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  • 151.
    Parmeggiani, Matteo
    et al.
    KTH, School of Engineering Sciences (SCI), Applied Physics.
    Dev, Apurba
    KTH, School of Engineering Sciences (SCI), Applied Physics. Uppsala University, Uppsala, Sweden.
    Björk, P.
    Linnros, Jan
    KTH, School of Engineering Sciences (SCI), Applied Physics.
    Electrokinetic-assisted gating in a microfluidic integrated Si nanoribbon ion sensor for enhanced sensitivity2018In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 262, p. 974-981Article in journal (Refereed)
    Abstract [en]

    Using the electrokinetic principle, we demonstrate a novel approach to modulate the response of an ion sensitive silicon-nanoribbon field-effect-transistor, effectively manipulating the device sensitivity to a change in surface potential. By using the streaming potential effect we show that the changes in the surface potential induced by e.g. a pH change can be accurately manipulated in a microfluidic-integrated chip leading to an enhanced response. By varying the flow velocity and the biasing condition along the microfluidic channel, we further demonstrate that the pH response from such a device can also be suppressed or even reversed as a function of the flow velocity and the biasing configuration. Experiments performed with different pH buffer shows that the sensor response can be enhanced/suppressed by several times in magnitude simply by using the streaming potential effects. A mathematical description is also presented for qualitative assessment of the electrokinetic influence on the gate terminal under different biasing condition. The approach presented here shows the prospect to exploit the electrokinetic modulation for developing highly sensitive nanoscale biosensors. © 2018 Elsevier B.V.

  • 152.
    Parmeggiani, Matteo
    et al.
    KTH Royal Institute of Technology, Sweden.
    Dev, Apurba
    KTH Royal Institute of Technology, Sweden ; Uppsala University, Sweden.
    Björk, Per
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Linnros, Jan
    KTH Royal Institute of Technology, Sweden.
    Electrokinetic-assisted gating in a microfluidic integrated Si nanoribbon ion sensor for enhanced sensitivity2018In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 262, p. 974-981Article in journal (Refereed)
    Abstract [en]

    Using the electrokinetic principle, we demonstrate a novel approach to modulate the response of an ion sensitive silicon-nanoribbon field-effect-transistor, effectively manipulating the device sensitivity to a change in surface potential. By using the streaming potential effect we show that the changes in the surface potential induced by e.g. a pH change can be accurately manipulated in a microfluidic-integrated chip leading to an enhanced response. By varying the flow velocity and the biasing condition along the microfluidic channel, we further demonstrate that the pH response from such a device can also be suppressed or even reversed as a function of the flow velocity and the biasing configuration. Experiments performed with different pH buffer shows that the sensor response can be enhanced/suppressed by several times in magnitude simply by using the streaming potential effects. A mathematical description is also presented for qualitative assessment of the electrokinetic influence on the gate terminal under different biasing condition. The approach presented here shows the prospect to exploit the electrokinetic modulation for developing highly sensitive nanoscale biosensors.

  • 153.
    Parmeggiani, Matteo
    et al.
    KTH Royal Inst Technol, Sch Sci & Engn, Dept Appl Phys, SE-10044 Stockholm, Sweden..
    Dev, Apurba
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics. KTH Royal Inst Technol, Sch Sci & Engn, Dept Appl Phys, SE-10044 Stockholm, Sweden.
    Björk, Per
    RISE Acreo Ab, SE-16440 Stockholm, Sweden..
    Linnros, Jan
    KTH Royal Inst Technol, Sch Sci & Engn, Dept Appl Phys, SE-10044 Stockholm, Sweden..
    Electrokinetic-assisted gating in a microfluidic integrated Si nanoribbon ion sensor for enhanced sensitivity2018In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 262, p. 974-981Article in journal (Refereed)
    Abstract [en]

    Using the electrokinetic principle, we demonstrate a novel approach to modulate the response of an ion sensitive silicon-nanoribbon field-effect-transistor, effectively manipulating the device sensitivity to a change in surface potential. By using the streaming potential effect we show that the changes in the surface potential induced by e.g. a pH change can be accurately manipulated in a microfluidic-integrated chip leading to an enhanced response. By varying the flow velocity and the biasing condition along the microfluidic channel, we further demonstrate that the pH response from such a device can also be suppressed or even reversed as a function of the flow velocity and the biasing configuration. Experiments performed with different pH buffer shows that the sensor response can be enhanced/suppressed by several times in magnitude simply by using the streaming potential effects. A mathematical description is also presented for qualitative assessment of the electrokinetic influence on the gate terminal under different biasing condition. The approach presented here shows the prospect to exploit the electrokinetic modulation for developing highly sensitive nanoscale biosensors.

  • 154.
    Pati, Palas Baran
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Organic chemodosimeter for cyanide: A nucleophilic approach2016In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 222, p. 374-390Article in journal (Refereed)
    Abstract [en]

    Out of the all anions cyanide is one of the most threaten for environmental and social system and abundance of cyanide in environment generate not only from industrial waste but also from the biological process of fungal and algae. It has very much toxic effect, after a certain limit it may cause to death. The interest for qualitative and quantitative detection of cyanide is growing on. Detection rely on the change in absorption and emission properties of probe upon binding with cyanide is important because of its simple analysis technique. Cyanide is a good nucleophile and this property can be very much useful to develop organic probes to detect its presence. Here this review deals with the organic chemodosimetric probes for cyanide, more specifically the detection mechanism is driven by the nucleophilic attack of cyanide ion to the probe. Discussed organic probes are divided into some classes according to their structural features and functional group present in the probe.

  • 155.
    Pearce, Ruth
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Iakimov, Tihomir
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, The Institute of Technology.
    Andersson, Mike
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Hultman, Lars
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film 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.
    Yakimova, Rositsa
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, The Institute of Technology.
    Epitaxially grown graphene based gas sensors for ultra sensitive NO(2) detection2011In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 155, no 2, p. 451-455Article in journal (Refereed)
    Abstract [en]

    Epitaxially grown single layer and multi layer graphene on SiC devices were fabricated and compared for response towards NO(2). Due to electron donation from SiC:, single layer graphene is n-type with a very low carrier concentration. The choice of substrate is demonstrated to enable tailoring of the electronic properties of graphene, with a SiC substrate realising simple resistive devices tuned for extremely sensitive NO(2) detection. The gas exposed uppermost layer of the multi layer device is screened from the SiC by the intermediate layers leading to a p-type nature with a higher concentration of charge carriers and therefore, a lower gas response. The single layer graphene device is thought to undergo an n-p transition upon exposure to increasing concentrations of NO(2) indicated by a change in response direction. This transition is likely to be due to the transfer of electrons to NO(2) making holes the majority carriers. (C) 2011 Elsevier B.V. All rights reserved.

  • 156.
    Petersson, Henrik
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics . Linköping University, The Institute of Technology.
    Holmberg, Martin
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics . Linköping University, The Institute of Technology.
    Initial studies on the possibility to use chemical sensors to monitor and control boilers2005In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 111-112, p. 487-493 Article in journal (Refereed)
    Abstract [en]

    Small-scale boilers are quite often installed in facilities like schools, households and at local heat distributors. Because of economical considerations such boilers often lack appropriate control-systems, which results in inefficient and pollutant combustions with high levels of carbon monoxides, hydrocarbons, and in ashes with unburned charcoal. Monitoring of oxygen, carbon monoxide, and hydrocarbons, which is essential to be able to control a boiler, requires expensive instruments like flame-ionization detectors, IR- and mass-spectrometers.

    We demonstrate the possibility to use a low-cost chemical sensor array to monitor a small-scaled boiler. By using metal oxide sensors, metal insulator silicon carbide field effect transistors, and by applying multivariate data modeling, promising results have been obtained. The data modeling was made using a joint approach based on blind source separations and multiple linear regressions. This approach showed similar result compared to results from the well-known PLSR algorithm.

  • 157.
    Petersson, Henrik
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics . Linköping University, The Institute of Technology.
    Klingvall, Roger
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics . Linköping University, The Institute of Technology.
    Holmberg, Martin
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, The Institute of Technology.
    Sensor Array Optimization using Variable Selection and a Scanning Light Pulse Technique2009In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 142, no 2, p. 435-445Article in journal (Refereed)
    Abstract [en]

    In the design of a chemical sensor. the constructor has several degrees of freedom setting parameters that influence the final characteristics of the component. For applications where several sensors are required, the number of possible parameter configurations increases dramatically. The work of configuring a sensor array is therefore tedious and many test sensors may need to be processed before a final configuration is found. The Scanning Light Pulse Technique (SLPT) is a technique for investigating insulator-semiconductor interfaces and can be used to scan surfaces with non-uniform properties, Thereby a virtual pool of test components can be evaluated simultaneously eliminating the need for processing individual test sensors. We report here on a method combining SLPT with algorithmic sensor selection techniques. This is a powerful combination providing the user with a candidate array configuration containing combinations of sensors optimal for the current application and data analysis algorithms. The need to process many individual test sensors is eliminated and the only sensor components that must be produced are those included in the final array. The selection techniques evaluated here are based on forward selection and Asymmetric Class Projection (ACP), Canonical Correlation Analysis (CCA), Linear Discriminant Analysis (LDA), and Mutual Information (MI). The Suggested method is successfully evaluated using an experiment in which the purpose was to find means to detect small amounts of hydrogen in a background dominated by an interfering gas, in this case ammonia. In this particular study, the selection techniques based on ACP and CCA showed the most promising result.

