TY  - JOUR
A1  - Murib, M. S.
A1  - Yeap, W. S.
A1  - Eurlings, Y.
A1  - Grinsven, B. van
A1  - Boyen, H.-G.
A1  - Conings, B.
A1  - Michiels, L.
A1  - Ameloot, M.
A1  - Carleer, R.
A1  - Warmer, J.
A1  - Kaul, P.
A1  - Haenen, K.
A1  - Schöning, Michael Josef
A1  - Ceuninck, W. de
A1  - Wagner, P.
T1  - Heat-transfer based characterization of DNA on synthetic sapphire chips
JF  - Sensors and Actuators B: Chemical
N2  - In this study, we show that synthetic sapphire (Al₂O₃), an established implant material, can also serve as a platform material for biosensors comparable to nanocrystalline diamond. Sapphire chips, beads, and powder were first modified with (3-aminopropyl) triethoxysilane (APTES), followed by succinic anhydride (SA), and finally single-stranded probe DNA was EDC coupled to the functionalized layer. The presence of the APTES-SA layer on sapphire powders was confirmed by thermogravimetric analyis and Fourier-transform infrared spectroscopy. Using planar sapphire chips as substrates and X-ray photoelectron spectroscopy (XPS) as surface-sensitive tool, the sequence of individual layers was analyzed with respect to their chemical state, enabling the quantification of areal densities of the involved molecular units. Fluorescence microscopy was used to demonstrate the hybridization of fluorescently tagged target DNA to the probe DNA, including denaturation- and re-hybridization experiments. Due to its high thermal conductivity, synthetic sapphire is especially suitable as a chip material for the heat-transfer method, which was employed to distinguish complementary- and non-complementary DNA duplexes containing single-nucleotide polymorphisms. These results indicate that it is possible to detect mutations electronically with a chemically resilient and electrically insulating chip material.
Y1  - 2016
U6  - https://doi.org/10.1016/j.snb.2016.02.027
SN  - 0925-4005
VL  - 230
IS  - 230
SP  - 260
EP  - 271
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Hamad, E. M.
A1  - Bilatto, S. E. R.
A1  - Adly, N. Y.
A1  - Correa, D. S.
A1  - Wolfrum, B.
A1  - Schöning, Michael Josef
A1  - Offenhäusser, A.
A1  - Yakushenko, A.
T1  - Inkjet printing of UV-curable adhesive and dielectric inks for microfluidic devices
JF  - Lab on a Chip
N2  - Bonding of polymer-based microfluidics to polymer substrates still poses a challenge for Lab-On-a-Chip applications. Especially, when sensing elements are incorporated, patterned deposition of adhesives with curing at ambient conditions is required. Here, we demonstrate a fabrication method for fully printed microfluidic systems with sensing elements using inkjet and stereolithographic 3D-printing.
Y1  - 2016
U6  - https://doi.org/10.1039/C5LC01195G
SN  - 1473-0189
VL  - 16
IS  - 1
SP  - 70
EP  - 74
PB  - Royal Society of Chemistry
CY  - Cambridge
ER  - 
TY  - JOUR
A1  - Dantism, Shahriar
A1  - Takenaga, Shoko
A1  - Wagner, Patrick
A1  - Wagner, Torsten
A1  - Schöning, Michael Josef
T1  - Determination of the extracellular acidification of Escherichia coli K12 with a multi-​chamber-​based LAPS system
JF  - Physica status solidi (a)
N2  - On-line monitoring of the metabolic activity of microorganisms involved in intermediate stages of biogas production plays an important role to avoid undesirable “down times” during the biogas production. In order to control this process, an on-chip differential measuring system based on the light-addressable potentiometric sensor (LAPS) principle combined with a 3D-printed multi-chamber structure has been realized. As a test microorganism, Escherichia coli K12 (E. coli K12) were used for cell-based measurements. Multi-chamber structures were developed to determine the metabolic activity of E. coli K12 in suspension for a different number of cells, responding to the addition of a constant or variable amount of glucose concentrations, enabling differential and simultaneous measurements.
