liu.seSearch for publications in DiVA
Change search
Refine search result
4567 301 - 328 of 328
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • oxford
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 301.
    Unéus, Lars
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Artursson, Tom
    AppliedSensor AB.
    Mattsson, Mattias
    Vattenfall Utveckling AB.
    Ljung, Per
    Vattenfall Utveckling AB.
    Wigren, Roger
    AppliedSensor AB.
    Mårtensson, Per
    Proxedra AB.
    Holmberg, Martin
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Lundström, Ingemar
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Lloyd-Spets, Anita
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Evaluation of on-line flue gas measurements by MISiCFET and metal-oxide sensors in boilers2005In: IEEE Sensors Journal, ISSN 1530-437X, E-ISSN 1558-1748, Vol. 5, no 1, p. 75-81Article in journal (Refereed)
    Abstract [en]

    Metal insulator silicon carbide field-effect transistor sensors, metal-oxide sensors, and a linear Lambda sensor in an electronic nose was used to measure on-line in hot flue gases from a boiler. Flue gas from a 100-MW pellets-fuelled boiler has been used to feed the experimental setup. Several reference instruments, which measure the flue gases in parallel to the sensor array, are connected to the electronic nose. Data was collected during six weeks and then evaluated. Using principal component analysis as the data evaluation method, different operating modes for the boiler have been identified in the data set. The different modes could be described in terms of high or low O 2 and CO concentration. Furthermore, we have shown that it seems possible to use a sensor array to determine the operating mode of the boiler and, by partial least-squares models, measure the CO concentration when the boiler operates in its optimum mode.

  • 302.
    Unéus, Lars
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Tobias, Peter
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Salomonsson, P.
    Volvo Technological Development, Gothenburg, Sweden.
    Lundström, Ingemar
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Lloyd Spetz, Anita
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Schottky diodes with thin catalytic gate metals for potential use as ammonia sensors for exhaust gases1999In: Sensors and materials, ISSN 0914-4935, Vol. 11, no 5, p. 305-318Article in journal (Refereed)
    Abstract [en]

    Selective catalytic reduction (SCR) is a method in which ammonia reacts with nitric oxides in a catalytic converter to form water and nitrogen. We show that catalytic Metal Insulator Silicon Carbide (MISiC) devices can be used as ammonia sensors for a SCR system in a diesel engine. Different catalytic metals, Pt and Ir, with a thickness of 30 or 50 nm were investigated. The temperature dependence of the ammonia response of the sensors was characterized. Maximum responses were found at temperatures between 225-250 degrees C. Preliminary experiments were performed to investigate how annealing in different gas ambient influences the response-temperature curve of the sensors. In synthetic diesel exhausts with ammonia added, the sensors showed very good selectivity for ammonia and a small interaction effect with oxygen. The influence of other gas components was almost negligible. Temperature in the diesel exhaust system can reach 550 degrees C; however, operating at temperatures above 400 degrees C limited the lifetime of the sensor. Anger electron spectroscopy (AES) revealed that island formation of the metal due to structural changes was the main reason for failure of the sensor.

  • 303.
    Vagin, Mikhail
    et al.
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering. Linköping University, Department of Physics, Chemistry and Biology.
    Sekretareva, Alina
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, Faculty of Science & Engineering. Stanford Univ, CA 94305 USA; Uppsala Univ, Sweden.
    Håkansson, Anna
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering. Linköping University, Department of Physics, Chemistry and Biology.
    Iakimov, Tihomir
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, Faculty of Science & Engineering. Graphens AB, Teknikringen 1F, SE-58330 Linkoping, Sweden.
    Ivanov, Ivan Gueorguiev
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, Faculty of Science & Engineering.
    Syväjärvi, Mikael
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, Faculty of Science & Engineering. Graphens AB, Teknikringen 1F, SE-58330 Linkoping, Sweden.
    Yakimova, Rositsa
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, Faculty of Science & Engineering. Graphens AB, Teknikringen 1F, SE-58330 Linkoping, Sweden.
    Lundström, Ingemar
    Linköping University, Department of Physics, Chemistry and Biology, Sensor and Actuator Systems. Linköping University, Faculty of Science & Engineering.
    Eriksson, Mats
    Linköping University, Department of Physics, Chemistry and Biology, Sensor and Actuator Systems. Linköping University, Faculty of Science & Engineering.
    Bioelectrocatalysis on Anodized Epitaxial Graphene and Conventional Graphitic Interfaces2019In: CHEMELECTROCHEM, ISSN 2196-0216, Vol. 6, no 14, p. 3791-3796Article in journal (Refereed)
    Abstract [en]

