TY  - JOUR
A1  - Wagner, Torsten
A1  - Werner, Frederik
A1  - Miyamoto, Ko-Ichiro
A1  - Schöning, Michael Josef
A1  - Yoshinobu, Tatsuo
T1  - Development and characterisation of a compact light-addressable potentiometric sensor (LAPS) based on the digital light processing (DLP) technology for flexible chemical imaging
JF  - Sensors and Actuators B: Chemical
N2  - Chemical imaging systems allow the visualisation of the distribution of chemical species on the sensor surface. This work represents a new flexible approach to read out light-addressable potentiometric sensors (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 addressed. The DLP approach has several advantages compared to conventional LAPS set-ups, e.g., the spot size and the shape 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 the measurement. In addition, the modulation frequency and intensity of the light beam are important parameters of the LAPS set-up. Within this work, the authors will discuss two different ways of light modulation by the DLP set-up, investigate the influence of different modulation frequencies and different light intensities as well as demonstrate the scanning capabilities of the new set-up by pH mapping on the sensor surface.
Y1  - 2012
U6  - http://dx.doi.org/10.1016/j.snb.2010.12.003
SN  - 0925-4005
N1  - Part of special issue "Eurosensors XXIV, 2010"
VL  - 170
SP  - 34
EP  - 39
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  - Wagner, Torsten
A1  - Werner, Frederik
A1  - Miyamoto, Ko-ichiro
A1  - Ackermann, Hans-Josef
A1  - Yoshinobu, Tatsuo
A1  - Schöning, Michael Josef
T1  - FPGA-based LAPS device for the flexible design of sensing sites on functional interfaces
JF  - Physica Status Solidi (A). 207 (2010), H. 4
Y1  - 2010
SN  - 1862-6300
N1  - Special Issue: Engineering of Functional Interfaces EnFI 2009
SP  - 844
EP  - 849
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  - Vornholt, Wolfgang
A1  - Werner, Frederik
A1  - Yoshinobu, Tatsuo
A1  - Miyamoto, Ko-Ichiro
A1  - Keusgen, Michael
A1  - Schöning, Michael Josef
T1  - Light-addressable potentiometric sensor (LAPS) combined with magnetic beads for pharmaceutical screening
JF  - Physics in medicine
N2  - The light-addressable potentiometric sensor (LAPS) has the unique feature to address different regions of a sensor surface without the need of complex structures. Measurements at different locations on the sensor surface can be performed in a common analyte solution, which distinctly simplifies the fluidic set-up. However, the measurement in a single analyte chamber prevents the application of different drugs or different concentrations of a drug to each measurement spot at the same time as in the case of multi-reservoir-based set-ups. In this work, the authors designed a LAPS-based set-up for cell culture screening that utilises magnetic beads loaded with the endotoxin (lipopolysaccharides, LPS), to generate a spatially distributed gradient of analyte concentration. Different external magnetic fields can be adjusted to move the magnetic beads loaded with a specific drug within the measurement cell. By recording the metabolic activities of a cell layer cultured on top of the LAPS surface, this work shows the possibility to apply different concentrations of a sample along the LAPS measurement spots within a common analyte solution.
Y1  - 2016
U6  - http://dx.doi.org/10.1016/j.phmed.2016.03.001
SN  - 2352-4510
VL  - 2016
IS  - 1
SP  - 2
EP  - 7
ER  - 
TY  - JOUR
A1  - Wagner, Torsten
A1  - Shigiahara, N.
A1  - Miyamoto, K.
A1  - Suzurikawa, J.
A1  - Finger, F.
A1  - Schöning, Michael Josef
A1  - Yoshinobu, T.
T1  - Light-addressable Potentiometric Sensors and Light–addressable Electrodes as a Combined Sensor-and-manipulator Microsystem with High Flexibility
JF  - Procedia Engineering
N2  - This work describes the novel combination of the light-addressable electrode (LAE) and the light-addressable potentiometric sensor (LAPS) into a microsystem set-up. Both the LAE as well as the LAPS shares the principle of addressing the active spot by means of a light beam. This enables both systems to manipulate resp. to detect an analyte with a high spatial resolution. Hence, combining both principles into a single set-up enables the active stimulation e.g., by means of electrolysis and a simultaneous observation e.g., the response of an entrapped biological cell by detection of extracellular pH changes. The work will describe the principles of both technologies and the necessary steps to integrate them into a single set-up. Furthermore, examples of application and operation of such systems will be presented.
