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  - Guo, Yuanyuan
A1  - Miyamoto, Ko-ichiro
A1  - Wagner, Torsten
A1  - Schöning, Michael Josef
A1  - Yoshinobu, Tatsuo
T1  - Theoretical study and simulation of light-addressable potentiometric sensors
JF  - Physica status solidi (A) : applications and materials
N2  - The light-addressable potentiometric sensor (LAPS) is a semiconductor-based potentiometric sensor using a light probe with an ability of detecting the concentration of biochemical species in a spatially resolved manner. As an important biomedical sensor, research has been conducted to improve its performance, for instance, to realize high-speed measurement. In this work, the idea of facilitating the device-level simulation, instead of using an equivalent-circuit model, is presented for detailed analysis and optimization of the performance of the LAPS. Both carrier distribution and photocurrent response have been simulated to provide new insight into both amplitude-mode and phase-mode operations of the LAPS. Various device parameters can be examined to effectively design and optimize the LAPS structures and setups for enhanced performance.
Y1  - 2014
U6  - http://dx.doi.org/10.1002/pssa.201330354
SN  - 0031-8965
VL  - 211
IS  - 6
SP  - 1467
EP  - 1472
PB  - Wiley-VCH
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  - Huck, Christina
A1  - Schiffels, Johannes
A1  - Herrera, Cony N.
A1  - Schelden, Maximilian
A1  - Selmer, Thorsten
A1  - Poghossian, Arshak
A1  - Baumann, Marcus
A1  - Wagner, Patrick
A1  - Schöning, Michael Josef
T1  - Metabolic responses of Escherichia coli upon glucose pulses captured by a capacitive field-effect sensor
JF  - Physica Status Solidi (A)
N2  - Living cells are complex biological systems transforming metabolites taken up from the surrounding medium. Monitoring the responses of such cells to certain substrate concentrations is a challenging task and offers possibilities to gain insight into the vitality of a community influenced by the growth environment. Cell-based sensors represent a promising platform for monitoring the metabolic activity and thus, the “welfare” of relevant organisms. In the present study, metabolic responses of the model bacterium Escherichia coli in suspension, layered onto a capacitive field-effect structure, were examined to pulses of glucose in the concentration range between 0.05 and 2 mM. It was found that acidification of the surrounding medium takes place immediately after glucose addition and follows Michaelis–Menten kinetic behavior as a function of the glucose concentration. In future, the presented setup can, therefore, be used to study substrate specificities on the enzymatic level and may as well be used to perform investigations of more complex metabolic responses. Conclusions and perspectives highlighting this system are discussed.
Y1  - 2013
U6  - http://dx.doi.org/10.1002/pssa.201200900
SN  - 0031-8965
VL  - 210
IS  - 5
SP  - 926
EP  - 931
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Werner, Frederik
A1  - Groebel, Simone
A1  - Krumbe, Christoph
A1  - Wagner, Torsten
A1  - Selmer, Thorsten
A1  - Yoshinobu, Tatsuo
A1  - Baumann, Marcus
A1  - Schöning, Michael Josef
T1  - Nutrient concentration-sensitive microorganism-based biosensor
JF  - Physica Status Solidi (a)
Y1  - 2012
U6  - http://dx.doi.org/10.1002/pssa.201100801
SN  - 1862-6319
VL  - 209
IS  - 5
SP  - 900
EP  - 904
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Bäcker, Matthias
A1  - Raue, Markus
A1  - Schusser, Sebastian
A1  - Jeitner, C.
A1  - Breuer, L.
A1  - Wagner, P.
A1  - Poghossian, Arshak
A1  - Förster, Arnold
A1  - Mang, Thomas
A1  - Schöning, Michael Josef
T1  - Microfluidic chip with integrated microvalves based on temperature- and pH-responsive hydrogel thin films
JF  - Physica Status Solidi  (a)
N2  - Two types of microvalves based on temperature-responsive poly(N-isopropylacrylamide) (PNIPAAm) and pH-responsive poly(sodium acrylate) (PSA) hydrogel films have been developed and tested. The PNIPAAm and PSA hydrogel films were prepared by means of in situ photopolymerization directly inside the fluidic channel of a microfluidic chip fabricated by combining Si and SU-8 technologies. The swelling/shrinking properties and height changes of the PNIPAAm and PSA films inside the fluidic channel were studied at temperatures of deionized water from 14 to 36 °C and different pH values (pH 3–12) of Titrisol buffer, respectively. Additionally, in separate experiments, the lower critical solution temperature (LCST) of the PNIPAAm hydrogel was investigated by means of a differential scanning calorimetry (DSC) and a surface plasmon resonance (SPR) method. Mass-flow measurements have shown the feasibility of the prepared hydrogel films to work as an on-chip integrated temperature- or pH-responsive microvalve capable to switch the flow channel on/off.
