TY - JOUR A1 - Poghossian, Arshak A1 - Schöning, Michael Josef T1 - "High-order” hybrid FET module for (bio)chemical and physical sensing JF - Integrated analytical systems / ed. by Salvador Alegret Y1 - 2003 SN - 0-444-51037-0 SP - 587 EP - 623 PB - Elsevier CY - Amsterdam [u.a.] ER - TY - JOUR A1 - Schöning, Michael Josef T1 - "Playing around“ with field-effect sensors on the basis of EIS structures, LAPS and ISFETs JF - Sensors. 5 (2005), H. 3 Y1 - 2005 SN - 1424-8220 SP - 126 EP - 138 ER - TY - JOUR A1 - Schöning, Michael Josef T1 - "Voltohmmetry" – a new transducer principle for electrochemical sensors JF - Ultrathin electrochemical chemo- and biosensors : technology and performance / Vladimir M. Mirsky Y1 - 2004 SN - 3-540-21285-X SP - 117 EP - 140 PB - Springer CY - Berlin [u.a.] ER - TY - JOUR A1 - Buniatyan, V. V. A1 - Matirosyan, N. W. A1 - Abouzar, Maryam H. A1 - Schöning, Michael Josef A1 - Poghossian, Arshak A1 - Schubert, J. A1 - Khachatryan, V. R. A1 - Soukiassyan, G. R. T1 - (Ba,Sr)TiO3 based electrolyte-insulator-semiconductor pHsensors: comparitive study JF - Semiconductor micro- and nanoelectronics : Proceedings of the Seventh International Conference , Tsakhcadzor, Armenia July 3-5 2009 Y1 - 2009 SP - 71 EP - 74 ER - TY - JOUR A1 - Poghossian, Arshak A1 - Lüth, H. A1 - Schultze, J. W. A1 - Schöning, Michael Josef T1 - (Bio-)chemical and physical microsensor array using an identical transducer principle JF - Scaling down in electrochemistry : electrochemical micro- and nanosystem technology ; proceedings of the 3rd International Symposium on Electrochemical Microsystem Technologies, Garmisch-Patenkirchen, Germany, 11 - 15 September 2000 / ed. by J. W. Schultz Y1 - 2001 SN - 0-08-044014-2 SP - 243 EP - 249 PB - Elsevier [u.a.] CY - Amsterdam [u.a.] ER - TY - JOUR A1 - Muschallik, Lukas A1 - Molinnus, Denise A1 - Bongaerts, Johannes A1 - Pohl, Martina A1 - Wagner, Torsten A1 - Schöning, Michael Josef A1 - Siegert, Petra A1 - Selmer, Thorsten T1 - (R,R)-Butane-2,3-diol Dehydrogenase from Bacillus clausii DSM 8716T: Cloning and Expression of the bdhA-Gene, and Initial Characterization of Enzyme JF - Journal of Biotechnology N2 - The gene encoding a putative (R,R)-butane-2,3-diol dehydrogenase (bdhA) from Bacillus clausii DSM 8716T was isolated, sequenced and expressed in Escherichia coli. The amino acid sequence of the encoded protein is only distantly related to previously studied enzymes (identity 33–43%) and exhibited some uncharted peculiarities. An N-terminally StrepII-tagged enzyme variant was purified and initially characterized. The isolated enzyme catalyzed the (R)-specific oxidation of (R,R)- and meso-butane-2,3-diol to (R)- and (S)-acetoin with specific activities of 12 U/mg and 23 U/mg, respectively. Likewise, racemic acetoin was reduced with a specific activity of up to 115 U/mg yielding a mixture of (R,R)- and meso-butane-2,3-diol, while the enzyme reduced butane-2,3-dione (Vmax 74 U/mg) solely to (R,R)-butane-2,3-diol via (R)-acetoin. For these reactions only activity with the co-substrates NADH/NAD+ was observed. The enzyme accepted a selection of vicinal diketones, α-hydroxy ketones and vicinal diols as alternative substrates. Although the physiological function of the enzyme in B. clausii remains elusive, the data presented herein clearly demonstrates that the encoded enzyme is a genuine (R,R)-butane-2,3-diol dehydrogenase with potential for applications in biocatalysis and sensor development. Y1 - 2017 U6 - http://dx.doi.org/10.1016/j.jbiotec.2017.07.020 SN - 0168-1656 VL - 258 SP - 41 EP - 50 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Achtsnicht, Stefan A1 - Tödter, Julia A1 - Niehues, Julia A1 - Telöken, Matthias A1 - Offenhäusser, Andreas A1 - Krause, Hans-Joachim A1 - Schröper, Florian T1 - 3D printed modular immunofiltration columns for frequency mixing-based multiplex magnetic immunodetection JF - Sensors N2 - For performing point-of-care molecular diagnostics, magnetic immunoassays constitute a promising alternative to established enzyme-linked immunosorbent assays (ELISA) because they are fast, robust and sensitive. Simultaneous detection of multiple biomolecular targets from one body fluid sample is desired. The aim of this work is to show that multiplex magnetic immunodetection based on magnetic frequency mixing by means of modular immunofiltration columns prepared for different targets is feasible. By calculations of the magnetic