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  • 51.
    Darmastuti, Zhafira
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Bhattacharyya, P.
    Dept. of Electronics and Telecommunication Engineering, Bengal Engineering and Science University, India.
    Andersson, Mike
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Kanungo, Jayita
    IC Design & Fabrication Centre, Dept. of Electronics & Telecommunications Engineering, Jadavpur University, Kolkata, India.
    Basu, Sukumar
    IC Design & Fabrication Centre, Dept. of Electronics & Telecommunications Engineering, Jadavpur University, Kolkata, India.
    Käll, Per-Olov
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Inorganic Chemistry.
    Ojamäe, Lars
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Chemistry.
    Lloyd Spetz, Anita
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    SiC-FET methanol sensors for process control and leakage detection2013In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 187, no SI, p. 553-562Article in journal (Refereed)
    Abstract [en]

    Two types of SiC based field effect transistor sensors, with Pt or Ir gate, were tested to detect methanol in the concentration range of 0–1600 ppm for both process control and leak detection applications. The methanol response was investigated both with and without oxygen, since the process control might be considered as oxygen free application, while the sensor is operated in air during leak detection. Pt sensors offered very fast response with appreciably high response magnitude at 200 °C, while Ir sensors showed both higher response and response time up to 300 °C, but this decreased considerably at 350 °C. Cross sensitivity effect in presence of oxygen, hydrogen, propene and water vapor was also investigated. The presence of oxygen improved the response of both sensors, which is favorable for the leak detection application. Hydrogen had a large influence on the methanol response of both sensors, propene had a negligible influence, while water vapor changed direction of the methanol response for the Pt sensor. The detection mechanism and different sensing behavior of Pt and Ir gate sensors were discussed in the light of model reaction mechanisms derived from hybrid density-functional theory quantum-chemical calculations.

  • 52.
    Darmastuti, Zhafira
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Applied Sensor Science. Linköping University, The Institute of Technology.
    Bur, Christian
    Linköping University, Department of Physics, Chemistry and Biology, Applied Sensor Science. Linköping University, The Institute of Technology. Saarland University.
    Lindqvist, Niclas
    Alstom Power AB, Växjö, Sweden.
    Anderson, Mike
    Linköping University, Department of Physics, Chemistry and Biology, Applied Sensor Science. Linköping University, The Institute of Technology.
    Schutza, Andreas
    Saarland University, Saarbrücken, Germany.
    Lloyd Spetz, Anita
    Linköping University, Department of Physics, Chemistry and Biology, Applied Sensor Science. Linköping University, The Institute of Technology.
    Hierarchical methods to improve the performance of the SiC - FET as SO2 sensors in flue gas desulphurization system2015In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 206, p. 609-616Article in journal (Refereed)
    Abstract [en]

    Experiments were performed both in the laboratory and a desulfurization pilot unit in order to improve the SiC-FET sensor performance using two-step data evaluation. In both cases, a porous Pt-gate enhancement type SiC-FET was utilized in a temperature cycled operation (TCO). Liner Discriminant Analysis (LDA) was chosen as the method for multivariate data analysis. Hierarchical methods with two-step LDA worked quite well in the laboratory tests with SO2 concentrations varied from 25-200 ppm. The same data evaluation was also applied to tests in the desulfurization pilot unit, with higher gas flow and a larger SO2 concentration range (up to 5000 ppm). The results from the SO2 quantification showed a significantly improved fit to corresponding reference instrument (FTIR) values.

  • 53.
    Darmastuti, Zhafira
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Applied Sensor Science. Linköping University, The Institute of Technology.
    Bur, Christian
    Linköping University, Department of Physics, Chemistry and Biology, Applied Sensor Science. Linköping University, The Institute of Technology.
    Möller, Peter
    Linköping University, Department of Physics, Chemistry and Biology, Applied Sensor Science. Linköping University, The Institute of Technology.
    Rahlin, R.
    Alstom Power AB, Sweden .
    Lindqvist, Niclas
    Alstom Power AB, Sweden .
    Andersson, Mike
    Linköping University, Department of Physics, Chemistry and Biology, Applied Sensor Science. Linköping University, The Institute of Technology.
    Schuetze, A.
    University of Saarland, Germany .
    Lloyd Spetz, Anita
    Linköping University, Department of Physics, Chemistry and Biology, Applied Sensor Science. Linköping University, The Institute of Technology.
    SiC-FET based SO2 sensor for power plant emission applications2014In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 194, p. 511-520Article in journal (Refereed)
    Abstract [en]

    Thermal power plants produce SO2 during combustion of fuel containing sulfur. One way to decrease the SO2 emission from power plants is to introduce a sensor as part of the control system of the desulphurization unit. In this study, SiC-FET sensors were studied as one alternative sensor to replace the expensive FTIR (Fourier Transform Infrared) instrument or the inconvenient wet chemical methods. The gas response for the SiC-FET sensors comes from the interaction between the test gas and the catalytic gate metal, which changes the electrical characteristics of the devices. The performance of the sensors depends on the ability of the test gas to be adsorbed, decomposed, and desorbed at the sensor surface. The feature of SO2, that it is difficult to desorb from the catalyst surface, makes it known as catalyst poison. It is difficult to quantify the SO2 with static operation, even at the optimum operation temperature of the sensor due to low response levels and saturation already at low concentration of SO2. The challenge of SO2 desorption can be reduced by introducing dynamic operation in a designed temperature cycle operation (TCO). The intermittent exposure to high temperature can help to desorb SO2. Simultaneously, additional features extracted from the sensor data can be used to reduce the influence of sensor drift. The TCO operation, together with pattern recognition, may also reduce the baseline and response variation due to changing concentration of background gases (4-10% O-2 and 0-70% RH), and thus it may improve the overall sensor performance. In addition to the laboratory experiment, testing in the desulphurization pilot unit was performed. Desulphurization pilot unit has less controlled environment compared to the laboratory conditions. Therefore, the risk of influence from the changing concentration of background gas is higher. In this study, linear discriminant analysis (LDA) and partial least square (PLS) were employed as pattern recognition methods. It was demonstrated that using LDA quantification of SO2 into several groups of concentrations up to 2000 ppm was possible. Additionally, PLS analysis indicated a good agreement between the predicted value from the model and the SO2 concentration from the reference instrument of the pilot plant.

  • 54. Davydova, Marina
    et al.
    Stuchlik, Martin
    Rezek, Bohuslav
    Larsson, Karin
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Kromka, Alexander
    Sensing of phosgene by a porous-like nanocrystalline diamond layer with buried metallic electrodes2013In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 188, p. 675-680Article in journal (Refereed)
    Abstract [en]

    Nanocrystalline diamond with a porous-like morphology was used as the functional part of a semiconductor gas sensor. The device function is based on the two-dimensional p-type surface conductivity of intrinsic diamond with a H-terminated surface. Metallic electrodes are buried beneath the diamond film. Therefore, these electrodes are protected from harmful substances, and the electronic connection is facilitated by grain boundaries. The gas sensing properties of the sensor structure were examined using oxidising gases (i.e., phosgene, humid air) at various operating temperatures. A pronounced and selective increase by two orders of magnitude was found in the surface conductivity after sensor exposure to phosgene gas (20 ppm) at 140 degrees C. Density functional theory calculations indicated no direct charge transfer between the phosgene molecule and diamond. We present a model in which phosgene indirectly yet efficiently increases the H3O+ concentration, which consequently leads to multiplied electron transfer and a pronounced sensor response. 

  • 55.
    Dini, Francesca
    et al.
    University of Roma Tor Vergata, Italy .
    Filippini, Daniel
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Paolesse, Roberto
    University of Roma Tor Vergata, Italy .
    Lundström, Ingemar
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, The Institute of Technology.
    Di Natale, Corrado
    University of Roma Tor Vergata, Italy .
    Computer screen assisted digital photography2013In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 179, no SI, p. 46-53Article in journal (Refereed)
    Abstract [en]

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

  • 56.
    Donarelli, Maurizio
    et al.
    SENSOR Lab., Department of Information Engineering, University of Brescia.
    Milan, Riccardo
    SENSOR Lab., Department of Information Engineering, University of Brescia.
    Rigoni, Federica
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science. SENSOR Lab., Department of Information Engineering, University of Brescia.
    Drera, Giovanni
    Department of Mathematics and Physics, Catholic University of Sacred Heart.
    Sangaletti, Luigi
    Department of Mathematics and Physics, Catholic University of Sacred Heart.
    Ponzoni, Andrea
    National Institute of Optics, National Research Council (CNR-INO), Unit of Brescia.
    Baratto, Camilla
    SENSOR Lab., Department of Information Engineering, University of Brescia.
    Sberveglier, Giorgio
    SENSOR Lab., Department of Information Engineering, University of Brescia.
    Comini, Elisabetta
    SENSOR Lab., Department of Information Engineering, University of Brescia.
    Anomalous gas sensing behaviors to reducing agents of hydrothermally grown α-Fe2O3 nanorods2018In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 273, p. 1237-1245Article in journal (Refereed)
    Abstract [en]

    α-Fe2O3 nanorods have been grown by hydrothermal method, dispersed in ethanol and drop casted on a pre-patterned alumina substrate with Pt electrodes. Their morphology, crystalline and electronic properties have been investigated by Scanning Electron Microscopy, Raman and X-ray Photoelectron Spectroscopies and X-ray Diffraction. The so-fabricated devices have been used for hydrogen gas sensing, showing their ability to detect H2 at operating temperatures > 200 °C, at relative humidity values comprised from 0% to 50%. The sensing behavior of α-Fe2O3 nanorods is compatible with an n to p conductivity transition when the operating temperature is increased up to 300 °C. Outstanding p-type hydrogen sensing performances of α-Fe2O3 have been observed and reported. Besides H2 detection, the α-Fe2O3 nanorods-based device is a good humidity sensor, at room temperature (n-type) and at 400 °C (p-type). CO and ethanol sensing performances have been investigated at different operating temperatures and relative humidity values. CO and ethanol anomalous acceptor-like behaviors at 200 °C in humid air has been explained by the interactions of these target gases with the water molecules adsorbed on the metal oxide surfaces. An explanation of the n–p behavior transition at T > 200 °C in terms of band bending is reported.

