TY  - JOUR
A1  - Wagner, Torsten
A1  - Molina, Roberto
A1  - Yoshinobu, Tatsuo
A1  - Kloock, Joachim P.
A1  - Biselli, Manfred
A1  - Canzoneri, Michele
A1  - Schnitzler, Thomas
A1  - Schöning, Michael Josef
T1  - Handheld multi-channel LAPS device as a transducer platform for possible biological and chemical multi-sensor applications
JF  - Electrochimica Acta. 53 (2007), H. 2
Y1  - 2007
SN  - 0013-4686
SP  - 305
EP  - 311
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  - Wagner, Torsten
A1  - Miyamoto, Ko-ichiro
A1  - Shigihara, Noriko
A1  - Schöning, Michael Josef
A1  - Yoshinobu, Tatsuo
T1  - Microfluidic systems with free definable sensor spots by an integrated light-addressable potentiometric sensor
JF  - Procedia Engineering. 25 (2011)
Y1  - 2011
SN  - 1877-7058
N1  - EurosensorsXXV ; Proc. Eurosensors XXV, September 4-7, 2011, Athens, Greece
SP  - 791
EP  - 794
PB  - Elsevier
CY  - Amsterdam
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. 5 (2010)
Y1  - 2010
SN  - 1877-7058
N1  - Eurosensor XXIV Conference
SP  - 520
EP  - 523
ER  - 
TY  - JOUR
A1  - Wagner, Torsten
A1  - Miyamoto, K.
A1  - Werner, Frederik
A1  - Schöning, Michael Josef
A1  - Yoshinobu, T.
T1  - Flexible electrochemical imaging with “zoom-in” functionality by using a new type of light-addressable potentiometric sensor
Y1  - 2011
N1  - 2011 16th International Solid-State Sensors, Actuators and Microsystems Conference (TRANSDUCERS) , Date: 5-9 June 2011
SP  - 2133
EP  - 2135
PB  - IEEE
CY  - New York
ER  - 
TY  - JOUR
A1  - Wagner, Torsten
A1  - Miyamoto, K.
A1  - Werner, Frederik
A1  - Schöning, Michael Josef
A1  - Yoshinobu, T.
T1  - Utilising Digital Micro-Mirror Device (DMD) as Scanning Light Source for Light-Addressable Potentiometric Sensors (LAPS)
Y1  - 2011
U6  - http://dx.doi.org/10.1166/sl.2011.1620
VL  - 9
IS  - 2
SP  - 812
EP  - 815
PB  - American Scientific Publishers
CY  - Stevenson Ranch, Calif.
ER  - 
TY  - JOUR
A1  - Wagner, Torsten
A1  - Maris, Rob J.
A1  - Ackermann, Hans-Josef
A1  - Otto, Ralph
A1  - Beging, Stefan
A1  - Poghossian, Arshak
A1  - Schöning, Michael Josef
T1  - Handheld measurement device for field-effect sensor structures: Practical evaluation and limitations
JF  - Sensors and Actuators B: Chemical  . 127 (2007), H. 1
Y1  - 2007
SN  - 0925-4005
SP  - 217
EP  - 223
ER  - 
TY  - JOUR
A1  - Wagner, Torsten
A1  - Kloock, Joachim P.
A1  - Schöning, Michael Josef
T1  - Determination of cadmium concentration and pH value in aqueous solutions by means of a handheld light-addressable potentiometric sensor (LAPS) device
JF  - Electrochemical sensor analysis / edited by S. Alegret ...
Y1  - 2007
SN  - 978-0-444-53133-9
N1  - Wilson & Wilson's comprehensive analytical chemistry ; 49
SP  - e35
EP  - e44
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Wagner, Torsten
A1  - Beging, Stefan
A1  - Rotter, L.
A1  - Poghossian, Arshak
A1  - Biselli, Manfred
A1  - Zang, Werner
A1  - Schöning, Michael Josef
T1  - Online-Messsysteme für die automatisierte Charakterisierung von feldeffektbasierten Biosensoren
JF  - 8. Dresdner Sensor-Symposium : Sensoren für Umwelt, Klima und Sicherheit, Biosensoren und Biosysteme, Sensoren und Sensorsysteme für die Prozesstechnik, Trends in der Sensortechnik, Materialentwicklung für die Sensorik; 8. Dresdner Sensor-Symposium, 10. - 12. Dezember 2007, Dresden / Gerald Gerlach ... (Hg.)
