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  - https://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  - Küppers, Tobias
A1  - Steffen, Victoria
A1  - Hellmuth, Hendrik
A1  - O'Connell, Timothy
A1  - Bongaerts, Johannes
A1  - Maurer, Karl-Heinz
A1  - Wiechert, Wolfgang
T1  - Developing a new production host from a blueprint: Bacillus pumilus as an industrial enzyme producer
JF  - Microbial cell factories
Y1  - 2014
U6  - https://doi.org/10.1186/1475-2859-13-46
SN  - 1475-2859 (E-Journal)
VL  - 13
SP  - Article No. 46
PB  - BioMed Central
CY  - London
ER  - 
TY  - JOUR
A1  - Yoshinobu, Tatsuo
A1  - Miyamoto, Ko-ichiro
A1  - Werner, Frederik
A1  - Poghossian, Arshak
A1  - Wagner, Torsten
A1  - Schöning, Michael Josef
T1  - Light-addressable potentiometric sensors for quantitative spatial imaging of chemical species
JF  - Annual Review of Analytical Chemistry
N2  - A light-addressable potentiometric sensor (LAPS) is a semiconductor-based chemical sensor, in which a measurement site on the sensing surface is defined by illumination. This light addressability can be applied to visualize the spatial distribution of pH or the concentration of a specific chemical species, with potential applications in the fields of chemistry, materials science, biology, and medicine. In this review, the features of this chemical imaging sensor technology are compared with those of other technologies. Instrumentation, principles of operation, and various measurement modes of chemical imaging sensor systems are described. The review discusses and summarizes state-of-the-art technologies, especially with regard to the spatial resolution and measurement speed; for example, a high spatial resolution in a submicron range and a readout speed in the range of several tens of thousands of pixels per second have been achieved with the LAPS. The possibility of combining this technology with microfluidic devices and other potential future developments are discussed.
Y1  - 2017
U6  - https://doi.org/10.1146/annurev-anchem-061516-045158
SN  - 1936-1327
VL  - 10
SP  - 225
EP  - 246
PB  - Annual Reviews
CY  - Palo Alto, Calif.
ER  - 
TY  - JOUR
A1  - Bäcker, Matthias
A1  - Pouyeshman, S.
A1  - Schnitzler, Thomas
A1  - Poghossian, Arshak
A1  - Wagner, Patrick
A1  - Biselli, Manfred
A1  - Schöning, Michael Josef
T1  - A silicon-based multi-sensor chip for monitoring of fermentation processes
JF  - Physica status solidi (a) : applications and material science. 208 (2011), H. 6
Y1  - 2011
SN  - 1862-6319
SP  - 1364
EP  - 1369
PB  - Wiley
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Abouzar, Maryam H.
A1  - Poghossian, Arshak
A1  - Pedraza, A. M.
A1  - Gandhi, D.
A1  - Ingebrandt, S.
A1  - Moritz, W.
A1  - Schöning, Michael Josef
T1  - An array of field-effect nanoplate SOI capacitors for (bio-)chemical sensing
JF  - Biosensors and Bioelectronics. 26 (2011), H. 6
Y1  - 2011
SN  - 0956-5663
SP  - 3023
EP  - 3028
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Poghossian, Arshak
A1  - Cherstvy, A.
A1  - Schöning, Michael Josef
T1  - Possibilities and limitations of label-free detection of DNA hybridization with field-effect based devices
JF  - Digest of technical papers : September 12 - 15, 2004, Rome, Italy, Pontificia Universitas Sancto Thoma Aquinate in Urbe / [conference chairperson: C. Di Natale].
Y1  - 2004
SN  - 88-7621-282-5
N1  - Eurosensors ; (18, 2004, Roma)
SP  - 173
EP  - 176
CY  - Roma
ER  - 
TY  - JOUR
A1  - Pinkenburg, Olaf
A1  - Schiffels, Johannes
A1  - Selmer, Thorsten
T1  - Das CoLibry-Konzept – ein Werkzeugkasten für die Synthetische Biologie: Bioproduktion
JF  - BIOspektrum
N2  - Regardless of size or destination, synthetic biology starts with com-parably small information units, which need to be combined and properly arranged in order to achieve a certain goal. This may be the de novo synthesis of individual genes from oligonucleotides, a shuffling of protein domains in order to create novel biocatalysts, the assembly of multiple enzyme encoding genes in metabolic pathway design, or strain development at the production stage. The CoLibry concept has been designed in order to close the gap between recombinant production of individual genes and genome editing.