  • 158.
    Poksinski, Michal
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Applied Optics . Linköping University, The Institute of Technology.
    Arwin, Hans
    Linköping University, Department of Physics, Chemistry and Biology, Applied Optics . Linköping University, The Institute of Technology.
    In situ monitoring of metal surfaces exposed to milk using total internal reflection ellipsometry2003In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 94, no 3, p. 247-252Article in journal (Refereed)
    Abstract [en]

    A technique combining ellipsometry with total internal reflection is presented. The method is called total internal reflection ellipsometry (TIRE) and is suitable for monitoring of internal surfaces which opens new possibilities for measuring adsorption on metal surfaces in opaque liquids. Results from measurements of adsorption of milk and subsequent cleaning with sodium hydroxide on metal surfaces are given. These include studies on gold, iron, and chromium surfaces. A schematic design of the instrument used in TIRE is included. The main advantages of the system are non-invasive probing, fast response, and high sensitivity. The method has potential for applications in monitoring of internal surfaces of pipelines in industrial processes.

  • 159.
    Polese, D
    et al.
    University of Roma Tor Vergata, Italy .
    Martinelli, E
    University of Roma Tor Vergata, Italy .
    Magna, G
    University of Roma Tor Vergata, Italy .
    Dini, F
    University of Roma Tor Vergata, Italy .
    Catini, A
    University of Roma Tor Vergata, Italy .
    Paolesse, R
    University of Roma Tor Vergata, Italy .
    Lundström, Ingemar
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, The Institute of Technology.
    Di Natale, C
    University of Roma Tor Vergata, Italy .
    Sharing data processing among replicated optical sensor arrays2013In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 179, no SI, p. 252-258Article in journal (Refereed)
    Abstract [en]

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

  • 160. Prajapati, C. S.
    et al.
    Visser, Dennis
    KTH, School of Engineering Sciences (SCI), Applied Physics, Semiconductor Materials, HMA.
    Anand, Srinivasan
    KTH, School of Engineering Sciences (SCI), Applied Physics.
    Bhat, N.
    Honeycomb type ZnO nanostructures for sensitive and selective CO detection2017In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 252, p. 764-772Article in journal (Refereed)
    Abstract [en]

    Excellent sensing performance for CO gas is demonstrated using inexpensive sensor devices based on honeycomb type ZnO nanostructures, fabricated by colloidal lithography and lift-off process. This newly proposed method for gas sensors is cost effective and provides significant enhancement of both sensitivity and selectivity of CO detection. Honeycomb type ZnO nano films developed in ∼21 nm ZnO layer consisting of 1 μm period hexagonal lattice of air-holes with diameter varying from ∼600–900 nm are investigated for CO sensing. These structures are fabricated by a combination of self-assembly of polystyrene (PS) spheres, their size reduction by oxygen plasma and magnetron-sputtering of ZnO followed by PS mask removal. The hole diameter and hence the width of ZnO honeycomb walls are determined by size reduction of PS spheres. Fabricated ZnO honeycomb type sensors show superior sensing performance compared to planar ZnO films, and response as high as ∼81.2% at 300 °C for a 3 ppm CO with a detection resolution of 500 ppb and response and recovery times of ∼180 and ∼210 s, respectively, were obtained. The repeatability of the observed results is confirmed and in addition, the CO selectivity is shown for gas mixtures consisting of CH4, H2S, CO2, NO2, SO2 and H2. The developed nanostructuring method is generic and can be adapted for improving performance of other metal-oxide based gas sensors.

  • 161.
    Renberg, Björn
    et al.
    KTH, School of Biotechnology (BIO), Proteomics and Nanobiotechnology.
    Andersson-Svahn, Helene
    KTH, School of Biotechnology (BIO), Proteomics and Nanobiotechnology.
    Hedhammar, My
    Mimicking silk spinning in a microchip2014In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 195, p. 404-408Article in journal (Refereed)
    Abstract [en]

    Nature's high performance material, spider silk, is formed during the passage of a protein solution through a spinning duct. Herein we present a microfluidic device with dual laminar mobile phases where silk formation can be mimicked and investigated. Recombinant miniature spidroins, with or without the pH-switching N-terminal domain, were used to investigate spinning conditions into silk-like fibers using this setup.

  • 162.
    Reyes, L. F.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Hoel, Anders
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Saukko, S.
    Heszler, Peter
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Lantto, V.
    Granqvist, Claes Göran
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Gas sensor response of pure and activated WO3 nanoparticle films made by advanced reactive gas deposition2006In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 117, no 1, p. 128-134Article in journal (Refereed)
    Abstract [en]

    Pure and activated (doped) nanocrystalline WO3 films, produced by advanced reactive gas deposition, were investigated for gas sensing applications. Activation took place by co-evaporation of Al or Au with tungsten oxide as the particles were produced. Structural characterization of the films was performed by electron microscopy and X-ray diffractometry. Sensitivity, response time, and recovery time of the sensors were systematically investigated as a function of annealing and operating temperature, using H2S, CO, and NO, as test gases. The sensitivity was found to lie below and around the ppm level for H2S and NO2, respectively.

  • 163.
    Ribet, Federico
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    De Pietro, Luca
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    Roxhed, Niclas
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    Stemme, Göran
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    Gas diffusion and evaporation control using EWOD actuation of ionic liquid microdroplets for gas sensing applications2018In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 267, p. 647-654Article in journal (Refereed)
    Abstract [en]

    The lifetime of electrochemical gas sensors suffers from electrolyte evaporation and from the impracticality to perform recalibration. To tackle these issues, a prototype of a microfabricated gas diffusion controlling system, based on coplanar electrowetting-on-dielectric (EWOD) actuation of ionic liquid microdroplets, is presented. The system is designed to be integrated with electrochemical gas sensors to allow on-demand sealing of the sensing chamber from the environment. The MEMS device can be electrically toggled between an open and a closed state, in which the microdroplets are used to cover or uncover the openings of a perforated membrane connecting to the sensing compartment, respectively. This ON/OFF diffusion-blocking valve mechanism potentially allows for recalibration and for liquid electrolyte evaporation reduction when the sensor is not in use, thus extending the gas sensor lifetime. A one order of magnitude reduction of evaporation rate and a more than three orders of magnitude reduction of gas diffusion time were experimentally demonstrated. Ionic liquid movement can be performed with an applied AC voltage as low as 18 V, using super-hydrophobic cover plates to facilitate droplet motion. Furthermore, the shown ionic liquid micro-droplet manipulation provides a robust and low voltage platform for digital microfluidics, readily adaptable to serve different applications.

  • 164. Risveden, K.
    et al.
    Bhand, S.
    Ponten, J.F.
    Anden, T.
    Calander, N.
    Willander, Magnus
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology.
    Danielsson, B.
    Signal frequency studies of an environmental application of a 65 nm region ion sensitive field effect transistor sensor2007In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 127, no 1, p. 198-203Article in journal (Refereed)
    Abstract [en]

    A rapid and sensitive novel type of bioelectronic Region Ion Sensitive Field Effect Transistor (RISFET) nanosensor was constructed on a chip with a 65 nm sensing electrode gap. The RISFET nanosensor was demonstrated for the environmental pesticide analysis of neurotoxic organocarbamate/carbofuran. The linear range for carbofuran analysis is ac signal frequency dependent, studied in the range (500 down-0.5 Hz, 50 mVpeak-peak ac) and a bias voltage applied between the bottom capacitor plate and the electrodes. The signal current response is measured using a low-noise pico ammeter. The inhibition of acetylcholinesterase (AChE) by carbofuran was detectable in a logarithmic linear range (0.1-100 nM) at 1.08 Hz, with a lower limit of detection of inhibition 0.1 nM with 10 min incubation time. The sensor is based on the principle of focusing charged reaction products with an electrical field in a region between the sensing electrodes. The current measurement by the sensor electrodes is correlated to the composition of the sample. The carbofuran detection is based on the ability to inhibit the enzyme AChE. The RISFET sensor chip is fabricated using conventional electron beam lithography. The encompassed sensor volume in the "nanocell" is in the attoliter range. © 2007 Elsevier B.V. All rights reserved.

