, LTA, and MEA using the same anticoagulant and agonist concentrations as for the commercial MEA test. Methods: Platelets were stimulated with two commonly used platelet agonists (ADP [6.5 mu molL(-1)] and PAR1-AP [TRAP, 32 mu molL(-1)]). The specified sample platelet counts were obtained by combining platelet-rich and platelet poor hirudinized plasma in different proportions with or without red blood cells. Results: For FC, P-selectin exposure and PAC-1 binding was reduced at 10x10(9)L(-1) after stimulation with PAR1-AP (by approximately 20% and 50%, respectively), but remained relatively unchanged when ADP was used as agonist (n=9). The platelet count-dependent effects observed with PAR1-AP were eliminated when samples were pre-incubated with apyrase, implying that reduced purinergic signaling was the main underlying factor (n=5). Both aggregometry-based PFTs showed a 50% reduction at 50x10(9)L(-1) and more than 80% reduction at 10x10(9)L(-1), irrespective of agonist used (n=7). Conclusions: Although FC-PFT is generally preferable to aggregometry-based PFTs in situations with low sample platelet counts, a careful optimization of experimental parameters is still required in order to eliminate platelet count-related effects.

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  • 45.
    Borén, Kristina
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biokemi. Linköpings universitet, Tekniska högskolan.
    Larsson, Marie
    Linköpings universitet, Institutionen för fysik, kemi och biologi. Linköpings universitet, Tekniska högskolan.
    Bergenhem, Nils
    Linköpings universitet, Institutionen för fysik, kemi och biologi. Linköpings universitet, Tekniska högskolan.
    Carlsson, Uno
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Kemi. Linköpings universitet, Tekniska högskolan.
    Rapid ion-exchange chromatography for preparative separation of proteins IV. Application to bovine carbonic anhydrase III from skeletal muscle1991Ingår i: Journal of Chromatography A, ISSN 0021-9673, E-ISSN 1873-3778, Vol. 588, nr 1-2, s. 139-145Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Bovine muscle carbonic anhydrase III was purified to homogeneity by the strategy of rapid ion-exchange chromatography. The ionic exchanger used was CM-cellulose, and this is the first application of this technique on a cation exchanger. Nitrogen gas was used to pressurize the chromatographic column to accelerate the elution. The results show that proteins with high isoelectric points can also be purified in this way. The procedure is very time-saving compared with conventional chromatography, reducing the elution time five-to ten-fold. The proteins are in addition protected against oxidation by air.

  • 46.
    Bouwman, Henk
    et al.
    Northwest University, South Africa.
    Choong Kwe Yive, Nee Sun
    University of MAuritius.
    Kylin, Henrik
    Linköpings universitet, Institutionen för tema, Tema vatten i natur och samhälle.
    Polder, Anushka
    Veterinary Institute, Norway.
    Organic pollutants in term eggs from Rodrigues Island – Indian Ocean.2012Konferensbidrag (Övrigt vetenskapligt)
  • 47.
    Bouwman, Henk
    et al.
    Northwest University, South Africa.
    Kylin, Henrik
    Linköpings universitet, Institutionen för tema, Tema vatten i natur och samhälle.
    van den Berg, Henk
    Wageningen University, South Africa.
    Bornman, Riana
    University of Pretoria, South Africa.
    Is precaution the way to manage the paradox of DDT use in malaria control?2012Konferensbidrag (Övrigt vetenskapligt)
  • 48.
    Bouwman, Hindrik
    et al.
    North West University, South Africa .
    Kylin, Henrik
    Linköpings universitet, Institutionen för tema, Tema vatten i natur och samhälle. Linköpings universitet, Filosofiska fakulteten.
    Sereda, Barbara
    Plant Protect Research Institute, South Africa .
    Bornman, Riana
    University of Pretoria, South Africa .
    High levels of DDT in breast milk: Intake, risk, lactation duration, and involvement of gender2012Ingår i: Environmental Pollution, ISSN 0269-7491, E-ISSN 1873-6424, Vol. 170, s. 63-70Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We investigated presence and levels of DDT in 163 breast milk samples from four South African villages where, in three of them, malaria is controlled with DDT-sprayed indoors. Mean Sigma DDT levels in breast milk were 18, 11, and 9.5 mg/kg mf (milk fat) from the three DDT-sprayed villages, respectively, including the highest Sigma DDT level ever reported for breast milk from South Africa (140 mg/kg mf). Understanding the causes for these differences would be informative for exposure reduction intervention. The Provisional Tolerable Daily Intake (PTDI) for DDT by infants, and the Maximum Residue Limit (MRL) were significantly exceeded. DDT had no effect on duration of lactation. There were indications (not significant) from DDT-sprayed villages that first-born female infants drink milk with more Sigma DDT than first-born male infants, and vice versa for multipara male and female infants, suggesting gender involvement on levels of DDT in breast milk - requiring further investigation.

