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  • 101.
    Ibupoto, Zafar Hussain
    et al.
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Jamal, N.
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Khun, Kimleang
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Willander, Magnus
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Development of a disposable potentiometric antibody immobilized ZnO nanotubes based sensor for the detection of C-reactive protein2012In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 166, p. 809-814Article in journal (Refereed)
    Abstract [en]

    In this paper, the fabrication of ZnO nanotubes was carried out through chemical etching of ZnO nanorods on the gold coated glass substrates. The monoclonal anti-C-reactive protein clone CRP-8 (mouse IgG1 isotype) with glutaraldehyde was immobilized on these ZnO nanotubes using simple physical adsorption method. The novelty of the present ZnO nanotubes based research is the generation of electromotive force (EMF) in the environment of rapid formation of complex between immobilized antibodies with CRP on the surface of ZnO nanotubes. The electrochemical response of the proposed C-reactive protein (CRP) of human plasma biosensor was measured using potentiometric technique. The antibody immobilized ZnO nanotubes based sensor electrode detected the concentration range of CRP from 1.0 x 10(-5) mg/L to 1.0 x 100 mg/L with an acceptable sensitivity of 13.17 +/- 0.42 mV/decade. This unusual behavior of the proposed ZnO nanotubes based sensor in no particular electrolytic atmosphere is opening a new way for the detection of proteins at the nanolevel. The response of CRP sensor was highly linear and stable for above detected concentrations. The time response of antibody immobilized ZnO nanotubes based sensor was observed less than 10 s with good selectivity, reproducibility, repeatability and stability. The life time of sensor was not more than three days after use, so it can be used as disposable sensor.

  • 102.
    Ionescu, Radu
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Cindemir, Umut
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Welearegay, Tesfalem Geremariam
    Calavia, Raul
    Haddi, Zouhair
    Topalian, Zareh
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Granqvist, Claes Göran
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Llobet, Eduard
    Fabrication of ultra-pure gold nanoparticles capped with dodecanethiol for Schottky-diode chemical gas sensing devices2017In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 239, p. 455-461Article in journal (Refereed)
    Abstract [en]

    Ultra-pure monolayer-capped gold nanoparticles for chemical gas sensing devices were prepared by a novel two-step process: a physical vapour deposition technique was first employed to make dispersed ultra-pure size-controlled gold nanoparticles, and this step was followed by a coating process for functionalization of the gold nanoparticles with an organic ligand, specifically dodecanethiol. X-ray photoelectron spectroscopy proved that the nano-assemblies had high purity. Chemical sensing devices based on these nano-assemblies showed Schottky-diode behaviour. We believe this is the first observation of Schottky-diodes fabricated from nanomaterials based on metallic nanoparticles. Gas sensing experiments demonstrated that these devices were suitable for detecting volatile organic compounds.

  • 103.
    Iqbal, Zafar
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Chemical and Optical Sensor Systems. Linköping University, Faculty of Science & Engineering.
    Eriksson, Mats
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Classification and quantitative optical analysis of liquid and solid samples using a mobile phone as illumination source and detector2013In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 185, p. 354-362Article in journal (Refereed)
    Abstract [en]

    A mobile phone has been used both as illumination source and image detector for quantitative optical analysis of colored liquid samples (4 different colorants) and solid samples (printed color patterns, plastic beads and colored sand grains). Even though the measurement conditions were far from ideal, because the light source was strongly polychromatic and the illumination was not a collimated light beam with homogeneous light intensity, a logarithmic concentration dependence, in accordance with the Beer-Lambert law, described the data of the colored liquids quite well. By utilizing blue-blue (420-510 nm), green-green (480-590 nm) and red-red (575-695 nm) illumination/detection combinations, each sample could be assigned a unique color signature for classification that agreed with reference absorbance spectra measured with a spectrometer. Quantification of validation samples within a few percent of the actual values was achieved. Also the long-term repeatability of the measurements was investigated and was surprisingly good for such a simple system. Analysis of the colored solid samples was more complex with results being dependent on the morphology and colorimetric properties of the samples.

  • 104. Islam, M. S.
    et al.
    Hussain, Tanveer
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Applied Material Physics. Uppsala University, Sweden, Univ Queensland, Australia.
    Rao, G. S.
    Panigrahi, P.
    Ahuja, Rajeev
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Augmenting the sensing aptitude of hydrogenated graphene by crafting with defects and dopants2016In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 228, p. 317-321Article in journal (Refereed)
    Abstract [en]

    Density functional theory (DFT) level calculations were performed to study the interaction of hydrogenated graphene (CH) monolayer towards methane (CH4) gas molecules. The structural, electronic and gas sensing properties of pure, defected and light metal-doped CH monolayer were investigated. For the pristine CH, the estimated binding energy of CH4 fell short of the desired physisorption range and limit its gas sensing application at ambient conditions. However, upon crafting defects on pure CH layer by introducing hydrogen vacancies, a sharp increase in adsorption energies were observed when the CH4 molecules approached the defected sites of CH. Further, the effect of metal doping was studied by uniformly distributing light metal adatoms on CH monolayer which significantly enhanced the CH4 adsorption. To have better accuracy in calculating adsorption energies, we have incorporated van der Waals type corrections to our calculations for these weakly interacting systems.

  • 105.
    Islam, Muhammed Shafiqul
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory.
    Hussain, Tanveer
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory. Royal Inst Technol KTH, Dept Mat & Engn, Appl Mat Phys, S-10044 Stockholm, Sweden.;Univ Queensland, Australian Inst Bioengn & Nanotechnol, Ctr Theoret & Computat Mol Sci, Brisbane, Qld 4072, Australia..
    Rao, G. S.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory.
    Panigrahi, P.
    Hindustan Univ, Clean Energy & Nano Convergence Ctr, Madras, Tamil Nadu, India..
    Ahuja, Rajeev
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory. Royal Inst Technol KTH, Dept Mat & Engn, Appl Mat Phys, S-10044 Stockholm, Sweden..
    Augmenting the sensing aptitude of hydrogenated graphene by crafting with defects and dopants2016In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 228, p. 317-321Article in journal (Refereed)
    Abstract [en]

    Density functional theory (DFT) level calculations were performed to study the interaction of hydrogenated graphene (CH) monolayer towards methane (CH4) gas molecules. The structural, electronic and gas sensing properties of pure, defected and light metal-doped CH monolayer were investigated. For the pristine CH, the estimated binding energy of CH4 fell short of the desired physisorption range and limit its gas sensing application at ambient conditions. However, upon crafting defects on pure CH layer by introducing hydrogen vacancies, a sharp increase in adsorption energies were observed when the CH4 molecules approached the defected sites of CH. Further, the effect of metal doping was studied by uniformly distributing light metal adatoms on CH monolayer which significantly enhanced the CH4 adsorption. To have better accuracy in calculating adsorption energies, we have incorporated van der Waals type corrections to our calculations for these weakly interacting systems.

  • 106.
    Ivarsson, Patrik
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, Faculty of Science & Engineering. Asko Cylinder AB.
    Johansson, Madeleine
    Asko Cylinda AB.
    Höjer, Nils-Erik
    Asko Cylinda AB.
    Krantz-Rülcher, Christina
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics.
    Winquist, Fredrik
    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.
    Supervision of rinses in a washing machine by a voltammetric electronic tongue2005In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 108, no 01-Feb, p. 851-857Article in journal (Refereed)
    Abstract [en]

    A study that investigates if it is possible to discriminate between the different rinses in a household washing machine with a voltammetric electronic tongue is concluded. The voltammetric electronic tongue applies a potential pulse train over two electrodes and measures the produced current. Multivariate data analysis is used to treat the data. In this paper, a simplified electronic tongue, with only 5% of the original current responses, is used. The rinses from 20 machine wash runs with four different prerequisites are investigated. Principal component analysis (PCA) and Soft-independent modelling of class analogy (SIMCA) are used in order to classify the rinses. In PCA, only one of the rinses is classified erroneous, and in SIMCA none of the rinses are classified only to the wrong class, although 38% of the rinses are classitied to more than one class. (c) 2005 Elsevier B.V. All rights reserved.