  • 57.
    Elhag, Sami
    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, Physics and Electronics. Linköping University, The Institute of Technology.
    Liu, Xianjie
    Linköping University, Department of Physics, Chemistry and Biology, Surface Physics and Chemistry. Linköping University, The Institute of Technology.
    Nur, Omer
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Willander, Magnus
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Dopamine wide range detection sensor based on modified Co3O4 nanowires electrode2014In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 203, p. 543-549Article in journal (Refereed)
    Abstract [en]

    Ultra-thin cobalt oxide (Co3O4) nanowires grown on gold coated glass substrates by the hydrothermal chemical deposition and have been used as a wide range dopamine potentiometric sensor. An anionic surfactant ( sodium dodecylbenzenesulfonate) was used to achieve assisted growth procedure. Moreover, a polymeric membrane containing polyvinyl chloride as plasticized polymer, p-cyclodextrin as ionophore, and potassium tetrakis (4-chlorophenyl) borate as ionic additive were immobilized on the Co3O4 nanostructures through electrostatic adsorption method. X-ray diffraction, X-ray photoelectron spectroscopy, and scanning electron microscopy were used to characterize the electrodes while ultraviolet-visible absorption was used to investigate the band gap of the Co3O4 nanostructures. The structural characterization showed a cubic crystalline, pure phase, and nanowires morphology of the Co3O4. However, the morphology is altered when the surfactant concentration has been changed. The Co3O4 chemical modified electrodes were used in potentiometric measurements for dopamine in a 10(-2) M acetic acid/sodium acetate solution having a pH of 5.45. For dopamine range from 10(-9) M to 10(-2) M, the potential response of the sensor electrode was linear with a slope of 52 mV/decade. The wide range and high sensitivity of the modified Co3O4 nanowires based sensor for dopamine is attributed to the defects on the metal oxide that is dictated by the used surfactant along with the high surface area-to-volume ratio.

  • 58.
    Eriksson, Jens
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Khranovskyy, Volodymyr
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, The Institute of Technology.
    Söderlind, Fredrik
    Linköping University, Department of Physics, Chemistry and Biology, Chemistry. Linköping University, Faculty of Science & Engineering.
    Käll, Per-Olov
    Linköping University, Department of Physics, Chemistry and Biology, Physical Chemistry. Linköping University, The Institute of Technology.
    Yakimova, Rositsa
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, The Institute of Technology.
    Lloyd-Spets, Anita
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    ZnO nanoparticles or ZnO films: A comparison of the gas sensing capabilities2009In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 137, no 1, p. 94-102Article in journal (Refereed)
    Abstract [en]

    Zinc oxide is an interesting material for bio and chemical sensors. it is a semiconducting metal oxide with potential as an integrated multisensing sensor platform, which simultaneously detects Parameters like change in field effect, mass and Surface resistivity. in this investigation we have used resistive sensor measurements regarding the oxygen gas sensitivity in order to characterize sensing layers based on electrochemically produced ZnO nanoparticles and PE-MOCVD grown ZnO films. Proper annealing procedures were developed in order to get stable sensing properties and the oxygen sensitivity towards operation temperature was investigated. The ZnO nanoparticles showed a considerably increased response to oxygen as compared to the films. Preliminary investigations were also performed regarding the selectivity to other gases present in car exhausts or flue gases.

  • 59.
    Eriksson, Mats
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Chemical and Optical Sensor Systems. Linköping University, Faculty of Science & Engineering.
    Ekedahl, Lars-Gunnar
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, The Institute of Technology.
    The influence of CO on the response of hydrogen sensitive Pd-MOS devices1997In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 42, no 3, p. 217-223Article in journal (Refereed)
    Abstract [en]

    In order to understand and correctly interpret the response of chemical sensors under measurement conditions, detailed studies of molecule—sensor interactions under well-controlled conditions are needed. In this work, the influence of CO on the response of a hydrogen sensitive Pd—metal-oxide-semiconductor (Pd—MOS) device with a dense Pd film is studied in ultrahigh vacuum (UHV). The results show that although CO by itself does not induce any response of the device, CO may have a significant influence on the hydrogen response, especially so in the presence of oxygen. It is also shown that high CO coverages on the Pd surface increases the time needed to obtain equilibrium between the gas phase hydrogen pressure and the response of the Pd—MOS device. This is due to a CO induced increase of the activation energies of the dissociation and association processes for hydrogen. The effect on the hydrogen response is small for CO coverages below 0.2 monolayers and increases dramatically above this coverage.

  • 60.
    Eriksson, Mats
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Iqbal, Zafar
    Linköping University, Department of Physics, Chemistry and Biology, Chemical and Optical Sensor Systems. Linköping University, Faculty of Science & Engineering.
    Two measurement modes for mobile phone optical sensing2014In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 195, p. 63-70Article in journal (Refereed)
    Abstract [en]

    The use of a mobile phone for classification and quantification of liquid samples is described. The screen of the phone is used for controlled illumination and the front side camera for imaging. No additional optical equipment is needed. It is shown that there are different regions of the captured image containing different information about the sample. One region contains light that has been specular reflected at the air-liquid interface and one is dominated by light that has propagated through the liquid. The specular reflected light contains information about the refractive index of the liquid sample whereas the transmitted light contains information about color and absorption. It is found that the specular reflectance increases linearly with increasing refractive index, n, in the range 1.33 less than n less than 1.38, as expected from the Fresnel equations. A change of the refractive index of about 0.004 refractive units can be detected. The transmitted light intensity is well described by the Beer-Lambert law over a large absorption range. Light from the two different areas of the image is used to analyze several types of liquid samples. It is shown that a combination of the two measurement modes improves the classification abilities of the mobile phone.

  • 61.
    Fan, Han
    et al.
    Örebro University, School of Science and Technology.
    Hernandez Bennetts, Victor
    Örebro University, School of Science and Technology.
    Schaffernicht, Erik
    Örebro University, School of Science and Technology.
    Lilienthal, Achim
    Örebro University, School of Science and Technology.
    A cluster analysis approach based on exploiting density peaks for gas discrimination with electronic noses in open environments2018In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 259, p. 183-203Article in journal (Refereed)
    Abstract [en]

    Gas discrimination in open and uncontrolled environments based on smart low-cost electro-chemical sensor arrays (e-noses) is of great interest in several applications, such as exploration of hazardous areas, environmental monitoring, and industrial surveillance. Gas discrimination for e-noses is usually based on supervised pattern recognition techniques. However, the difficulty and high cost of obtaining extensive and representative labeled training data limits the applicability of supervised learning. Thus, to deal with the lack of information regarding target substances and unknown interferents, unsupervised gas discrimination is an advantageous solution. In this work, we present a cluster-based approach that can infer the number of different chemical compounds, and provide a probabilistic representation of the class labels for the acquired measurements in a given environment. Our approach is validated with the samples collected in indoor and outdoor environments using a mobile robot equipped with an array of commercial metal oxide sensors. Additional validation is carried out using a multi-compound data set collected with stationary sensor arrays inside a wind tunnel under various airflow conditions. The results show that accurate class separation can be achieved with a low sensitivity to the selection of the only free parameter, namely the neighborhood size, which is used for density estimation in the clustering process.