Y1  - 2016
U6  - https://doi.org/10.1007/s12268-016-0734-8
VL  - 22
IS  - 6
SP  - 593
EP  - 595
PB  - Springer
CY  - Berlin
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  - https://doi.org/10.1016/j.phmed.2016.03.001
SN  - 2352-4510
VL  - 2016
IS  - 1
SP  - 2
EP  - 7
ER  - 
TY  - JOUR
A1  - Doll, Theodor
A1  - Wagner, Torsten
A1  - Wagner, Patrick
A1  - Schöning, Michael Josef
T1  - Engineering of functional interfaces / Theodor Doll ; Torsten Wagner ; Patrick Wagner ; Michael J. Schöning (eds.)
JF  - Physica status solidi (a)
Y1  - 2016
U6  - https://doi.org/10.1002/pssa.201670641
SN  - 1862-6319
VL  - 213
IS  - 6
SP  - 1393
EP  - 1394
PB  - Wiley-VCH
CY  - Weinheim
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  - https://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  - Welden, Rene
A1  - Scheja, Sabrina
A1  - Schöning, Michael Josef
A1  - Wagner, Patrick
A1  - Wagner, Torsten
T1  - Electrochemical Evaluation of Light‐Addressable Electrodes Based on TiO2 for the Integration in Lab‐on‐Chip Systems
JF  - physica status solidi a : applications and materials sciences
N2  - In lab-on-chip systems, electrodes are important for the manipulation (e.g., cell stimulation, electrolysis) within such systems. An alternative to commonly used electrode structures can be a light-addressable electrode. Here, due to the photoelectric effect, the conducting area can be adjusted by modification of the illumination area which enables a flexible control of the electrode. In this work, titanium dioxide based light-addressable electrodes are fabricated by a sol–gel technique and a spin-coating process, to deposit a thin film on a fluorine-doped tin oxide glass. To characterize the fabricated electrodes, the thickness, and morphological structure are measured by a profilometer and a scanning electron microscope. For the electrochemical behavior, the dark current and the photocurrent are determined for various film thicknesses. For the spatial resolution behavior, the dependency of the photocurrent while changing the area of the illuminated area is studied. Furthermore, the addressing of single fluid compartments in a three-chamber system, which is added to the electrode, is demonstrated.
Y1  - 2018
U6  - https://doi.org/10.1002/pssa.201800150
SN  - 1862-6319
VL  - 215
IS  - 15
SP  - Article number 1800150
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Jildeh, Zaid B.
A1  - Oberländer, Jan
A1  - Kirchner, Patrick
A1  - Wagner, Patrick H.
A1  - Schöning, Michael Josef
T1  - Thermocatalytic Behavior of Manganese (IV) Oxide as Nanoporous Material on the Dissociation of a Gas Mixture Containing Hydrogen Peroxide
JF  - Nanomaterials
N2  - In this article, we present an overview on the thermocatalytic reaction of hydrogen peroxide (H₂O₂) gas on a manganese (IV) oxide (MnO₂) catalytic structure. The principle of operation and manufacturing techniques are introduced for a calorimetric H₂O₂ gas sensor based on porous MnO₂. Results from surface analyses by X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) of the catalytic material provide indication of the H₂O₂ dissociation reaction schemes. The correlation between theory and the experiments is documented in numerical models of the catalytic reaction. The aim of the numerical models is to provide further information on the reaction kinetics and performance enhancement of the porous MnO₂ catalyst.
Y1  - 2018
U6  - https://doi.org/10.3390/nano8040262
SN  - 2079-4991
VL  - 8
IS  - 4
PB  - MDPI
CY  - Basel
ER  - 
TY  - JOUR
A1  - Bäcker, M.
A1  - Rakowski, D.
A1  - Krappen, E.