Y1  - 2007
SN  - 978-3-940046-45-1
N1  - Dresdner Sensor-Symposium <8, 2007, Dresden> ; Dresdner Beiträge zur Sensorik ; 29
SP  - 257
EP  - 260
PB  - TUDpress, Verl. der Wissenschaften
CY  - Dresden
ER  - 
TY  - JOUR
A1  - Vahidpour, Farnoosh
A1  - Guthman, Eric
A1  - Arreola, Julia
A1  - Alghazali, Yousef H. M.
A1  - Wagner, Torsten
A1  - Schöning, Michael Josef
T1  - Assessment of Various Process Parameters for Optimized Sterilization Conditions Using a Multi-Sensing Platform
JF  - Foods
N2  - In this study, an online multi-sensing platform was engineered to simultaneously evaluate various process parameters of food package sterilization using gaseous hydrogen peroxide (H₂O₂). The platform enabled the validation of critical aseptic parameters. In parallel, one series of microbiological count reduction tests was performed using highly resistant spores of B. atrophaeus DSM 675 to act as the reference method for sterility validation. By means of the multi-sensing platform together with microbiological tests, we examined sterilization process parameters to define the most effective conditions with regards to the highest spore kill rate necessary for aseptic packaging. As these parameters are mutually associated, a correlation between different factors was elaborated. The resulting correlation indicated the need for specific conditions regarding the applied H₂O₂ gas temperature, the gas flow and concentration, the relative humidity and the exposure time. Finally, the novel multi-sensing platform together with the mobile electronic readout setup allowed for the online and on-site monitoring of the sterilization process, selecting the best conditions for sterility and, at the same time, reducing the use of the time-consuming and costly microbiological tests that are currently used in the food package industry.
KW  - spore kill rate
KW  - sterility
KW  - aseptic parameters
KW  - multi-sensing platform
KW  - gaseous hydrogen peroxide
Y1  - 2022
U6  - http://dx.doi.org/10.3390/foods11050660
SN  - 2304-8158
N1  - This article belongs to the Special Issue "Sensors and Biosensors Application for Food Industries"
VL  - 11
IS  - 5
PB  - MDPI
CY  - Basel
ER  - 
TY  - JOUR
A1  - Takenaga, Shoko
A1  - Schneider, Benno
A1  - Erbay, E.
A1  - Biselli, Manfred
A1  - Schnitzler, Thomas
A1  - Schöning, Michael Josef
A1  - Wagner, Torsten
T1  - Fabrication of biocompatible lab-on-chip devices for biomedical applications by means of a 3D-printing process
JF  - Physica status solidi (a)
N2  - A new microfluidic assembly method for semiconductor-based biosensors using 3D-printing technologies was proposed for a rapid and cost-efficient design of new sensor systems. The microfluidic unit is designed and printed by a 3D-printer in just a few hours and assembled on a light-addressable potentiometric sensor (LAPS) chip using a photo resin. The cell growth curves obtained from culturing cells within microfluidics-based LAPS systems were compared with cell growth curves in cell culture flasks to examine biocompatibility of the 3D-printed chips. Furthermore, an optimal cell culturing within microfluidics-based LAPS chips was achieved by adjusting the fetal calf serum concentrations of the cell culture medium, an important factor for the cell proliferation.
Y1  - 2015
U6  - http://dx.doi.org/10.1002/pssa.201532053
SN  - 1862-6319
VL  - 212
IS  - 6
SP  - 1347
EP  - 1352
PB  - Wiley
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Takenaga, Shoko
A1  - Biselli, Manfred
A1  - Schnitzler, Thomas
A1  - Öhlschläger, Peter
A1  - Wagner, Torsten
A1  - Schöning, Michael Josef
T1  - Toward multi-analyte bioarray sensors: LAPS-based on-chip determination of a Michaelis–Menten-like kinetics for cell culturing
JF  - Physica status solidi A : Applications and materials science
N2  - The metabolic activity of Chinese hamster ovary (CHO) cells was observed using a light-addressable potentiometric sensor (LAPS). The dependency toward different glucose concentrations (17–200 mM) follows a Michaelis–Menten kinetics trajectory with Kₘ = 32.8 mM, and the obtained Kₘ value in this experiment was compared with that found in literature. In addition, the pH shift induced by glucose metabolism of tumor cells transfected with the HPV-16 genome (C3 cells) was successfully observed. These results indicate the possibility to determine the tumor cells metabolism with a LAPS-based measurement device.