  • 62.
    Fernández, C. De Julián
    et al.
    Dipartimento di Fisica Sperimentale, Università di Torino.
    Manera, M. G.
    CNR-IMM Sezione di Bologna.
    Spadavecchia, J.
    CNR-IMM Sezione di Bologna.
    Maggioni, G.
    Dipartimento di Fisica Sperimentale, Università di Torino.
    Quaranta, A.
    Laboratori Nazionali di Legnaro.
    Mattei, G.
    Dipartimento di Fisica Sperimentale, Università di Torino.
    Bazzan, M.
    Dipartimento di Fisica Sperimentale, Università di Torino.
    Cattaruzza, E.
    Dipartimento di Fisica Sperimentale, Università di Torino.
    Bonafini, M.
    Dipartimento di Fisica Sperimentale, Università di Torino.
    Negro, E.
    Dipartimento di Fisica Sperimentale, Università di Torino.
    Vomiero, Alberto
    Dipartimento di Fisica, Università di Padova.
    Carturan, S.
    Dipartimento di Fisica Sperimentale, Università di Torino.
    Scian, C.
    Dipartimento di Fisica Sperimentale, Università di Torino.
    Mea, G. Della
    Laboratori Nazionali di Legnaro.
    Rella, R.
    CNR-IMM Sezione di Bologna.
    Vasanelli, L.
    CNR-IMM Sezione di Bologna.
    Mazzoldi, P.
    Dipartimento di Fisica Sperimentale, Università di Torino.
    Study of the gas optical sensing properties of Au-polyimide nanocomposite films prepared by ion implantation2005In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 111-112, no SUPPL., p. 225-229Article in journal (Refereed)
    Abstract [en]

    Au-polyimide nanocomposites have been synthesized by implanting Au + ions in pyromellitic dianhydride-4,4′ oxydianiline polyimide films prepared by glow discharge vapor deposition polymerisation (GDVDP). A structural and optical characterization shows that Au clusters grow only implanting 5 × 1016 Au+/cm2. This sample class shows interesting dynamic optical absorption sensing responses towards methanol and ethanol vapors in the spectral range corresponding to the surface plasmon resonance (SPR) peak of the gold nanoparticles. Traditional surface plasmon resonance measurements performed onto virgin polyimide thin films in controlled atmosphere show a sensing activity due to a variation of the film thickness and of the real part of refractive index. The comparison of the results obtained onto virgin films and implanted ones suggests that the sensing mechanisms can be attributed both to the modification of polymer optical properties and to the chemical activity of gold nanoparticles. © 2005 Elsevier B.V. All rights reserved.

  • 63.
    Filippini, D.
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Fraigi, L.
    Laboratorio de Sensores, CITEI-National Institute of Industrial Technology, CC 157, 1650 San Martín, Argentina.
    Aragon, R.
    Aragón, R., Laboratorio de Películas Delgadas, Fac. de Ing., Univ. de Buenos Aires and PRINSO-CONICET-CITEFA, Paseo Colon 850, 1063 Cap. Fed., Argentina.
    Weimar, U.
    Institute of Physical and Theoretical Chemistry, University of Tübingen, auf der Morgenstelle 8, D-72076 Tübingen, Germany.
    Thick film Au-gate field-effect devices sensitive to NO22002In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 81, no 2-3, p. 296-300Article in journal (Refereed)
    Abstract [en]

    Screen printed thick film gold gate MOS capacitors are selectively sensitive to the presence of NO2 in air. Metallo-organic gold inks produce open gate structures, with positive flat-band-voltage shifts of 2.72mV/ppm at 140ppm of NO2 in air, comparable to PVD deposited thin film devices. Standard gold pastes are denser, coarser grained thick films of alloyed composition, which reverse the polarity of the flat-band-voltage shift. No cross sensitivity to H2 or NO is apparent. © 2002 Elsevier Science B.V. All rights reserved.

  • 64.
    Filippini, D.
    et al.
    Institute of Physical and Theoretical Chemistry, University of Tübingen, Auf der Morgenstelle 8, D-72076 Tübingen, Germany.
    Weiss, T.
    Weiß, T., Institute of Physical and Theoretical Chemistry, University of Tübingen, Auf der Morgenstelle 8, D-72076 Tübingen, Germany.
    Aragon, R.
    Aragón, R., Laboratorio de Películas Delgadas, Facultad de Ingeniería, Universidad de Buenos Aires and Prinso-Conicet-Citefa, Paseo Colón 850 (1063), Capital Federal, Argentina.
    Weimar, U.
    Institute of Physical and Theoretical Chemistry, University of Tübingen, Auf der Morgenstelle 8, D-72076 Tübingen, Germany, Division of Applied Physics, Department of Physics and Measurement Technology, Linkoping University, SE-581 83 Linkoping, Sweden.
    New NO2 sensor based on Au gate field effect devices2001In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 78, no 1-3, p. 195-201Article in journal (Refereed)
    Abstract [en]

    A new NO2 field effect gas sensor based on Au gates is demonstrated and the influence of gate morphology on sensor response is evaluated. A sensitization mechanism, for non-catalytic continuous gates, based on grain boundary diffusion is proposed. The sensors are fabricated as MOS (metal-oxide-semiconductor) capacitors with sputtered or thermal evaporated Au gates (at different substrate temperatures) with thickness between 75 and 960 nm. The devices' sensitivity, in the range of 15-200 ppm of NO2 in dry air, depends strongly on gate morphology, shorter response times and larger voltage shifts are correlated with smaller grain sizes. Scanning-electron-microscope (SEM) images show that the microstructure is very stable after 5 months of gas exposure at temperatures up to 200°C. The sensors are selective to NO2 (with NO, H2 and CO as interfering gases) and selectivity depends also on gate structure. © 2001 Elsevier Science B.V. All rights reserved.

  • 65.
    Filippini, Daniel
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Bakker, Jimmy
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Optics .
    Lundström, Ingemar
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Fingerprinting of fluorescence substances for diagnostic purposes using computer screen illumination2004In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 106, p. 302-310Article in journal (Refereed)
  • 66.
    Filippini, Daniel
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Bakker, Jimmy
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Optics .
    Lundström, Ingemar
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Fingerprinting of fluorescent substances for diagnostic purposes using computer screen illumination2005In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 106, p. 302-310Article in journal (Refereed)
  • 67.
    Filippini, Daniel
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Comina, G.
    Thin Films Laboratory, Science Faculty, Universidad Nacional De Ingenieria, Lima 31, Peru.
    Lundström, Ingemar
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Computer screen photo-assisted reflectance fingerprinting2005In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 107, no 2, p. 580-586Article in journal (Refereed)
    Abstract [en]

    The characterization of opaque color samples using reflected light is demonstrated with a computer screen photo-assisted technique (CSPT). CSPT utilizes standard computer screens as light sources and conventional web cameras as detectors to perform colorimetric or fluorescent evaluations that retain key spectral features of the tested substances. In this work, the fingerprinting of samples spectral reflectances is achieved by evaluating the reflected light under controlled computer screen illumination. Two different methods for processing of features are investigated, revealing complementary properties for classifications purposes. The attainable classification enables to distinguish different colors from just hues of a same color. © 2004 Elsevier B.V. All rights reserved.

  • 68.
    Filippini, Daniel
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics.
    Comina, G.
    Thin Films Laboratory Universidad National de Ingenieria, Lima, Peru.
    Lundström, Ingemar
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics.
    Computer screen photo-assisted reflectance fingerprinting2004In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 107, p. 580-586Article in journal (Refereed)
  • 69.
    Filippini, Daniel
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Di Natale, Corrado
    University of Rome, Italy.
    Paolesse, R
    Univresity of Rome, Italy.
    D´Amico, A.
    University of Rome, Italy.
    Lundström, Ingemar
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Computer screen photo-assisted techniques for global monitoring of environmental and sanitary parameters2007In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 121, no 1, p. 93-102Article in journal (Refereed)
    Abstract [en]

    The computer screen photo-assisted technique (CSPT) is a measuring method that uses regular computer screens as controlled light sources and web cameras as imaging detectors for optical evaluations of sensing substances, which optical properties respond to target analytes. The fact, that CSPT uses a globally distributed and familiar infrastructure as instrumentation and that is able to serve multiple targets with the same setup, makes it an attractive candidate for home testing. This article reviews the CSPT concept and focuses in two recent studies that demonstrate thorough CSPT determinations using a handy and eventually disposable assay format, with the potential to be as ubiquitous as the CSPT platforms themselves. The implications of such combination of technologies is discussed, and its potential to support the global monitoring of environmental and sanitary parameters, using Internet geography browsers, is analyzed. © 2006 Elsevier B.V. All rights reserved.

  • 70.
    Filippini, Daniel
    et al.
    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 .
    Distinctive photocurrent chemical images on bare SiO2 between continuous metal gates2003In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 95, no 1-3, p. 116-122Conference paper (Other academic)
    Abstract [en]

    Distinctive two-dimensional chemical images of hydrogen, ammonia and nitrogen dioxide have been obtained using a scanning light pulse technique (SLPT) on a metal-oxide-semiconductor (MOS) device. The sensor consists of an MOS capacitor with two continuous metal gates of Pd (40nm) and Au (50nm) arranged in a concurrent geometry, leaving a bare silicon dioxide region in between the biased gates. The present arrangement provides a new robust alternative to the existing strategies used to induce spatially distributed chemical responses, required for SLPT and allows to measure the response in a different place than where the biasing electrodes operate. Accordingly, the splitting of biasing and detection coordinates enables to optimize electrical and chemical functions separately providing a higher versatility in the choice of functional sensing materials or stable biasing electrodes. © 2003 Elsevier B.V. All rights reserved.