  • 107.
    Jager, Edwin
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, The Institute of Technology.
    Masurkar, Nirul
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, The Institute of Technology.
    Felix Nworah, Nnamdi
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, The Institute of Technology.
    Gaihre, Babita
    University of Wollongong, Australia .
    Alici, Gursel
    University of Wollongong, Australia University of Wollongong, Australia .
    Spinks, Geoffrey M.
    University of Wollongong, Australia University of Wollongong, Australia .
    Patterning and electrical interfacing of individually controllable conducting polymer microactuators2013In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 183, p. 283-289Article in journal (Refereed)
    Abstract [en]

    Conducting polymer actuators such as polypyrrole (PPy) microactuators are interesting candidates to drive autonomous microrobotic devices that require low weight and low power. Simple PPy tri-layer bending type microactuators that operate in air have been demonstrated previously but they lack individual control and had problems with short circuiting due to electrical connections. The lack of micropatterning methods and proper interfacing are currently major obstacles in the development of PPy tri-layer microactuators. Here, we report for the first time methods for successfully patterning and interfacing of such tri-layer PPy microactuators. The PPy tri-layer actuators were patterned using adapted microfabrication technology including photolithography. The interface was based on a flexible printed circuit board comprising the electronic circuit into which the actuator unit was embedded. It showed that the microfabricated tri-layer actuators functioned as good as the normally fabricated actuators. The new interface seemed to actually improve the actuator performance. This interfacing method could also be applied to other electroactive polymer devices, such as ion polymer metal composites (IPMC) and dielectric elastomers (DE).

  • 108.
    Jager, Edwin
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics . Linköping University, The Institute of Technology.
    Smela, Elisabeth
    Risø National Lab, Roskilde.
    Inganäs, Olle
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics . Linköping University, The Institute of Technology.
    On-chip microelectrodes for electrochemistry with moveable PPy bilayer actuators as working electrodes1999In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 56, no 1-2, p. 73-78Article in journal (Refereed)
    Abstract [en]

    We present electrochemical microactuators which have all the electrodes necessary for the actuation—the working, counter, and reference electrodes—on-chip. This is a first step towards an all-polymer system, i.e., a system that does not require a liquid electrolyte. The microactuators' performance was as good as when standard, off-chip counter and reference electrodes were used. Specifically, the speed of actuation was the same. In addition, we obtained a good cyclic voltammogram, although the oxidation and reduction peaks were shifted and some noise was present. Apart from application in an all-polymer system, we will also use these microactuators for studies on the effect of mechanical stimulation of living cells.

  • 109. Jeanneret, Stephane
    et al.
    Crespo, Gaston A.
    Afshar, Majid Ghahraman
    Bakker, Eric
    GalvaPot, a custom-made combination galvanostat/potentiostat and high impedance potentiometer for decentralized measurements of ionophore-based electrodes2015In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 207, p. 631-639Article in journal (Refereed)
    Abstract [en]

    We report here on a portable, custom-made instrument for decentralized measurements with ionophore based electrodes. It allows one to perform most common electrochemical protocols based on applied current or potential as well as zero current potentiometry measurements. Each protocol is customizable via a programmable interface by use of either an external PC or a touch screen panel on the device. The programmable interface provides flexibility to trigger peripheral devices for the additional implementation of actuators, pumps and other external devices in the electrochemical routines.

    To characterize the electronic performance of the instrument, three different electrochemical protocols were used with ionophore based electrodes and compared with a commercial work station: (1) open circuit potentiometric measurements with calcium ion-selective membranes; (2) chronoamperometry based on three successive pulses with simultaneous control of fluidic delivery by a peristaltic pump and switching valve, followed by on board current integration to obtain a coulometric readout; (3) a chronopotentiometric protocol using protamine selective membranes with current pulses of 5-s duration, including an automatic computation of the time-derivative to find the transition time as the analytical signal. At 500 g, the instrument is portable yet sufficiently versatile for performing and analyzing most electrochemical measurements without the need for an external computer. It may become an attractive tool for applications in environmental and clinical analysis where field portability, flexibility and integration are desired.

  • 110. Johanson, Urmas
    et al.
    Mäeorg, Uno
    Sammelselg, Väino
    Brandell, Daniel
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Materials Chemistry, Structural Chemistry.
    Punning, Andres
    Kruusmaa, Marja
    Aabloo, Alvo
    Electrode reactions in Cu-Pt coated Nafion® actuators2008In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 131, p. 340-346Article in journal (Refereed)
  • 111.
    Jönsson, Mats
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Anderson, Henrik
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Lindberg, Ulf
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Aastrup, Teodor
    Quartz crystal microbalance biosensor design: II. Simulation of sample transport2007In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 123, no 1, p. 21-26Article in journal (Refereed)
    Abstract [en]

    The influence of flow cell geometry on sample dispersion in a quartz crystal microbalance (QCM) biosensor system was investigated. A circular and a rectangular flow cell and corresponding sensor electrodes were studied experimentally and modelled using a coupled Navier-Stokes and convection-diffusion model. Finite element simulations showed that dispersion phenomena in a flow cell can be significantly reduced with the rectangular flow cell compared to a circular system. Experimental results from measurement of the time-dependent viscosity change of a model sample indicate that the sample delivery system has a predominant effect on the dispersion of the whole sensor system. Consequently, improvement of the sensor flow cell should be accompanied with improvement of the sample delivery system. With reference to kinetic studies of biological interactions, the current dispersion should have little effect on the results for studies of interaction pairs with relatively slow to normal binding rates such as antibody-antigen interactions. Incentive for further development of the flow cell and sample delivery system exists primarily for applications with high reaction rates such as for certain receptor ligand interactions.

     

  • 112.
    Kanungo, Jayita
    et al.
    IC Design & Fabrication Centre, Dept. of Electronics & Telecommunications Engineering, Jadavpur University, Kolkata, India.
    Andersson, Mike
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Darmastuti, Zhafira
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Basu, Sukumar
    IC Design & Fabrication Centre, Dept. of Electronics & Telecommunications Engineering, Jadavpur University, Kolkata, India.
    Käll, Per-Olov
    Linköping University, Department of Physics, Chemistry and Biology, Physical Chemistry. Linköping University, The Institute of Technology.
    Ojamäe, Lars
    Linköping University, Department of Physics, Chemistry and Biology, Physical Chemistry. 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.
    Development of SiC-FET methanol sensor2011In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 160, no 1, p. 72-78Article in journal (Refereed)
    Abstract [en]

    A silicon carbide based field effect transistor (SiC-FET) structure was used for methanol sensing. Due to the chemical stability and wide band gap of SiC, these sensors are suitable for applications over a wide temperature range. Two different catalytic metals, Pt and Ir, were tested as gate contacts for detection of methanol. The sensing properties of both Ir gate and Pt gate SiC-FET sensors were investigated in the concentration range 0.3–5% of methanol in air and in the temperature range 150–350 °C. It was observed that compared to the Ir gate sensor, the Pt gate sensor showed higher sensitivity, faster response and recovery to methanol vapour at comparatively lower temperature, with an optimum around 200 °C. Quantum-chemical calculations were used to investigate the MeOH adsorption and to rationalize the observed non-Langmuir behavior of the response functions. The methanol sensing mechanism of the SiC-FET is discussed.