Y1  - 2014
U6  - http://dx.doi.org/10.1002/pssa.201330464
SN  - 1521-396X (E); 1862-6319 (E-Journal); 0031-8965 (Print); 1862-6300 (Print)
VL  - 211
IS  - 6
SP  - 1410
EP  - 1415
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Schöning, Michael Josef
A1  - Wagner, Torsten
A1  - Wang, C.
A1  - Otto, R.
A1  - Yoshinobu, T.
T1  - Development of a handheld 16 channel pen-type LAPS for electrochemical sensing
JF  - Sensors and Actuators B. 108 (2005)
Y1  - 2005
SN  - 0925-4005
SP  - 808
EP  - 814
ER  - 
TY  - JOUR
A1  - Schöning, Michael Josef
A1  - Wagner, Torsten
A1  - Wang, C.
A1  - Otto, R.
A1  - Yoshinobu, T.
T1  - Development of a handheld 16 channel pen-type LAPS for electrochemical sensing
JF  - Technical digest of the 10th International Meeting on Chemical Sensors, July 11 - 14, 2004, Tsukuba, Japan / Japan Association of Chemical Sensors
Y1  - 2004
N1  - Chemical sensors ; 20.2004 Suppl. B. IMCS ; (10, 2004, Tsukuba) ; International Meeting on Chemical Sensors ; (10 : ; 2004.07.11-14 : ; Tsukuba)
SP  - 136
EP  - 137
PB  - Japan Association of Chemical Sensors
CY  - Fukuoka
ER  - 
TY  - JOUR
A1  - Reisert, Steffen
A1  - Geissler, H.
A1  - Florke, R.
A1  - Wagner, P.
A1  - Wagner, Torsten
A1  - Schöning, Michael Josef
T1  - Controlling aseptic sterilization processes by means of a multi-sensor system
Y1  - 2011
N1  - 2011 IEEE Workshop on Merging Fields of Computational Intelligence and Sensor Technology ; 11.-15. April 2011 Paris, France
SP  - 18
EP  - 22
PB  - IEEE
CY  - New York
ER  - 
TY  - JOUR
A1  - Poghossian, Arshak
A1  - Werner, Frederik
A1  - Buniatyan, V. V.
A1  - Wagner, Torsten
A1  - Miamoto, K.
A1  - Yoshinobu, T.
A1  - Schöning, Michael Josef
T1  - Towards addressability of light-addressable potentiometric sensors: Shunting effect of non-illuminated region and cross-talk
JF  - Sensor and Actuators B: Chemical
N2  - The LAPS (light-addressable potentiometric sensor) platform is one of the most attractive approaches for chemical and biological sensing with many applications ranging from pH and ion/analyte concentration measurements up to cell metabolism detection and chemical imaging. However, although it is generally accepted that LAPS measurements are spatially resolved, the light-addressability feature of LAPS devices has not been discussed in detail so far. In this work, an extended electrical equivalent-circuit model of the LAPS has been presented, which takes into account possible cross-talk effects due to the capacitive coupling of the non-illuminated region. A shunting effect of the non-illuminated area on the measured photocurrent and addressability of LAPS devices has been studied. It has been shown, that the measured photocurrent will be determined not only by the local interfacial potential in the illuminated region but also by possible interfacial potential changes in the non-illuminated region, yielding cross-talk effects. These findings were supported by the experimental investigations of a penicillin-sensitive multi-spot LAPS and a metal-insulator-semiconductor LAPS as model systems.