A1  - Schöning, Michael Josef
T1  - Reinigungsprozesse in der Lebensmittelindustrie. Entwicklung eines Demonstrators zur Überwachung
JF  - GIT Labor-Fachzeitschrift
Y1  - 2017
SN  - 0016-3538
VL  - 61
IS  - 8
SP  - 26
EP  - 28
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Aboulnaga, E. A.
A1  - Zou, H.
A1  - Selmer, Thorsten
A1  - Xian, M.
T1  - Development of a plasmid-based, tunable, tolC-derived expression system for application in Cupriavidus necator H16
JF  - Journal of Biotechnology
N2  - Cupriavidus necator H16 gains increasing attention in microbial research and biotechnological application due to its diverse metabolic features. Here we present a tightly controlled gene expression system for C. necator including the pBBR1-vector that contains hybrid promoters originating from C. necator native tolC-promoter in combination with a synthetic tetO-operator. The expression of the reporter gene from these plasmids relies on the addition of the exogenous inducer doxycycline (dc). The novel expression system offers a combination of advantageous features as; (i) high and dose-dependent recombinant protein production, (ii) tight control with a high dynamic range (On/Off ratio), which makes it applicable for harmful pathways or for toxic protein production, (iii) comparable cheap inducer (doxycycline, dc), (iv) effective at low inducer concentration, that makes it useful for large scale application, (v) rapid, diffusion controlled induction, and (vi) the inducer does not interfere within the cell metabolism. As applications of the expression system in C. necator H16, the growth ability on glycerol was enhanced by constitutively expressing the E. coli glpk gene-encoding for glycerol kinase. Likewise, we used the system to overcome the expression toxicity of mevalonate pathway in C. necator H16. With this system, the mevalonate-genes were successfully introduced in the host and the recombinant strains could produce about 200 mg/l mevalonate.
Y1  - 2018
U6  - https://doi.org/10.1016/j.jbiotec.2018.03.007
SN  - 0168-1656
VL  - 274
SP  - 15
EP  - 27
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Pilas, Johanna
A1  - Yazici, Y.
A1  - Selmer, Thorsten
A1  - Keusgen, M.
A1  - Schöning, Michael Josef
T1  - Application of a portable multi-analyte biosensor for organic acid determination in silage
JF  - Sensors
N2  - Multi-analyte biosensors may offer the opportunity to perform cost-effective and rapid analysis with reduced sample volume, as compared to electrochemical biosensing of each analyte individually. This work describes the development of an enzyme-based biosensor system for multi-parametric determination of four different organic acids. The biosensor array comprises five working electrodes for simultaneous sensing of ethanol, formate, d-lactate, and l-lactate, and an integrated counter electrode. Storage stability of the biosensor was evaluated under different conditions (stored at +4 °C in buffer solution and dry at −21 °C, +4 °C, and room temperature) over a period of 140 days. After repeated and regular application, the individual sensing electrodes exhibited the best stability when stored at −21 °C. Furthermore, measurements in silage samples (maize and sugarcane silage) were conducted with the portable biosensor system. Comparison with a conventional photometric technique demonstrated successful employment for rapid monitoring of complex media.
Y1  - 2018
U6  - https://doi.org/10.3390/s18051470
SN  - 1424-8220
VL  - 18
IS  - 5
PB  - MDPI
CY  - Basel
ER  - 
TY  - JOUR
A1  - Dantism, Shahriar
A1  - Röhlen, Desiree
A1  - Wagner, Torsten
A1  - Wagner, Patrick
A1  - Schöning, Michael Josef
T1  - Optimization of Cell-Based Multi-Chamber LAPS Measurements Utilizing FPGA-Controlled Laser-Diode Modules
JF  - physica status solidi a : applications and materials sciences
N2  - A light-addressable potentiometric sensor (LAPS) is a field-effect-based potentiometric device, which detects concentration changes of an analyte solution on the sensor surface in a spatially resolved way. It uses a light source to generate electron–hole pairs inside the semiconductor, which are separated in the depletion region due to an applied bias voltage across the sensor structure and hence, a surface-potential-dependent photocurrent can be read out. However, depending on the beam angle of the light source, scattering effects can occur, which influence the recorded signal in LAPS-based differential measurements. To solve this problem, a novel illumination unit based on a field programmable gate array (FPGA) consisting of 16 small-sized tunable infrared laser-diode modules (LDMs) is developed. Due to the improved focus of the LDMs with a beam angle of only 2 mrad, undesirable scattering effects are minimized. Escherichia coli (E. coli) K12 bacteria are used as a test microorganism to study the extracellular acidification on the sensor surface. Furthermore, a salt bridge chamber is built up and integrated with the LAPS system enabling multi-chamber differential measurements with a single Ag/AgCl reference electrode.