  • 71.
    Filippini, Daniel
    et al.
    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 .
    Pennazza, G.
    Santonico, M.
    diNatale, C.
    Paolesse, R.
    Bellincontro, A.
    Mencarelli, F.
    DAmico, A.
    Sorting of apricots with computer screen photoassisted spectral reflectance analysis and electronic nose2006In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 119, no 1, p. 70-77Article in journal (Refereed)
    Abstract [en]

    Optical properties and aroma have been indicated as sources of information for the analysis of quality of fruits. Optical properties can be measured with several experimental arrangements and equipments that are often complex with result difficult to interpret. In recent years, a number of suggestions arose in the sensor community proposing the use of conventional computer peripheral devices as analytical instruments. Among them the combination of a computer screen and a webcam was demonstrated to be suitable to measure optical properties of materials. In this paper this arrangement is utilized to characterize the reflectance of apricot fruits that underwent different post-harvest treatment and mechanical damages. Optical measurements were complemented by aroma analysis with an electronic nose. The response of fruits to treatments was also monitored measuring CO2 (indicator of respiration) and ethylene (indicator of ripening), both these parameters are known to be influenced by post-harvest treatment and mechanical damages. Results show that a computer screen-webcam combination and an electronic nose are both sensitive to mechanical damages of fruits devising their use, after due optimization, for routine fruit sorting. © 2005.

  • 72.
    Filippini, Daniel
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Manzano, J
    Lundström, Ingemar
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    LCD-aided computer screen photo-assisted technique for colorimetric assays evaluation2004In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 103, no 01-Feb, p. 158-164Article in journal (Refereed)
    Abstract [en]

    The ability of the computer screen photo-assisted technique (CSPT) to evaluate color samples through its light transmittance profiles is demonstrated by using liquid crystal displays (LCD) as light sources. Transmittance profiles are more drastically affected by angular dependencies than those obtained with CRT illumination. A local light reference computation is introduced to counteract this effect yielding equivalent profiles for both kinds of displays thus allowing for a broader universe of platforms to perform CSPT experiments, including mobile devices. (C) 2004 Elsevier B.V. All rights reserved.

  • 73.
    Filippini, Daniel
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Åsberg, Peter
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics .
    Nilsson, Peter
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics .
    Inganäs, Olle
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics .
    Lundström, Ingemar
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Computer screen photo-asssited detection of complementary DNA strands using a luminescent zwitterionic polythiophene derivative2006In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 1132006, p. 410-418Article in journal (Refereed)
  • 74.
    Francioso, L.
    et al.
    University Campus, Lecce, Italy.
    Bjorklund, Robert
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Krantz-Rülcker, Tina
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Siciliano, P.
    University Campus, Lecce, Italy.
    Classification of multiple defect concentrations in white wine by platinum microelectrode voltammetry2007In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 125, no 2, p. 462-467Article in journal (Refereed)
    Abstract [en]

    Concentrations of defect pairs added to a white wine were classified by voltammetric measurements on interdigitated platinum microelectrodes using principal component analysis of the current responses. Combinations of 0, 1, 2 and 3 mM concentrations were investigated. The defect pair ascorbic acid/acetaldehyde exhibited little interaction with each other and the pair-wise concentrations were symmetrically positioned in a score plot around a center axis of equimolar concentrations. The ascorbic acid/sulfur dioxide pair exhibited a center axis for the equimolar concentrations shifted toward the 3 mM sulfur dioxide sample. The defect pair having the strongest interaction through complex formation, acetaldehyde/sulfur dioxide, had the equimolar concentrations in score plots located near the white wine control sample. © 2007 Elsevier B.V. All rights reserved.

  • 75.
    Fredj, Zina
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, Faculty of Science & Engineering. University of Sousse, Higher Institute of Applied Sciences and Technology of Sousse, GREENS-ISSAT, Cité Ettafala, 4003 Ibn Khaldoun Sousse, Tunisia.
    Azzouzi, Sawsen
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, Faculty of Science & Engineering. University of Sousse, Higher Institute of Applied Sciences and Technology of Sousse, GREENS-ISSAT, Cité Ettafala, 4003 Ibn Khaldoun Sousse, Tunisia.
    Turner, Anthony
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, Faculty of Science & Engineering.
    Ali, Mounir, Ben
    University of Sousse, Higher Institute of Applied Sciences and Technology of Sousse, GREENS-ISSAT, Cité Ettafala, 4003 Ibn Khaldoun Sousse, Tunisia.
    Mak, Wing Cheung
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, Faculty of Science & Engineering.
    Neutravidin biosensor for direct capture of dual-functional biotin-molecular beacon-AuNP probe for sensitive voltammetric detection of microRNA2017In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 248, p. 8p. 77-84Article in journal (Refereed)
    Abstract [en]

    We have demonstrated a new approach using a neutravidin-based biosensor combined with a dual-function gold nanoparticle (AuNP) biolabel, for simple and sensitive detection of microRNA-21 (miRNA-21). The selectivity of the biosensor is provided by the intrinsic properties of the dual-functional biotin-MB-AuNP label. The assay procedure is relatively simple, exploiting a one-pot assay concept where the affinity capture of the miRNA-21/dual-functional biotin-MB-AuNP complex, via the strong biotin-neutravidin supramolecular interaction, and simultaneous detection of the captured AuNPs label with stripping voltammetry, is performed in a single step. This electrochemical miRNA biosensor could detect miRNA-21 with limit of detection of 0.1×10less thansuperscriptgreater than−12less than/superscriptgreater than and a dynamic range from 0.5×10less thansuperscriptgreater than−12less than/superscriptgreater than to 1.0×10less thansuperscriptgreater than−9less than/superscriptgreater thanM. The performance of the miRNA-21biosensor was further improved after silver deposition onto the AuNPs, delivering an enhanced detection limit of 4.0×10less thansuperscriptgreater than−15less than/superscriptgreater thanM of miRNA-21, and an extremely wide analytic dynamic range from 10×10less thansuperscriptgreater than−15less than/superscriptgreater than to 1×10less thansuperscriptgreater than−9less than/superscriptgreater thanM (5 orders of magnitude). This exceptionally broad dynamic range demonstrates the advantage of the one-pot assay approach with direct capture of the dual functional biotin-MB-AuNP via the strong biotin-neutravidin supramolecular interaction. Furthermore, we demonstrated the detection of miRNA-21 in spiked serum at clinically relevant concentrations. The miRNA biosensor displayed excellent analytical performance for the detection of miRNA and could provide a powerful and convenient tool for biomedical research and applications in cancer diagnostics.

  • 76.
    Fu, Ying
    et al.
    KTH Royal Institute of Technology, Sweden.
    Jussi, Johnny
    RISE - Research Institutes of Sweden, ICT, Acreo. KTH Royal Institute of Technology, Sweden.
    Wang, Qin
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Brismar, Hjalmar
    KTH Royal Institute of Technology, Sweden.
    Liu, Yushen
    College of Physics and Electronic Engineering, China.
    Yang, Xifeng
    College of Physics and Electronic Engineering, China.
    Chen, Yun
    University of Gothenburg, Sweden.
    Endocytic pathway of vascular cell adhesion molecule 1 in human umbilical vein endothelial cell identified in vitro by using functionalized nontoxic fluorescent quantum dots2019In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 297, article id 126702Article in journal (Refereed)
    Abstract [en]

    Studies about vascular cell adhesion molecule 1 (VCAM1) in tumor growth, metastasis, and angiogenesis suggest that targeting VCAM1 expression is an attractive strategy for diagnosis and anti-tumor therapy. However, the endocytic pathway of VCAM1 in vascular cells has not been well characterized. In this study we visualize the endocytic pathway of tumor necrosis factor α (TNFα) induced VCAM1 in human umbilical vein endothelial cell (HUVEC) in vitro using 5-carboxyfluorescein labeled VCAM1 binding peptides and fluorescent water-dispersible 3-mercaptopropionic acid (3MPA)-coated CdSe-CdS/Cd0.5Zn0.5S/ZnS core–multishell nontoxic quantum dots (3MPA-QDs) functionalized with VCAM1 binding peptides. Clear key in vitro observations are as follows: (a) 3MPA-QDs functionalized with VCAM1 binding peptides, denoted as VQDs, adhered and aggregated cumulatively to cell membrane around 2 h after VQD deposition to cell culture medium and were found in lysosomes in TNFα-treated HUVECs approximately 24 h after VQD deposition; (b) VQDs remained in TNFα-treated HUVECs for the whole 16 days of the experimental observation period; (c) quite differently, 3MPA-QDs were endocytosed then exocytosed by HUVECs via endosomes in about 24–48 h after 3MPA-QD deposition. Our study suggests that VCAM1 molecules, initially expressed on cell membrane induced by TNFα treatment, are internalized into lysosomes. This provides a novel means to deliver materials to lysosomes such as enzyme replacement therapy. Moreover, our meticulous sensing methodology of devising fluorescent nontoxic QDs advances biosensing technique for studying cellular activities in vitro and in vivo. © 2019 The Authors

  • 77.
    Fulati, Alimujiang
    et al.
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Usman Ali, Syed M.
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Asif, Muhammad H.
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology. Pakistan.
    Hassan Alvi, Naveed Ul
    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.
    Brännmark, Cecilia
    Linköping University, Department of Clinical and Experimental Medicine, Cell Biology. Linköping University, Faculty of Health Sciences.
    Strålfors, Peter
    Linköping University, Department of Clinical and Experimental Medicine, Cell Biology. Linköping University, Faculty of Health Sciences.
    Börjesson, Sara I.
    Linköping University, Department of Clinical and Experimental Medicine, Cell Biology. Linköping University, Faculty of Health Sciences.
    Elinder, Fredrik
    Linköping University, Department of Clinical and Experimental Medicine, Cell Biology. Linköping University, Faculty of Health Sciences.
    Danielsson, Bengt
    Lund University, Sweden.
    An intracellular glucose biosensor based on nanoflake ZnO2010In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 150, no 2, p. 673-680Article in journal (Other academic)
    Abstract [en]