Y1  - 2016
U6  - https://doi.org/10.1002/pssa.201533043
SN  - 1862-6300
VL  - 213
IS  - 6
SP  - 1479
EP  - 1485
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Breuer, Lars
A1  - Raue, Markus
A1  - Strobel, M.
A1  - Mang, Thomas
A1  - Schöning, Michael Josef
A1  - Thoelen, R.
A1  - Wagner, Torsten
T1  - Hydrogels with incorporated graphene oxide as light-addressable actuator materials for cell culture environments in lab-on-chip systems
JF  - Physica status solidi (a)
N2  - Abstractauthoren Graphene oxide (GO) nanoparticles were incorporated in temperature-sensitive Poly(N-isopropylacrylamide) (PNIPAAm) hydrogels. The nanoparticles increase the light absorption and convert light energy into heat efficiently. Thus, the hydrogels with GO can be stimulated spatially resolved by illumination as it was demonstrated by IR thermography. The temporal progression of the temperature maximum was detected for different concentrations of GO within the polymer network. Furthermore, the compatibility of PNIPAAm hydrogels with GO and cell cultures was investigated. For this purpose, culture medium was incubated with hydrogels containing GO and the viability and morphology of chinese hamster ovary (CHO) cells was examined after several days of culturing in presence of this medium.
Y1  - 2016
U6  - https://doi.org/10.1002/pssa.201533056
SN  - 1862-6300
VL  - 213
IS  - 6
SP  - 1520
EP  - 1525
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - CHAP
A1  - Kasper, Katharina
A1  - Schiffels, Johannes
A1  - Krafft, Simone
A1  - Kuperjans, Isabel
A1  - Elbers, Gereon
A1  - Selmer, Thorsten
T1  - Biogas Production on Demand Regulated by Butyric Acid Addition
T2  - IOP Conference Series: Earth and Environmental Science. Bd. 32
Y1  - 2016
U6  - https://doi.org/10.1088/1755-1315/32/1/012009
SN  - 1755-1315
N1  - ICARET 2016, International Conference on Advances in Renewable Energy and Technologies, Putrajaya, MY, Feb 23-25, 2016
VL  - 32
SP  - 012009/1
EP  - 012009/4
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  - CHAP
A1  - Bäcker, Matthias
A1  - Koch, C.
A1  - Geiger, F.
A1  - Eber, F.
A1  - Gliemann, H.
A1  - Poghossian, Arshak
A1  - Schöning, Michael Josef
T1  - A New Class of Biosensors Based on Tobacco Mosaic Virus and Coat Proteins as Enzyme Nanocarrier
T2  - Procedia Engineering
Y1  - 2016
U6  - https://doi.org/10.1016/j.proeng.2016.11.228
SN  - 1877-7058
N1  - Proceedings of the 30th anniversary Eurosensors Conference – Eurosensors 2016, 4-7. Sepember 2016, Budapest, Hungary
VL  - Vol. 168
SP  - 618
EP  - 621
ER  - 
TY  - JOUR
A1  - Molinnus, Denise
A1  - Sorich, Maren
A1  - Bartz, Alexander
A1  - Siegert, Petra
A1  - Willenberg, Holger S.
A1  - Lisdat, Fred
A1  - Poghossian, Arshak
A1  - Keusgen, Michael
A1  - Schöning, Michael Josef
T1  - Towards an adrenaline biosensor based on substrate recycling amplification in combination with an enzyme logic gate
JF  - Sensors and Actuators B: Chemical
N2  - An amperometric biosensor using a substrate recycling principle was realized for the detection of low adrenaline concentrations (1 nM) by measurements in phosphate buffer and Ringer’s solution at pH 6.5 and pH 7.4, respectively. In proof-of-concept experiments, a Boolean logic-gate principle has been applied to develop a digital adrenaline biosensor based on an enzyme AND logic gate. The obtained results demonstrate that the developed digital biosensor is capable for a rapid qualitative determination of the presence/absence of adrenaline in a YES/NO statement. Such digital biosensor could be used in clinical diagnostics for the control of a correct insertion of a catheter in the adrenal veins during adrenal venous-sampling procedure.