Y1  - 2017
U6  - http://dx.doi.org/10.1016/j.snb.2017.01.047
SN  - 0925-4005
IS  - 244
SP  - 1071
EP  - 1079
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Muschallik, Lukas
A1  - Molinnus, Denise
A1  - Jablonski, Melanie
A1  - Kipp, Carina Ronja
A1  - Bongaerts, Johannes
A1  - Pohl, Martina
A1  - Wagner, Torsten
A1  - Schöning, Michael Josef
A1  - Selmer, Thorsten
A1  - Siegert, Petra
T1  - Synthesis of α-hydroxy ketones and vicinal (R, R)-diols by Bacillus clausii DSM 8716ᵀ butanediol dehydrogenase
JF  - RSC Advances
N2  - α-hydroxy ketones (HK) and 1,2-diols are important building blocks for fine chemical synthesis. Here, we describe the R-selective 2,3-butanediol dehydrogenase from B. clausii DSM 8716ᵀ (BcBDH) that belongs to the metal-dependent medium chain dehydrogenases/reductases family (MDR) and catalyzes the selective asymmetric reduction of prochiral 1,2-diketones to the corresponding HK and, in some cases, the reduction of the same to the corresponding 1,2-diols. Aliphatic diketones, like 2,3-pentanedione, 2,3-hexanedione, 5-methyl-2,3-hexanedione, 3,4-hexanedione and 2,3-heptanedione are well transformed. In addition, surprisingly alkyl phenyl dicarbonyls, like 2-hydroxy-1-phenylpropan-1-one and phenylglyoxal are accepted, whereas their derivatives with two phenyl groups are not substrates. Supplementation of Mn²⁺ (1 mM) increases BcBDH's activity in biotransformations. Furthermore, the biocatalytic reduction of 5-methyl-2,3-hexanedione to mainly 5-methyl-3-hydroxy-2-hexanone with only small amounts of 5-methyl-2-hydroxy-3-hexanone within an enzyme membrane reactor is demonstrated.
Y1  - 2020
U6  - http://dx.doi.org/10.1039/D0RA02066D
SN  - 2046-2069
VL  - 10
SP  - 12206
EP  - 12216
PB  - Royal Society of Chemistry (RSC)
CY  - Cambridge
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  - Molinnus, Denise
A1  - Muschallik, Lukas
A1  - Gonzalez, Laura Osorio
A1  - Bongaerts, Johannes
A1  - Wagner, Torsten
A1  - Selmer, Thorsten
A1  - Siegert, Petra
A1  - Keusgen, Michael
A1  - Schöning, Michael Josef
T1  - Development and characterization of a field-effect biosensor for the detection of acetoin
JF  - Biosensors and Bioelectronics
N2  - A capacitive electrolyte-insulator-semiconductor (EIS) field-effect biosensor for acetoin detection has been presented for the first time. The EIS sensor consists of a layer structure of Al/p-Si/SiO₂/Ta₂O₅/enzyme acetoin reductase. The enzyme, also referred to as butane-2,3-diol dehydrogenase from B. clausii DSM 8716T, has been recently characterized. The enzyme catalyzes the (R)-specific reduction of racemic acetoin to (R,R)- and meso-butane-2,3-diol, respectively. Two different enzyme immobilization strategies (cross-linking by using glutaraldehyde and adsorption) have been studied. Typical biosensor parameters such as optimal pH working range, sensitivity, hysteresis, linear concentration range and long-term stability have been examined by means of constant-capacitance (ConCap) mode measurements. Furthermore, preliminary experiments have been successfully carried out for the detection of acetoin in diluted white wine samples.
Y1  - 2018
U6  - http://dx.doi.org/10.1016/j.bios.2018.05.023
VL  - 115
SP  - 1
EP  - 6
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Miyamoto, Koichiro
A1  - Seki, Kosuke
A1  - Suto, Takeyuki
A1  - Werner, Frederik
A1  - Wagner, Torsten
A1  - Schöning, Michael Josef
A1  - Yoshinobu, Tatsuo
T1  - Improved spatial resolution of the chemical imaging sensor with a hybrid illumination that suppresses lateral diffusion of photocarriers
JF  - Sensor and Actuators B: Chemical
N2  - The chemical imaging sensor is a semiconductor-based chemical sensor capable of visualizing pH and ion distributions. The spatial resolution depends on the lateral diffusion of photocarriers generated by illumination of the semiconductor substrate. In this study, two types of optical setups, one based on a bundle of optical fibers and the other based on a binocular tube head, were developed to project a hybrid illumination of a modulated light beam and a ring-shaped constant illumination onto the sensor plate. An improved spatial resolution was realized by the ring-shaped constant illumination, which suppressed lateral diffusion of photocarriers by enhanced recombination due to the increased carrier concentration.
Y1  - 2018
U6  - http://dx.doi.org/10.1016/j.snb.2018.07.016
SN  - 0925-4005
VL  - 273
SP  - 1328
EP  - 1333
PB  - Elsevier
CY  - Amsterdam
ER  -