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

    The full text will be freely available from 2020-07-01 15:20
  • 304.
    Vagin, Mikhail
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Chemical and Optical Sensor Systems. Linköping University, The Institute of Technology.
    Sekretareva, Alina
    Linköping University, Department of Physics, Chemistry and Biology, Chemical and Optical Sensor Systems. Linköping University, The Institute of Technology.
    Sanchez, Rafael
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Lundström, Ingemar
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, The Institute of Technology.
    Winquist, Fredrik
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, The Institute of Technology.
    Eriksson, Mats
    Linköping University, Department of Physics, Chemistry and Biology, Chemical and Optical Sensor Systems. Linköping University, The Institute of Technology.
    Arrays of Screen-Printed Graphite Microband Electrodes as a Versatile Electroanalysis Platform2014In: ChemElectroChem, ISSN 2196-0216, Vol. 1, no 4, p. 755-762Article in journal (Refereed)
    Abstract [en]

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

  • 305.
    Vagin, Mikhail Y
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Chemical and Optical Sensor Systems. Linköping University, The Institute of Technology.
    Lundström, Ingemar
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, The Institute of Technology.
    Turner, Anthony
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, The Institute of Technology.
    Beni, Valerio
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, The Institute of Technology.
    Eriksson, Mats
    Linköping University, Department of Physics, Chemistry and Biology, Chemical and Optical Sensor Systems. Linköping University, The Institute of Technology.
    Boron-doped diamond microelectrode arrays for electrochemical monitoring of antibiotics contamination in water2014In: 15th International Conference on Electroanalysis (ESEAC), 2014Conference paper (Other academic)
    Abstract [en]

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

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

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

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

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

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

     

  • 306.
    Vagin, Mikhail Y
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Chemical and Optical Sensor Systems. Linköping University, The Institute of Technology.
    Sekretaryova, Alina N
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, The Institute of Technology.
    Reategui, Rafael Sanchez
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics.
    Lundström, Ingemar
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics.
    Turner, Anthony
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, The Institute of Technology.
    Eriksson, Mats
    Linköping University, Department of Physics, Chemistry and Biology, Chemical and Optical Sensor Systems. Linköping University, The Institute of Technology.
    Screen-printed graphite microbands as a versatile biosensor platform2014In: 24th Anniversary World Congress on Biosensors – Biosensors 2014, Elsevier, 2014Conference paper (Other academic)
    Abstract [en]

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

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

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

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

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

  • 307.
    Vagin, Mikhail Y
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Chemical and Optical Sensor Systems. Linköping University, The Institute of Technology.
    Sekretaryova, Alina N
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, The Institute of Technology.
    Reategui, Rafael Sanchez
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, The Institute of Technology.
    Lundström, Ingemar
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, The Institute of Technology.
    Turner, Anthony
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, The Institute of Technology.
    Eriksson, Mats
    Linköping University, Department of Physics, Chemistry and Biology, Chemical and Optical Sensor Systems. Linköping University, The Institute of Technology.
    Screen-printed graphite microbands for electroanalysis2014In: 15th International Conference on Electroanalysis (ESEAC), 2014Conference paper (Other academic)
  • 308.
    Vagin, Mikhail Yu
    et al.
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Sekretareva, Alina
    Linköping University, Department of Physics, Chemistry and Biology, Chemical and Optical Sensor Systems. Linköping University, Faculty of Science & Engineering.
    Lindgren, Petter
    Håkansson, Anna
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Eriksson, Mats
    Linköping University, Department of Physics, Chemistry and Biology, Chemical and Optical Sensor Systems. Linköping University, Faculty of Science & Engineering.
    Lundström, Ingemar
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, Faculty of Science & Engineering.
    Syväjärve, Mikael
    Yakimova, Rositsa
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, Faculty of Science & Engineering.
    Direct bioelectrocatalysis on anodized epitaxial graphene2015In: Program of the XXIII International Symposium on Bioelectrochemistry and Bioenergetics of the Bioelectrochemical Society14-18 June, 2015Malmö, Sweden, Lausanne: Bioelectrochemical Society , 2015, p. 170-170Conference paper (Other academic)
    Abstract [en]