  • 165. Rosental, Arnold
    et al.
    Tarre, Aivar
    Gerts, Alar
    Sundqvist, Jonas
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Materials Chemistry.
    Hårsta, Anders
    Aidla, Alex
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Materials Chemistry.
    Aarik, Jaan
    Sammelselg, Veino
    Uustare, Teet
    Gas sensing properties of epitaxial SnO2 thin films prepared by atomic layer deposition2003In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 93, no 1-3, p. 552-555Article in journal (Refereed)
    Abstract [en]

    Undoped SnO2 thin films are grown on α-Al2O3(0 1 2) (r-cut sapphire) substrates by gas phase atomic layer deposition (ALD). Two precursor pairs, SnI4–O2 and SnCl4–H2O2, both new for ALD, are used. The films have a cassiterite structure and are (1 0 1)[0 1 0]cassiterite||(0 1 2)[1 0 0]sapphire oriented. A good epitaxial quality and the conductivity acceptable from the standpoint of semiconductor gas sensors are achieved for ultrathin films grown from SnI4–O2 at 600 °C. The sensitivity of these films to CO in air has a maximum at a thickness of about 10 nm. Response rise and decay times belonging to a several seconds interval are measured. The films are assumed to function as a single grain.

  • 166.
    Saidi, Tarik
    et al.
    Moulay Ismail Univ, Dept Phys, Fac Sci, Sensor Elect & Instrumentat Grp, BP 11201, Zitoune, Meknes, Morocco;Moulay Ismail Univ, Fac Sci, Dept Biol, Biotechnol Agroalimentary & Biomed Anal Grp, BP 11201, Zitoune, Meknes, Morocco.
    Palmowski, Dariusz
    Gdansk Univ Technol, Dept Metrol & Optoelect, Gdansk, Poland.
    Babicz-Kiewlicz, Sylwia
    Gdansk Univ Technol, Dept Metrol & Optoelect, Gdansk, Poland.
    Welearegay, Tesfalem Geremariam
    Rovira & Virgili Univ, Dept Elect Elect & Automat Engn, E-43007 Tarragona, Spain.
    El Bari, Nezha
    Moulay Ismail Univ, Fac Sci, Dept Biol, Biotechnol Agroalimentary & Biomed Anal Grp, BP 11201, Zitoune, Meknes, Morocco.
    Ionescu, Radu
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Smulko, Janusz
    Gdansk Univ Technol, Dept Metrol & Optoelect, Gdansk, Poland.
    Bouchikhi, Benachir
    Moulay Ismail Univ, Dept Phys, Fac Sci, Sensor Elect & Instrumentat Grp, BP 11201, Zitoune, Meknes, Morocco.
    Exhaled breath gas sensing using pristine and functionalized WO3 nanowire sensors enhanced by UV-light irradiation2018In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 273, p. 1719-1729Article in journal (Refereed)
    Abstract [en]

    The development of advanced metal-oxide-semiconductor sensing technologies for the detection of Volatile Organic Compounds (VOCs) present in exhaled breath is of great importance for non-invasive, cheap and fast medical diagnostics. Our experimental studies investigate the effects of operating temperature selection and UV-light irradiation on improving the response of WO3 nanowire sensors towards exhaled breath exposure. Herein, six WO3 nanowire sensors (both pristine and doped with a range of metal nanoparticles such as Pt, Au, Au/Pt, Ni and Fe) were synthesised via Aerosol-Assisted Chemical Vapour Deposition (AACVD) and characterized by means of Atomic Force Microscopy (AFM), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) and Energy Dispersive X-ray (EDX-ray). Breath measurements were performed in the dark and under UV-light irradiation at various sensor operating temperatures. The results demonstrate that UV-light irradiation combined with the optimisation of the sensors' operating temperature can greatly enhance the sensors' responses towards breath exposure.

  • 167.
    Sandstrom, KJM
    et al.
    Natl Institute Working Life, Department Chemistry, S-90713 Umea, Sweden; Umea University, Department Publ Hlth and Clin Med, S-90581 Umea, Sweden; Cranfield University, Cranfield Biotechnol Centre, Cranfield MK43 0AL, Beds, England; .
    Newman, J
    Natl Institute Working Life, Department Chemistry, S-90713 Umea, Sweden; Umea University, Department Publ Hlth and Clin Med, S-90581 Umea, Sweden; Cranfield University, Cranfield Biotechnol Centre, Cranfield MK43 0AL, Beds, England; .
    Sunesson, AL
    Natl Institute Working Life, Department Chemistry, S-90713 Umea, Sweden; Umea University, Department Publ Hlth and Clin Med, S-90581 Umea, Sweden; Cranfield University, Cranfield Biotechnol Centre, Cranfield MK43 0AL, Beds, England; .
    Levin, JO
    Natl Institute Working Life, Department Chemistry, S-90713 Umea, Sweden; Umea University, Department Publ Hlth and Clin Med, S-90581 Umea, Sweden; Cranfield University, Cranfield Biotechnol Centre, Cranfield MK43 0AL, Beds, England; .
    Turner, APF
    Cranfield University, UK.
    Amperometric biosensor for formic acid in air2000In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 70, no 03-jan, p. 182-187Article in journal (Refereed)
    Abstract [en]

    The possibility of developing a simple, inexpensive and specific personal passive "real-time" air sampler incorporating a biosensor for formic acid was investigated. The sensor is based on the enzymatic reaction between formic acid and formate dehydrogenase (FDH) with nicotinamide adenine dinucleotide (NAD(+)) as a co-factor and Meldolas blue as mediator. An effective way to immobilise the enzyme, co-factor and Meldolas blue on screen-printed, disposable, electrodes was found to be in a mixture of glycerol and phosphate buffer covered with a gas-permeable membrane. Steady-state current was reached after 4-15 min and the limit of detection was calculated to be below 1 mg/m(3). However, the response decreased by 50% after storage at -15 degreesC for 1 day. (C) 2000 Elsevier Science B.V. All rights reserved.

  • 168.
    Sandström, K. J. Mattias
    et al.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Occupational Medicine. Cranfield Biotechnology Centre, Cranfield University, UK; Department of Chemistry, National Institute for Working Life, Umeå, Sweden.
    Newman, Jeffrey
    Cranfield Biotechnology Centre, Cranfield University, UK.
    Sunesson, Anna-Lena
    Department of Chemistry, National Institute for Working Life, Umeå, Sweden.
    Levin, Jan-Olof
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Occupational Medicine. Department of Chemistry, National Institute for Working Life, Umeå, Sweden.
    Turner, Anthony P. F.
    Cranfield Biotechnology Centre, Cranfield University, UK.
    Amperometric biosensor for formic acid in air2000In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 70, no 1–3, p. 182-187Article in journal (Refereed)
    Abstract [en]

    The possibility of developing a simple, inexpensive and specific personal passive “real-time” air sampler incorporating a biosensor for formic acid was investigated. The sensor is based on the enzymatic reaction between formic acid and formate dehydrogenase (FDH) with nicotinamide adenine dinucleotide (NAD+) as a co-factor and Meldola's blue as mediator. An effective way to immobilise the enzyme, co-factor and Meldola's blue on screen-printed, disposable, electrodes was found to be in a mixture of glycerol and phosphate buffer covered with a gas-permeable membrane. Steady-state current was reached after 4–15 min and the limit of detection was calculated to be below 1 mg/m3. However, the response decreased by 50% after storage at −15°C for 1 day.

  • 169.
    Santangelo, Francesca
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Sensor and Actuator Systems. Linköping University, Faculty of Science & Engineering.
    Shtepliuk, Ivan
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, Faculty of Science & Engineering.
    Filippini, Daniel
    Linköping University, Department of Physics, Chemistry and Biology, Sensor and Actuator Systems. Linköping University, Faculty of Science & Engineering.
    Ivanov, Ivan Gueorguiev
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, Faculty of Science & Engineering.
    Yakimova, Rositsa
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, Faculty of Science & Engineering.
    Eriksson, Jens
    Linköping University, Department of Physics, Chemistry and Biology, Sensor and Actuator Systems. Linköping University, Faculty of Science & Engineering.
    Real-time sensing of lead with epitaxial graphene-integrated microfluidic devices2019In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 288, p. 425-431Article in journal (Refereed)
    Abstract [en]

    Since even low concentrations of toxic heavy metals can seriously damage human health, it is important to develop simple, sensitive and accurate methods for their detection. Graphene, which is extremely sensitive to foreign species, is a key element in the development of a sensing platform where low concentrations of analyte have to be detected. This work discusses the proof of concept of a sensing platform for liquid-phase detection of heavy metals (e.g. Pb) based on epitaxial graphene sensors grown on Si-face 4H-SiC substrate (EG/SiC). The sensing platform developed includes a microfluidic chip incorporating all the features needed to connect and execute the Lab-on-chip (LOC) functions using 3D printing fast prototyping technology. Herein, we present the response of EG to concentrations of Pb2+ solutions ranging from 125 nM to 500 mu M, showing good stability and reproducibility over time and an enhancement of its conductivity with a Langmuir correlation between signal and Pb2+ concentration. Density functional theory (DFT) calculations are performed and clearly explain the conductivity changes and the sensing mechanism in agreement with the experimental results reported, confirming the strong sensitivity of the sensor to the lowest concentrations of the analyte. Furthermore, from the calibration curve of the system, a limit of detection (LoD) of 95 nM was extrapolated.