  • 113.
    Khaldi, Alexandre
    et al.
    Linköping University, Faculty of Science & Engineering. Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics.
    Maziz, Ali
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, Faculty of Science & Engineering.
    Alici, Gursel
    University of Wollongong, Australia.
    Spinks, Geoffrey M.
    University of Wollongong, Australia.
    Jager, Edwin
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, Faculty of Science & Engineering. University of Wollongong, Australia.
    Bottom-up microfabrication process for individually controlled conjugated polymer actuators2016In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 230, p. 818-824Article in journal (Refereed)
    Abstract [en]

    Handling of soft and fragile sub-millimeter sized samples such as cells and tissues requires new tools that allow delicate manipulation. Conducting polymer actuators show unique characteristics suitable to driving such manipulators, however despite their potential, the current fabrication method of the trilayer structures does not allow constructing advanced micromanipulators operating in air using this technology. Here we show a novel bottom-up microfabrication process for conjugated polymer trilayer actuators using various solid polymer electrolytes. In addition, the process design integrates contact pads, which has been an issue for small scale conducting polymer actuators. The microfabrication process starts with a patterned layer of conjugated polymer, followed by depositing a polymer electrolyte and a second patterning of the second conjugated polymer layer. The process resulted in successful fabrication of individually controllable conducting polymer trilayer actuators comprising polyvinylidenefluoride and poly( vinylidenefluoride-co-hexafluoropropylene) membranes and showed good interfacial adhesion between the different layers in the final device. The polyvinylidenefluoride trilayer actuator showed good actuation capability. The developed bottom-up microfabrication method paves the way for the development of novel micromanipulation tools. (C) 2016 Elsevier B.V. All rights reserved.

  • 114.
    Khun, Kimleang
    et al.
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Ibupoto, Zafar Hussain
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Lu, Jun
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, The Institute of Technology.
    AlSalhi, M. S.
    King Saud University, Saudi Arabia King Saud University, Saudi Arabia .
    Atif, M.
    King Saud University, Saudi Arabia .
    Ansari, Anees A.
    King Saud University, Saudi Arabia .
    Willander, Magnus
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Potentiometric glucose sensor based on the glucose oxidase immobilized iron ferrite magnetic particle/chitosan composite modified gold coated glass electrode2012In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 173, p. 698-703Article in journal (Refereed)
    Abstract [en]

    A potentiometric glucose sensor based on the glucose oxidase immobilized on iron ferrite (Fe3O4) nanoparticles/chitosan composite modified gold coated glass substrate was fabricated. The electrode has advantages of both the inorganic Fe3O4 magnetic nanoparticles and the organic substance chitosan. The freshly prepared iron ferrite magnetic nanoparticles were characterized by X-ray diffraction (xRD) and transmission electron microscopy (TEM) technique was used for the analysis of dispersed iron ferrite magnetic nanoparticles in the mixture of glucose oxidase and chitosan. The electrostatic interaction of Fe3O4 nanoparticles with chitosan and the glucose oxidase molecules was investigated by the infra-red reflection absorption spectroscopy (IRAS) study. The glucose oxidase enzyme was immobilized on the surface of iron ferrite/chitosan composite without the use of Nafion or cross linker molecules. The fabricated glucose sensor has shown acceptable potentiometric response for the wide range of glucose concentrations from 1.0 x 10(-6) to 3.0 x 10(-2) M. The sensor electrode showed a sensitivity of 27.3 +/- 0.8 mV/decade and also fast response time of 7.0s. Moreover, the present glucose sensor has demonstrated good reproducibility, repeatability, selectivity and the storage stability. All the obtained results indicated that the glucose sensor based on the glucose oxidase immobilized iron ferrite/chitosan composite modified gold coated glass electrode can be used for the monitoring of glucose concentrations in human serum, drugs and may be applicable to detect glucose in the presence of other analytes.

  • 115.
    Kiefer, Rudolf
    et al.
    University of Tartu, Estonia .
    Aydemir, Nihan
    University of Auckland, New Zealand .
    Torop, Janno
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, The Institute of Technology. University of Tartu, Estonia .
    Tamm, Tarmo
    University of Tartu, Estonia .
    Temmer, Rauno
    University of Tartu, Estonia .
    Travas-Sejdic, Jadranka
    University of Auckland, New Zealand .
    Must, Indrek
    University of Tartu, Estonia .
    Kaasik, Friedrich
    University of Tartu, Estonia .
    Aabloo, Alvo
    University of Tartu, Estonia .
    Carbide-derived carbon as active interlayer of polypyrrole tri-layer linear actuator2014In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 201, p. 100-106Article in journal (Refereed)
    Abstract [en]

    Electro-chemo-mechanical deformations (ECMD) of electrochemically prepared tri-layer polypyrrole (PPy) linear actuators with active nanoporous carbide-derived carbon (CDC) based actuating interlayers were studied under isotonic (constant length) and isometric (constant force) conditions and compared with those of single-layer CDC and PPy linear actuators. The goal of this study was to combine two active materials with different electroactive and mechanical properties for obtaining improved tri-layer PPy linear actuators. CDC linear actuators were used as electrode materials for the electrochemical deposition of PPy. SEM images showed the PPy and polymeric CDC layers could be clearly distinguished. The CDC, CDC-PPy and PPy linear actuators were cycled in aqueous electrolyte in the voltage range of +/- 0.8 V. The CDC-PPy actuators had improved mechanical and electro-chemo-mechanical properties, compared to the free-standing CDC and PPy linear actuators. The Raman spectra did not show any signs of degradation of either CDC or PPy layers during actuation.

  • 116.
    Kindlundh, M
    et al.
    RISE, Swedish ICT, Acreo.
    Norlin, P
    RISE, Swedish ICT, Acreo.
    Hofmann, U G
    A neural probe process enabling variable electrode configurations2004In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 102, p. 51-58Article in journal (Refereed)
  • 117.
    Klingvall, Roger
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Lundström, Ingemar
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, The Institute of Technology.
    Eriksson, Mats
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Robust gas detection at sub ppm concentrations2011In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 160, no 1, p. 571-579Article in journal (Refereed)
    Abstract [en]

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

  • 118. Kukkola, Jarmo
    et al.
    Mohl, Melinda
    Leino, Anne-Riikka
    Maklin, Jani
    Halonen, Niina
    Shchukarev, Andrey
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Konya, Zoltan
    Jantunen, Heli
    Kordas, Krisztian
    Room temperature hydrogen sensors based on metal decorated WO3 nanowires2013In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 186, p. 90-95Article in journal (Refereed)
    Abstract [en]

    The emerging hydrogen economy has created a demand for the development of improved hydrogen sensors operating at room temperature. In this work, we present hydrogen detectors based on metal decorated WO3 nanowires that were able to detect 1000 ppm of H-2, even at room temperature (30 degrees C), with relatively short recovery time and high sensitivity. The nanowires were synthesized by a hydrothermal process and decorated with PdO and PtOx nanoparticles by decomposition of Pd(acac)(2) and Pt(acac)(2) precursors. The gas responses were tested for H-2, NO, H2S and CO analyte gases in an air buffer at 150,200 and 250 degrees C (H-2 also at 30,70 and 130 degrees C).

  • 119. Kukkola, Jarmo
    et al.
    Mäklin, Jani
    Halonen, Niina
    Kyllönen, Teemu
    Tóth, Géza
    Szabó, Maria
    Shchukarev, Andrey
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Mikkola, Jyri-Pekka
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Jantunen, Heli
    Kordás, Krisztián
    Gas sensors based on anodic tungsten oxide2011In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 153, no 2, p. 293-300Article in journal (Refereed)
    Abstract [en]

    Nanostructured porous tungsten oxide materials were synthesized by the means of electrochemical etching (anodization) of tungsten foils in aqueous NaF electrolyte. Formation of the sub-micrometer size mesoporous particles has been achieved by infiltrating the pores with water. The obtained colloidal anodic tungsten oxide dispersions have been used to fabricate resistive WO3 gas sensors by drop casting the sub-micrometer size mesoporous particles between Pt electrodes on Si/SiO2 substrate followed by calcination at 400 °C in air for 2 h. The synthesized WO3 films show slightly nonlinear current–voltage characteristics with strong thermally activated carrier transport behavior measured at temperatures between −20 °C and 280 °C. Gas response measurements carried out in CO, H2, NO and O2 analytes (concentration from 1 to 640 ppm) in air as well as in Ar buffers (O2 only in Ar) exhibited a rapid change of sensor conductance for each gas and showed pronounced response towards H2 and NO in Ar and air, respectively. The response of the sensors was dependent on temperature and yielded highest values between 170 °C and 220 °C.