Y1  - 2016
U6  - https://doi.org/10.1016/j.snb.2016.06.064
SN  - 0925-4005
VL  - 237
SP  - 190
EP  - 195
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - CHAP
A1  - Poghossian, Arshak
A1  - Bronder, Thomas
A1  - Scheja, S.
A1  - Wu, Chunsheng
A1  - Metzger-Boddien, C.
A1  - Keusgen, M.
A1  - Schöning, Michael Josef
T1  - Label-free Electrostatic Detection of DNA Amplification by PCR Using Capacitive Field-effect Devices
T2  - Procedia Engineering
N2  - A capacitive field-effect EIS (electrolyte-insulator-semiconductor) sensor modified with a positively charged weak polyelectrolyte of poly(allylamine hydrochloride) (PAH)/single-stranded probe DNA (ssDNA) bilayer has been used for a label-free electrostatic detection of pathogen-specific DNA amplification via polymerase chain reaction (PCR). The sensor is able to distinguish between positive and negative PCR solutions, to detect the existence of target DNA amplicons in PCR samples and thus, can be used as tool for a quick verification of DNA amplification and the successful PCR process.
Y1  - 2016
U6  - https://doi.org/10.1016/j.proeng.2016.11.512
SN  - 1877-7058
N1  - Proceedings of the 30th anniversary Eurosensors Conference – Eurosensors 2016, 4-7. Sepember 2016, Budapest, Hungary
VL  - Vol. 168
SP  - 514
EP  - 517
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Wu, Chunsheng
A1  - Poghossian, Arshak
A1  - Bronder, Thomas
A1  - Schöning, Michael Josef
T1  - Sensing of double-stranded DNA molecules by their intrinsic molecular charge using the light-addressable potentiometric sensor
JF  - Sensors and Actuators B: Chemical
N2  - A multi-spot light-addressable potentiometric sensor (LAPS), which belongs to the family of semiconductor field-effect devices, was applied for label-free detection of double-stranded deoxyribonucleic acid (dsDNA) molecules by their intrinsic molecular charge. To reduce the distance between the DNA charge and sensor surface and thus, to enhance the electrostatic coupling between the dsDNA molecules and the LAPS, the negatively charged dsDNA molecules were electrostatically adsorbed onto the gate surface of the LAPS covered with a positively charged weak polyelectrolyte layer of PAH (poly(allylamine hydrochloride)). The surface potential changes in each spot of the LAPS, induced by the layer-by-layer adsorption of a PAH/dsDNA bilayer, were recorded by means of photocurrent-voltage and constant-photocurrent measurements. In addition, the surface morphology of the gate surface before and after consecutive electrostatic adsorption of PAH and dsDNA layers was studied by atomic force microscopy measurements. Moreover, fluorescence microscopy was used to verify the successful adsorption of dsDNA molecules onto the PAH-modified LAPS surface. A high sensor signal of 25 mV was registered after adsorption of 10 nM dsDNA molecules. The lower detection limit is down to 0.1 nM dsDNA. The obtained results demonstrate that the PAH-modified LAPS device provides a convenient and rapid platform for the direct label-free electrical detection of in-solution hybridized dsDNA molecules.