  • 170.
    Sberveglieri, G.
    et al.
    CNR IDASC SENSOR Lab.
    Baratto, C.
    CNR IDASC SENSOR Lab.
    Comini, E.
    CNR IDASC SENSOR Lab.
    Faglia, G.
    CNR IDASC SENSOR Lab.
    Ferroni, M.
    CNR IDASC SENSOR Lab.
    Ponzoni, A.
    CNR IDASC SENSOR Lab.
    Vomiero, Alberto
    INFM-CNR Sensor Lab.
    Synthesis and characterization of semiconducting nanowires for gas sensing2007In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 121, no 1, p. 208-213Article in journal (Refereed)
    Abstract [en]

    Quasi one-dimensional nanostructures of semiconducting metal oxides are promising for the development of nano-devices. Tin, indium, and zinc oxides were produced in form of single-crystalline nanowires through condensation from vapor phase. Such a growth occurs in controlled thermodynamical condition and size reduction effects on the electrical and optical response to gases have been exploited. Preparation, microstructural, and electrical characterization of nanowires are presented and the peculiarities of these innovative structures are highlighted. © 2006 Elsevier B.V. All rights reserved.

  • 171.
    Schanzenbach, Christoph
    et al.
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Ilver, Dag
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Blomgren, Jacob
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Jonasson, Christian
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Johansson, Christer
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Krozer, Aanatol
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Ye, Lei
    Lund University, Sweden.
    Rustas, Bengt-Ove
    SLU Swedish University of Agricultural Science, Sweden.
    Preparation and characterisation of a sensing system for wireless pH measurements in vivo, in a rumen of a cow2017In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 242, p. 637-644Article in journal (Refereed)
    Abstract [en]

    We describe a sensing system that is able to measure pH in-vivo, in the rumen of a cow, in real time. The sensing principle is based on gravimetric transduction using a magnetoelastic ribbon functionalized by pH-sensitive nanobeads that is placed in the rumen where it is actuated and read-out wirelessly. We describe a generic procedure that enables one to deposit monolayers or multilayers of nano- and micro beads onto virtually any substrate. The topography of the resulting layers as well as interlayer coverages were characterised using optical microscopy and scanning profilometry. First we determined performance of the system in-vitro, in phosphate-buffered saline, in McDougall's buffer and in a rumen fluid. Thereafter we also performed in-vivo measurements. Using buffers we determined pH response in the liquids both at the fundamental frequency of the functionalised foils, and at the 1st overtone. We argue that observed frequency changes vs pH are mainly due to changes of trapped liquid when the bead layers shrink or expand as a response to changed pH. The data obtained from the pH response of magnetoelastic foils at different bead coverages was modelled by a simple two-parameter model that corroborates this assumption.

  • 172.
    Scharnagl, K.
    et al.
    Faculty of Electrical Engineering, Institute of Physics, Universität der Bundeswehr München, Werner-Heisenberg-Weg 39, 85577 Neubiberg, Germany.
    Eriksson, Mats
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Karthigeyan, A.
    DAAD Fellow, Central Electronics Engineering Research Institute, Pilani 333031, India.
    Burgmair, M.
    Faculty of Electrical Engineering, Institute of Physics, Universität der Bundeswehr München, Werner-Heisenberg-Weg 39, 85577 Neubiberg, Germany.
    Zimmer, M.
    Faculty of Electrical Engineering, Institute of Physics, Universität der Bundeswehr München, Werner-Heisenberg-Weg 39, 85577 Neubiberg, Germany.
    Eisele, I.
    Faculty of Electrical Engineering, Institute of Physics, Universität der Bundeswehr München, Werner-Heisenberg-Weg 39, 85577 Neubiberg, Germany.
    Hydrogen detection at high concentrations with stabilised palladium2001In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 78, no 1-3, p. 138-143Article in journal (Refereed)
    Abstract [en]

    In order to improve the stability to high hydrogen concentrations, of hybrid suspended gate field effect transistors (HSGFETs) with thin palladium films as sensitive layer, Pd-Ni and Pd-Ag alloys have been produced by co-evaporation techniques in UHV. In this paper, the preparation methods as well as hydrogen response measurements are presented. The observed results show that the Pd-Ni alloy is an appropriate material for hydrogen sensing at concentrations up to 2% H2, even at room temperature. The response to 2% H2 is around 500 mV at dry conditions. It is reduced to less than half of this value with moistened carrier gas, but at the same time, the desorption time is lowered. In contrast, the Pd-Ag alloy was not stable. A large drift of the sensor signal was observed and the morphology as well as the composition had changed after the test gas exposures. © 2001 Published by Elsevier Science B.V.

  • 173.
    SCHUBERT, F
    et al.
    CTR INST MOLEC BIOL,W-1115 BERLIN,GERMANY; CRANFIELD INST TECHNOL,CTR BIOTECHNOL,CRANFIELD MK43 0AL,BEDS,ENGLAND; .
    SAINI, S
    CTR INST MOLEC BIOL,W-1115 BERLIN,GERMANY; CRANFIELD INST TECHNOL,CTR BIOTECHNOL,CRANFIELD MK43 0AL,BEDS,ENGLAND; .
    TURNER, APF
    Cranfield University, UK.
    SCHELLER, F
    CTR INST MOLEC BIOL,W-1115 BERLIN,GERMANY; CRANFIELD INST TECHNOL,CTR BIOTECHNOL,CRANFIELD MK43 0AL,BEDS,ENGLAND; .
    ORGANIC-PHASE ENZYME ELECTRODES FOR THE DETERMINATION OF HYDROGEN-PEROXIDE AND PHENOL1992In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 7, no 03-jan, p. 408-411Article in journal (Refereed)
    Abstract [en]

    An amperometric horseradish peroxidase electrode is described for the determination of hydrogen peroxide in organic solvents. The enzyme was co-adsorbed with an electron mediator, hexacyanoferrate(II), to the surface of a graphite foil electrode making reagentless measurement possible. The electrochemical reduction of the enzymatically oxidized mediator was utilized as the analytical signal. The electrode can be operated in dioxane, chloroform and chlorobenzene, the presence of a small quantity of aqueous buffer being essential for activity. On this basis a small, probe-type sensor has been assembled the response of which is linearly related to hydrogen peroxide concentration between 0.05 and 1 mM. A tyrosinase sensor has been constructed by combining a Clark-type oxygen electrode with a membrane bearing adsorbed enzyme. The sensor is capable of measuring between 0.1 and 5 mM phenol in chloroform saturated with aqueous buffer.

  • 174.
    Sherrell, Peter
    et al.
    Linköping University, Department of Biomedical Engineering, Biomedical Instrumentation. Linköping University, The Institute of Technology.
    Elmén, Karin
    Linköping University, Department of Biomedical Engineering. Linköping University, Faculty of Science & Engineering.
    Cieslar-Pobuda, Artur
    Linköping University, Department of Clinical and Experimental Medicine, Division of Cell Biology. Linköping University, Faculty of Medicine and Health Sciences. Silesian Technical University, Poland.
    Wiechec, Emilia
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuro and Inflammation Science. Linköping University, Faculty of Medicine and Health Sciences.
    Lemoine, Mark
    Linköping University, Department of Biomedical Engineering. Linköping University, Faculty of Science & Engineering.
    Arzhangi, Zahra
    University of Ottawa, Canada.
    Silverå Ejneby, Malin
    Linköping University, Department of Clinical and Experimental Medicine, Division of Cell Biology. Linköping University, Faculty of Medicine and Health Sciences.
    Brask, Johan
    Linköping University, Department of Clinical and Experimental Medicine, Division of Cell Biology. Linköping University, Faculty of Medicine and Health Sciences.
    Daka, Joseph N.
    Health Canada, Canada.
    Rafat, Mehrdad
    Linköping University, Department of Biomedical Engineering, Biomedical Instrumentation. Linköping University, Faculty of Science & Engineering. Health Canada, Canada; LinkoCare Life Science AB, Linkoping, Sweden.
    Cardiac and stem cell-cocooned hybrid microspheres: A multi factorial design approach2016In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 236, p. 480-489Article in journal (Refereed)
    Abstract [en]

    Cell therapy is a promising approach for the treatment of patients suffering from myocardial infarction. Most recent therapies involve direct injection of cells into the damaged heart tissue to induce regeneration and help restore its functions, however, anoikis and the harsh environment at the sight of injection limit the therapeutic efficacy of current techniques. Biopolymeric microspheres such as alginate have been widely used for cells encapsulation and delivery for cell therapy applications. However, majority of these techniques are not standardized that is a big challenge for translation into clinically-relevant treatment options. In addition, purely-alginate base microspheres are limited by poor biodegradability and lack of strong interaction between the encapsulated cells and their surrounding alginate matrix. In this work, we have shown that the addition of type I collagen into alginate microspheres, systematically optimized by a multivariate experimental design, improves the biocompatibility of the microspheres towards induced pluripotent stem cells (iPS), cardiomyocytes, and blood outgrowth endothelial cells (BOEC), whilst improving diffusion between outside environment and the inner sphere. The addition of collagen allows for multiple routes for sphere degradation leading to potentially greater control over cell release once delivered. Mathematical models were developed and utilized to effectively evaluate and predict the influence of various factors such as polymer ratios, micronization air flow rate, and air-gap distance on spheres size and shape, which play a key role in cell viability, degradation rate of microspheres, as well as controlled production of the cell cocoons toward clinically-relevant cell therapies for treatment of myocardial infarction. (C) 2016 Elsevier B.V. All rights reserved.