response signal, the required spacing between the modules was determined. Immunofiltration columns were manufactured by 3D printing and antibody immobilization was performed in a batch approach. It was shown experimentally that two different target molecules in a sample solution could be individually detected in a single assaying step with magnetic measurements of the corresponding immobilization filters. The arrangement order of the filters and of a negative control did not influence the results. Thus, a simple and reliable approach to multi-target magnetic immunodetection was demonstrated. Y1 - 2019 U6 - http://dx.doi.org/10.3390/s19010148 SN - 1424-8220 VL - 19 IS - 1 PB - MDPI CY - Basel ER - TY - JOUR A1 - Schöning, Michael Josef A1 - Arzdorf, M. A1 - Mulchandani, P. A1 - Chen, W. A1 - Mulchandani, A. T1 - A capacitive field-effect sensor for the direct determination of organophosphorus pesticides JF - Sensors and Actuators B. 91 (2003), H. 1-3 Y1 - 2003 SN - 0925-4005 SP - 92 EP - 97 ER - TY - JOUR A1 - Haeger, Gerrit A1 - Bongaerts, Johannes A1 - Siegert, Petra T1 - A convenient ninhydrin assay in 96-well format for amino acid-releasing enzymes using an air-stable reagent JF - Analytical Biochemistry N2 - An improved and convenient ninhydrin assay for aminoacylase activity measurements was developed using the commercial EZ Nin™ reagent. Alternative reagents from literature were also evaluated and compared. The addition of DMSO to the reagent enhanced the solubility of Ruhemann's purple (RP). Furthermore, we found that the use of a basic, aqueous buffer enhances stability of RP. An acidic protocol for the quantification of lysine was developed by addition of glacial acetic acid. The assay allows for parallel processing in a 96-well format with measurements microtiter plates. Y1 - 2022 U6 - http://dx.doi.org/10.1016/j.ab.2022.114819 SN - 1096-0309 IS - 624 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Bohrn, Ulrich A1 - Mucha, Andreas A1 - Werner, Frederik A1 - Trattner, Barbara A1 - Bäcker, Matthias A1 - Krumbe, Christoph A1 - Schienle, Meinrad A1 - Stütz, Evamaria A1 - Schmitt-Landsiedel, Doris A1 - Fleischer, Maximilian A1 - Wagner, Patrick A1 - Schöning, Michael Josef T1 - A critical comparison of cell-based sensor systems for the detection of Cr (VI) in aquatic environment JF - Sensors and actuators. B: Chemical Y1 - 2013 SN - 1873-3077 (E-Journal); 0925-4005 (Print) VL - Vol. 182 SP - 58 EP - 65 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Schöning, Michael Josef A1 - Krause, R. A1 - Block, K. A1 - Musameh, M. A1 - Mulchandani, A. A1 - Wang, J. T1 - A dual amperometric / potentiometric FIA-based biosensor for the distinctive detection of organophosphorus pesticides JF - Book of abstracts / ed. by J. Saneistr. Y1 - 2002 SN - 80-01-02576-4 N1 - Eurosensors ; (16, 2002, Praha) SP - 76 EP - 79 PB - Czech Technical University, Faculty of Electrical Engineering, Department of Measurement CY - Prague ER - TY - JOUR A1 - Schöning, Michael Josef A1 - Krause, R. A1 - Block, K. A1 - Musahmeh, M. A1 - Mulchandani, A. A1 - Wang, J. T1 - A dual amperometric/potentiometric FIA-based biosensor for the distinctive detection of organophosphorus pesticides JF - Sensors and Actuators B. 95 (2003), H. 1-3 Y1 - 2003 SN - 0925-4005 SP - 291 EP - 296 ER - TY - JOUR A1 - Schiffels, Johannes A1 - Selmer, Thorsten T1 - A flexible toolbox to study protein-assisted metalloenzyme assembly in vitro JF - Biotechnology and Bioengineering Y1 - 2015 U6 - http://dx.doi.org/10.1002/bit.25658 SN - 1097-0290 VL - 112 IS - 11 SP - 2360 EP - 2372 PB - Wiley CY - Weinheim ER - TY - JOUR A1 - Wagner, Torsten A1 - Schöning, Michael Josef A1 - Otto, R. A1 - Yoshinobu, T. T1 - A handheld 16 channel pen-type LAPS as a platform for (bio-)electrochemical sensing JF - Biomedizinische Technik. 49 (2004), H. 2 Y1 - 2004 SN - 0932-4666 SP - 996 EP - 997 ER - TY - JOUR A1 - Wagner, Torsten A1 - Werner, Frederik A1 - Miyamoto, K. A1 - Schöning, Michael Josef A1 - Yoshinobu, T. T1 - A high-density multi-point LAPS set-up using a VCSEL array and FPGA control JF - Procedia Chemistry. 1 (2009), H. 1 Y1 - 2009 SN - 1876-6196 N1 - Proceedings of the Eurosensors XXIII conference ; Eurosensors 23 SP - 1483 EP - 1486 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Wagner, Torsten A1 - Werner, Frederik A1 - Miyamoto, Ko-Ichiro A1 - Schöning, Michael Josef A1 - Yoshinobu, Tatsuo T1 - A high-density multi-point LAPS set-up using a VCSEL array and FPGA control JF - Sensors and Actuators B: Chemical. 