Y1  - 2018
U6  - https://doi.org/10.1002/pssa.201800058
SN  - 1862-6319
VL  - 215
IS  - 15
SP  - Article number 1800058
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Vahidpour, Farnoosh
A1  - Oberländer, Jan
A1  - Schöning, Michael Josef
T1  - Flexible Calorimetric Gas Sensors for Detection of a Broad Concentration Range of Gaseous Hydrogen Peroxide: A Step Forward to Online Monitoring of Food-Package Sterilization Processes
JF  - Phys. Status Solidi A
N2  - In this study, flexible calorimetric gas sensors are developed for specificdetection of gaseous hydrogen peroxide (H₂O₂) over a wide concentrationrange, which is used in sterilization processes for aseptic packaging industry.The flexibility of these sensors is an advantage for identifying the chemical components of the sterilant on the corners of the food boxes, so-called “coldspots”, as critical locations in aseptic packaging, which are of great importance. These sensors are fabricated on flexible polyimide films by means of thin-film technique. Thin layers of titanium and platinum have been deposited on polyimide to define the conductive structures of the sensors. To detect the high-temperature evaporated H₂O₂, a differential temperature set-up is proposed. The sensors are evaluated in a laboratory-scaled sterilizationsystem to simulate the sterilization process. The concentration range of the evaporated H₂O₂ from 0 to 7.7% v/v was defined and the sensors have successfully detected high as well as low H₂O₂ concentrations with a sensitivity of 5.04 °C/% v/v. The characterizations of the sensors confirm their precise fabrication, high sensitivity and the novelty of low H₂O₂ concentration detections for future inline monitoring of food-package sterilization.
Y1  - 2018
U6  - https://doi.org/10.1002/pssa.201800044
VL  - 215
IS  - 15
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Morais, Paulo V.
A1  - Silva, Anielle C. A.
A1  - Dantas, Noelio O.
A1  - Schöning, Michael Josef
A1  - Siqueira, José R., Jr.
T1  - Hybrid Layer‐by‐Layer Film of Polyelectrolytes‐Embedded Catalytic CoFe2O4 Nanocrystals as Sensing Units in Capacitive Electrolyte‐Insulator‐Semiconductor Devices
JF  - physica status solidi a : applications and materials sciences
Y1  - 2019
U6  - https://doi.org/10.1002/pssa.201900044
VL  - 216
IS  - 1900044
SP  - 1
EP  - 9
PB  - Wiley
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Breuer, Lars
A1  - Pilas, Johanna
A1  - Guthmann, Eric
A1  - Schöning, Michael Josef
A1  - Thoelen, Ronald
A1  - Wagner, Torsten
T1  - Towards light-addressable flow control: responsive hydrogels with incorporated graphene oxide as laser-driven actuator structures within microfluidic channels
JF  - Sensor and Actuators B: Chemical
Y1  - 2019
U6  - https://doi.org/10.1016/j.snb.2019.02.086
SN  - 0925-4005
VL  - 288
SP  - 579
EP  - 585
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Cornelis, Peter
A1  - Givanoudi, Stella
A1  - Yongabi, Derick
A1  - Iken, Heiko
A1  - Duwé, Sam
A1  - Deschaume, Olivier
A1  - Robbens, Johan
A1  - Dedecker, Peter
A1  - Bartic, Carmen
A1  - Wübbenhorst, Michael
A1  - Schöning, Michael Josef
A1  - Heyndrickx, Marc
A1  - Wagner, Patrick
T1  - Sensitive and specific detection of E. coli using biomimetic receptors in combination with a modified heat-transfer method
JF  - Biosensors and Bioelectronics
Y1  - 2019
U6  - https://doi.org/10.1016/j.bios.2019.04.026
SN  - 0956-5663
VL  - 136
SP  - 97
EP  - 105
PB  - Elsevier
CY  - Amsterdam
ER  -