  • 175.
    Shukla, Sudheesh K.
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, Faculty of Science & Engineering. University of Johannesburg, South Africa.
    Demir, Mustafa M.
    Izmir Institute Technology, Turkey.
    Govender, Penny P.
    University of Johannesburg, South Africa.
    Tiwari, Ashutosh
    Linköping University, Faculty of Science & Engineering. Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics.
    Shukla, S. K.
    University of Delhi, India.
    Optical fibre based non-enzymatic glucose sensing over Cu2+-doped polyaniline hybrid matrix2017In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 242, p. 522-528Article in journal (Refereed)
    Abstract [en]

    The opto-chemical glucose sensing over cupric ion doped polyaniline (Cu+2/PANI) hybrid polymer matrix coated glass rod based optode has been demonstrated.Cu+2/PANI hybrid matrix was synthesized by in situ chemical polymerization of intrinsically functionalized aniline. Furthermore, developed optode has been explored for direct oxidisation of glucose on Cu+2/PANI hybrid matrix for non-enzymatic glucose sensing employing O-dianisidine indicator system. The proposed glucose sensor works well in range of 50 mg/dL-200 mg/dL with response time of 15 s in artificial as well as in biological samples along with 40 days of lifespan. (C) 2016 Elsevier B.V. All rights reserved.

  • 176.
    Solis, J. L.
    et al.
    The Ångström Laboratory, Department of Materials Science, Uppsala University, Uppsala, Sweden.
    Kish, L. B.
    The Ångström Laboratory, Department of Materials Science, Uppsala University, Uppsala, Sweden.
    Vajtai, R.
    The Ångström Laboratory, Department of Materials Science, Uppsala University, Uppsala, Sweden.
    Granqvist, C. G.
    The Ångström Laboratory, Department of Materials Science, Uppsala University, Uppsala, Sweden.
    Olsson, J.
    Department of Microbiology, Swedish University of Agricultural Sciences, Uppsala, Sweden.
    Schnürer, Johan
    Department of Microbiology, Swedish University of Agricultural Sciences, Uppsala, Sweden.
    Lantto, V.
    Microelectronics and Materials Physics Laboratories, University of Oulu, Linnanmaa, Oulu, Finland.
    Identifying natural and artificial odours through noise analysis with a sampling-and-hold electronic nose2001In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 77, no 1-2, p. 312-315Article in journal (Refereed)
    Abstract [en]

    A sampling-and-hold type electronic nose was used to investigate "frozen" sensor dynamics. The sensor was heated to the sensing temperature and exposed to a chemical environment for a short time. Then, while keeping the sensor in the chemical environment, the heating was switched off so that the sensor cooled down to room temperature. Chemicals species become trapped in the sensor film, and therefore, the current transport in the film is changed. The trapped chemicals are usually located at grain boundaries, and they influence the charge transport in the grains and between the grains. This gives random fluctuations to the local conductivity. Resistance noise was employed to extract chemical information from the sensor in the cold state.

  • 177.
    Soomro, Razium Ali
    et al.
    University of Sindh, Pakistan.
    Ibupoto, Zafar Hussain
    University of Sindh, Pakistan.
    Sirajuddin, n/a
    Univ Sindh, Natl Ctr Excellence Analyt Chem, Jamshoro 76080, Pakistan.
    Abro, Muhammad Ishaq
    Mehran Univ Engn & Technol, Dept Met & Mat Engn, Jamshoro 76080, Pakistan.
    Willander, Magnus
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Electrochemical sensing of glucose based on novel hedgehog-like NiO nanostructures2015In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 209, p. 966-974Article in journal (Refereed)
    Abstract [en]

    The present study reports the synthesis of novel hedgehog-like NiO nanostructures via hydrothermal method using L-cysteine as a structure directing agent. The as-synthesized hedgehog-like NiO nanostructures were characterized by scanning electron microscopy (SEM), X-ray photoelectron microscopy (XPS) X-ray diffraction (XRD) and Fourier transform infrared (FTIR) techniques for morphological, compositional and structural studies respectively. The prepared NiO nanostructures were applied for the design and engineering of non-enzymatic glucose sensor in the alkaline medium. The electrode material for glucose sensing based on the hedgehog-like NiO nanostructures demonstrated extremely high electrochemical response with high sensitivity (1052.8 mu A mM(-1) cm(-2)), low detection limit (LOD) (1.2 mu M), high selectivity, wide linear range (0.1-5.0 mu M) (R-2 = 0.9982) and the outstanding reproducibility. A plausible growth mechanism has been proposed to explain the formation process of the hedgehog-like NiO nanostructures. The excellent sensing performance can be attributed to the unique surface architectures, which enhanced the electron transfer rate and the molecular approach during the electrochemical sensing of glucose. Furthermore, the sensor showed excellent performance for the quantification of glucose in real blood sera reflecting universal nature of the presented glucose sensor. (C) 2014 Elsevier B.V. All rights reserved.

  • 178.
    Suriyanarayanan, Subramanian
    et al.
    Linnaeus Univ, Ctr Biomat Chem, Dept Chem & Biomed Sci, Bioorgan & Biophys Chem Lab, SE-39182 Kalmar, Sweden..
    Mandal, Sudip
    Indian Inst Technol Madras, Dept Chem, Chennai 600036, Tamil Nadu, India..
    Ramanujam, Kothandaraman
    Indian Inst Technol Madras, Dept Chem, Chennai 600036, Tamil Nadu, India..
    Nicholls, Ian
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Organic Chemistry. Linnaeus Univ, Ctr Biomat Chem, Dept Chem & Biomed Sci, Bioorgan & Biophys Chem Lab, SE-39182 Kalmar, Sweden.
    Electrochemically synthesized molecularly imprinted polythiophene nanostructures as recognition elements for an aspirin-chemosensor2017In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 253, p. 428-436Article in journal (Refereed)
    Abstract [en]

    A chemosensor utilizing electro-polymerized film, as recognition element, has been devised and tested for selective determination of aspirin. The sensor consists of molecularly imprinted polymer (MIP) recognition elements electrodeposited as polymeric nanowires on gold-coated quartz resonator. A nano structures were prepared by electrochemical co-polymerization of the preformed complex between the template, aspirin, the functional monomers, 3-thienylboronic acid (3-TBA) and 3-thiopheneacetic acid (3-TAA), and thiophene, which was employed as a cross-linker. This nanostructure upon leaching aspirin serve as MIP. Polymerizations were performed in acetonitrile (MIP-org) as well as a micelle forming medium (MIP-mic). For MIP nanowire (MIP-ano) synthesis, sacrificial alumina templates were used during electro-polymerization in acetonitrile. Scanning electron microscope studies revealed compactly arranged polythiophene nanowires of uniform thickness in MIP-ano film, and MIP-mic film produced aggregated micron sized polymer structures. Density functional theoretical studies indicated a stable hydrogen bond-based complexation of aspirin by 3-TBA and 3-TAA in the pre-polymerization mixture implying that the MIP film thus prepared could selectively rebind the aspirin template. The MIP-ano-based chemosensor was sensitive towards aspirin (0.5-10 mM), over clinically relevant range (0.15-0.5 mM) under optimized FIA conditions. The sensitivity (20.62 Hz/mM) of the MIP-ano was eight and fifteen times higher than the MIP-mic (2.80 Hz/mM) and MIP-org (1.10 Hz/mM). Notably, the sensor selectively discriminates aspirin from structurally or functionally related interferants and metabolites, such as, salicylic acid, acetylsalicyloyl chloride and ibuprofen.

