TY - JOUR A1 - Buniatyan, Vahe V. A1 - Abouzar, Maryam H. A1 - Martirosyan, Norayr W. A1 - Schubert, Jürgen A1 - Gevorgian, Spartak A1 - Schöning, Michael Josef A1 - Poghossian, Arshak T1 - pH-sensitive properties of barium strontium titanate (BST) thin films prepared by pulsed laser deposition technique JF - Physica Status Solidi (A). 207 (2010), H. 4 Y1 - 2010 SN - 1862-6300 N1 - Special Issue: Engineering of Functional Interfaces EnFI 2009 SP - 824 EP - 830 ER - TY - JOUR A1 - Beging, Stefan A1 - Mlynek, Daniela A1 - Hataihimakul, Sudkanung A1 - Poghossian, Arshak A1 - Baldsiefen, Gerhard A1 - Busch, Heinz A1 - Laube, Norbert A1 - Kleinen, Lisa A1 - Schöning, Michael Josef T1 - Field-effect calcium sensor for the determination of the risk of urinary stone formation JF - Sensors and Actuators B: Chemical. 144 (2010), H. 2 Y1 - 2010 N1 - 22nd International Conference on Eurosensors - Dresden, Germany, 7-10 September 2008 ; Eurosensors ; (22, 2008, Dresden) SP - 374 EP - 379 ER - TY - JOUR A1 - Ribitsch, D. A1 - Karl, W. A1 - Birner-Gruenberger, R. A1 - Gruber, K. A1 - Eiteljoerg, I. A1 - Remler, P. A1 - Wieland, S. A1 - Siegert, Petra A1 - Maurer, Karl-Heinz A1 - Schwab, H. T1 - C-terminal truncation of a metagenome-derived detergent protease for effective expression in E. coli JF - Journal of biotechnology N2 - Recently, a new alkaline protease named HP70 showing highest homology to extracellular serine proteases of Stenotrophomonas maltophilia and Xanthomonas campestris was found in the course of a metagenome screening for detergent proteases (Niehaus et al., submitted for publication). Attempts to efficiently express the enzyme in common expression hosts had failed. This study reports on the realization of overexpression in Escherichia coli after structural modification of HP70. Modelling of HP70 resulted in a two-domain structure, comprising the catalytic domain and a C-terminal domain which includes about 100 amino acids. On the basis of the modelled structure the enzyme was truncated by deletion of most of the C-terminal domain yielding HP70-C477. This structural modification allowed effective expression of active enzyme using E. coli BL21-Gold as the host. Specific activity of HP70-C477 determined with suc-l-Ala-l-Ala-l-Pro-l-Phe-p-nitroanilide as the substrate was 30 ± 5 U/mg compared to 8 ± 1 U/mg of the native enzyme. HP70-C477 was most active at 40 °C and pH 7–11; these conditions are prerequisite for a potential application as detergent enzyme. Determination of kinetic parameters at 40 °C and pH = 9.5 resulted in KM = 0.23 ± 0.01 mM and kcat = 167.5 ± 3.6 s⁻¹. MS-analysis of peptide fragments obtained from incubation of HP70 and HP70-C477 with insulin B indicated that the C-terminal domain influences the cleavage preferences of the enzyme. Washing experiments confirmed the high potential of HP70-C477 as detergent protease. Y1 - 2010 U6 - https://doi.org/10.1016/j.jbiotec.2010.09.947 SN - 1873-4863 (E-Journal); 0168-1656 (Print) VL - 150 IS - 3 SP - 408 EP - 416 PB - Elsevier CY - Amsterdam ER - TY - CHAP A1 - Beging, Stefan A1 - Poghossian, Arshak A1 - Mlynek, D. A1 - Hataihimakul, S. A1 - Pedraza, A. A1 - Dhawan, S. A1 - Laube, N. A1 - Kleinen, Lisa A1 - Baldsiefen, Gerhard A1 - Busch, Heinrich von A1 - Schöning, Michael Josef T1 - Ion-selective sensors for the determination of the risk of urinary stone formation T2 - Micro- and Nanosystems in biochemical diagnosis : Principles and applications Y1 - 2010 SP - 74 EP - 80 CY - Warsaw ER - TY - JOUR A1 - Miyamoto, Ko-ichiro A1 - Kaneko, Kazumi A1 - Matsuo, Akira A1 - Wagner, Torsten A1 - Kanoh, Shin`ichiro A1 - Schöning, Michael Josef