Y1  - 2012
U6  - http://dx.doi.org/10.1016/j.proeng.2012.09.290
SN  - 1877-7058
N1  - Part of special issue "26th European Conference on Solid-State Transducers, EUROSENSOR 2012"
IS  - 47
SP  - 890
EP  - 893
PB  - Elsevier
CY  - Amsterdam
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  - Schöning, Michael Josef
T1  - Light-addressable potentiometric sensors (LAPS): recent trends and applications
JF  - Electrochemical sensor analysis / edited by S. Alegret ...
Y1  - 2007
SN  - 978-0-444-53053-0
N1  - Wilson & Wilson's comprehensive analytical chemistry ; 49
SP  - 87
EP  - 128
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Wagner, Torsten
A1  - Rao, C.
A1  - Otto, R.
A1  - Yoshinobu, T.
A1  - Kloock, Joachim P.
A1  - Schöning, Michael Josef
T1  - Chipkarten-basierter Multikanal lichtadressierbarer potentiometrischer Sensor für analytische Anwendungen in flüssigen Medien
JF  - Neue Herausforderungen und Anwendungen in der Sensortechnik : 7. Dresdner Sensor-Symposium ; 12. - 14. Dezember 2005, Dresden / [Forschungsgesellschaft für Messtechnik, Sensorik und Medizintechnik e.V.]. Gerald Gerlach ... (Hg.)
Y1  - 2005
SN  - 3-938863-29-3
N1  - Dresdner Beiträge zur Sensorik ; 24
SP  - 11
EP  - 14
PB  - TUDpress
CY  - Dresden
ER  - 
TY  - JOUR
A1  - Wagner, Torsten
A1  - Rao, C.
A1  - Kloock, Joachim P.
A1  - Yoshinobu, T.
A1  - Otto, R.
A1  - Keusgen, M.
A1  - Schöning, Michael Josef
T1  - “LAPS Card”—A novel chip card-based light-addressable potentiometric sensor (LAPS)
JF  - Sensors and Actuators B: Chemical. 118 (2006), H. 1-2
Y1  - 2006
SN  - 0925-4005
N1  - Eurosensors XIX - Eurosensors XIX - The 19th European Conference on Solid-State Transducers
SP  - 33
EP  - 40
ER  - 
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  - CHAP
A1  - Takenaga, Shoko
A1  - Herrera, Cony F.
A1  - Werner, Frederik
A1  - Biselli, Manfred
A1  - Schnitzler, Thomas
A1  - Schöning, Michael Josef
A1  - Öhlschläger, Peter
A1  - Wagner, Torsten
T1  - Detection of the metabolic activity of cells by differential measurements based on a single light-addressable potentiometric sensor chip
T2  - 11. Dresdner Sensor-Symposium : 9.-11.12.2013
Y1  - 2013
SN  - 978-3-9813484-5-3
SP  - 63
EP  - 67
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  - CHAP
A1  - Schöning, Michael Josef
A1  - Wagner, Torsten
A1  - Poghossian, Arshak
A1  - Miyamoto, K.I.
A1  - Werner, C.F.
A1  - Krause, S.
A1  - Yoshinobu, T.
T1  - Light-addressable potentiometric sensors for (bio-)chemical sensing and imaging
T2  - Encyclopedia of Interfacial Chemistry: Surface Science and Electrochemistry. Vol. 7
Y1  - 2018
SN  - 9780128097397
SP  - 295
EP  - 308
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - CHAP
A1  - Schöning, Michael Josef
A1  - Abouzar, Maryam H.
A1  - Wagner, Torsten
A1  - Näther, Niko
A1  - Rolka, David
A1  - Yoshinobu, Tatsuo
A1  - Kloock, Joachim P.