  • 120.
    Larsson, Oscar
    et al.
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Wang, Xiaodong
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology. null.
    Berggren, Magnus
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology. null.
    Crispin, Xavier
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology. null.
    Proton motion in a polyelectrolyte: A probe for wireless humidity sensors2010In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 143, no 2, p. 482-486Article in journal (Refereed)
    Abstract [en]

    Low-cost passive wireless electronic sensor labels glued onto packages are highly desirable since they enable monitoring of the status of the packages for instance along the logistic chain or while stored at a shelf. Such additional sensing feature would be of great value for many producers and vendors, active in e.g. the food or construction industries. Here, we explore a novel concept for wireless sensing and readout, in which the humidity sensitive ionic motion in a polyelectrolyte membrane is directly translated into a shift of the resonance frequency of a resonance circuit. Thanks to its simplicity, the wireless sensor device itself can be manufactured entirely using common printing techniques and can be integrated into a low-cost passive electronic sensor label.

  • 121.
    Lloyd Spetz, Anita
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Applied Sensor Science. Linköping University, The Institute of Technology.
    Huotari, Joni
    University of Oulu, Finland.
    Bur, Christian
    Saarland University, Saarbrücken, Germany.
    Bjorklund, Robert
    Linköping University, Department of Physics, Chemistry and Biology, Applied Sensor Science. Linköping University, The Institute of Technology.
    Lappalainen, Jyrki
    University of Oulu, Finland.
    Jantunen, Heli
    University of Oulu, Finland.
    Schütze, Andreas
    Saarland University, Saarbrücken, Germany.
    Andersson, Mike
    Linköping University, Department of Physics, Chemistry and Biology, Applied Sensor Science. Linköping University, The Institute of Technology.
    Chemical sensor systems for emission control from combustions2013In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 187, no SI, p. 184-190Article in journal (Refereed)
    Abstract [en]

    Environmental and health concern has increased the importance to monitor and control emissions like toxic gases and particulate matter from combustion processes. The silicon carbide-field effect transistor (SiC-FET) technology offers versatile and powerful sensors for gas detection also in combination with combustion of particles. Emission control has been demonstrated e. g. for small and medium sized power plants and diesel exhausts. The potential danger of nanoparticles makes such detectors interesting not only for detection of concentration and size of particles but also detection of the content of particles. Due to the possibility of operating the sensor devices in different independent modes (e. g. temperature- and bias-modulated) the SiC-FET technology also lends itself for the future development of sensor adaptation, self-diagnosis and auto calibration, which is expected to improve the performance of such a combined gas/particle sensor system. Here we report progress on the sensor technology itself, the application of a sensor system as an alarm for ammonia emission and preliminary results of particle detection in diesel exhausts and particles from a power plant and a steel plant.

  • 122.
    Lloyd-Spets, Anita
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Tobias, P.
    Unéus, Lars
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Svenningstorp, H.
    Ekedahl, Lars-Gunnar
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology.
    Lundström, Ingemar
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    High temperature catalytic metal field effect transistor for industrial applications2000In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 70, no 1-3, p. 67-76Article in journal (Refereed)
    Abstract [en]

    Field effect chemical sensors, utilising silicon carbide as semiconductor, can be operated at high temperature and in rough environments. Gas sensitive field effect transistors, MISiCFET, are now developed (ACREO, Kista in Sweden). This will increase the number of possible applications for field effect gas sensors. The first batch of MISiCFET devices is possible to operate in intermittent pulses of hydrogen/oxygen up to 775°C. At temperature above 600°C, the gas response of the MISiC devices has very short time constants for a change between oxidising and reducing atmosphere and cylinder specific monitoring of a combustion engine has been demonstrated. Other industrial applications, like exhaust diagnosis and flue gas monitoring, have been demonstrated by the use of MISiC Schottky diodes at lower temperatures, 200°C-500°C.

  • 123.
    Lundström, Ingemar
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Ederth, Thomas
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Kariis, Hans
    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.
    Spetz, Anita.
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Winquist, Fredrik
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Recent developments in field-effect gas sensors1995In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 23, no 2-3, p. 127-133Article in journal (Refereed)
    Abstract [en]

    Some of the ongoing studies at our laboratory of gas-sensitive field-effect devices with catalytic metal gates are reviewed. More particularly, we discuss the use of such devices in so-called electronic noses due to the possibility of changing the selectivity patterns of the devices by the choice of catalytic metal and operation temperature. Several examples of the application of electronic noses consisting of field-effect devices in combination with metal oxide-based sensors are given. Finally, a summary is given of some remaining scientific problems and studies related to the understanding and development of gas-sensitive field-effect devices.

  • 124.
    Lundström, Ingemar
    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.
    Winquist, Fredrik
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Ackelid, U.
    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.
    Catalytic metals and field-effect devices—a useful combination1990In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 1, no 1-6, p. 15-20Article in journal (Refereed)
    Abstract [en]

    The properties of gas-sensitive field-effect devices with catalytic metal gates are described. We demonstrate especially how the selectivity of these sensors depends on parameters such as the choice of catalytic metal, the structure of the catalytic metal film and the operation temperature of the device. The sensitivity towards molecules like hydrogen, ammonia, ethanol and ethylene is demonstrated. The selectivity pattern of devices with catalytic metal gates is discussed in relation to the fabrication of multisensor arrays and the development of 'artificial olfactory senses'.

  • 125.
    Lundström, Ingemar
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Sundgren, Hans
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Winquist, Fredrik
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Eriksson, Mats
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Krantz-Rülcker, Tina
    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 .
    Twenty-five years of field effect gas sensor research in Linköping2007In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 121, no 1, p. 247-262Article in journal (Refereed)
    Abstract [en]

    The present contribution contains an overview of the development of gas sensitive field-effect devices in Linköping during the last 25 years. It is completely centred to the work at the Laboratory of Applied Physics at Linköping University, and is therefore not a proper review of a research field where many important contributions have been made by several other research groups. © 2006 Elsevier B.V. All rights reserved.

  • 126.
    Lundström, Ingemar
    et al.
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, The Institute of Technology.
    Svensson, Christer
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    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.
    From hydrogen sensors to olfactory images — twenty years with catalytic field-effect devices1993In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 13, no 1-3, p. 16-23Article in journal (Refereed)
    Abstract [en]

    A personal description of the history of gas-sensitive field-effect devices is given. It is shown how the originally described palladium-gate metal-oxide-semiconductor field-effect transistor has developed into sensing surfaces enabling the production of response images to odours. Images obtained for the odour from different cheeses are presented as examples of such artificial olfactory images.

  • 127.
    Luyo, C
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Ionescu, R
    Reyes, L. F.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Topalian, Zareh
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Estrada, W
    Llobet, E
    Granqvist, Claes-Göran
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Heszler, Peter
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Gas Sensing Response of NiO Nanoparticle Films Made by Reactive Gas Deposition2009In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 138, no 1, p. 14-20Article in journal (Refereed)
    Abstract [en]

    Nanocrystalline films comprised of NiO particles were prepared by advanced reactive gas evaporation and were investigated for gas sensing applications, specifically for detecting reducing (H2S) and oxidizing (NO2) species. The films were studied in as-deposited state and after annealing at temperatures up to 400,C, and the sensors were operated   from room temperature to 325 degrees C. The optimal operating temperature was in the 150-162 degrees C range for H2S and in the 100-125 degrees C range for NO2. We believe that this is the first report of high-sensitivity detection of H2S with NiO-based sensors, as well as the first proof that such sensors can work at room temperature.