    In this study, an improved potentiometric intracellular glucose biosensor was fabricated with immobilization of glucose oxidase on a ZnO nanoporous material. The ZnO nanoporous material with a wall thickness around 200 nm was grown on the tip of a borosilicate glass capillary and used as a selective intracellular glucose sensor for the measurement of glucose concentrations in human adipocytes and frog oocytes. The results showed a fast response within 4 s and a linear glucosedependent electrochemical response over a wide range of glucose concentration (500 nM-10 mM). The measurements of intracellular glucose concentrations with our biosensor were consistent with the values of intracellular glucose concentrations reported in the literature. The sensor also demonstrated its capability by detecting an increase in the intracellular glucose concentration induced by insulin. We found that the ZnO nanoporous material provides sensitivity as high as 1.8 times higher than that obtained using ZnO nanorods under the same conditions. Moreover, the fabrication method in our experiment is simple and the excellent performance of the developed nanosensor in sensitivity, stability, selectivity, reproducibility and anti-interference was achieved. All these advantageous features of this intracellular glucose biosensor based on functionalised ZnO nanoporous material compared to ZnO nanorods demonstrate a promising way of enhancing glucose biosensor performance to measure reliable intracellular glucose concentrations within single living cells.

  • 78.
    Gatty, Hithesh K.
    et al.
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Leijonmarck, Simon
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Applied Electrochemistry.
    Antelius, Mikael
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Stemme, Göran
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Roxhed, Niclas
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    An amperometric nitric oxide sensor with fast response and ppb-level concentration detection relevant to asthma monitoring2015In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 209, p. 639-644Article in journal (Refereed)
    Abstract [en]

    A MEMS-based amperometric nitric oxide (NO) gas sensor is reported in this paper. The sensor is designed to detect NO gas for the purpose of asthma monitoring. The unique property of this sensor lies in the combination of a microporous high-surface area electrode that is coated with Nafion (TM), together with a liquid electrolyte. The sensor is able to detect gas concentrations of the order of parts-per-billion (ppb) and has a measured NO sensitivity of 0.045 nA/ppb and an operating range between 25 and 65% relative humidity. The settling time of the sensor is measured to 8s. The selectivity to interfering gases such as ammonia (NH3) and carbon monoxide (CO) was high when placing an activated carbon fiber filter above the sensor. The ppb-level detection capability of this sensor combined with its relatively fast response, high selectivity to CO and NH3 makes the sensor potentially applicable in gas monitoring for asthma detection.

  • 79. Ghaani, M.
    et al.
    Rovera, C.
    Pucillo, F.
    Ghaani, M. R.
    Olsson, Richard T.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology, Polymeric Materials.
    Scampicchio, M.
    Farris, S.
    Determination of 2,4-diaminotoluene by a bionanocomposite modified glassy carbon electrode2018In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 277, p. 477-483Article in journal (Refereed)
    Abstract [en]

    This work describes the development of a modified glassy carbon electrode (GCE) for the selective determination of 2,4-diaminotoluene (TDA), a primary aromatic amines (PAAs) that can be formed in food packaging materials including aromatic polyurethane (PU) adhesives. The electrode's surface was modified with multi-walled carbon nanotubes (MWCNTs), MWCNTs in chitosan (CS), and gold nanoparticles (AuNPs). The highest current response was achieved with AuNPs/MWCNTs-CS/GC electrodes, which exhibited an oxidation peak of 9.87 μA by cyclic voltammetry (CV), compared with 1.39 μA of the bare GCE. A detection limit of 35 nM was estimated by amperometry experiments. The oxidation of TDA was strongly dependent on the pH of the medium, having maximum sensitivity at pH ∼ 7. From a mechanistic point of view, the diffusion coefficient of TDA (D = 6.47 × 10−4 cm2 s−1) and the number of electrons (n ≈ 2) involved in the catalytic oxidation of TDA at the surface of the AuNPs/MWCNTs-CS/GCE were determined. The practical utility of this nanocomposite modified electrode was demonstrated by migration studies from conventional food packaging materials. 

  • 80.
    Golabi, Mohsen
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, Faculty of Science & Engineering.
    Turner, Anthony
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, Faculty of Science & Engineering.
    Jager, Edwin
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, Faculty of Science & Engineering.
    Tunable conjugated polymers for bacterial differentiation2016In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 222, p. 839-848Article in journal (Refereed)
    Abstract [en]

    A novel rapid method for bacterial differentiation is explored based on the specific adhesion pattern of bacterial strains to tunable polymer surfaces. Different types of counter ions were used to electrochemically fabricate dissimilar polypyrrole (PPy) films with diverse physicochemical properties such as hydrophobicity, thickness and roughness. These were then modulated into three different oxidation states in each case. The dissimilar sets of conducting polymers were exposed to five different bacterial strains, Deinococcus proteolyticus, Serratia marcescens, Pseudomonas fluorescens, Alcaligenes faecalis and Staphylococcus epidermidis. By analysis of the fluorescent microscope images, the number of bacterial cells adhered to each surface were evaluated. Generally, the number of cells of a particular bacterial strain that adhered varied when exposed to dissimilar polymer surfaces, due to the effects of the surface properties of the polymer on bacterial attachment. Similarly, the number of cells that adhered varied with different bacterial strains exposed to the same surface, reflecting the different surface properties of the bacteria. Principal component analysis showed that each strain of bacteria had its own specific adhesion pattern. Hence, they could be discriminated by this simple, label-free method based on tunable polymer arrays combined with pattern recognition. (C) 2015 Elsevier B.V. All rights reserved.

  • 81.
    Gonzàlez Monroy, Javier
    et al.
    University of Málaga, Málaga, Spain.
    Lilienthal, Achim J.
    Örebro University, School of Science and Technology.
    Blanco, Jose Luis
    University of Almería, Almería, Spain.
    Gonzàlez Jimenez, Javier
    University of Málaga, Málaga, Spain.
    Trincavelli, Marco
    Örebro University, School of Science and Technology.
    Probabilistic gas quantification with MOX sensors in open sampling systems: a gaussian process approach2013In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 188, p. 298-312Article in journal (Refereed)
    Abstract [en]

    Gas quantification based on the response of an array of metal oxide (MOX) gas sensors in an Open Sampling System is a complex problem due to the highly dynamic characteristic of turbulent airflow and the slow dynamics of the MOX sensors. However, many gas related applications require to determine the gas concentration the sensors are being exposed to. Due to the chaotic nature that dominates gas dispersal, in most cases it is desirable to provide, together with an estimate of the mean concentration, an estimate of the uncertainty of the prediction. This work presents a probabilistic approach for gas quantification with an array of MOX gas sensors based on Gaussian Processes, estimating for every measurement of the sensors a posterior distribution of the concentration, from which confidence intervals can be obtained. The proposed approach has been tested with an experimental setup where an array of MOX sensors and a Photo Ionization Detector (PID), used to obtain ground truth concentration, are placed downwind with respect to the gas source. Our approach has been implemented and compared with standard gas quantification methods, demonstrating the advantages when estimating gas concentrations.

  • 82. Gu, Bobo
    et al.
    Yin, Ming-Jie
    Zhang, A. Ping
    Qian, Jin-Wen
    He, Sailing
    KTH, School of Electrical Engineering (EES), Electromagnetic Engineering.
    Fiber-optic metal ion sensor based on thin-core fiber modal interferometer with nanocoating self-assembled via hydrogen bonding2011In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 160, no 1, p. 1174-1179Article in journal (Refereed)
    Abstract [en]

    A new fiber-optic metal ion sensor based on a thin-core fiber modal interferometer (TCFMI) is presented. Poly(4-vinylpyridine) (P4VP) and poly(acrylic acid) (PAA) are layer-by-layer deposited on the side surface of the TCFMI via hydrogen bonding for the detection of metal ion in aqueous solutions. Ultraviolet-visible (UV-vis) absorption spectroscopy is employed to monitor the self-assembly process, and the thickness and morphology of the nanocoating are characterized by scanning electron microscopy (SEM). When the sensor is immersed into the aqueous solutions containing metal ions, the refractive index (RI) of the nanocoating is changed because of the association of metal ions with the nanocoating, which was verified by energy dispersive X-ray (EDX). Based on the RI sensing capability of TCFMI, one can detect the concentration of metal ions through the measurement of the dip wavelength of the sensor's transmission spectrum. The experiment results exhibit that the sensor is reusable and with a fast response in a wide metal ion concentration range (10 nM-0.1 M). The limit of detection (LOD) of the sensor is around 9.6 nM experimentally.