154 (2011), H. 2 Y1 - 2011 SN - 1873-3077 N1 - EUROSENSORS XXIII SP - 124 EP - 128 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Miyamoto, Ko-ichiro A1 - Hayashi, Kosuke A1 - Sakamoto, Azuma A1 - Werner, Frederik A1 - Wagner, Torsten A1 - Schöning, Michael Josef A1 - Yoshinobu, Tatsuo T1 - A high-Q resonance-mode measurement of EIS capacitive sensor by elimination of series resistance JF - Sensor and Actuators B: Chemical N2 - An EIS capacitive sensor is a semiconductor-based potentiometric sensor, which is sensitive to the ion concentration or pH value of the solution in contact with the sensing surface. To detect a small change in the ion concentration or pH, a small capacitance change must be detected. Recently, a resonance-mode measurement was proposed, in which an inductor was connected to the EIS capacitive sensor and the resonant frequency was correlated with the pH value. In this study, the Q factor of the resonant circuit was enhanced by canceling the internal resistance of the reference electrode and the internal resistance of the inductor coil with the help of a bypass capacitor and a negative impedance converter, respectively. 1% variation of the signal in the developed system corresponded to a pH change of 3.93 mpH, which was about 1/12 of the conventional method, suggesting a better performance in detection of a small pH change. KW - Negative impedance convertor KW - Resonance-mode measurement KW - Chemical sensor KW - EIS capacitive sensor Y1 - 2017 U6 - http://dx.doi.org/10.1016/j.snb.2017.03.002 SN - 0925-4005 VL - 248 SP - 1006 EP - 1010 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Dantism, Shahriar A1 - Röhlen, Desiree A1 - Wagner, Torsten A1 - Wagner, P. A1 - Schöning, Michael Josef T1 - A LAPS-based differential sensor for parallelized metabolism monitoring of various bacteria JF - Sensors N2 - Monitoring the cellular metabolism of bacteria in (bio)fermentation processes is crucial to control and steer them, and to prevent undesired disturbances linked to metabolically inactive microorganisms. In this context, cell-based biosensors can play an important role to improve the quality and increase the yield of such processes. This work describes the simultaneous analysis of the metabolic behavior of three different types of bacteria by means of a differential light-addressable potentiometric sensor (LAPS) set-up. The study includes Lactobacillus brevis, Corynebacterium glutamicum, and Escherichia coli, which are often applied in fermentation processes in bioreactors. Differential measurements were carried out to compensate undesirable influences such as sensor signal drift, and pH value variation during the measurements. Furthermore, calibration curves of the cellular metabolism were established as a function of the glucose concentration or cell number variation with all three model microorganisms. In this context, simultaneous (bio)sensing with the multi-organism LAPS-based set-up can open new possibilities for a cost-effective, rapid detection of the extracellular acidification of bacteria on a single sensor chip. It can be applied to evaluate the metabolic response of bacteria populations in a (bio)fermentation process, for instance, in the biogas fermentation process. Y1 - 2019 U6 - http://dx.doi.org/10.3390/s19214692 SN - 1424-8220 VL - 19 IS - 21 PB - MDPI CY - Basel ER - TY - JOUR A1 - Wagner, Torsten A1 - Molina, R. A1 - Biselli, Manfred A1 - Canzoneri, Michele A1 - Schnitzler, Thomas A1 - Yoshinobu, Tatsuo A1 - Schöning, Michael Josef T1 - A light-addressable potentiometric sensor system for fast, simultaneous and spatial detection of the metabolic activity of biological cells JF - Transducers '07 Eurosensors XXI : digest of technical papers ; the14th International Conference on Solid-State Sensors, Actuators and Microsystems, June 10-14, 2007, Lyon, France / Gilles Delapierre (Ed.) Y1 - 2007 SN - 1-4244-0841-5 N1 - Eurosensors 21, 2007, Lyon ; International Conference on Solid-State Sensors, Actuators and Microsystems 14, 2007, Lyon SP - 1107 EP - 1110 PB - IEEE CY - Piscataway ER - TY - JOUR A1 - Simonis, A. A1 - Ruge, C. A1 - Müller-Veggian, Mattea A1 - Lüth, H. A1 - Schöning, Michael Josef T1 - A long-term stable macroporoustype EIS structure for electrochemical sensor applications JF - Sensors and Actuators B. 91 (2003), H. 1-3 Y1 - 2003 SN - 0925-4005 SP - 21 EP - 25 ER -