  • 128.
    Lvova, Larisa
    et al.
    University of Roma Tor Vergata, Italy; St Petersburg State University, Russia.
    Pudi, Rajesh
    University of Roma Tor Vergata, Italy.
    Galloni, Pierluca
    University of Roma Tor Vergata, Italy.
    Lippolis, Vito
    University of Cagliari, CA USA.
    Di Natale, Corrado
    University of Roma Tor Vergata, Italy.
    Lundström, Ingemar
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, The Institute of Technology.
    Paolesse, Roberto
    University of Roma Tor Vergata, Italy.
    Multi-transduction sensing films for Electronic Tongue applications2015In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 207, p. 1076-1086Article in journal (Refereed)
    Abstract [en]

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

  • 129.
    Löfdahl, Mikael
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology.
    Eriksson, Mats
    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 .
    Chemical images2000In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 70, no 1-3, p. 77-82Article in journal (Refereed)
    Abstract [en]

    Chemical sensors can be used to generate a vast amount of information about the emissions from bio- and chemical processes, from food and bacteria and from a number of products. These emissions are either wanted or should be avoided. Wolfgang Gopel was one of those who recognized early the large potential of chemical sensor arrays and different modes of operation of a given sensor. We describe how large area field effect devices, with catalytic metal gates, can be used for the construction of a response image of a gaseous emission. More specifically, we discuss the new possibilities obtained through the use of catalytic metals with a gradient in thickness. Some basic features of such sensing surfaces are demonstrated and, finally, time-dependent response images from aging meat are used to demonstrate the potential of the method used. It is based on a scanning light pulse technique (SLPT) which measures local polarization or work function changes in two dimensions and, e.g. a sensing surface consisting of bands of different catalytic metals with a gradient in thickness.

  • 130.
    Löfdahl, Mikael
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology.
    Utaiwasin, C.
    Carlsson, Andreas
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology.
    Lundström, Ingemar
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Eriksson, Mats
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Gas response dependence on gate metal morphology of field-effect devices2001In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 80, no 3, p. 183-192Article in journal (Refereed)
    Abstract [en]

    The dependence of the gas response on the gate metal morphology of field-effect gas sensors has been investigated in a new systematic way by using a scanning light pulse technique (SLPT) together with fabrication of metal gates where the metal morphology is continuously varied over the gate area. With the SLPT the local gas response at different points of the gate area can be measured. Furthermore, a mass spectrometric local gas sampling technique has been applied in combination with the local gas response measurements, which gives complementary information about the surface chemistry and how it changes with the morphology of the metal gate. Three different gate metals, Pd, Pt and Ir, have been studied by analysing the morphology and the gas response to five different gases, H2, NH3, C2H5OH, C2H4 and CH3CHO. Morphological aspects such as crack coverage, concentration of cracks and the length of the crack boundary, have been calculated from acquired scanning electron microscopy (SEM) images. Different possible response mechanisms are discussed in order to explain the observed responses and to understand the role of the morphology and the choice of the catalytic metal. Only in the case of ammonia a direct correlation between the morphological aspects, e.g. crack coverage, and the response was found. For Pd large changes in the local water pressure close to the metal gate surface have been measured at different parts of the metal gate by using the local gas sampling technique and a correlation is observed with the simultaneously measured gas response. Of the response mechanisms discussed in this contribution only a dissociative mechanism, where hydrogen atoms trapped at the interface between the metal gate and the insulator gives the response of the device, is consistent with all obtained results. © 2001 Elsevier Science B.V. All rights reserved.

  • 131. Manzano, J.
    et al.
    Filippini, Daniel
    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 .
    Computer screen illumination for the characterization of colorimetric assays2003In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 96, no 1-2, p. 173-179Article in journal (Refereed)
    Abstract [en]

    Colorimetric evaluation of samples sorted in a two-dimensional (2D) array is performed with a computer screen used as a controlled light source and a web camera as detector. The transmittance profiles are predicted with a 12 parameters model within errors of 5 or 10% for qualitative or semi-quantitative purposes, respectively. The use of random colour illumination additionally enables robust acquisition with only 50 snap-shots (in less than 1min) that contains the information of the whole array, independently of the number of samples. © 2003 Published by Elsevier B.V.

  • 132.
    Masunaga, Kumi
    et al.
    Kyushu University Graduate School of Systems Life Sciences.
    Michiwaki, Shintaro
    Kyushu University Graduate School of Information Science and Electrial Engineering.
    Izumi, Ryosuke
    Kyushu University Graduate School of Information Science and Electrial Engineering.
    Ivarsson, Patrik
    Asko Cylinda AB .
    Björefors, Fredrik
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Sensor Science and Molecular Physics.
    Lundström, Ingemar
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics.
    Hayashi, Kenshi
    Kyushu University Graduate School of Information Science and Electrial Engineering.
    Toko, Kiyoshi
    Kyushu University Graduate School of Information Science and Electrial Engineering.
    Development of sensor surface with recognition of molecular substructure2008In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 130, no 1, p. 330-337Article in journal (Refereed)
    Abstract [en]

    A biological olfaction system is one of the highest performance chemical sensing systems for low-molecular-weight compounds. An ability of recognizing a various molecular properties based on their structures is essential for a biological odor recognition process. For the development of a sensor mimicking the olfactory system, we have formed benzene-patterned self-assembled monolayer (SAM) on the sensor surface using SAMs with nanostructure that serves as adsorption sites for benzene ring, which is representative substructure of aromatics. The structure of the benzene-patterned SAM surface was analyzed by contact-angle measurement, ellipsometry, cyclic voltammetry (CV) and atomic force microscopy (AFM). Moreover, the electrodes evaluated as sensor surfaces with cyclic surface-polarization impedance (cSPI) sensor that measures changes in impedance of the electrode surface by adsorption of substances. The results of cSPI indicated the benzene-patterned SAM surface could distinguish benzene by recognizing of the hydrophobicity and the molecular size. © 2007 Elsevier B.V. All rights reserved.

  • 133.
    Melin, Jessica
    et al.
    KTH, Superseded Departments, Signals, Sensors and Systems.
    Roxhed, Niclas
    KTH, Superseded Departments, Signals, Sensors and Systems.
    Gimenez, Guillem
    KTH, Superseded Departments, Signals, Sensors and Systems.
    Griss, Patrick
    KTH, Superseded Departments, Signals, Sensors and Systems.
    van der Wijngaart, Wouter
    KTH, Superseded Departments, Signals, Sensors and Systems.
    Stemme, Göran
    KTH, Superseded Departments, Signals, Sensors and Systems.
    A liquid-triggered liquid microvalve for on-chip flow control2004In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 100, no 3, p. 463-468Article in journal (Refereed)
    Abstract [en]

    This work introduces a novel surface tension and geometry based liquid-triggered liquid microvalve for on-chip liquid flow control. The simultaneous presence of two liquid plugs at the uncomplicated valve junction triggers the further movement of the liquids and overcomes the stop valve function of the device, thereby providing a precise means of timing liquid movement on-chip. The generic structure was shown to successfully function and forms the basis for several novel and useful functions, including fluidic AND gates, contactless on-chip liquid sample control, timing of independent processes on the same microchip, bubble-free joining of liquids, all of which pose great challenges in the area of microfluidics. The device may be applied to chemical analysis, drug discovery, medical diagnostics and biochemistry.

  • 134.
    Mira, Isabel
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor, Life Science.
    Swerin, Agne
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor.
    Ink-jettable paper-based sensor for charged macromolecules and surfactants2014In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 195, no May, p. 389-395Article in journal (Refereed)
    Abstract [en]

    The use of metachromatic dye-based formulations for the preparation of inkjettable prototype indicators suitable for the detection of charged macromolecules, surfactants or other low molecular weight molecules was investigated. Such indicators were based on the use of metachromatic o-toluidine blue (OTB) that undergoes a characteristic change in color (from blue to pink) upon interaction with anionic macromolecules. When applied onto absorbing substrates such as paper and paperboard, solutions containing OTB and the same dye in the presence of potassium polyvinyl sulfate (KPVS), proved to indicate negatively charged polymers and cationic surfactants. The colorimetric responses suggest a detection limit and sensitivity both are in the order of 1 mM of charged species but can be further improved. Interactions between active species in the indicators and some of the additives in inkjettable formulations (surfactant and humectants) interfered with the mechanism by which an OTB/KVPS-based system work only to a minor degree and could be overcome by priming the substrate. An OTB-based system was formulated into an inkjettable formulation that, once applied to a substrate, was showed to indicate charged polymers and surfactants. This concept has the potential for sensing/indication of other charged macromolecules, such as carboxylates and polyphosphates, which are relevant in biomedical (e.g. fouling due to microbial activity), packaging applications (e.g. migration or release of compounds, food spoilage), microfluidic devices or a simple dipstick application to indicate the presence of charged components.