  • 179.
    Suriyanarayanan, Subramanian
    et al.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Chemistry and Biomedical Sciences.
    Mandal, Sudip
    Indian Inst Technol Madras, India.
    Ramanujam, Kothandaraman
    Indian Inst Technol Madras, India.
    Nicholls, Ian A.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Chemistry and Biomedical Sciences. Uppsala University.
    Electrochemically synthesized molecularly imprinted polythiophene nanostructures as recognition elements for an aspirin-chemosensor2017In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 253, p. 428-436Article in journal (Refereed)
    Abstract [en]

    A chemosensor utilizing electro-polymerized film, as recognition element, has been devised and tested for selective determination of aspirin. The sensor consists of molecularly imprinted polymer (MIP) recognition elements electrodeposited as polymeric nanowires on gold-coated quartz resonator. A nano structures were prepared by electrochemical co-polymerization of the preformed complex between the template, aspirin, the functional monomers, 3-thienylboronic acid (3-TBA) and 3-thiopheneacetic acid (3-TAA), and thiophene, which was employed as a cross-linker. This nanostructure upon leaching aspirin serve as MIP. Polymerizations were performed in acetonitrile (MIP-org) as well as a micelle forming medium (MIP-mic). For MIP nanowire (MIP-ano) synthesis, sacrificial alumina templates were used during electro-polymerization in acetonitrile. Scanning electron microscope studies revealed compactly arranged polythiophene nanowires of uniform thickness in MIP-ano film, and MIP-mic film produced aggregated micron sized polymer structures. Density functional theoretical studies indicated a stable hydrogen bond-based complexation of aspirin by 3-TBA and 3-TAA in the pre-polymerization mixture implying that the MIP film thus prepared could selectively rebind the aspirin template. The MIP-ano-based chemosensor was sensitive towards aspirin (0.5-10 mM), over clinically relevant range (0.15-0.5 mM) under optimized FIA conditions. The sensitivity (20.62 Hz/mM) of the MIP-ano was eight and fifteen times higher than the MIP-mic (2.80 Hz/mM) and MIP-org (1.10 Hz/mM). Notably, the sensor selectively discriminates aspirin from structurally or functionally related interferants and metabolites, such as, salicylic acid, acetylsalicyloyl chloride and ibuprofen. (C) 2017 Elsevier B.V. All rights reserved.

  • 180. Sutka, A.
    et al.
    Mezinskis, G.
    Lusis, A.
    Stingaciu, M.
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK), Inorganic and Structural Chemistry.
    Gas sensing properties of Zn-doped p-type nickel ferrite2012In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 171, p. 354-360Article in journal (Refereed)
    Abstract [en]

    The influence of zinc ion to the NiFe2O4 p-type semiconductor gas response characteristics is demonstrated. For characterization of gas sensor material, synthesized by sol-gel auto combustion method. X-ray diffraction (XRD), scanning electron microscopy (SEM), DC resistance and impedance spectroscopy (IS) measurements were employed. The response change of Zn doped nickel ferrite is related to the interruption of hole hopping between nickel ions. This was improved by change of conductivity type with temperature and gas exposure.

  • 181. Svenningstorp, H.
    et al.
    Widén, Björn
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology.
    Salomonsson, P.
    Volvo TU, Applied Physics, 6130, Chalmers Teknikpark, SE-412 88 Göteborg, Sweden.
    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 .
    Tobias, P.
    Lloyd-Spets, Anita
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Detection of HC in exhaust gases by an array of MISiC sensors2001In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 77, no 1-2, p. 177-185Article in journal (Refereed)
    Abstract [en]

    Future legislations for car emissions make direct measurements in exhaust gases of hydrocarbon (HC) as well as CO and NOx interesting. Robust sensors that can stand the high temperature and rough environment in the exhaust gases are needed. Silicon carbide has the advantage of being a chemically very inert material, which, due to its high band gap, is a semiconductor even at temperatures around 800°C. Catalytic metal insulator silicon carbide Schottky diode sensors respond to gases like H2, HC, NOx in exhaust gases. The choice of catalytic metal, structure of the metal, and the operation temperature determines the response pattern to different gases. Here we will demonstrate that an array of different MISiC sensors to some extent predicts the HC concentration in gasoline exhaust gases. Chemometric methods are used for the evaluation of the signals. © 2001 Elsevier Science B.V.

  • 182.
    Svenningstorp, Henrik
    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.
    Lundström, Ingemar
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, The Institute of Technology.
    Salomonsson, Per
    AB Volvo Technological Development, Göteborg, Sweden.
    Mårtensson, Per
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Ekedahl, Lars-Gunnar
    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 catalytic reactivity on the response of metal-oxide-silicon carbide sensor to exhaust gases1999In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 57, no 1-3, p. 159-165Article in journal (Refereed)
    Abstract [en]

    Catalytic metal insulator silicon carbide, MISiC, Schottky diodes are promising devices for on board exhaust diagnosis in cars. These sensors show a direct or indirect sensitivity to gases like H-2, CO, HC (hydrocarbons) and O-2. The catalytic reactivity of the sensor will effect the gas sensing conditions. In some situations knowledge about the reactivity of the catalytic surface may give more information about the exhaust gas composition. For instance, the sensor signal normally moves to a lower voltage in an ambient containing H-2 and HC, however, under certain conditions when exposed to rich gas mixtures, the HC response is opposite the one for H-2. Measurements performed by the MISiC sensors on simulated exhaust gas mixtures, either rich or lean, are shown here. Some fundamental studies of the HC response have been performed. Reaction limitation conditions are suggested as an explanation for the response of HC opposite the one of H-2.

  • 183.
    Swerin, Agne
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface and Corrosion Science.
    Mira, I.
    Ink-jettable paper-based sensor for charged macromolecules and surfactants2014In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 195, 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.

  • 184.
    Söderström, Charlotte
    et al.
    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 .
    Krantz-Rülcher, Christina
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Recognition of six microbial species with an electronic tongue2003In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 89, no 3, p. 248-255Article in journal (Refereed)
    Abstract [en]

    An electronic tongue based on pulsed voltammetry over an array of electrodes with different selectivity and sensitivity patterns was used to recognize six different microorganisms: one yeast, two bacteria, and three molds. Measurements were performed during the whole growth period, from the lag phase to the stationary phase. The electrode array was dipped into the malt extract growth medium and voltage was applied over the electrodes in pulses of different amplitude and the resulting current data was sampled and collected in a matrix. Evaluation of the electronic tongue data was made with principal component analysis (PCA) and soft independent modeling of class analogy (SIMCA). PCA was performed on data from the lag, the logarithmic, and also the stationary growth phase. In the lag growth phase no recognition of species was visible in the PCA score plots. After further growth however all the included microbial species could be recognized from each other. The ability to predict membership of new replicates of the species to the right classes was verified with SIMCA. © 2003 Elsevier Science B.V. All rights reserved.

  • 185. Tang, Y.
    et al.
    Ding, Y.
    Li, Xin
    KTH, School of Biotechnology (BIO), Theoretical Chemistry and Biology.
    Ågren, Hans
    KTH, School of Biotechnology (BIO), Theoretical Chemistry and Biology.
    Li, T.
    Zhang, W.
    Xie, Y.
    Acylation of dipyrromethanes at the α and β positions and further development of fluorescent Zn2+ probes2014In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 206, p. 291-302Article in journal (Refereed)
    Abstract [en]

    The acylation of 5-aryl dipyrromethanes afforded products with interestingly rich substitution modes, i.e.; α- and β-monoacylated (modes a and b), and α, α′-, α, β′- and β, β′-diacylated (modes c-e). Especially, the β- and β, β′-acylation modes are unprecedented. And most of these products can be synthesized at a gram scale. The anisoyl substituted 5-(4-cyanophenyl) dipyrromethanes (1a-1e) were oxidized with DDQ. Thus, 1a and 1b afforded the corresponding dipyrrins 1a-DPR, and 1b-DPR. More interestingly, the diacylated ones 1c-1e could not be oxidized by DDQ. Instead, 1c-OH-1e-OH were obtained with a hydroxyl group attached to the 5-position. 1a-DPR-1e-OH were further developed as fluorescence turn-on Zn2+ probes. 1d-OH showed the highest sensitivity, with a detection limit of 1.5 × 10-8 M, and it was successfully applied in Zn2+ imaging in Hela cells. Furthermore, single crystals of two Zn2+ complexes were obtained and analyzed by X-ray diffraction.

  • 186. Teleki, A.
    et al.
    Pratsinis, S. E.
    Kalyanasundaram, K.
    Gouma, P. I.
    Sensing of organic vapors by flame-made TiO2 nanoparticles2006In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 119, no 2, p. 683-690Article in journal (Refereed)
    Abstract [en]

    Nanostructured anatase TiO2 was produced by flame spray pyrolysis (FSP) and tested for sensing of volatile organic compounds and CO at 500 degrees C. The as-prepared powders were characterized by transmission/scanning electron microscopy, X-ray diffraction and nitrogen adsorption. Titania films about 30 mu m thick on alumina substrates interdigitated with gold electrodes were prepared by drop-coating a heptanol suspension of these powders. The films showed a high signal of n-type sensor to isoprene, acetone and ethanol at concentrations ranging from 1 to 75 ppm in dry N-2/O-2 at 500 degrees C. The response (within seconds) and recovery (within minutes) times were very fast. Heat-treatment at 900 degrees C caused a nearly complete anatase to rutile transformation and a transition to p-type sensing behavior. That resulted in a poor sensor signal to all hydrocarbons tested and considerably longer recovery times than that of the anatase sensor. That rutile sensor could detect CO that the original, anatase sensor could not. For ethanol the sensor response changed back to n-type. (c) 2006 Elsevier B.V. All rights reserved.