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

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

  • 309.
    Vagin, Mikhail
    et al.
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Sekretareva, Alina
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, Faculty of Science & Engineering. Department of Chemistry, Stanford University, Stanford, USA.
    Ivanov, Ivan Gueorguiev
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, Faculty of Science & Engineering.
    Håkansson, Anna
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Iakimov, Tihomir
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, Faculty of Science & Engineering. Graphensic AB, Teknikringen 1F, Linköping, Sweden.
    Syväjärvi, Mikael
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, Faculty of Science & Engineering. Graphensic AB, Teknikringen 1F, Linköping, Sweden.
    Yakimova, Rositsa
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, Faculty of Science & Engineering. Graphensic AB, Teknikringen 1F, Linköping, Sweden.
    Lundström, Ingemar
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, Faculty of Science & Engineering.
    Eriksson, Mats
    Linköping University, Department of Physics, Chemistry and Biology, Chemical and Optical Sensor Systems. Linköping University, Faculty of Science & Engineering.
    Monitoring of epitaxial graphene anodization2017In: Electrochimica Acta, ISSN 0013-4686, E-ISSN 1873-3859, Vol. 238, p. 91-98Article in journal (Refereed)
    Abstract [en]

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

  • 310.
    Vikinge, Trine P.
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Hansson, Kenny
    Linköping University, Department of Biomedicine and Surgery, Clinical Chemistry. Linköping University, Faculty of Health Sciences.
    Benesch, Johan
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Johansen, Knut
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Rånby, Mats
    Linköping University, Department of Biomedicine and Surgery, Clinical Chemistry. Linköping University, Faculty of Health Sciences.
    Lindahl, Tomas
    Linköping University, Department of Biomedicine and Surgery, Clinical Chemistry. Linköping University, Faculty of Health Sciences.
    Liedberg, Bo
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Lundström, Ingemar
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Tengvall, Pentti
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Blood plasma coagulation studied by surface plasmon resonance2000In: Journal of Biomedical Optics, ISSN 1083-3668, E-ISSN 1560-2281, Vol. 5, no 1, p. 51-55Article in journal (Refereed)
    Abstract [en]

    A surface plasmon resonance (SPR) apparatus was used to investigate blood plasma coagulation in real time as a function of thromboplastin and heparin concentrations. The response curves were analyzed by curve fitting to a sigmoid curve equation, followed by extraction of the time constant. Clotting activation by thromboplastin resulted in increased time constant, as compared to spontaneously clotted plasma, in a dose dependent way. Addition of heparin to the thromboplastin-activated plasma counteracted this effect. Atomic force microscopy (AFM) pictures of sensor surfaces dried after completed clotting, revealed differences in fibrin network structures as a function of thromboplastin concentration, and the fiber thickness increased with decreased thromboplastin concentration. The physical reason for the SPR signal observed is ambiguous and is therefore discussed. However, the results summarized in the plots and the fibrin network properties observed by AFM correlate well with present common methods used to analyze blood coagulation.

  • 311.
    Vikinge, Trine P.
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Hansson, Kenny
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, The Institute of Technology.
    Benesch, Johan
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Johansen, Knut
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Rånby, Mats
    Östergötlands Läns Landsting, Centre for Diagnostics, Department of Clinical Chemistry. Linköping University, Faculty of Health Sciences.
    Lindahl, Tomas
    Linköping University, Department of Clinical and Experimental Medicine, Clinical Chemistry. Linköping University, Faculty of Health Sciences.
    Lundström, Ingemar
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Tengvall, Pentti
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Blood plasma coagulation studied by surface plasmon resonance1999In: BIOMEDICAL SENSORS, FIBERS, AND OPTICAL DELIVERY SYSTEMS, PROCEEDINGS, SPIE - International Society for Optical Engineering, 1999, Vol. 76, no 1, p. 107-114Conference paper (Refereed)
    Abstract [en]

    A surface plasmon resonance (SPR) apparatus was used to investigate blood plasma coagulation in real-time as a function of thromboplastin and heparin concentrations. The physical reason for the SPR signal observed is discussed and 3 different models are proposed. The response curves were analyzed by multivariable curve fitting followed by feature extraction. Interesting parameters of the sigmoid curves were lag time, slope and maximum response. When thromboplastin concentrations were increased, the lag-time decreased and the slope of the curve increased. A prolonged clotting time was mostly followed by increased maximum response, with exception for samples with no or very little thromboplastin added. High heparin concentrations changed the clotting kinetics, as seen from the lag-time vs. slope relation. Atomic force microscopy (AFM) pictures of sensor surfaces dried after completed clotting, revealed differences in fibrin network structures as a function of thromboplastin concentration, and fiber thickness increased with lower thromboplastin concentration. The results correlate well with present common methods.