  • 135.
    Mirajkar, Abhishek L.
    et al.
    Univ Mumbai, Dept Chem, Bombay 400098, Maharashtra, India.
    Mittapelli, Lavanya L.
    Univ Mumbai, Dept Chem, Bombay 400098, Maharashtra, India.
    Nawale, Ganesh N.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Polymer Chemistry.
    Gorea, Kiran R.
    Univ Mumbai, Dept Chem, Bombay 400098, Maharashtra, India.
    Synthetic green fluorescent protein (GFP) chromophore analog for rapid, selective and sensitive detection of cyanide in water and in living cells2018In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 265, p. 257-263Article in journal (Refereed)
    Abstract [en]

    Here, we report Green Fluorescent Protein (GFP) chromophore analog as a turn-on fluorescent chemodosimeter (THBI) for selective detection of cyanide in water, on solid state and in living cells. The detection limit was found to be 0.17 mu M (4.5 ppb). The time dependent study revealed that there is a rapid enhancement in fluorescence intensity (in less than 5s) and was constant over the period of 1 h. Cell imaging data exhibited that THBI was successfully crossed cell membrane and visualized fluorescence response in live HCT cells. 

  • 136. Mirea, Teona
    et al.
    Yantchev, Ventsislav
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Influence of liquid properties on the performance of S-0-mode Lamb wave sensors: A theoretical analysis2015In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 208, p. 212-219Article in journal (Refereed)
    Abstract [en]

    Sensors based on thin film electroacoustic (TEA) devices have emerged as a promising alternative to quartz crystal microbalance and surface acoustic wave devices, in view of sensibility, miniaturization and easy integration. TEA devices include quasi-shear film bulk acoustic resonators (QS-FBAR) and S-0 mode Lamb wave resonators (S-0-LWR) based on AlN films. Despite the work done on the application of TEA devices as in-liquid biological and chemical sensors, a theoretical framework for S-0-LWRs properly describing their sensing mechanisms is still needed. Here we validate a finite element analysis model on QS-FBARs and study the sensing mechanisms of S-0-LWRs in liquid media. We show that S-0-LWRs can sense changes in the dielectric permittivity of the liquid and demonstrate different sensitivities to viscosity and density. A complementary assessment of the S-0-LWRs losses, dependent in a non-specific manner on the square root of the density viscosity product, provides the ability to discriminate density from viscosity changes on the entire device surface. Finally, with an S-0-LWR optimization study we show that resolution improves with the decrease of the membrane thickness; however, a trade-off between sensitivity, quality factor and membrane fragility has to be considered.

  • 137.
    Mittapelli, Lavanya L.
    et al.
    Univ Mumbai, Dept Chem, Mumbai 400098, Maharashtra, India.
    Nawale, Ganesh N.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Polymer Chemistry.
    Gholap, Sachin P.
    Indian Inst Technol, Dept Chem, Mumbai 400076, Maharashtra, India.
    Varghese, Oommen P.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Polymer Chemistry.
    Gore, Kiran R.
    Univ Mumbai, Dept Chem, Mumbai 400098, Maharashtra, India.
    A turn-on fluorescent GFP chromophore analog for highly selective and efficient detection of H2S in aqueous and in living cells2019In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 298, article id 126875Article in journal (Refereed)
    Abstract [en]

    Hydrogen sulphide is a gaseous neurotransmitter responsible for neuronal function and controls vast range of physiological functions. Herein, we report the synthesis and evaluation of novel Green Fluorescent Protein (GFP) chromophore analog, acryloyl-4-(p-hydroxybenzylidene)-5-imidazolidinone (AHBI) for turn-on fluorescent detection of H2S over wide range of anions and various biologically important competitive thiols. AHBI probe exhibited high selectivity and sensitivity, high fluorescence stability, large stokes shift and lower detection limit (15.85 ppb) for H2S in complete water medium. Cell imaging studies in human colon cancer cells (HCT116) and normal human dermal fibroblasts (HDF) confirmed the compatibility and versatility of AHBI probe at micromolar level. Overall, we believe the AHBI, as an optical probe will be useful to investigate the role of H2S in various physiological processes, regulation of cancer cell growth, and in pathogenic events.

  • 138. Molnar, Matyas
    et al.
    Ning, Z. -J
    Chen, Y.
    Friberg, P.
    Gan, L. -M
    Fu, Y.
    Effects of K+ and Na+ ions on the fluorescence of colloidal CdSe/CdS and CdSe/ZnS quantum dots2011In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 155, p. 823-830Article in journal (Refereed)
    Abstract [en]

    In this work we studied the effects of K+ and Na+ ions on fluorescence properties of the colloidal quantum dots (QDs). It was found that the fluorescence intensity was enhanced when low concentration of ions was introduced to QD solutions, while it became weakened when ion concentrations reached their physiological levels in many bio environments. Such fluorescence changes can be attributed to interactions between QD surface ligands and ions as well as the Coulomb potential of ions that displaces the wave functions of the electron and hole confined inside the QD. These results are important for understanding the influence of different biological environments, such as extracellular and intracellular compartments, on optical properties of colloidal QDs.

  • 139.
    Molnár, Mátyás
    et al.
    KTH, School of Biotechnology (BIO), Theoretical Chemistry (closed 20110512).
    Ning, Zhijun
    KTH, School of Biotechnology (BIO), Theoretical Chemistry (closed 20110512).
    Chen, Y.
    Friberg, Peter
    Gan, L.-M.
    Fu, Ying
    KTH, School of Biotechnology (BIO), Theoretical Chemistry (closed 20110512).
    Effects of K+ and Na+ ions on the fluorescence of colloidal CdSe/CdS and CdSe/ZnS quantum dots2011In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 155, no 2, p. 823-830Article in journal (Refereed)
    Abstract [en]

    In this work we studied the effects of K+ and Na+ ions on fluorescence properties of the colloidal quantum dots (QDs). It was found that the fluorescence intensity was enhanced when low concentration of ions was introduced to QD solutions, while it became weakened when ion concentrations reached their physiological levels in many bio environments. Such fluorescence changes can be attributed to interactions between QD surface ligands and ions as well as the Coulomb potential of ions that displaces the wave functions of the electron and hole confined inside the QD. These results are important for understanding the influence of different biological environments, such as extracellular and intracellular compartments, on optical properties of colloidal QDs.

  • 140. Moreno-Guzman, Maria
    et al.
    Garcia-Carmona, Laura
    Molinero-Fernandez, Agueda
    Cava, Felipe
    Umeå University, Faculty of Medicine, Molecular Infection Medicine Sweden (MIMS). Umeå University, Faculty of Medicine, Department of Molecular Biology (Faculty of Medicine). Umeå University, Faculty of Medicine, Umeå Centre for Microbial Research (UCMR).
    Lopez Gil, Miguel Angel
    Escarpa, Alberto
    Bi-enzymatic biosensor for on-site, fast and reliable electrochemical detection of relevant D-amino acids in bacterial samples2017In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 242, p. 95-101Article in journal (Refereed)
    Abstract [en]

    In this work, a bi-enzymatic biosensor allowed the total content of D-amino acids (DAAs) determination in highly relevant matrices involving bacteria. The strategy is based on the unique coimmobilization of D-amino acid oxidase (DAAO) and horseradish peroxidase (HRP) enzymes onto a multi-walled carbon nanotubes (MWCNTs) and gold nanoparticles (AuNPs) modified screen-printed electrode (SPCE). The greater amount of AuNPs deposited and hence the greater loading of both enzymes was observed when they were deposited after the activation of the carboxylated MWCNTs with EDC/Sulfo-NHS chemistry. These platforms provided a fast (300s) and selective quantification of DAAs with excellent precision (RSD < 5%) and accuracy (Recoveries 100-104%) in bacterial samples. Collectively, the electrochemical bi-enzymatic biosensor become an universal, fast, sensitive and easy-to-use approach to determine total content of DAAs in complex matrices.