KW  - Layer-by-layer adsorption
KW  - Poly(allylamine hydrochloride)
KW  - Label-free detection
KW  - DNA biosensor
KW  - LAPS
KW  - Field effect
Y1  - 2016
U6  - https://doi.org/10.1016/j.snb.2016.02.004
SN  - 0925-4005
IS  - 229
SP  - 506
EP  - 512
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Oberländer, Jan
A1  - Bromm, Alexander
A1  - Wendeler, Luisa
A1  - Iken, Heiko
A1  - Palomar Duran, Marlena
A1  - Greeff, Anton
A1  - Kirchner, Patrick
A1  - Keusgen, Michael
A1  - Schöning, Michael Josef
T1  - Towards a biosensor to monitor the sterilisation efficiency of aseptic filling machines
JF  - Physica status solidi (a)
N2  - Sterilisation processes are compulsory in medicine, pharmacy, and food industries to prevent infections of consumers and microbiological contaminations of products. Monitoring the sterilisation by conventional microbiological methods is time- and lab-consuming. To overcome this problem, in this work a novel biosensor has been proposed. The sensor enables a fast method to evaluate sterilisation processes. By means of thin-film technology the sensor's transducer structures in form of IDEs (interdigitated electrodes) have been fabricated on a silicon substrate. Physical characterisation of the developed sensor was done by AFM, SEM, and profilometry. Impedance analyses were conducted for the electrical characterisation. As microbiological layer spores of B. atrophaeus have been immobilised on the sensing structure; spores of this type are a well-known sterilisation test organism. Impedance measurements at a fixed frequency over time were performed to monitor the immobilisation process. A sterilisation process according to aseptic filling machines was applied to demonstrate the sensor functionality. After both, immobilisation and sterilisation, a change in impedance could successfully be detected.
Y1  - 2015
U6  - https://doi.org/10.1002/pssa.201431900
SN  - 1862-6319
VL  - 212
IS  - 6
SP  - 1299
EP  - 1305
PB  - Wiley
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Jildeh, Zaid B.
A1  - Wagner, Torsten
A1  - Schöning, Michael Josef
A1  - Pieper, Martin
T1  - Simulating the electromagnetic‐thermal treatment of thin aluminium layers for adhesion improvement
JF  - Physica status solidi (a)
N2  - A composite layer material used in packaging industry is made from joining layers of different materials using an adhesive. An important processing step in the production of aluminium-containing composites is the surface treatment and consequent coating of adhesive material on the aluminium surface. To increase adhesion strength between aluminium layer and the adhesive material, the foil is heat treated. For efficient heating, induction heating was considered as state-of-the-art treatment process. Due to the complexity of the heating process and the unpredictable nature of the heating source, the control of the process is not yet optimised. In this work, a finite element analysis of the process was established and various process parameters were studied. The process was simplified and modelled in 3D. The numerical model contains an air domain, an aluminium layer and a copper coil fitted with a magnetic field concentrating material. The effect of changing the speed of the aluminium foil (or rolling speed) was studied with the change of the coil current. Statistical analysis was used for generating a general control equation of coil current with changing rolling speed.
Y1  - 2015
U6  - https://doi.org/10.1002/pssa.201431893
SN  - 1862-6319
VL  - Vol. 212
IS  - 6
SP  - 1234
EP  - 1241
PB  - Wiley
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Pilas, Johanna
A1  - Iken, Heiko
A1  - Selmer, Thorsten
A1  - Keusgen, Michael
A1  - Schöning, Michael Josef
T1  - Development of a multi‐parameter sensor chip for the simultaneous detection of organic compounds in biogas processes
JF  - Physica status solidi (a)
N2  - An enzyme-based multi-parameter biosensor is developed for monitoring the concentration of formate, d-lactate, and l-lactate in biological samples. The sensor is based on the specific dehydrogenation by an oxidized β-nicotinamide adenine dinucleotide (NAD+)-dependent dehydrogenase (formate dehydrogenase, d-lactic dehydrogenase, and l-lactic dehydrogenase, respectively) in combination with a diaphorase from Clostridium kluyveri (EC 1.8.1.4). The enzymes are immobilized on a platinum working electrode by cross-linking with glutaraldehyde (GA). The principle of the determination scheme in case of l-lactate is as follows: l-lactic dehydrogenase (l-LDH) converts l-lactate into pyruvate by reaction with NAD+. In the presence of hexacyanoferrate(III), the resulting reduced β-nicotinamide adenine dinucleotide (NADH) is then regenerated enzymatically by diaphorase. The electrochemical detection is based on the current generated by oxidation of hexacyanoferrate(II) at an applied potential of +0.3 V vs. an Ag/AgCl reference electrode. The biosensor will be electrochemically characterized in terms of linear working range and sensitivity. Additionally, the successful practical application of the sensor is demonstrated in an extract from maize silage.
