TY  - JOUR
A1  - Arreola, Julio
A1  - Mätzkow, Malte
A1  - Durán, Marlena Palomar
A1  - Greeff, Anton
A1  - Keusgen, Michael
A1  - Schöning, Michael Josef
T1  - Optimization of the immobilization of bacterial spores on glass substrates with organosilanes
JF  - Physica status solidi (A) : Applications and materials science
N2  - Spores can be immobilized on biosensors to function as sensitive recognition elements. However, the immobilization can affect the sensitivity and reproducibility of the sensor signal. In this work, three different immobilization strategies with organosilanes were optimized and characterized to immobilize Bacillus atrophaeus spores on glass substrates. Five different silanization parameters were investigated: nature of the solvent, concentration of the silane, silanization time, curing process, and silanization temperature. The resulting silane layers were resistant to a buffer solution (e.g., Ringer solution) with a polysorbate (e.g., Tween®80) and sonication.
KW  - silanization
KW  - organosilanes
KW  - immobilization
KW  - endospores
KW  - biosensors
KW  - Bacillus atrophaeus
Y1  - 2016
U6  - http://dx.doi.org/10.1002/pssa.201532914
SN  - 1862-6319
VL  - 213
IS  - 6
SP  - 1463
EP  - 1470
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  - http://dx.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  - 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  - http://dx.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  - 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  - http://dx.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  - 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  - http://dx.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  - 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  - http://dx.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  - 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  - 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  - 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  - http://dx.doi.org/10.1016/j.snb.2016.06.064
SN  - 0925-4005
VL  - 237
SP  - 190
EP  - 195
PB  - Elsevier
CY  - Amsterdam
ER  - 
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  - http://dx.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  -