A1  - Turek, Monika
A1  - Ingebrandt, Sven
A1  - Poghossian, Arshak
T1  - A semiconductor-based field-effect platform for (bio-)chemical and physical sensors: From capacitive EIS sensors and LAPS over ISFETs to nano-scale devices
T2  - MRS Proceedings
Y1  - 2006
U6  - http://dx.doi.org/10.1557/PROC-0952-F08-02
N1  - Vol. 952 - Symposium F - Integrated Nanosensors
SP  - 1
EP  - 9
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  - 
TY  - JOUR
A1  - Miyamoto, Ko-ichiro
A1  - Yu, Bing
A1  - Isoda, Hiroko
A1  - Wagner, Torsten
A1  - Schöning, Michael Josef
A1  - Yoshinobu, Tatsuo
T1  - Visualization of the recovery process of defects in a cultured cell layer by chemical imaging sensor
JF  - Sensors and Actuators B: Chemical
N2  - The chemical imaging sensor is a field-effect sensor which is able to visualize both the distribution of ions (in LAPS mode) and the distribution of impedance (in SPIM mode) in the sample. In this study, a novel cell assay is proposed, in which the chemical imaging sensor operated in SPIM mode is applied to monitor the recovery of defects in a cell layer brought into proximity of the sensing surface. A reduced impedance at a defect formed artificially in a cell layer was successfully visualized in a photocurrent image. The cell layer was cultured over two weeks, during which the temporal change of the photocurrent distribution corresponding to the recovery of the defect was observed.
Y1  - 2016
U6  - http://dx.doi.org/10.1016/j.snb.2016.04.018
SN  - 0925-4005
VL  - 236
SP  - 965
EP  - 969
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Miyamoto, Ko-ichiro
A1  - Yoshida, Midori
A1  - Sakai, Taito
A1  - Matsuzaka, Atsushi
A1  - Wagner, Torsten
A1  - Kanoh, Sanoh
A1  - Yoshinobu, Tatsuo
A1  - Schöning, Michael Josef
T1  - Differential setup of light-addressable potentiometric sensor with an enzyme reactor in a flow channel
JF  - Japanese Journal of Applied Physics. 50 (2011)
Y1  - 2011
SN  - 0021-4922
SP  - 04DL08-1
EP  - 04DL08-5
PB  - Japan Society of Applied Physics
CY  - Bristol
ER  - 
TY  - JOUR
A1  - Miyamoto, Ko-ichiro
A1  - Wagner, Torsten
A1  - Yoshinobu, Tatsuo
A1  - Kanoh, Shin`ichiro
A1  - Schöning, Michael Josef
T1  - Phase-mode LAPS and its application to chemical imaging
JF  - Sensors and Actuators B: Chemical. 154 (2011), H. 1
Y1  - 2011
SN  - 1873-3077
SP  - 28
EP  - 32
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Miyamoto, Ko-ichiro
A1  - Wagner, Torsten
A1  - Yoshinobu, Tatsuo
A1  - Kanoh, Shin`ichiro
A1  - Schöning, Michael Josef
T1  - Phase-mode operation of FDM-LAPS
JF  - Sensor letters
Y1  - 2011
SN  - 1546-1971
VL  - 9
IS  - 2
SP  - 691
EP  - 694
PB  - American Scientific Publishers
CY  - Stevenson Ranch, Calif.