  • 141.
    Mousavisani, Seyedeh Zeinab
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Sensor and Actuator Systems. Linköping University, Faculty of Science & Engineering. Eletroanalytical Chemistry Research Laboratory, Department of Analytical Chemistry, Faculty of Chemistry, University of Mazandaran, Babolsar, Iran.
    Raoof, Jahan-Bakhsh
    Eletroanalytical Chemistry Research Laboratory, Department of Analytical Chemistry, Faculty of Chemistry, University of Mazandaran, Babolsar, Iran.
    Turner, Anthony
    Linköping University, Department of Physics, Chemistry and Biology, Sensor and Actuator Systems. Linköping University, Faculty of Science & Engineering.
    Ojani, Reza
    Eletroanalytical Chemistry Research Laboratory, Department of Analytical Chemistry, Faculty of Chemistry, University of Mazandaran, Babolsar, Iran.
    Mak, Wing Cheung
    Linköping University, Department of Physics, Chemistry and Biology, Sensor and Actuator Systems. Linköping University, Faculty of Science & Engineering.
    Label-free DNA sensor based on diazonium immobilisation for detection of DNA damage in breast cancer 1 gene2018In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 264, p. 59-66Article in journal (Refereed)
    Abstract [en]

    Electrochemical DNA biosensors offer simple and rapid tools for detection of DNA sequences or damaged genes associated with human disease. The performance of electrochemical DNA sensors is critically dependent on the quality of the DNA immobilisation. Many DNA biosensors have been focused on studying DNA hybridisation preformed under relatively mild assay conditions, while the development of stable DNA biosensors to study DNA damage under a much harsher condition typically in the presence of reactive oxygen species is more challenging. In this article, we developed an electrochemical DNA biosensor based on a stable diazonium-modified screen-printed carbon electrode (SPCE) for the detection of damage in DNA sequences related to the BRCA1 gene by using electrochemical impedance spectroscopy (EIS). The successful preparation of the DNA sensor was confirmed by FTIR-ATR, contact angle and electrochemical measurements. The DNA sensor exhibited good reproducibility and high stability and could also have potential for investigation of the glutathione antioxidant effect. (C) 2018 Elsevier B.V. All rights reserved.

  • 142.
    Nakagomi, Shinji
    et al.
    School of Science and Engineering Ishinomaki Senshu University.
    Fukumura, Akira
    School of Science and Engineering Ishinomaki Senshu University.
    Kokubun, Yoshihiro
    School of Science and Engineering Ishinomaki Senshu University.
    Savage, Susan
    Acreo AB.
    Wingbrant, Helena
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Andersson, Mike
    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 .
    Löfdahl, Mikael
    AppliedSensor AB.
    Lloyd-Spets, Anita
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Influence of gate bias of MISiC-FET gas sensor device on the sensing properties2005In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 108, p. 501-507Article in journal (Refereed)
    Abstract [en]

    The influence of gate bias on the gas sensing properties of SiC-based field effect transistors with catalytic gate and a buried short channel has been studied. The drain current-voltage (I-d-V-D) characteristics of the device reveal non-saturation property, which is a consequence of the short channel design. The drain current is larger in hydrogen ambient than in oxygen ambient at the same drain voltage. The threshold voltage decreases with increasing positive gate bias, and increases with increasing negative gate bias. When a positive bias is applied to the gate, the I-d-V-D characteristics reveal a tendency to saturate. A positive gate bias increases the drain voltage response to hydrogen, as compared with a negative applied gate bias. However, a positive gate bias decreases the stability of the device signal. A change in the channel resistivity is the main reason for the change in the electrical properties when a positive gate bias is applied. A physical model that explains the influence of the gate bias has been studied, and the behavior of the barrier height in the channel was estimated by using the temperature dependence of the I-d-V-D characteristics.

  • 143.
    Nakagomi, Shinji
    et al.
    School of Science and Engineering, Ishinomaki Senshu University, Ishinomaki, Japan.
    Tobias, Peter
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, The Institute of Technology. Univ, S SENCE, S-58183 Linkoping, Sweden; Linkoping Univ, Appl Phys Lab, S-58183 Linkoping, Sweden; Ishinomaki Senshu Univ, Sch Sci and Engn, Ishinomaki 98680, Japan; .
    Baranzahi, Amir
    Linköping University, Department of Science and Technology, Physics and Electronics. 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.
    Mårtensson, Per
    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, Applied Physics. Linköping University, The Institute of Technology.
    Influence of carbon monoxide, water and oxygen on high temperature catalytic metal-oxide-silicon carbide structures1997In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 45, no 3, p. 183-191Article in journal (Refereed)
    Abstract [en]

    High temperature sensors, Schottky diodes and capacitors, based on catalytic metal-oxide-silicon carbide devices are investigated. Reducing gases like hydrogen and other hydrogen containing gases, decrease the barrier height and the flat band voltage, respectively, which is used as the sensor signal. The sensitivity of the devices at 600 degrees C to mixtures of carbon monoxide and oxygen with and without water vapour is studied in this paper. A large binary response of the sensors to carbon monoxide similar to the sensor response to hydrogen gas is observed. Close to the stoichiometric ratio of carbon monoxide and oxygen, the signal changes from a high to a low value corresponding to an excess of carbon monoxide and an excess of oxygen, respectively. When hydrogen is added to a mixture of carbon monoxide and oxygen, the signal changes from a high to a low value at a higher oxygen concentration. Since the response of these devices to hydrogen and hydrogen containing gases is supposed to emanate from hydrogen atoms, the mechanism of the response to carbon monoxide is discussed. The signal to carbon monoxide as well as to hydrogen decreases in the presence of water vapour and the reason for this is discussed.

  • 144.
    Nakagomi, Shinji
    et al.
    Ishinomaki Senshu University.
    Wingqvist, Gunilla
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Åbom, Anna Elisabeth
    Helmersson, Ulf
    Lloyd Spetz, Anita
    Hydrogen sensing by NKN thin film with high dielectric constant and ferroelectric property2005In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 108, no 1-2, p. 490-495Article in journal (Refereed)
    Abstract [en]

    Hydrogen sensing properties of sodium potassium niobate NaxKyNbOz (NKN) thin films were studied. The NKN thin films were prepared by reactive rf magnetron sputtering. NKN is a ferroelectric material with high dielectric constant. The polarization increases in hydrogen ambient and decreases in oxygen ambient. The conductivity of the NKN film in hydrogen ambient is higher than in oxygen ambient, and these changes are reversible. The threshold voltage of the current–voltage (IV) characteristics depends on the hydrogen concentration, and a large response of 3.3 V was obtained.

  • 145.
    Nakagomia, Shinji
    et al.
    Ishinomaki Senshu University.
    Wingqvist, Gunilla
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, The Institute of Technology.
    Åbom, Elisabeth
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, The Institute of Technology.
    Helmersson, Ulf
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Plasma and Coating Physics .
    Lloyd-Spets, Anita
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Hydrogen sensing by NKN thin film with high dielectric constant and ferroelectric property2005In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 108, p. 490-495Article in journal (Refereed)
    Abstract [en]

    Hydrogen sensing properties of sodium potassium niobate NaxKyNbOz (NKN) thin films were studied. The NKN thin films were prepared by reactive rf magnetron sputtering. NKN is a ferroelectric material with high dielectric constant. The polarization increases in hydrogen ambient and decreases in oxygen ambient. The conductivity of the NKN film in hydrogen ambient is higher than in oxygen ambient, and these changes are reversible. The threshold voltage of the current-voltage (I-V) characteristics depends on the hydrogen concentration, and a large response of 3.3V was obtained.