Y1  - 2012
U6  - http://dx.doi.org/10.1002/pssa.201100763
SN  - 1862-6319
VL  - 209
IS  - 5
SP  - 839
EP  - 845
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Bäcker, Matthias
A1  - Rakowski, D.
A1  - Poghossian, Arshak
A1  - Biselli, Manfred
A1  - Wagner, Patrick
A1  - Schöning, Michael Josef
T1  - Chip-based amperometric enzyme sensor system for monitoring of bioprocesses by flow-injection analysis
JF  - Journal of Biotechnology
N2  - A microfluidic chip integrating amperometric enzyme sensors for the detection of glucose, glutamate and glutamine in cell-culture fermentation processes has been developed. The enzymes glucose oxidase, glutamate oxidase and glutaminase were immobilized by means of cross-linking with glutaraldehyde on platinum thin-film electrodes integrated within a microfluidic channel. The biosensor chip was coupled to a flow-injection analysis system for electrochemical characterization of the sensors. The sensors have been characterized in terms of sensitivity, linear working range and detection limit. The sensitivity evaluated from the respective peak areas was 1.47, 3.68 and 0.28 μAs/mM for the glucose, glutamate and glutamine sensor, respectively. The calibration curves were linear up to a concentration of 20 mM glucose and glutamine and up to 10 mM for glutamate. The lower detection limit amounted to be 0.05 mM for the glucose and glutamate sensor, respectively, and 0.1 mM for the glutamine sensor. Experiments in cell-culture medium have demonstrated a good correlation between the glutamate, glutamine and glucose concentrations measured with the chip-based biosensors in a differential-mode and the commercially available instrumentation. The obtained results demonstrate the feasibility of the realized microfluidic biosensor chip for monitoring of bioprocesses.
Y1  - 2013
U6  - http://dx.doi.org/10.1016/j.jbiotec.2012.03.014
SN  - 0168-1656
VL  - 163
IS  - 4
SP  - 371
EP  - 376
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Bäcker, Matthias
A1  - Delle, L.
A1  - Poghossian, Arshak
A1  - Biselli, Manfred
A1  - Zang, Werner
A1  - Wagner, P.
A1  - Schöning, Michael Josef
T1  - Electrochemical sensor array for bioprocess monitoring
JF  - Electrochimica Acta (2011)
Y1  - 2011
VL  - 56
IS  - 26
SP  - 9673
EP  - 9678
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Werner, Frederik
A1  - Krumbe, Christoph
A1  - Schumacher, Katharina
A1  - Groebel, Simone
A1  - Spelthahn, Heiko
A1  - Stellberg, Michael
A1  - Wagner, Torsten
A1  - Yoshinobu, Tatsuo
A1  - Selmer, Thorsten
A1  - Keusgen, Michael
A1  - Baumann, Marcus
A1  - Schöning, Michael Josef
T1  - Determination of the extracellular acidification of Escherichia coli by a light-addressable potentiometric sensor
JF  - Physica status solidi (a) : applications and material science. 208 (2011), H. 6
Y1  - 2011
SN  - 1862-6319
SP  - 1340
EP  - 1344
PB  - Wiley
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Bäcker, Matthias
A1  - Beging, Stefan
A1  - Biselli, Manfred
A1  - Poghossian, Arshak
A1  - Wang, J.
A1  - Zang, Werner
A1  - Wagner, Patrick
A1  - Schöning, Michael Josef
T1  - Concept for a solid-state multi-parameter sensor system for cell-culture monitoring
JF  - Electrochimica Acta. 54 (2009), H. 25 Sp. Iss. SI
Y1  - 2009
SN  - 0013-4686
SP  - 6107
EP  - 6112
PB  - Elsevier
CY  - Amsterdam
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  - 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  - Turek, Monika
A1  - Ketterer, Lothar
A1  - Claßen, Melanie
A1  - Berndt, Heinz
A1  - Elbers, Gereon
A1  - Krüger, Peter
A1  - Keusgen, Michael
A1  - Schöning, Michael Josef
T1  - Development and Electrochemical Investigations of an EIS-(Electrolyte-Insulator-Semiconductor) based Biosensor for Cyanide Detection
JF  - Sensors
Y1  - 2007
SN  - 1424-8220
VL  - 7
IS  - 8
SP  - 1415
EP  - 1426
ER  -