ER  - 
TY  - JOUR
A1  - Miyamoto, Ko-ichiro
A1  - Wagner, Torsten
A1  - Mimura, Shuhei
A1  - Kanoh, Shiníchiro
A1  - Yoshinobu, Tatsuo
A1  - Schöning, Michael Josef
T1  - Constant-phase-mode operation of the light-addressable potentiometric sensor
JF  - Sensors and Actuators B: Chemical. 154 (2011), H. 2
Y1  - 2011
SN  - 1873-3077
N1  - EUROSENSORS XXIII
SP  - 119
EP  - 123
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Miyamoto, Ko-ichiro
A1  - Wagner, Torsten
A1  - Mimura, Shuhei
A1  - Kanoh, Shin`ichiro
A1  - Yoshinobu, Tatsuo
A1  - Schöning, Michael Josef
T1  - Constant-phase-mode operation of the light-addressable potentiometric sensor
JF  - Procedia Chemistry. 1 (2009), H. 1
Y1  - 2009
SN  - 1876-6196
N1  - Proceedings of the Eurosensors XXIII conference ; Eurosensors 23
SP  - 1487
EP  - 1490
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - CHAP
A1  - Miyamoto, Ko-ichiro
A1  - Suto, Takeyuki
A1  - Werner, Frederik
A1  - Wagner, Torsten
A1  - Schöning, Michael Josef
A1  - Yoshinobu, Tatsuo
T1  - Restraining the Diffusion of Photocarriers to Improve the Spatial Resolution of the Chemical Imaging Sensor
T2  - MDPI Proceedings
Y1  - 2017
U6  - http://dx.doi.org/10.3390/proceedings1040477
N1  - Eurosensors 2017 Conference, Paris, France, 3–6 September 2017
VL  - 1
IS  - 4
ER  - 
TY  - JOUR
A1  - Miyamoto, Ko-ichiro
A1  - Sugawara, Yuri
A1  - Kanoh, Shin´ichiro
A1  - Yoshinobu, Tatsuo
A1  - Wagner, Torsten
A1  - Schöning, Michael Josef
T1  - Image correction method for the chemical imaging sensor
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  - 344
EP  - 348
ER  - 
TY  - JOUR
A1  - Miyamoto, Ko-Ichiro
A1  - Sato, Takuya
A1  - Abe, Minami
A1  - Wagner, Torsten
A1  - Schöning, Michael Josef
A1  - Yoshinobu, Tatsuo
T1  - Light-addressable potentiometric sensor as a sensing element in plug-based microfluidic devices
JF  - Micromachines
N2  - A plug-based microfluidic system based on the principle of the light-addressable potentiometric sensor (LAPS) is proposed. The LAPS is a semiconductor-based chemical sensor, which has a free addressability of the measurement point on the sensing surface. By combining a microfluidic device and LAPS, ion sensing can be performed anywhere inside the microfluidic channel. In this study, the sample solution to be measured was introduced into the channel in a form of a plug with a volume in the range of microliters. Taking advantage of the light-addressability, the position of the plug could be monitored and pneumatically controlled. With the developed system, the pH value of a plug with a volume down to 400 nL could be measured. As an example of plug-based operation, two plugs were merged in the channel, and the pH change was detected by differential measurement.
KW  - light-addressable potentiometric sensor
KW  - plug-based microfluidic device
KW  - chemical sensor
Y1  - 2016
U6  - http://dx.doi.org/10.3390/mi7070111
SN  - 2072-666X
N1  - This article belongs to the Special Issue "Micro/Nano Devices for Chemical Analysis"
VL  - 7
IS  - 7
SP  - 111
PB  - MDPI
CY  - Basel
ER  - 
TY  - JOUR
A1  - Miyamoto, Ko-ichiro
A1  - Kaneko, Kazumi
A1  - Matsuo, Akira
A1  - Wagner, Torsten
A1  - Kanoh, Shiníchiro
A1  - Schöning, Michael Josef
A1  - Yoshinobu, Tatsuo
T1  - Miniaturized chemical imaging sensor system using an OLED display panel
JF  - Sensors and Actuators B: Chemical
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 current–voltage characteristics and the pH sensitivity were investigated and pH imaging with this miniaturized system was demonstrated.
KW  - LAPS
KW  - Light-addressable potentiometric sensor
KW  - Chemical imaging sensor
KW  - Organic light-emitting diode display
Y1  - 2012
U6  - http://dx.doi.org/10.1016/j.snb.2011.02.029
SN  - 0925-4005
N1  - Part of special issue "Eurosensors XXIV, 2010"
VL  - 170
SP  - 82
EP  - 87
PB  - Elsevier
CY  - Amsterdam
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. 5 (2010)
Y1  - 2010
SN  - 1877-7058
N1  - Eurosensor XXIV Conference
SP  - 516
EP  - 519
ER  - 
TY  - JOUR
A1  - Miyamoto, Ko-ichiro
A1  - Itabashi, Akinori
A1  - Wagner, Torsten
A1  - Schöning, Michael Josef
A1  - Yoshinobu, Tatsuo
T1  - High-speed chemical imaging inside a microfluidic channel
JF  - Sensors and actuators. B: Chemical
N2  - In this study, a high-speed chemical imaging system was developed for visualization of the interior of a microfluidic channel. A microfluidic channel was constructed on the sensor surface of the light-addressable potentiometric sensor (LAPS), on which the ion concentrations could be measured in parallel at up to 64 points illuminated by optical fibers. The temporal change of pH distribution inside the microfluidic channel was recorded at a maximum rate of 100 frames per second (fps). The high frame rate allowed visualization of moving interfaces and plugs in the channel even at a flow velocity of 111 mm/s, which suggests the feasibility of plug-based microfluidic devices for flow-injection analysis (FIA).