Y1  - 2015
U6  - https://doi.org/10.1002/pssa.201431894
SN  - 1862-6319
VL  - 212
IS  - 6
SP  - 1306
EP  - 1312
PB  - Wiley
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Breuer, Lars
A1  - Raue, Markus
A1  - Kirschbaum, M.
A1  - Mang, Thomas
A1  - Schöning, Michael Josef
A1  - Thoelen, R.
A1  - Wagner, Torsten
T1  - Light-controllable polymeric material based on temperature-sensitive hydrogels with incorporated graphene oxide
JF  - Physica status solidi (a)
N2  - Poly(N-isopropylacrylamide) (PNIPAAm) hydrogel films with incorporated graphene oxide (GO) were developed and tested as light-stimulated actuators. GO dispersions were synthesized via Hummers method and characterized toward their optical properties and photothermal energy conversion. The hydrogels were prepared by means of photopolymerization. In addition, the influence of GO within the hydrogel network on the lower critical solution temperature (LCST) was investigated by differential scanning calorimetry (DSC). The optical absorbance and the response to illumination were determined as a function of GO concentration for thin hydrogel films. A proof of principle for the stimulation with light was performed.
Y1  - 2015
U6  - https://doi.org/10.1002/pssa.201431944
SN  - 1862-6319
VL  - 212
IS  - 6
SP  - 1368
EP  - 1374
PB  - Wiley
CY  - Weinheim
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  - https://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  - Dantism, S.
A1  - Takenaga, S.
A1  - Wagner, P.
A1  - Wagner, Torsten
A1  - Schöning, Michael Josef
T1  - Light-addressable Potentiometric Sensor (LAPS) Combined with Multi-chamber Structures to Investigate the Metabolic Activity of Cells
JF  - Procedia Engineering
N2  - LAPS are field-effect-based potentiometric sensors which are able to monitor analyte concentrations in a spatially resolved manner. Hence, a LAPS sensor system is a powerful device to record chemical imaging of the concentration of chemical species in an aqueous solution, chemical reactions, or the growth of cell colonies on the sensor surface, to record chemical images. In this work, multi-chamber 3D-printed structures made out of polymer (PP-ABS) were combined with LAPS chips to analyse differentially and simultaneously the metabolic activity of Escherichia coli K12 and Chinese hamster ovary (CHO) cells, and the responds of those cells to the addition of glucose solution.
Y1  - 2015
U6  - https://doi.org/10.1016/j.proeng.2015.08.647
SN  - 1877-7058
N1  - Part of special issue "Eurosensors 2015"
VL  - 120
SP  - 384
EP  - 387
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Pilas, Johanna
A1  - Mariano, K.
A1  - Keusgen, M.
A1  - Selmer, Thorsten
A1  - Schöning, Michael Josef
T1  - Optimization of an Enzyme-based Multi-parameter Biosensor for Monitoring Biogas Processes
JF  - Procedia Engineering
Y1  - 2015
U6  - https://doi.org/10.1016/j.proeng.2015.08.702
SN  - 1877-7058
N1  - Part of special issue "Eurosensors 2015"
VL  - 120
SP  - 532
EP  - 535
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  - https://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  -