  • 312.
    Vikinge, Trine P.
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Hansson, Kenny
    Linköping University, Department of Biomedicine and Surgery, Clinical Chemistry. Linköping University, Faculty of Health Sciences.
    Sandström, Pär
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, The Institute of Technology.
    Liedberg, Bo
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Lindahl, Tomas
    Linköping University, Department of Biomedicine and Surgery, Clinical Chemistry. Linköping University, Faculty of Health Sciences.
    Lundström, Ingemar
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Tengvall, Pentti
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Höök, Fredrik
    Department of Applied Physics, Chalmers University of Technology, Göteborg and Department of Cell and Molecular Biology, Lundberg Institute, Göteborg.
    Comparison of surface plasmon resonance and quartz crystal microbalance in the study of whole blood and plasma coagulation2000In: Biosensors & bioelectronics, ISSN 0956-5663, E-ISSN 1873-4235, Vol. 15, no 11-12, p. 605-613Article in journal (Refereed)
    Abstract [en]

    The coagulation of blood plasma and whole blood was studied with a surface plasmon resonance (SPR) based device and a quartz crystal microbalance instrument with energy dissipation detection (QCM-D). The SPR and QCM-D response signals were similar in shape but differing in time scales, reflecting differences in detection mechanisms. The QCM-D response time was longer than SPR, as a physical coupling of the sample to the substrate is required for molecules to be detected by the QCM-method. Change of sample properties within the evanescent field is sufficient for detection with SPR. Both the SPR signals and the QCM-D frequency and dissipation shifts showed dependency on concentrations of coagulation activator and sensitivity to heparin additions. The ratio of dissipation to frequency shifts, commonly considered to reflect viscoelastic properties of the sample, varied with the concentration of activator in blood plasma but not in whole blood. Additions of heparin to the thromboplastin activated whole blood sample, however, made the ratio variation reoccur. Implications of these observations for the understanding of the blood coagulation processes as well as the potential of the two methods in the clinic and in research are discussed.

  • 313.
    Wingbrant, Helena
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics . Linköping University, The Institute of Technology.
    Lundström, Ingemar
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics . Linköping University, The Institute of Technology.
    Lloyd Spetz, Anita
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics . Linköping University, The Institute of Technology.
    The speed of response of MISiCFET devices2003In: Sensors and Actuators B: Chemical, ISSN 0925-4005, Vol. 93, no 1-3, p. 286-294Article in journal (Refereed)
    Abstract [en]

    The metal oxide silicon carbide field effect transistor (MISiCFET) sensor has several possible car engine applications, such as an ammonia sensor in selective catalytic reduction (SCR) systems or as a lambda-sensitive device for enhancing catalytic converter efficiency. Both these applications involve closed loop control of the engine and thereby require fast sensors, that is why it is important to investigate the speed of response of the devices. The sensor consists of a SiC-based MOSFET device with a buried channel design and a catalytic gate metal, which makes it sensitive to a wide range of different gases. The selectivity and sensitivity of the sensor to a specific gas depends mainly on the choice of gate metal, its structure and the operating temperature. In this presentation, the speed of response of MISiCFET devices with many different gate metals at several operating temperatures are compared. The tests have been performed in the laboratory using the moving gas outlet (MGO) equipment. The equipment allows two gas outlets to move back and forth under the sensor, which makes it possible to change the atmosphere surrounding the sensor from synthetic air to the test gas quickly. The method is verified by changing the temperature of the device and frequency of the moving gas outlets. The test gas is either ammonia or hydrogen. The time constant of the sensors is shown to be very small; <100 ms when exposing a 25 nm porous Pt sensor to ammonia at 300 °C and <10 ms for a 10 nm TaSix 100 nm Pt device exposed to hydrogen. The temperature is found to have a large influence on the speed of response. The results show that the speed of response is well beyond the current requirements for use in both SCR and lambda control systems, respectively.