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  • 49.
    Bouwman, Hindrik
    et al.
    North West University, South Africa .
    Kylin, Henrik
    Linköpings universitet, Institutionen för tema, Tema vatten i natur och samhälle. Linköpings universitet, Filosofiska fakulteten.
    Sun Choong Kwet Yive, Nee
    Mauritian Wildlife Fdn, Mauritius .
    Loken, Katharina
    Norwegian School Vet Science, Norway .
    Utne Skaare, Janneche
    Norwegian School Vet Science, Norway .
    Polder, Anuschka
    Norwegian School Vet Science, Norway .
    First report of chlorinated and brominated hydrocarbon pollutants in marine bird eggs from an oceanic Indian Ocean island2012Ingår i: Environmental Research, ISSN 0013-9351, E-ISSN 1096-0953, Vol. 118, s. 53-64Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We report for the first time levels of persistent organic pollutants in marine bird eggs from an oceanic island in the Indian Ocean, the worlds third largest ocean. Ten eggs each of the Common Noddy, also known as the Brown Noddy (Anous stolidus), and Sooty Tern (Sterna fuscata) were collected from Ile Cocos off the coast of the island of Rodrigues, located 560 km east of the island of Mauritius. Sigma PCBs had the highest levels (2.2 and 2.6 ng/g wm, wet mass; 20 and 19 ng/g lm, lipid mass) for common Noddy and Sooty Tern, respectively (and following), then Sigma DDT (1.9 and 3.1 ng/g wm; 17 and 23 ng/g lm), and mirex (0.96 and 0.69 ng/g wm; 8.7 and 5.0 ng/g lm). Sigma Chlordanes (0.094 and 0.15 ng/g wm; 0.48 and 0.73 ng/g lm) and Sigma toxaphenes (0.26 and 0.61 ng/g wm; 2.4 and 5.9 ng/g lm) are rare data for these compounds from this ocean. Brominated flame retardants were low (0.08 and 0.07 ng/g wm; 0.7 and 0.7 ng/g lm). Multivariate analyses indicated different contamination patterns in the prey items as Sooty Terns had significantly higher levels of mean Sigma chlordanes and Sigma toxaphenes, as well as CB105, -108 and -157. p,p-DDE had an association with thinner eggshells in the Sooty Tern. Although the contaminant levels were in all respects low, industrialisation, development on the periphery, commercial exploitation of the marine environment, and pollutants transferred over long distances by marine debris is likely to add to chemical pressure in this region. Monitoring changes in background levels of pollutants in remote regions will indicate such trends, and marine bird eggs from Rodrigues would be an excellent site.

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  • 50.
    Bovens, Michael
    et al.
    Zurich Forensic Science Institute, Switzerland.
    Ahrens, Björn
    Federal Criminal Police Office, Wiesbaden, Germany.
    Alberink, Ivo
    Netherlands Forensic Institute, The Hague, Netherlands.
    Nordgaard, Anders
    National Forensic Centre, Swedish Police Authority, Linköping, Sweden.
    Salonen, Tuomas
    University of Helsinki, Faculty of Science, Department of Mathematics and Statistics.
    Huhtala, Sami
    National Bureau of Investigation, Helsinki, Finland.
    Chemometrics in forensic chemistry — Part I: Implications to the forensic workflow2019Ingår i: Forensic Science International, ISSN 0379-0738, E-ISSN 1872-6283, Vol. 301, s. 82-90Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The forensic literature shows a clear trend towards increasing use of chemometrics (i.e. multivariate analysis and other statistical methods). This can be seen in different disciplines such as drug profiling, arson debris analysis, spectral imaging, glass analysis, age determination, and more. In particular, current chemometric applications cover low-dimensional (e.g. drug impurity profiles) and high-dimensional data (e.g. Infrared and Raman spectra) and are therefore useful in many forensic disciplines. There is a dominant and increasing need in forensic chemistry for reliable and structured processing and interpretation of analytical data. This is especially true when classification (grouping) or profiling (batch comparison) is of interest.

    Chemometrics can provide additional information in complex crime cases and enhance productivity by improving the processes of data handling and interpretation in various applications. However, the use of chemometrics in everyday work tasks is often considered demanding by forensic scientists and, consequently, they are only reluctantly used. This article and following planned contributions are dedicated to those forensic chemists, interested in applying chemometrics but for any reasons are limited in the proper application of statistical tools — usually made for professionals — or the direct support of statisticians. Without claiming to be comprehensive, the literature reviewed revealed a sufficient overview towards the preferably used data handling and chemometric methods used to answer the forensic question. With this basis, a software tool will be designed (part of the EU project STEFA-G02) and handed out to forensic chemist with all necessary elements of data handling and evaluation.

    Because practical casework is less and less accompanied from the beginning to the end out of the same hand, more and more interfaces are built in through specialization of individuals. This article presents key influencing elements in the forensic workflow related to the most meaningful chemometric application and evaluation.

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