  • 187. Teleki, Alexandra
    et al.
    Bjelobrk, Nada
    Pratsinis, Sotiris E.
    ETH, Dept Mech & Proc Engn, Inst Proc Engn, Particle Technol Lab, CH-8092 Zurich, Switzerland..
    Flame-made Nb- and Cu-doped TiO2 sensors for CO and ethanol2008In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 130, no 1, p. 449-457Article in journal (Refereed)
    Abstract [en]

    Nb- and Cu-doped TiO2 nanoparticles were produced by flame spray pyrolysis (FSP) and tested for sensing of CO and ethanol at 400 degrees C in dry air. The as-prepared powders were characterized by transmission electron microscopy, X-ray diffraction, Raman spectroscopy and nitrogen adsorption. Niobium stabilized the anatase phase and retarded grain growth up to 600 degrees C. Copper promoted rutile formation and an anatase to rutile transformation was already observed just above 400 degrees C during post-synthesis calcination. This was accompanied by a segregation of large (>100 nm) CuO crystals which were initially small (<5 nm) asperities on the titania surface. Pure as well as doped TiO2 showed an n-type signal to CO and ethanol. Both dopants improved the sensitivity towards CO over that of pure TiO2- In contrast, for ethanol a high increase in sensitivity was observed. only for Nb/TiO2. (C) 2007 Elsevier B.V All rights reserved.

  • 188.
    Tereshchenko, Alla
    et al.
    Odessa National II Mechnikov University, Ukraine.
    Bechelany, Mikhael
    University of Montpellier, France.
    Viter, Roman
    University of Latvia, Latvia.
    Khranovskyy, Volodymyr
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, Faculty of Science & Engineering.
    Smyntyna, Valentyn
    Odessa National II Mechnikov University, Ukraine.
    Starodub, Nikolay
    National University of Life and Environm Science, Ukraine.
    Yakimova, Rositsa
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, Faculty of Science & Engineering.
    Optical biosensors based on ZnO nanostructures: advantages and perspectives. A review2016In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 229, p. 664-677Article, review/survey (Refereed)
    Abstract [en]

    This review article highlights the application of beneficial physico-chemical properties of ZnO nanostructures for the detection of wide range of biological compounds. As the medical diagnostics require accurate, fast and inexpensive biosensors, the advantages inherent optical methods of detection are considered. The crucial points of the immobilization process, responsible for biosensor performance (biomolecule adsorption, surface properties, surface defects role, surface functionalization etc.) along with the interaction mechanism between biomolecules and ZnO are disclosed. The latest achievements in surface plasmon resonance (SPR), surface enhanced Raman spectroscopy (SERS) and photoluminescence based biosensors along with novel trends in the development of ZnO biosensor platform are presented. (c) 2016 Elsevier B.V. All rights reserved.

  • 189.
    Thorslund, Sara
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Larsson, Rolf
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology.
    Nikolajeff, Fredrik
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Bergquist, Jonas
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Physical and Analytical Chemistry, Analytical Chemistry.
    Sanchez, Javier
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology.
    Bioactivated PDMS microchannel evaluated as sensor for human CD4+ cells: The concept of a point-of-care method for HIV monitoring2007In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 123, no 2, p. 847-855Article in journal (Refereed)
    Abstract [en]

    Up to today, the number of CD4(+) lymphocytes remains the most important biological marker to determine the clinical stage of an HIV-infection. Analysis by flow cytometry, the standard method used today, is unsuitable in many developing countries, because of high costs involved and practical inconveniences. We here present the concept of an inexpensive PDMS-based point-of-care device for CD4(-)count. A simple fluorescence microscope for stained leucocytes counting is the only detection equipment needed. The biosensor surface consists of an initial heparin-based coating that adds hydrophilicity and thromboresistance to the PDMS material. The specific capturing chemistry is based on an avidin/biotin-antibody surface architecture. Pure capillary forces draw whole blood, as well as rinsing buffer, into the biosensor channel, minimizing the need of external equipment. Detection of the captured cells was performed by fluorescence imaging of HOECHST (stains cell nuclei) and CD3-FITC signals. It was shown that the non-specific adsorption of CD4(-) leucocytes was minimal to none. and the detection could therefore be done by only counting the easy identifiable HOECHST+ cells. Characterization of the biosensor coating process was additionally performed with the quartz crystal microbalance-dissipation technique.

  • 190.
    Tobias, Peter
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Mårtensson, Per
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Baranzahi, Amir
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Salomonsson, Per
    AB Volvo Technological Development, Göteborg, Sweden.
    Lundström, Ingemar
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, The Institute of Technology.
    Åbom, Lisa
    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.
    Response of metal-insulator-silicon carbide sensors to different components in exhaust gases1998In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 47, no 1-3, p. 125-130Article in journal (Refereed)
    Abstract [en]

    The effects of different components in simulated car exhaust gases on silicon carbide based field effect sensors are studied using a two-level factorial design. Strong effects are observed for H-2, hydrocarbons, and CO. The effects vary with temperature and can possibly be used for a multi-component analysis of exhaust gases.

  • 191.
    Tobias, Peter
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Mårtensson, Per
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Göras, Anders
    MECEL AB, Åmål, Sweden.
    Lundström, Ingemar
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. 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.
    Moving gas outlets for the evaluation of fast gas sensors1999In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 58, no 1-3, p. 389-393Article in journal (Refereed)
    Abstract [en]

    A new method for the evaluation of fast gas sensors is described. By using moving gas outlets, we can quickly change the ambient around a sensor. Different platinum-insulator-silicon carbide (MISiC) structures are investigated. Their sensor response contains fast components, which respond within milliseconds to a change in the ambient from a reducing gas to an oxidising gas and vice versa. Cylinder specific monitoring of car engines with the MISiC structures is discussed.

  • 192.
    Trawka, Maciej
    et al.
    Gdansk Univ Technol, Fac Elect Telecommun & Informat, Narutowicza 11-12, PL-80233 Gdansk, Poland..
    Smulko, Janusz
    Gdansk Univ Technol, Fac Elect Telecommun & Informat, Narutowicza 11-12, PL-80233 Gdansk, Poland..
    Hasse, Lech
    Gdansk Univ Technol, Fac Elect Telecommun & Informat, Narutowicza 11-12, PL-80233 Gdansk, Poland..
    Granqvist, Claes-Göran
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Annanouch, Fatima Ezahra
    Univ Rovira & Virgili, Dept Elect Elect & Automat Engn, E-43007 Tarragona, Spain..
    Ionescu, Radu
    Univ Rovira & Virgili, Dept Elect Elect & Automat Engn, E-43007 Tarragona, Spain..
    Fluctuation enhanced gas sensing with WO3-based nanoparticle gas sensors modulated by UV light at selected wavelengths2016In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 234, p. 453-461Article in journal (Refereed)
    Abstract [en]

    The sensitivity and selectivity of WO3-based gas sensors can be enhanced by UV-irradiation-induced modulation, especially if different wavelengths are employed. We used fluctuation-enhanced gas sensing, based on measurements of resistance fluctuations in the gas sensor, to study the effects of such modulation on the noise intensity for ambient atmospheres of synthetic air without and with additions of small amounts of ethanol, methane and formaldehyde. Our data confirmed that the method is energy efficient and can be applied to improve gas detection sensitivity and selectivity. The results are strongly dependent on the gaseous species, and a single UV-modulated WO3-based gas sensor discriminate between different gases.

  • 193.
    Trincavelli, Marco
    et al.
    Örebro University, School of Science and Technology.
    Coradeschi, Silvia
    Örebro University, School of Science and Technology.
    Loutfi, Amy
    Örebro University, School of Science and Technology.
    Odour classification system for continuous monitoring applications2009In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 58, no 2, p. 265-273Article in journal (Refereed)
    Abstract [en]

    In this paper, we investigate the classification performance of an electronic nose system, based on tin dioxide gas sensors. In contrast to previous studies, the electronic nose is mounted on a mobile platform and samples are analyzed using only transient information in the signals. The motivation behind this work is to explore the feasibility of using electronic nose devices for odour classification in a number of future application domains which require fast and possibly real-time odour identification. To perform transient based analysis of the signals, a comparative study of different methods for feature extraction was performed. Additionally, the application of a relevance vector machine classifier is explored to further analyze the classification performance based on quality of the obtained samples. The results presented in this study can be used for the development of electronic nose devices particularly suitable for environmental monitoring applications.