  • 314.
    Wingbrant, Helena
    et al.
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics . Linköping University, The Institute of Technology.
    Svenningstorp, H.
    Salomonsson, P.
    Volvo Technology Corporation (VTEC), Department 06130, Emission Control and Catalysis, Chalmers Science Park, Göteborg, Sweden.
    Tengström, P.
    Volvo Car Corporation, Exhaust Gas Aftertreatment Systems, Department 97621, Göteborg, Sweden.
    Lundström, Ingemar
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics . Linköping University, The Institute of Technology.
    Lloyd Spetz, Anita
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics . Linköping University, The Institute of Technology.
    Using a MISiCFET device as a cold start sensor2003In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 63, no 1-3, p. 295-303Article in journal (Refereed)
    Abstract [en]

    As a consequence of the formation of water droplets in the car engine at cold start, the fragile ZrO2 λ sensor cannot be heated until the engine is sufficiently warm. A possibility to shorten the time before closed loop λ control would decrease the exhaust emission. As a solution to this problem, the metal insulator silicon carbide field effect transistor (MISiCFET) sensor, which presumably is more thermo shock resistant than the ZrO2 sensor, could be used at cold start. The requirements for a cold start sensor are, among others, sensitivity to λ (air to fuel ratio) close to stochiometry, selectivity to λ and high speed of response. In this communication, the possibility of using the MISiCFET sensor at cold start is treated. The sensor consists of a SiC based MOSFET device with a buried channel design and a catalytic gate metal of 10 nm TaSix and 100 nm Pt. The response depends linearly on λ at 500 °C. The sensitivity of the device has been tested both in artificial atmospheres and in an engine. Two-level factorial designed experiments showed a high selectivity to λ compared to other gases such as CO, hydrocarbons, NOx and H2. The response time was found to be <10 ms at 500 °C when changing from an oxidizing to a reducing atmosphere. The MISiCFET sensor response showed interesting differences in λ stairs when the λ-value was varied by changing the oxygen, hydrogen or CO concentration. The results show that the MISiCFET sensor is a promising choice as a future cold start sensor.

  • 315.
    Winquist, Fredrik
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Bjorklund, Robert
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Krantz-Rülcher, Christina
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Lundström, Ingemar
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Ostergren, K
    Skoglund, T
    An electronic tongue in the dairy industry2005In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 111, p. 299-304Article in journal (Refereed)
    Abstract [en]

    The concept of electronic tongues or taste sensors has developed rapidly during recent years due to their large potential. They are based on electrochemical sensors combined with multivariate data analysis. Voltammetric electronic tongues have proven valuable in many applications. Due to their ruggedness and simplicity, they have been found especially suitable for on-line monitoring of industrial processes. A voltammetric electronic tongue, specially designed for use in the dairy industry is described. It consisted of four working electrodes (gold, platinum, rhodium and stainless steel), embedded in PEEK (TM). It was mounted in a housing of stainless steel, which was inserted in the process line for direct on-line measurements. The voltammetric electronic tongue was used to follow different sources of milk coming into the process and to monitor the cleaning process. (c) 2005 Elsevier B.V. All rights reserved.

  • 316.
    Winquist, Fredrik
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Holmin, Susanne
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Krantz-Rülcher, Christina
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Wide, Peter
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Clinical and Experimental Medicine, Pediatrics . Östergötlands Läns Landsting, Centre of Paediatrics and Gynecology and Obstetrics, Department of Paediatrics in Linköping.
    Lundström, Ingemar
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    A hybrid electronic tongue2000In: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 406, no 2, p. 147-157Article in journal (Refereed)
    Abstract [en]

    A hybrid electronic tongue is described based on a combination of potentiometry, voltammetry and conductivity. It was used for classification of six different types of fermented milk. Using ion-selective electrodes, pH, carbon dioxide and chloride ion concentrations were measured. The voltammetric electronic tongue consisted of six working electrodes of different metals (gold, iridium, palladium, platinum, rhenium and rhodium) and an Ag/AgCl reference electrode. The measurement principle is based on pulse voltammetry in which current transients are measured due to the onset of voltage pulses at decreasing potentials. The data obtained from the measurements were treated by multivariate data processing based on principal components analysis and an artificial neural net. The hybrid tongue could separate all six samples. Also, the nature of the micro-organisms in the different fermentations was reflected in the principal component analysis. Copyright (C) 2000 Elsevier Science B.V.