  • 146.
    Neumann, Felix
    et al.
    Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics. Stockholm University, Science for Life Laboratory (SciLifeLab).
    Madaboosi, Narayanan
    Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics. Stockholm University, Science for Life Laboratory (SciLifeLab).
    Hernández-Neuta, Iván
    Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics. Stockholm University, Science for Life Laboratory (SciLifeLab).
    Salas, Jeanpierre
    Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics. Stockholm University, Science for Life Laboratory (SciLifeLab).
    Ahlford, Annika
    Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics. Stockholm University, Science for Life Laboratory (SciLifeLab). Devyser AB, Sweden.
    Mecea, Vasile
    Nilsson, Mats
    Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics. Stockholm University, Science for Life Laboratory (SciLifeLab).
    QCM mass underestimation in molecular biotechnology: Proximity ligation assay for norovirus detection as a case study2018In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 273, p. 742-750Article in journal (Refereed)
    Abstract [en]

    The development of piezoelectric mass-sensitive devices is based on the shift in resonance frequency that is proportional to the deposited mass. However, this holds true only for small, rigid masses, while it can result in mass underestimation for heavy, non-rigid masses. In this work, we demonstrate this 'missing mass' phenomenon by measurement of high molecular weight biomolecules on a Quartz Crystal Microbalance (QCM) platform. For this, we present a model bioassay consisting of a sandwich-type proximity ligation assay for the detection of norovirus-like particles, and its real-time build-up on QCM as an experimental evidence. Upon combination with a localized QCM platform, we explain the pronounced slipping effect in multilayer biological systems resulting in energy dissipation and subsequent mass underestimation. This helps in pointing out the limitations of mega-gravity field sensors for molecular diagnostics where absolute quantification of pathogen load becomes indispensable towards biosensing applications.

  • 147.
    Nguyen, Hugo
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Quy, Chu Thi
    Hanoi University of Science and Technology.
    Hoa, Nguyen Duc
    Hanoi University of Science and Technology.
    Lam, Nguyen The
    Hanoi Pedagogical University No 2, Vinhphuc, Viet Nam.
    Duy, Nguyen Van
    Hanoi University of Science and Technology.
    Quang, Vu Van
    Hanoi University of Science and Technology.
    Hieu, Nguyen Van
    Hanoi University of Science and Technology.
    Controllable growth of ZnO nanowires grown on discrete islands of Au catalyst for realization of planar-type micro gas sensors2014In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 193, p. 888-894Article in journal (Refereed)
    Abstract [en]

    The proper engineering design of gas sensors and the controlled synthesis of sensing materials for the high-performance detection of toxic gas are very important in the fabrication of handheld devices. In this study, an effective design for gas sensor chips is developed to control the formation of grown ZnO nanowires (NWs).The design utilizes the dendrite islands of Au catalyst deposited on and between Pt electrodes of a planar-type micro gas sensor so that NWs can grow on instead of a continuous Au seed layer. This method results in an increase of NW-NW junctions on the device and also eliminates current leakage through the seed layer, which results in a higher sensitivity. The results show that the developed gas-sensing devices could be used to monitor NO2 at moderate temperature (~250 °C) and/or ethanol at a high temperature (~400 °C).

  • 148.
    Olsson, John
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics . Linköping University, The Institute of Technology.
    Winquist, Fredrik
    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 self polishing electronic tongue2006In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 118, no 1-2, p. 461-465Article in journal (Refereed)
    Abstract [en]

    An investigation to obtain reproducible measurements with a pulse voltammetric electronic tongue has lead to the development of self polishing device. A grit paper covered bar rotating over the working electrodes is performing the polishing, to avoid measurements while the polishing bar covers the electrodes an angular decoder is fitted. Measurements in buffer, 2 mM K3[Fe(CN)6] and a buffered tea samples shows that polishing reduces drift, sensitivity decreases with electrode fouling, pre-treatment or conditioning of electrodes post polishing must be optimised concerning the analyte. Also found was that drift due to electrode fouling is a repeatable mechanism which pattern can be used to increase information about the analyte. © 2006 Elsevier B.V. All rights reserved.

  • 149.
    Pardo, M.
    et al.
    INFM and Gas Sensor Laboratory, Dept. Chem. Phys. Mat., Univ. B., Brescia, Italy.
    Niederjaufner, G.
    INFM and Gas Sensor Laboratory, Dept. Chem. Phys. Mat., Univ. B., Brescia, Italy.
    Benussi, G.
    INFM and Gas Sensor Laboratory, Dept. Chem. Phys. Mat., Univ. B., Brescia, Italy.
    Comini, E.
    INFM and Gas Sensor Laboratory, Dept. Chem. Phys. Mat., Univ. B., Brescia, Italy.
    Faglia, G.
    INFM and Gas Sensor Laboratory, Dept. Chem. Phys. Mat., Univ. B., Brescia, Italy.
    Sberveglieri, G.
    INFM and Gas Sensor Laboratory, Dept. Chem. Phys. Mat., Univ. B., Brescia, Italy.
    Holmberg, M.
    S-SENCE and Div. of Applied Physics, Linkoping University, S-581 83, Linkoping, Sweden.
    Lundstrom, I.
    S-SENCE and Div. of Applied Physics, Linkoping University, S-581 83, Linkoping, Sweden.
    Data preprocessing enhances the classification of different brands of Espresso coffee with an electronic nose2000In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 69, no 3, p. 397-403Article in journal (Refereed)
    Abstract [en]

    Two different ways of preprocessing chemical sensor data are presented as a means to improve the interpretation and the classification ability of an electronic nose (EN). The practical problem at hand is the distinction between four commercial coffee blends - containing up to 12 types of coffees - all of which are to be consumed as Espresso. Coffee was sampled in three successive preparation phases: a beans, ground (powder) or liquid (the actual Espresso). In the case of beans, stress is put on the improved clusters visualization after the preprocessing and before the actual classification is performed. Different catalysed sensors and successive extractions were used to differentiate the response pattern towards the various coffees. The features which permitted the best samples' classification as judged from Principal Component Analysis (PCA) score plots were selected. To this end, an empirical search strategy inside the feature space is presented. Scores from PCA were subsequently utilized as inputs for a feed forward multilayer perceptron (MLP) with cross-validation resulting in 100% correct classification with just two sensors. In the case of ground coffee, a (supervised) drift compensation algorithm was developed. It essentially consists of removing the first principal component (PC) for every cluster since this is seen to be given by the drift. An 87.5% classification performance was achieved. Liquid coffee, on the other hand, was not successfully classified, probably due to the difficulty in assuring reproducible sampling conditions.

  • 150.
    Pardon, Gaspard
    et al.
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Ladhani, Laila
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Sandström, Niklas
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Ettori, Maxime
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Lobov, Gleb
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    van der Wijngaart, Wouter
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Aerosol sampling using an electrostatic precipitator integrated with a microfluidic interface2015In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 212, p. 344-352Article in journal (Refereed)
    Abstract [en]

    In this work, the development of a point-of-care (PoC) system to capture aerosol from litres of air directly onto a microfluidic lab-on-chip for subsequent analysis is addressed. The system involves an electrostatic precipitator that uses corona charging and electrophoretic transport to capture aerosol droplets onto a microfluidic air-to-liquid interface for downstream analysis. A theoretical study of the governing geometric and operational parameters for optimal electrostatic precipitation is presented. The fabrication of an electrostatic precipitator prototype and its experimental validation using a laboratory-generated aerosolized dye is described. Collection efficiencies were comparable to those of a state-of-the-art Biosampler impinger, with the significant advantage of providing samples that are at least 10 times more concentrated. Finally, we discuss the potential of such a system for breath-based diagnostics.

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