  • 194.
    Trinh, Minh Ngoc
    et al.
    Hanoi University of Science and Technology.
    Duy, Nguyen Van
    Hanoi University of Science and Technology.
    Nguyen Duc, Hoa
    Hanoi University of Science and Technology.
    Chu, Manh Hung
    Hanoi University of Science and Technology.
    Nguyen, Hugo
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Hieu, Nguyen Van
    Faculty of Electrical and Electronics Engineering and Phenikaa Institute for Advanced Study, Phenikaa University, Viet Nam ; Phenikaa Research and Technology Institute (PRATI), A&A Green Phoenix Group, Viet Nam.
    Effective design and fabrication of low-power-consumption self-heated SnO2 nanowire sensors for reducing gases2019In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 295, p. 144-152Article in journal (Refereed)
    Abstract [en]

    Developing metal oxide gas sensors for internet-of-things (IoT) and portable applications require low-power consumption because of the limited battery in devices. This requirement is challenging because metal oxide sensors generally need high working temperatures, especially for reducing gases. Herein, we present an effective design and fabrication method of a SnO2 nanowire (NW) sensor for reducing gases by using the Joule heating effect at NW nanojunctions without needing an external or integrated heater. The sensor’s low-power consumption at around 4 mW was controlled by the size and nanojunction density of the device. The sensor has a simple design and is easy to fabricate. A proof-of-concept of a portable gas sensor module can be realised for monitoring highly toxic reducing gases, such as H 2S, NH3 and C2H5OH, by using the developed self-heated NWs.

    The full text will be freely available from 2021-05-23 11:25
  • 195.
    Tybrandt, Klas
    et al.
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Babu Kollipara, Suresh
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Berggren, Magnus
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Organic electrochemical transistors for signal amplification in fast scan cyclic voltammetry2014In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 195, p. 651-656Article in journal (Refereed)
    Abstract [en]

    Fast scan cyclic voltammetry (FSCV) is an electrochemical method commonly used in neuroscience for spatiotemporal measurement of the concentration of dopamine and other electroactive species. Since FSCV involves wide bandwidth measurements of low currents, the technique is normally very sensitive to electrical noise and is typically performed inside a Faraday cage. In order to reduce the electrical noise and to enable measurements in an unshielded environment, we take use of an organic electrochemical transistor (OECT) to amplify the FSCV signals. OECTs based on the conducting polymer poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) were microfabricated and characterized. A patterned 10 mu m gold microelectrode was used as the sensing electrode and the FSCV signal was amplified by the OECT. With this approach, successful measurements of dopamine concentrations in the 10 mu m range were performed in a completely unshielded measurement setup. Our results demonstrate how OECTs can successfully be used in an on-site amplification application to characterize biochemical signals, thus open up new trails for flexible multifunctional organic bioelectronics systems.

  • 196. Uchida, H
    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 .
    Unsupervised scanning light pulse technique for chemical sensing2004In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 103, no 01-Feb, p. 225-232Article in journal (Refereed)
    Abstract [en]

    A scanning light pulse technique (SLPT) operating in a totally unsupervised way suitable for chemical sensing and the efficient screening of new sensing materials is demonstrated. The procedure automatically determines inflexion points (optimum biasing condition) and photocurrent amplitudes from locally acquired i-V characteristics of metal-insulator-semiconductor structures that enables optimum biased measurements properly re-scaled to avoid spurious amplifying effects. Additionally, the procedure allows composing flat-band voltage shift patterns within the same experiment, and avoiding feedback mode measurements. Optimum bias patterns when used to modulate subsequent measurements, allow a fast recording mode. (C) 2004 Elsevier B.V. All rights reserved.

  • 197.
    Ulrich, Christian
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics . Linköping University, The Institute of Technology.
    Petersson, Henrik
    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.
    Björefors, Fredrik
    Linköping University, Department of Physics, Chemistry and Biology, Sensor Science and Molecular Physics . Linköping University, The Institute of Technology.
    Krantz-Rülcker, Christina
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics . Linköping University, The Institute of Technology.
    Simultaneous estimation of soot and diesel contamination in engine oil using electrochemical impedance spectroscopy2007In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 127, no 2, p. 613-618Article in journal (Refereed)
    Abstract [en]

    In this paper, we explore the combination of electrochemical impedance spectroscopy and multivariate data analysis to simultaneously predict the concentrations of soot and diesel in engine oil. For this purpose, we use a well defined measurement set-up to minimize interference from ambient noise, and to obtain a large amount of data in a short period of time. An imperative requirement is that soot and diesel affect the impedance in different ways over the employed frequency range. It was, for example, found that diesel had a larger influence at lower frequencies. Using partial least squares modelling we show that it is possible to simultaneously predict the concentrations of both soot and diesel in engine oil. Since the temperature in an engine varies, the influence of the oil temperature is investigated in a preliminary experiment. This study is a part of the development of an electrochemical on-board sensor for real-time monitoring of engine oil.

  • 198.
    Usman Ali, Syed
    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.
    Salman, Salah
    Acromed Invest AB, SE-22643 Lund, Sweden .
    Nur, Omer
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Willander, Magnus
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Danielsson, Bengt
    Acromed Invest AB.
    Selective determination of urea using urease immobilized on ZnO nanowires2011In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 160, no 1, p. 637-643Article in journal (Refereed)
    Abstract [en]

    Well-aligned zinc oxide (ZnO) nanowire arrays were fabricated on gold-coated plastic substrates using a low-temperature aqueous chemical growth (ACG) method. The ZnO nanowire arrays with 50-130 nm diameters and similar to 1 mu m in lengths were used in an enzyme-based urea sensor through immobilization of the enzyme urease that was found to be sensitive to urea concentrations from 0.1 mM to 100 mM. Two linear sensitivity regions were observed when the electrochemical responses (EMF) of the sensors were plotted vs. the logarithmic concentration range of urea from 0.1 mM to 100 mM. The proposed sensor showed a sensitivity of 52.8 mV/decade for 0.1-40 mM urea and a fast response time less than 4s was achieved with good selectivity, reproducibility and negligible response to common interferents such as ascorbic acid and uric acid, glucose. K(+) and Na(+) ions.

  • 199.
    Usman Ali, Syed M
    et al.
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Nour, Omer
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Willander, Magnus
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Danielsson, B.
    Lund University.
    A fast and sensitive potentiometric glucose microsensor based on glucose oxidase coated ZnO nanowires grown on a thin silver wire2010In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 145, no 2, p. 869-874Article in journal (Refereed)
    Abstract [en]

    In this study, a potentiometric glucose biosensor was fabricated by immobilization of glucose oxidase on to zinc oxide nanowires. Zinc oxide nanowires with 250-300 nm diameters and approximately 1.2 mu m lengths were grown on the surface of silver wires with a diameter of 250 mu m. Glucose oxidase (GOD) was electrostatically immobilized on the surface of the well aligned zinc oxide nanowires resulting in sensitive, selective, stable and reproducible glucose biosensors. The potentiometric response vs. Ag/AgCl reference electrode was found to be linear over a relatively wide logarithmic concentration range (0.5-1000 mu M) suitable for intracellular glucose detection. By applying a membrane on the sensor the linear range could be extended to 0.5 mu M to 10 mM, which increased the response time from less than 1 to 4s. On the other hand the membrane increased the sensor durability considerably. The sensor response was unaffected by normal concentrations of common interferents with glucose sensing such as uric acid and ascorbic acid.

  • 200.
    Usman Ali, Syed
    et al.
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Ul Hassan Alvi, Naveed
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Hussain Ibupoto, Zafar
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Nur, Omer
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Willander, Magnus
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Danielsson, Bengt
    Acromed Invest AB.
    Selective potentiometric determination of uric acid with uricase immobilized on ZnO nanowires2011In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 152, no 2, p. 241-247Article in journal (Refereed)
    Abstract [en]

    In this study, a potentiometric uric acid biosensor was fabricated by immobilization of uricase onto zinc oxide (ZnO) nanowires. Zinc oxide nanowires with 80-150 nm in diameter and 900 nm to 1.5 mu m in lengths were grown on the surface of a gold coated flexible plastic substrate. Uricase was electrostatically immobilized on the surface of well aligned ZnO nanowires resulting in a sensitive, selective, stable and reproducible uric acid biosensor. The potentiometric response of the ZnO sensor vs Ag/AgCl reference electrode was found to be linear over a relatively wide logarithmic concentration range (1-650 mu M) suitable for human blood serum. By applying a Nafion (R) membrane on the sensor the linear range could be extended to 1-1000 mu M at the expense of an increased response time from 6.25 s to less than 9 s. On the other hand the membrane increased the sensor durability considerably. The sensor response was unaffected by normal concentrations of common interferents such as ascorbic acid, glucose, and urea.

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