  • 317.
    Winquist, Fredrik
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Krantz-Rülcher, Christina
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Lundström, Ingemar
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    A miniaturized voltammetric electronic tongue2008In: Analytical Letters, ISSN 0003-2719, E-ISSN 1532-236X, Vol. 41, no 5, p. 917-924Article in journal (Refereed)
    Abstract [en]

    A miniaturized electronic tongue based on pulsed voltammetry has been developed. It was made by inserting three types of wires acting as working electrodes (gold, platinum, and rhodium, diameter 0.25 mm) into a platinum tube acting as a counter electrode (diameter 2 mm, length 4 mm). The arrangement was connected to a potentiostat controlled by a computer. Due to the small size of the miniaturized electronic tongue, and since no reference electrode is used, the setup is very simple and convenient. In order to characterize the analytical possibilities of the miniaturized electronic tongue, some initial experiments were performed. These include the determination of trace amounts of cadmium and lead (in the µM range) in 5 µL samples. Furthermore, the setup was placed under the real tongue of a volunteer to follow saliva composition during exercise. Copyright © Taylor & Francis Group, LLC.

  • 318.
    Winquist, Fredrik
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Krantz-Rülcher, Christina
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Lundström, Ingemar
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Electronic tongues2004In: MRS bulletin, ISSN 0883-7694, E-ISSN 1938-1425, Vol. 29, no 10, p. 726-731Article in journal (Refereed)
    Abstract [en]

    The use of multivariate data analysis combined with sensors with partially overlapping selectivities has become a very powerful tool in measurement technology. These systems are often referred to as artificial senses, because they function in a way similar to the human senses. One such system is the electronic nose. This article focuses on similar concepts as the electronic nose, but for use in aqueous solutions. Because these systems are related to the human sense of taste in the same way the electronic nose is related to olfaction, they have been termed taste sensors, or "electronic tongues." Various measurement principles that can be used in electronic tongues are described and discussed in this article, These include electrochemical techniques such as potentiometry, voltammetry, and conductometry. Also, optical techniques based on light absorption at specific wavelengths or the use of surface plasmon resonance are described. Mass-sensitive devices based on piezoelectric crystals have also been used and are described here. A special emphasis is given to the voltammetric electronic tongue.

  • 319.
    Winquist, Fredrik
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Rydberg, Elinor
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology.
    Holmin, Susanne
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Krantz-Rülcher, Christina
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Lundström, Ingemar
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Flow injection analysis applied to a voltammetric electronic tongue2002In: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 471, no 2, p. 159-172Article in journal (Refereed)
    Abstract [en]

    A measurement system, based on flow injection analysis (FIA) technique applied to a voltammetric electronic tongue is described. A reference solution was thus continuously pumped through a cell with a voltammetric electronic tongue, and test samples were injected into the flow stream. Responses were obtained by measuring the resulting pulse height. The FIA technique offered several advantages, since relative measurements are performed, the system is less influenced by sensor baseline drift, calibration samples and/or washing solutions can be injected within a measurement series, and the system is well adapted for automatization. The system was used to analyze standard solutions of H2O2, KCl, CuNO3, K4[Fe(CN)6], K3[Fe(CN)6] and NaCl, and results obtained were treated with multivariate data analysis. Principal component analysis performed showed that electrode drift could be considerably decreased, and the set-up was also used for classification of different apple juices. © 2002 Elsevier Science B.V. All rights reserved.

  • 320.
    Winquist, Fredrik
    et al.
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, The Institute of Technology.
    Spetz, Anita
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Armgarth, M.
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Lundström, Ingemar
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, The Institute of Technology.
    DANIELSSON, B.
    University of Lund, Sweden.
    Biosensors based on ammonia sensitive metal-oxide-semiconductor structures1985In: Sensors and Actuators, ISSN 0250-6874, Vol. 8, no 2, p. 91-100Article in journal (Refereed)
    Abstract [en]

    The physical principles behind the ammonia gas sensitivity of thin catalytic metal-oxide-semiconductor structures are briefly described. in particular, it is shown that room temperature operation is possible with good performance. Biosensors based on the combination of these structures with immobilized enzymes are also described. Several substrates of clinical interest, such as urea, creatinine and amino acids are determined by the combination of the structure and corresponding immobilized enzymes. A flow injection analysis system and a 'bioprobe' are described and discussed.