A1 - Yoshinobu, Tatsuo T1 - Miniaturized chemical imaging sensor system using an OLED display panel JF - Procedia Engineering N2 - The chemical imaging sensor is a semiconductor-based chemical sensor that can visualize the two-dimensional distribution of specific ions or molecules in the solution. In this study, we developed a miniaturized chemical imaging sensor system with an OLED display panel as a light source that scans the sensor plate. In the proposed configuration, the display panel is placed directly below the sensor plate and illuminates the back surface. The measured area defined by illumination can be arbitrarily customized to fit the size and the shape of the sample to be measured. The waveform of the generated photocurrent, the currentvoltage characteristics and the pH sensitivity were investigated and pH imaging with this miniaturized system was demonstrated. Y1 - 2010 U6 - https://doi.org/10.1016/j.proeng.2010.09.160 SN - 1877-7058 N1 - Eurosensor XXIV Conference, 5-8 September 2010, Linz, Austria VL - 5 SP - 516 EP - 519 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Kirchner, Patrick A1 - Oberländer, Jan A1 - Friedrich, Peter A1 - Rysstad, Gunnar A1 - Berger, Jörg A1 - Keusgen, Michael A1 - Schöning, Michael Josef T1 - Realization of a calorimetric gas sensor on polyimide foil for applications in aseptic food industry JF - Procedia Engineering N2 - A calorimetric gas sensor is presented for the monitoring of gas-phase H2O2 at elevated temperature during sterilization processes in aseptic food industry. The sensor consists of two temperature-sensitive thin-film resistances built up on a polyimide foil with a thickness of 25 μm, which are passivated with a layer of SU-8 photo resist and catalytically activated with manganese(IV) oxide. Instead of an active heating structure, the calorimetric sensor utilizes the elevated temperature of an evaporated H2O2 aerosol. In an experimental set-up, the sensor has shown a sensitivity of 4.78 °C/(%v/v) in a H2O2 concentration range of 0 to 10% v/v at an evaporation temperature of 240 ∘C. Furthermore, the sensor possesses the same, unchanged sensor signal even at varied evaporation temperatures of the gas stream. The sensor characterization demonstrates the suitability of the calorimetric gas sensor for monitoring the efficiency of sterilization processes. Y1 - 2010 U6 - https://doi.org/10.1016/j.proeng.2010.09.098 SN - 1877-7058 N1 - Eurosensor XXIV Conference, 5-8 September 2010, Linz, Austria VL - 5 SP - 264 EP - 267 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Bohrn, Ulrich A1 - Stütz, Evamaria A1 - Fleischer, Maximilian A1 - Schöning, Michael Josef T1 - Real-time detection of CO by eukaryotic cells JF - Procedia Engineering N2 - In this contribution, we focus on the detection of toxic gases with living eukaryotic cells. A cell-based gas sensor system, able to measure the effects of direct exposure of gases to cells in real-time, was set up. Impedance data as well as oxygen consumption of Chinese hamster lung fibroblast cells (V79) were analysed upon exposure to carbon monoxide (CO). The CO (diluted in wet synthetic air) affects the cell respiration as indicated by an attenuated respiration signal after the CO exposure as well as an instant increase of the capacitive part of the impedance signal during the gas exposure. Y1 - 2010 SN - 1877-7058 N1 - Eurosensor XXIV Conference, 5-8 September 2010, Linz, Austria VL - 5 SP - 17 EP - 20 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Spelthahn, Heiko A1 - Schaffrath, Sophie A1 - Coppe, Thomas A1 - Rufi, Frederic A1 - Schöning, Michael Josef T1 - Development of an