Y1  - 2014
U6  - http://dx.doi.org/10.1016/j.snb.2013.12.090
SN  - 1873-3077 (E-Journal); 0925-4005 (Print)
VL  - 194
SP  - 521
EP  - 527
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Miyamoto, Ko-ichiro
A1  - Ichimura, Hiroki
A1  - Wagner, Torsten
A1  - Schöning, Michael Josef
A1  - Yoshinobu, Tatsuo
T1  - Chemical imaging of the concentration profile of ion diffusion in a microfluidic channel
JF  - Sensors and actuators. B: Chemical
N2  - The chemical imaging sensor is a device to visualize the spatial distribution of chemical species based on the principle of LAPS (light-addressable potentiometric sensor), which is a field-effect chemical sensor based on semiconductor. In this study, the chemical imaging sensor has been applied to investigate the ion profile of laminar flows in a microfluidic channel. The chemical images (pH maps) were collected in a Y-shaped microfluidic channel while injecting HCl and NaCl solutions into two branches. From the chemical images, it was clearly observed that the injected solutions formed laminar flows in the channel. In addition, ion diffusion across the laminar flows was observed, and the diffusion coefficient could be derived by fitting the pH profiles to the Fick's equation.
Y1  - 2013
U6  - http://dx.doi.org/10.1016/j.snb.2013.04.057
SN  - 1873-3077 (E-Journal); 0925-4005 (Print)
N1  - Part of special issue "Selected Papers from the 26th European Conference on Solid-State Transducers"
VL  - 189
SP  - 240
EP  - 245
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Miyamoto, Ko-ichiro
A1  - Hirayama, Yuji
A1  - Wagner, Torsten
A1  - Schöning, Michael Josef
A1  - Yoshinobu, Tatsuo
T1  - Visualization of enzymatic reaction in a microfluidic channel using chemical imaging sensor
JF  - Electrochimica acta
Y1  - 2013
SN  - 1873-3859 (E-Journal); 0013-4686 (Print)
SP  - Publ. online
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  - Miyamoto, Ko-ichiro
A1  - Bing, Yu
A1  - Wagner, Torsten
A1  - Yoshinobu, Tatsuo
A1  - Schöning, Michael Josef
T1  - Visualization of Defects on a Cultured Cell Layer by Utilizing Chemical Imaging Sensor
JF  - Procedia Engineering
N2  - The chemical imaging sensor is a field-effect sensor which is able to visualize both the distribution of ions (in LAPS mode) and the distribution of impedance (in SPIM mode) inthe sample. In this study, a novel wound-healing assay is proposed, in which the chemical imaging sensor operated in SPIM mode is applied to monitor the defect of a cell layer brought into proximity of the sensing surface.A reduced impedance inside the defect, which was artificially formed ina cell layer, was successfully visualized in a photocurrent image.
Y1  - 2015
U6  - http://dx.doi.org/10.1016/j.proeng.2015.08.806
SN  - 1877-7058
N1  - Part of special issue "Eurosensors 2015"
VL  - 120
SP  - 936
EP  - 939
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Miyamoto, K.
A1  - Wagner, Torsten
A1  - Schöning, Michael Josef
A1  - Yoshinobu, T.
T1  - Multi-well structure for cell culture on the chemical imaging sensor
Y1  - 2011
N1  - 2011 16th International Solid-State Sensors, Actuators and Microsystems Conference (TRANSDUCERS) , Date: 5-9 June 2011
SP  - 2130
EP  - 2132
PB  - IEEE
CY  - New York
ER  -