  • 321.
    Winquist, Fredrik
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Spetz, Anita
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Armgarth, M.
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Nylander, Claes
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Lundström, Ingemar
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Modified palladium metal‐oxide‐semiconductor structures with increased ammonia gas sensitivity1983In: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 43, no 9, p. 839-841Article in journal (Refereed)
    Abstract [en]

    It is known that palladium metal‐oxide‐semiconductor (Pd‐MOS) structures are sensitive detectors for hydrogen gas. We show that the evaporation of a thin film of catalytically active metals on top of the structure can increase the sensitivity towards ammonia considerably. It was found that the thin metal must be in contact with the oxide to cause the increased sensitivity. The largest increase was observed with the transition metals Ir and Pt. The ammonia sensitivity could be enhanced about 60 times compared to that of an unmodified structure

  • 322.
    Winquist, Fredrik
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Spetz, Anita
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Lundström, Ingemar
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Danielsson, B.
    University of Lund, Sweden.
    Determination of ammonia in air and aqueous samples with a gas-sensitive semiconductor capacitor1984In: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 164, p. 127-138Article in journal (Refereed)
    Abstract [en]

    The properties of a new type of ammonia gas-sensitive semiconductor capacitor are described. The sensor is based on a palladium MOS field-effect capacitor with a thin layer (3 nm) of iridium surrounding the palladium gate. The lower limit of detection for ammonia in air is 1 ppm (0.59 mg kg−1). The analytical characteristics and temperature-dependence of the sensor in measurements of ammonia in air are evaluated. Ammonia in aqueous solutions is determined by the use of a continuous flow system utilizing a gaspermeable membrane in combination with the sensor. The calibration plot of the voltage drop of the capacitor vs. ammonia concentration in 150-μl samples is linear in the concentration range 0.2 × 10−6–5 × 10−5 M. Ammonia is determined in rain and river water as well as in whole blood and blood serum; 15 samples per hour can be assayed. Analytical recovery studies and the selectivity properties of the system are described and discussed. Finally, the properties of the flow-through system in continuous monitoring are described.

  • 323.
    Winquist, Fredrik
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Spetz, Anita
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Lundström, Ingemar
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Danielsson, B.
    University of Lund, Sweden.
    Determination of urea with an ammonia gas-sensitive semiconductor device in combination with urease1984In: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 163, p. 143-149Article in journal (Refereed)
    Abstract [en]

    An ammonia gas-sensitive Ir/Pd MOS capacitor is used for urea determinations with the aid of urease in two different systems. One combination utilizes a reaction column with immobilized urease in a flow-injection system. The lower limit of urea detection for 150-μl samples was 0.2 μM. Urea in whole blood and blood serum was determined after a 500-fold dilution, and 15 samples per hour could be assayed. The relative standard deviation was 4.6% (n=10). Recovery tests were satisfactory. Values obtained for urea in serum correlated well with those from a spectrophotometric method. The other combination is based on a small flow cell with free urease enclosed between a dialysis membrane and a gas-permeable membrane. Urea was determined in the concentration range 0.01–50 mM. The enzyme probe could be used for up to four days without changes of behaviour.

  • 324.
    Winquist, Fredrik
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Sundgren, Hans
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Hedborg, Eva
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Spetz, Anita
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Lundström, Ingemar
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Visual images of gas mixtures produced with field-effect structures1992In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 6, no 1-3, p. 157-161Article in journal (Refereed)
    Abstract [en]

    The details of a recently demonstrated possibility of making two-dimensional response maps of a gas mixture are discussed. It is described how maps of work-function changes due to the interaction between molecules like ethanol and ammonia and thin catalytic metal films as gates on field-effect structures can be created with a scanning light-pulse technique. Simple image processing is shown to enhance the differences in the response patterns created by different molecules.

  • 325.
    Winquist, Fredrik
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Wide, P
    Eklov, T
    Linkoping Univ, Dept Phys & Measurement Technol, S-58183 Linkoping, Sweden Wasabrod AB, S-68282 Filipstad, Sweden.
    Hjort, C
    Linkoping Univ, Dept Phys & Measurement Technol, S-58183 Linkoping, Sweden Wasabrod AB, S-68282 Filipstad, Sweden.
    Lundström, Ingemar
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Crispbread quality evaluation based on fusion of information from the sensor analogies to the human olfactory, auditory and tactile senses1999In: Journal of food process engineering, ISSN 0145-8876, E-ISSN 1745-4530, Vol. 22, no 5, p. 337-358Article in journal (Refereed)
    Abstract [en]

    Appreciation of food is based on the perception all five human senses, vision, tactile, auditory, taste and olfaction. Sensory integration of chewing resistance, melting properties, crisp sound etc. will give a further perception of the food, which is called the mouth feel. In this report, a model experiment performed on crispbread is described, which was based on information fusion from human sense analogies of olfaction, auditory and tactile. Five samples of crispbread with various hardness and flour composition were placed in a special "crush chamber". While crushed, information corresponding to three senses could be obtained - auditory by a microphone, tactile by a force sensor and smell by leading gases from the crushed material to a gas sensor array. To evaluate the information obtained, multivariate pattern recognition methods, i.e. principal component analysis and artificial neural nets were used to search for structure and correlation in the data. It was shown that by using only the auditory information, the samples could not be separated. The tactile information alone could separate three samples, and the smell information one sample. By combining all sense analogues, all five samples could be separated.