  • 83.
    Guanais Goncalves, Carla
    et al.
    University of Roma Tor Vergata, Italy.
    Dini, Francesca
    University of Roma Tor Vergata, Italy.
    Martinelli, Eugenio
    University of Roma Tor Vergata, Italy.
    Catini, Alexandro
    University of Roma Tor Vergata, Italy.
    Lundström, Ingemar
    Linköping University, Department of Physics, Chemistry and Biology, Biosensors and Bioelectronics. Linköping University, Faculty of Science & Engineering.
    Paolesse, Roberto
    University of Roma Tor Vergata, Italy.
    Di Natale, Corrado
    University of Roma Tor Vergata, Italy.
    Detection of diverse potential threats in water with an array of optical sensors2016In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 236, p. 997-1004Article in journal (Refereed)
    Abstract [en]

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

  • 84.
    Guha, Arnab
    et al.
    Centre for Biological Engineering, Loughborough University, Loughborough, UK.
    Sandström, Niklas
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    Ostanin, Victor
    Department of Chemistry, University of Cambridge, Cambridge, UK.
    van der Wijngaart, Wouter
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    Klenerman, David
    Department of Chemistry, University of Cambridge, Cambridge, UK.
    Ghosh, Sourav
    Centre for Biological Engineering, Loughborough University, Loughborough, UK.
    Simple and ultrafast resonance frequency and dissipation shift measurements using a fixed frequency drive2018In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 281, p. 960-970Article in journal (Refereed)
    Abstract [en]

    A new method for determination of resonance frequency and dissipation of a mechanical oscillator is presented. Analytical expressions derived using the Butterworth-Van Dyke equivalent electrical circuit allow the determination of resonance frequency and dissipation directly from each impedance datapoint acquired at a fixed amplitude and frequency of drive, with no need for numerical fitting or measurement dead time unlike the conventional impedance or ring-down analysis methods. This enables an ultrahigh time resolution and superior noise performance with relatively simple instrumentation. Quantitative validations were carried out successfully against the impedance analysis method for inertial and viscous loading experiments on a 14.3 MHz quartz crystal resonator (QCR). Resonance frequency shifts associated with the transient processes of quick needle touches on a thiol self-assembled-monolayer functionalised QCR in liquid were measured with a time resolution of 112 μs, which is nearly two orders of magnitude better than the fastest reported quartz crystal microbalance. This simple and fast fixed frequency drive (FFD) based method for determination of resonance frequency and dissipation is potentially more easily multiplexable and implementable on a single silicon chip delivering economies of scale.

  • 85. Guidi, Vincenzo
    et al.
    Martinelli, Giuliano
    Schiffrer, Giuliano
    Vomiero, Alberto
    INFN - Legnaro National Laboratories.
    Scian, Carlo
    INFN - Legnaro National Laboratories.
    Mea, Gianantonio Della
    INFN - Legnaro National Laboratories.
    Comini, Elisabetta
    Department of Physics and Chemistry, INFM — University of Brescia.
    Ferroni, Matteo
    Department of Physics and Chemistry, INFM — University of Brescia.
    Sberveglieri, Giorgio
    Department of Physics and Chemistry, INFM — University of Brescia.
    Selective sublimation processing of thin films for gas sensing2005In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 108, no 1-2 SPEC. ISS., p. 15-20Article in journal (Refereed)
    Abstract [en]

    The selective sublimation processing (SSP) is a useful and easy method for production of semiconducting thin films via reactive sputtering for gas sensing. We have investigated the mechanism of film growth and processing for an insight into the main parameters that control the preparation methodology. A model based on diffusion equation, in the framework of a linear theory, has been proposed and compared to experimental evidences. Rutherford backscattering spectrometry has been extensively used as a tool for determination of concentration profiles in the layers. The model allowed a deeper understanding of film preparation with a physical description of the processes involved, which would open up the design of innovative nanostructured materials that rely on SSP. Titania thin films produced by this methodology and proved capable of sensing target gases of interest for many applications. © 2004 Elsevier B.V. All rights reserved.

  • 86.
    Gutes, A.
    et al.
    Gutés, A., Sensors and Biosensors Group, Department of Chemistry, Autonomous University of Barcelona, Edifici Cn, 08193 Bellaterra, Spain.
    Cespedes, F.
    Sensors and Biosensors Group, Department of Chemistry, Autonomous University of Barcelona, Edifici Cn, 08193 Bellaterra, Spain.
    del, Valle M.
    del Valle, M., Sensors and Biosensors Group, Department of Chemistry, Autonomous University of Barcelona, Edifici Cn, 08193 Bellaterra, Spain.
    Louthander, D.
    Krantz-Rülcher, Christina
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Winquist, Fredrik
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    A flow injection voltammetric electronic tongue applied to paper mill industrial waters2006In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 115, no 1, p. 390-395Article in journal (Refereed)
    Abstract [en]

    A voltammetric electronic tongue with automated operation based on the flow injection (FIA) technique was applied to the characterization of wastewaters coming from the paper mill industry. A metallic multielectrode array - formed by platinum, gold and rhodium electrodes - was employed as the detection system, while the measurements were based on large amplitude pulse voltammetry (LAPV). LAPV consisted in scans of pulses from to 0 to 1.8 V at 0.2 V steps. Five current values were recorded for each pulse, so a set of 300 current values (three electrodes × 20 pulses × five values) was recorded for each sample. Samples were first discriminated using Principal Component Analysis (PCA), while Artificial Neural Networks were used for the characterization and prediction of chemical oxygen demand, conductivity and pH. The system may be used for the quick identification and monitoring of the quality of used waters in these industrial facilities. © 2005 Elsevier B.V. All rights reserved.

  • 87.
    Haraldsson, Klas Tommy
    et al.
    Department of Chemical and Biological Engineering, ECCH 111, UCB424, University of Colorado.
    Hutchison, J.
    Department of Chemical and Biological Engineering, ECCH 111, UCB424, University of Colorado.
    Sebra, Robert
    Department of Chemical and Biological Engineering, ECCH 111, UCB424, University of Colorado.
    Good, Brian
    Department of Chemical and Biological Engineering, ECCH 111, UCB424, University of Colorado.
    Anseth, Kristi
    Department of Chemical and Biological Engineering, ECCH 111, UCB424, University of Colorado.
    Bowman, Christopher
    Department of Chemical and Biological Engineering, ECCH 111, UCB424, University of Colorado.
    3D Polymeric Microfluidic Device Fabrication via Contact Liquid Photolithographic Polymerization (CLiPP)2006In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 113, no 1, p. 454-460Article in journal (Refereed)
    Abstract [en]

    In this contribution, a new method for the fabrication of complex polymeric microfluidic devices is presented. The technology, contact liquid photolithographic polymerization (CLIPP). overcomes many of the draw backs associated kith other rapid prototyping schemes, such as limited materials choices and time-consuming microassembly protocols. CUPP shares many traits with other photolithographic methods, but three distinct features: (i) liquid photoresists in contact with the photomask. (ii) readily removed sacrificial Materials. and (iii) living radical processes, enable multiple polymeric chemistries and mechanical properties while simultaneously enabling facile fabrication of 3D geometries and surface chemistry control. This contribution details fabrication techniques and methods for the fabrication of high aspect ratio posts covalently bonded to a polymeric substrate, an array of independently stacked bars on top of perpendicular bars, multiple undercut structures fabricated simultaneously, and a complex 3D geometry with intertwined channels.

  • 88. Hashemi, Payman
    et al.
    Zarjani, Razieh Afzari
    Abolghasemi, Mir Mehdi
    Olin, Åke
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry.
    Agarose film coated glass slides for preparation of pH optical sensors2007In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 121, no 2, p. 396-400Article in journal (Refereed)
    Abstract [en]

    A method for preparation of optical sensors was developed by agarose film coating on aminosilanated glass slides. An optical pH sensor was accordingly prepared by epoxy activation of the agarose film, followed by chemical immobilization of Neutral Red dye. In an optimized coupling pH of 12 and a dye concentration of 10(-2) mol L-1 a pH sensor for a pH range of 2-8.5 was obtained. A theoretical equation was derived using the extended Henderson-Hasselbalch equation that reproduced the measured data well. The sensor was mounted in a flow cell and successfully applied for on-line pH measurements. The sensor responded rapidly to the pH changes with a response time of less than 2 min and reproducibility better than 0.40% (R.S.D.). In comparison to a stand-alone agarose membrane, the agarose coated glass slide showed better physical properties and easier handling and application but slightly slower response times. No evidence of leaching of the dye or any signal drift was observed.

  • 89.
    Hedborg, Eva
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Spetz, Anita
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Winquist, Fredrik
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Lundström, Ingemar
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Polymer membranes for modification of the selectivity of field-effect gas sensors1992In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 7, no 1-3, p. 661-664Article in journal (Refereed)
    Abstract [en]

    Polymer membranes are used to increase the selectivity to certain gases of metal silicon dioxide-semiconductor (MOS) structures. Other parameters which influence the selectivity of MOS structures are the type of gate metal, its microstructure (dense or porous) and the operating temperature of the device. Photoresists as membranes can be patterned by photolithographic methods. Membranes, 1-2-mu-m thick, of positive and negative photoresist are applied on MOS capacitors with 6 nm iridium as the gate metal, operated at 150-degrees-C. The influence of the membranes on the response to three gases, hydrogen, ammonia and ethanol, has been investigated. The hydrogen response decreases bv about half with the use of a photoresist membrane. The ammonia response shows a characteristic change in the kinetics, while the ethanol response almost disappears. Positive and negative resist influence the gas response in similar ways, in spite of their different molecular structures.

  • 90.
    Heideman, René
    et al.
    MESA Research Institute, University of Twente.
    Veldhuis, Gert
    MESA Research Institute, University of Twente.
    Jager, Edwin
    MESA Research Institute, University of Twente.
    Lambeck, Paul
    Fabrication and packaging of integrated chemo-optical sensors1996In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 35, no 1-3, p. 234-240Article in journal (Refereed)
    Abstract [en]

    This paper describes the design and fabrication of a sensitive integrated chemo-optical sensor supplied with on-chip fiber-to-waveguide connectors. The sensor is designed for TE-polarized light with wavelength of 633 nm. The fiber-to-chip connectors are based on easily fabricated silicon V-grooves combined with a smooth sawcut. The sawcut is defining the channel waveguide endface. The sensor is based on a phase modulated Mach-Zehnder interferometer, using the electro-optic effect of the waveguiding material zinc oxide (ZnO). The fiber-to-chip connector units have a typical coupling efficiency of 0.1–1%. The electro-optical voltage × length product Vπ is 15 ± 4 V cm at frequencies above 100 Hz. Preliminary experiments on the general (passive) sensor response showing its expected high sensitivity are discussed.

  • 91.
    Holmin, Susanne
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Spångéus, Per
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology.
    Krantz-Rülcher, Christina
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Winquist, Fredrik
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Physics .
    Compression of electronic tongue data based on voltammetry - A comparative study2001In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 76, no 1-3, p. 455-464Conference paper (Other academic)
    Abstract [en]

    In this paper, three data compression methods are investigated to determine their ability to reduce large data sets obtained by a voltammetric electronic tongue without loss of information, since compressed data sets will save data storage and computational time. The electronic tongue is based on a combination of non-specific sensors and pattern recognition tools, such as principal component analysis (PCA). A series of potential pulses of decreasing amplitude are applied to one working electrode at a time and resulting current transients are collected at each potential step. Voltammograms containing up to 8000 variables are subsequently obtained. The methods investigated are wavelet transformation (WT) and hierarchical principal component analysis (HPCA). Also, a new chemical/physical model based on voltammetric theory is developed in order to extract interesting features of the current transients, revealing different information about species in solutions. Two model experiments are performed, one containing solutions of different electroactive compounds and the other containing complex samples, such as juices from fruits and tomatoes. It is shown that WT and HPCA compress the data sets without loss of information, and the chemical/physical model improves the separations slightly. HPCA is able to compress the two data sets to the largest extent, from 8000 to 16 variables. When data sets are scaled to unit variance, the separation ability improves even further for HPCA and the chemical/physical model. © 2001 Elsevier Science B.V.

  • 92.
    Hu, Jiwen
    et al.
    Tongji University, Peoples R China.
    Hu, Zhang-Jun
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, The Institute of Technology. Tongji University, Peoples R China.
    Cui, Yang
    Tongji University, Peoples R China.
    Zhang, Xuanjun
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, The Institute of Technology.
    Gao, Hong-Wen
    Tongji University, Peoples R China.
    Uvdal, Kajsa
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, The Institute of Technology.
    A rhodamine-based fluorescent probe for Hg2+ and its application for biological visualization2014In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 203, p. 452-458Article in journal (Refereed)
    Abstract [en]

    A new visible light excitable fluorescent probe (1) is synthesized by appending a hydroxymethyl-pyridine to rhodamine B hydrazide. The probe displays very specific Hg2+-induced colour change and fluorescent enhancement in the aqueous systems. The "turn-on" response of fluorescence is based on a binding-induced ring-opening process from the spirolactam (nonfluorescent) to acyclic xanthene (fluorescent) in rhodamine B. The coordinating atoms O-center dot-N-N-O-center dot from the hydroxymethyl-pyridine and rhodamine B hydrazide play dominant role in the formation of a complex with 1:1 stoichiometry of Hg2+ to 1. It exhibits a linear response in the range of 0.1-5 mu M with the limit of detection (LOD) of 15.7 nM (3 sigma/slope), while the calculated value of the association constant of Hg2+/1 is 0.70 x 10(5) M-1. Furthermore, confocal microscopy imaging experiment demonstrates the probe 1 can be applied as a fluorescent probe for visualization of Hg2+ in living HeLa cells.

  • 93.
    Hu, Jiwen
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering. Tongji University, Peoples R China.
    Hu, Zhang-Jun
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Liu, Sheng
    Huaibei Normal University, Peoples R China.
    Zhang, Qiong
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Gao, Hong-Wen
    Tongji University, Peoples R China.
    Uvdal, Kajsa
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    A new ratiometric fluorescent chemodosimeter based on an ICT modulation for the detection of Hg2+2016In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 230, p. 639-644Article in journal (Refereed)
    Abstract [en]

    We design and synthesize a new ratiometric fluorescent chemodosimeter (S1) for the selective and sensitive detection of Hg2+. Upon addition of Hg2+, the emission of the S1 exhibits a large bathochromic shift from 393 to 515 nm (up to 122 nm) which is ascribed to an intramolecular charge transfer process in the resultant. The Hg2+-induced dethioacetalization for sensing mechanism has been demonstrated by using high-performance liquid chromatography analysis of the sensing process. The interference experiments further demonstrate that S1 exhibits very high selectivity towards Hg2+ over other coexisting cations/anions. Subsequently, a good linearity of the concentrations of Hg2+ (0-15 mu M) vs the ratiometric signals (I-515/I-393) allows a fluorogenic method for the quantitative detection of Hg2+, with the limitation of detection determined to be 5.22 x 10(-7) M. (C) 2016 Elsevier B.V. All rights reserved.

  • 94.
    Hu, Jiwen
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering. Shanghai Univ, Peoples R China.
    Liu, TingTing
    Tongji Univ, Peoples R China.
    Gao, Hong-Wen
    Tongji Univ, Peoples R China.
    Lu, Senlin
    Shanghai Univ, Peoples R China.
    Uvdal, Kajsa
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Hu, Zhang-Jun
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering. Shanghai Univ, Peoples R China.
    Selective detections of Hg2+ and F- by using tailor-made fluorogenic probes2018In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 269, p. 368-376Article in journal (Refereed)
    Abstract [en]

    By ingeniously using a (imino)coumarin-precursor, three reactive fluorogenic probes of MP, FP, and FMP have been fabricated in a single facile synthetic route. MP and FP are able to respectively act as selective "turn-on" fluorescent probes for detecting Hg2+ and F- in buffer solution via specific analyte-induced reactions. Linear ranges for the detection of Hg2+ and F- are 0-10 mu M and 0-100 mu M with the limits of detection (LODs) of 4.0 x 10(-8) M and 1.14 x 10(-6) M (3 delta/slope), respectively. FMP is able to work as a molecular "AND" logic gate-based fluorogenic probe for monitoring the coexistence of Hg2+ and F- via a multistep reaction cascade. The analytes-induced sensing mechanisms have been determined by using high-performance liquid chromatography analysis (HPLC). In addition, three probes show negligible toxicity under the experimental conditions, and are successfully used for monitoring Hg2+ and F- in living cells with good cell permeability. The success of the work demonstrates that ingenious utility of specific analyte-induced reactions and conventional concepts on the appropriate molecular scaffold can definitely deliver tailor-made probes for various intended sensing purposes. (C) 2018 Published by Elsevier B.V.

    The full text will be freely available from 2020-05-05 01:20
  • 95.
    Hu, Zhang-Jun
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Yang, Guanqing
    Anhui Univ, Peoples R China.
    Hu, Jiwen
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Wang, Hui
    Anhui Univ, Peoples R China.
    Eriksson, Peter
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Zhang, Ruilong
    Anhui Univ, Peoples R China.
    Zhang, Zhongping
    Anhui Univ, Peoples R China.
    Uvdal, Kajsa
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Real-time visualizing the regulation of reactive oxygen species on Zn2+ release in cellular lysosome by a specific fluorescent probe2018In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 264, p. 419-425Article in journal (Refereed)
    Abstract [en]

    Reactive oxygen species (ROS) regulating the release of free zinc ions (Zn2+) in cellular lysosome is closely related to various pathways of cellular signal transduction, such as inflammation and oxidative stress. Directly visualizing Zn2+ release in lysosome is essential for in-depth understanding these physiological processes, and is still an atelic challenge. In this work, we successfully fabricate a lysosome-specific Zn2+ fluorescent probe and achieve the visualization of ROS-induced Zn2+ release in lysosome of inflammatory cells. The as-prepared probe combines a green fluorophore, an ionophore with five-dentate sites, and a morpholine as the lysosome-specific localization moiety. The fluorescence of the fluorophore in the free probe is suppressed by a photoinduced electron transfer (PET) process from nitrogen atoms in the ionophore. Upon the addition of Zn2+, the fluorescence can be promoted immediately, achieving the real-time detection. Meanwhile, the probe is sensitive and selective to Zn2+, which provides the capability to detect low-concentration of free Zn2+ in lysosomes. Accordingly, the Zn2+ release was clearly observed in lysosome with the increase of ROS levels when the inflammation occurred in living cells. (c) 2018 Published by Elsevier B.V.

    The full text will be freely available from 2020-03-07 12:11
  • 96.
    Huotari, J.
    et al.
    University of Oulu, Finland.
    Bjorklund, Robert
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, Faculty of Science & Engineering.
    Lappalainen, J.
    University of Oulu, Finland.
    Lloyd Spetz, Anita
    Linköping University, Department of Physics, Chemistry and Biology, Applied Sensor Science. Linköping University, Faculty of Science & Engineering. University of Oulu, Finland.
    Pulsed Laser Deposited Nanostructured Vanadium Oxide Thin Films Characterized as Ammonia Sensors2015In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 217, p. 22-29Article in journal (Refereed)
    Abstract [en]

    Vanadium oxide thin films were fabricated by pulsed laser deposition. The microstructure and crystal symmetry of the deposited films were studied with X-ray diffraction, scanning electron microscopy (SEM), and Raman spectroscopy, respectively. The films surface morphology was examined by atomic force microscopy. Raman spectroscopy and XRD results showed that the thin film phase-structure was composed of pure orthorhombic V2O5 phase, or they had a mixed phase structure of orthorhombic V2O5 and triclinic V7O16. Surface morphology of the films consisted of nanosized particles, although in pure V2O5 films some bigger agglomerates and flakes were also seen. The conductivity based gas sensing measurements showed a clear response already at ppb-levels of NH3 and strong selectivity to ammonia was found when compared to NO and CO gases. Also, the films showed promising gas sensing behavior in cross-sensitivity measurements between NO and NH3, being able to sense ammonia even in the presence of NO. This is an important property when considering possible sensing applications to control Selective Catalytic Reduction processes, e.g. in diesel engine exhausts, where introduced ammonia, or urea, transforms nitrogen oxide gases in a catalytic converter to nitrogen and water. (C) 2015 Elsevier B.V. All rights reserved.

  • 97.
    Huotari, Joni
    et al.
    University of Oulu, Finland.
    Puustinen, Jarko
    University of Oulu.
    Lappalainen, Jyrki
    University of Oulu.
    Lloyd Spetz, Anita
    Linköping University, Department of Physics, Chemistry and Biology, Applied Sensor Science. Linköping University, The Institute of Technology.
    Gas Sensing Properties of Pulsed Laser Deposited Vanadium OxideThin Films with Various Crystal Structures2013In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 187, no SI, p. 386-394Article in journal (Refereed)
    Abstract [en]

    Vanadium oxide thin films were fabricated by pulsed laser deposition. The crystal structure and symmetry of the deposited films were studied with X-ray diffraction and Raman spectroscopy, respectively. The film microstructure was also studied with atomic force microscopy and scanning electron microscopy. The thin film crystal structures varied between almost pure V2O5 phase and another phase, suggested being V7O16, generally found in samples composed of nanotubes and identified as VOx-NT. The measured optical transmission spectra of the films also supported the existence of two different phases. The electrical resistivity of the films as a function of temperature behaved like in a typical semiconductor. The gas sensing properties of the films were characterized for different NOx, CO and H-2 concentrations. The results showed a response to NOx and H-2, which varied from oxidative to reducing according to the film composition and gas background environment. Only very small response was seen towards CO. Gas response and resistivity measurements indicated that the VOx-NT-type phase has both n-type and p-type conduction mechanisms.

  • 98.
    Hussain Ibupoto, Zafar
    et al.
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Jamal, N
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Khun, Kimleang
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Liu, Xianjie
    Linköping University, Department of Physics, Chemistry and Biology, Surface Physics and Chemistry. Linköping University, The Institute of Technology.
    Willander, Magnus
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    A potentiometric immunosensor based on silver nanoparticles decorated ZnO nanotubes, for the selective detection of d-dimer2013In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 182, p. 104-111Article in journal (Refereed)
    Abstract [en]

    In this study, a new, simple, fast and highly sensitive potentiometric immunosensor for the selective detection of d-dimer is developed using silver nanoparticles decorated ZnO nanotubes. The d-dimer is a biomarker and found at high levels in the human body when it suffers from deep vein thrombosis (DVT) disorders. ZnO nanotubes were obtained by the chemical etching of nanorods using a hydrothermal method. The silver nanoparticles were deposited on the ZnO nanotubes using an electrodepositing technique. The structure and the composition characterization was measured by scanning electron microscopy (SEM), X-ray diffraction (XRD), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) techniques respectively. The ZnO nanorods are perpendicular to the substrate with uniform distribution. The etching of the nanorods into nanotubes is almost complete and the nanotubes are fully covered with silver nanoparticles. The mouse anti human d-dimer antibody was immobilized on the silver nanoparticles decorated ZnO nanotubes for the selective detection of d-dimer. The potentiometric immunosensor has shown a highly sensitive and linear response for the wide range of 1.00 x 10(-5)-1.00 x 10(0) mu g/ml d-dimer concentrations prepared in the phosphate buffer solution of pH 7.4. The presented d-dimer biosensor exhibited a detection limit of 1.00 x 10(-6) mu g/ml. The antibody immobilized immunosensor presents a fast response time of less than 5 s with acceptable selectivity, reproducibility and storage stability. The observed performance of the developed immunosensor demonstrates the high usability for the selective detection of the d-dimer from clinical and real samples.

  • 99. Hussain, Tanveer
    et al.
    Vovusha, Hakkim
    Kaewmaraya, Thanayut
    Amornkitbamrung, Vittaya
    Ahuja, Rajeev
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Applied Material Physics.
    Adsorption characteristics of DNA nucleobases, aromatic amino acids and heterocyclic molecules on silicene and germanene monolayers2018In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 255, p. 2713-2720Article in journal (Refereed)
    Abstract [en]

    Binding of DNA/RNA nucleobases, aromatic amino acids and heterocyclic molecules on two-dimensional silicene and germanene sheets have been investigated for the application of sensing of biomolecules using first principle density functional theory calculations. Binding energy range for nucleobases, amino acids and heterocyclic molecules with both the sheets have been found to be (0.43-1.16 eV), (0.70-1.58 eV) and (0.22-0.96 eV) respectively, which along with the binding distances show that these molecules bind to both sheets by physisorption and chemisorption process. The exchange of electric charges between the monolayers and the incident molecules has been examined by means of Bader charge analysis. It has been observed that the introduction of DNA/RNA nucleobases, aromatic amino acids and heterocyclic molecules alters the electronic properties of both silicene and germanene nano sheets as studied by plotting the total (TDOS) and partial (PDOS) density of states. The DOS plots reveal the variation in the band gaps of both silicene and germanene caused by the introduction of studied molecules. Based on the obtained results we suggest that both silicene and germanene monolayers in their pristine form could be useful for sensing of biomolecules.

  • 100.
    Hussain, Tanveer
    et al.
    Univ Queensland, Ctr Theoret & Computat Mol Sci, Australian Inst Bioengn & Nanotechnol, Brisbane, Qld 4072, Australia..
    Vovusha, Hakkim
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory. KAUST, Phys Sci & Engn Div PSE, Thuwal 239556900, Saudi Arabia.
    Kaewmaraya, Thanayut
    Khon Kaen Univ, Integrated Nanotechnol Res Ctr, Dept Phys, Khon Kaen, Thailand..
    Amornkitbamrung, Vittaya
    Khon Kaen Univ, Integrated Nanotechnol Res Ctr, Dept Phys, Khon Kaen, Thailand.;Nanotec KKU Ctr Excellence Adv Nanomat Energy Pro, Khon Kaen, Thailand..
    Ahuja, Rajeev
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory. Royal Inst Technol KTH, Appl Mat Phys, Dept Mat & Engn, S-10044 Stockholm, Sweden..
    Adsorption characteristics of DNA nucleobases, aromatic amino acids and heterocyclic molecules on silicene and germanene monolayers2018In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 255, p. 2713-2720Article in journal (Refereed)
    Abstract [en]

    Binding of DNA/RNA nucleobases, aromatic amino acids and heterocyclic molecules on two-dimensional silicene and germanene sheets have been investigated for the application of sensing of biomolecules using first principle density functional theory calculations. Binding energy range for nucleobases, amino acids and heterocyclic molecules with both the sheets have been found to be (0.43-1.16 eV), (0.70-1.58 eV) and (0.22-0.96 eV) respectively, which along with the binding distances show that these molecules bind to both sheets by physisorption and chemisorption process. The exchange of electric charges between the monolayers and the incident molecules has been examined by means of Bader charge analysis. It has been observed that the introduction of DNA/RNA nucleobases, aromatic amino acids and heterocyclic molecules alters the electronic properties of both silicene and germanene nano sheets as studied by plotting the total (TDOS) and partial (PDOS) density of states. The DOS plots reveal the variation in the band gaps of both silicene and germanene caused by the introduction of studied molecules. Based on the obtained results we suggest that both silicene and germanene monolayers in their pristine form could be useful for sensing of biomolecules.

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