electrolyte-insulator-semiconductor (EIS) based capacitive heavy metal sensor for the detection of Pb2+ und Cd2+ ions JF - Physica status solidi (a) : applications and material science N2 - Chalcogenide glass materials as membranes for potentiometric sensors for chemical analysis in solutions have been studied since more than 20 years. In this work, an electrolyte–insulator–semiconductor structure was combined with chalcogenide glass membranes prepared by means of the pulsed laser deposition technique. Depending on the membrane composition a selectivity to different ions (Cd2+ and Pb2+) is achieved. The different sensor membranes have been physically characterised using microscopy, ellipsometry, profilometry, atomic force microscopy (AFM), scanning electron microscopy (SEM) and Rutherford backscattering spectrometry (RBS). The electrochemical behaviour has been investigated via capacitance/voltage (C/V) and constant capacitance (ConCap) measurements and results in a Cd2+ sensitivity of 23.1 ± 0.6 mV per decade in a linear range from 7 × 10−6 to 10−2 mol/l and 24.4 ± 0.5 mV per decade in a linear range from 5 × 10−6 to 10−2 mol/l for Pb2+, respectively. Y1 - 2010 U6 - https://doi.org/10.1002/pssa.200983306 SN - 1862-6300 N1 - Special Issue: Engineering of Functional Interfaces EnFI 2009 VL - 207 IS - 4 SP - 930 EP - 934 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Wagner, Torsten A1 - Miyamoto, Ko-ichiro A1 - Schöning, Michael Josef A1 - Yoshinobu, Tatsuo T1 - Novel combination of digital light processing (DLP) and light-addressable potentiometric sensors (LAPS) for flexible chemical imaging JF - Procedia Engineering N2 - Chemical imaging systems allow the visualisation of the distribution of chemical species on the sensor surface. This work represents a new flexible approach of read out in a light-addressable potentiometric sensor (LAPS) with the help of a digital light processing (DLP) set-up. The DLP, known well for video projectors, consists of a mirror-array MEMS device which allows fast and flexible generation of light patterns. With the help of these light patterns the sensor surface of the LAPS device can be read out sequentially in a raster like scheme (scanning LAPS). The DLP approach has several advantages compared to conventional scanning LAPS set-ups, e.g., the spot size, the shape and the intensity of the light pointer can be changed easily and no mechanical movement is necessary, which reduces the size of the set-up and increases the stability and speed of measurement. Y1 - 2010 U6 - https://doi.org/10.1016/j.proeng.2010.09.161 SN - 1877-7058 N1 - Eurosensor XXIV Conference, 5-8 September 2010, Linz, Austria VL - 5 SP - 520 EP - 523 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Abouzar, Maryam H. A1 - Pedraza, A. M. A1 - Schöning, Michael Josef A1 - Poghossian, Arshak T1 - Label-free DNA hybridization and denaturation detection by means of field-effect nanoplate SOI capacitors functionalized with gold nanoparticles JF - Procedia Engineering N2 - A new approach for a label-free electrical detection of DNA hybridization and denaturation using an array of individually addressable field-effect nanoplate SOI (silicon-on-insulator) capacitors functionalized with gold nanoparticles is presented. By using a constant-capacitance measuring setup in a differential mode, signal changes of ∼110 mV and ∼70 mV have been registered after the DNA hybridization and denaturation events, respectively. Y1 - 2010 U6 - https://doi.org/10.1016/j.proeng.2010.09.259 SN - 1877-7058 N1 - Eurosensor XXIV Conference, 5-8 September 2010, Linz, Austria VL - 5 SP - 918 EP - 921 PB - Elsevier CY - Amsterdam ER -