  • 326.
    Zairov, Rustem
    et al.
    Russian Academic Science, Russia; Kazan Volga Regional Federal University, Russia.
    Mustafina, Asiya
    Russian Academic Science, Russia; Kazan Volga Regional Federal University, Russia.
    Shamsutdinova, Nataliya
    Russian Academic Science, Russia; Kazan Volga Regional Federal University, Russia.
    Nizameev, Irek
    Russian Academic Science, Russia; Kazan National Research Technology University, Russia.
    Moreira, Beatriz
    University of Gothenburg, Sweden.
    Sudakova, Svetlana
    Russian Academic Science, Russia.
    Podyachev, Sergey
    Russian Academic Science, Russia.
    Fattakhova, Alfia
    Kazan Volga Regional Federal University, Russia.
    Safina, Gulnara
    University of Gothenburg, Sweden; Chalmers, Sweden.
    Lundström, Ingemar
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, Faculty of Science & Engineering. Luleå University of Technology, Sweden.
    Gubaidullin, Aidar
    Russian Academic Science, Russia.
    Vomiero, Alberto
    Luleå University of Technology, Sweden.
    High performance magneto-fluorescent nanoparticles assembled from terbium and gadolinium 1,3-diketones2017In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 7, article id 40486Article in journal (Refereed)
    Abstract [en]

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

  • 327.
    Zangooie, S
    et al.
    Linkoping Univ, S SENCE, SE-58183 Linkoping, Sweden Linkoping Univ, Div Appl Phys, SE-58183 Linkoping, Sweden Linkoping Univ, Lab Appl Opt, SE-58183 Linkoping, Sweden.
    Arwin, Hans
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Optics .
    Lundström, Ingemar
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Lloyd-Spets, Anita
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Ozone treatment of SiC for improved performance of gas sensitive Schottky diodes2000In: Materials Science Forum, ISSN 0255-5476, E-ISSN 1662-9752, Vol. 338-3, p. 1085-1088Article in journal (Refereed)
    Abstract [en]

    Schottky diodes with catalytic metal gates fabricated on SiC are suitable for sensing of hydrogen containing gases. The device performance, including reproducibility and long term stability, is improved by including an ozone treatment in the device processing. In this investigation, the properties of the oxide layer formed on 4H SiC by such ozone treatment are studied with spectroscopic ellipsometry. It was found that both the oxide thickness and its properties are different compared to those for a native oxide formed without ozone treatment.

  • 328.
    Zubkans, J.
    et al.
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, The Institute of Technology.
    Lloyd Spetz, Anita
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, The Institute of Technology.
    Sundgren, Hans
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, The Institute of Technology.
    Winquist, Fredrik
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, The Institute of Technology.
    Kleperis, J.
    University of Latvia, Riga, Latvia.
    Lusis, A.
    University of Latvia, Riga, Latvia.
    Lundström, Ingemar
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, The Institute of Technology.
    In-situ modification of the NOx sensitivity of thin discontinuous platinum films as gates of chemical sensors1995In: Thin Solid Films, ISSN 0040-6090, E-ISSN 1879-2731, Vol. 268, no 1-2, p. 140-143Article in journal (Refereed)
    Abstract [en]

    It is shown how chemically sensitive metal-oxide semiconductor field-effect transistors with a thin discontinuous platinum gate can be modified for the detection of NOx. After a pulse of ammonia the sensors show an increased sensitivity to NOx. The threshold voltage shift induced by NOx is opposite to the direction before the ammonia pulse. The threshold voltage now increases due to NOx exposure, while hydrogen, ammonia and hydrocarbons cause a decrease of the threshold voltage. The temperature dependence of the NOx sensitivity suggests that after the ammonia pulse there are two competing polarisation phenomena caused by the interaction between NOx and the sensing surface. The results are of general interest since they indicate how thin sensing layers can be modified after fabrication to promote sensitivity towards specific molecules. Furthermore they shed some new light on the detection mechanisms of thin discontinuous metal gates.

4567 301 - 328 of 328
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • oxford
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf