TY  - JOUR
A1  - Molinnus, Denise
A1  - Hardt, Gabriel
A1  - Siegert, Petra
A1  - Willenberg, Holger S.
A1  - Poghossian, Arshak
A1  - Keusgen, Michael
A1  - Schöning, Michael Josef
T1  - Detection of Adrenaline in Blood Plasma as Biomarker for Adrenal Venous Sampling
JF  - Electroanalysis
N2  - An amperometric bi-enzyme biosensor based on substrate recycling principle for the amplification of the sensor signal has been developed for the detection of adrenaline in blood. Adrenaline can be used as biomarker verifying successful adrenal venous sampling procedure. The adrenaline biosensor has been realized via modification of a galvanic oxygen sensor with a bi-enzyme membrane combining a genetically modified laccase and a pyrroloquinoline quinone-dependent glucose dehydrogenase. The measurement conditions such as pH value and temperature were optimized to enhance the sensor performance. A high sensitivity and a low detection limit of about 0.5–1 nM adrenaline have been achieved in phosphate buffer at pH 7.4, relevant for measurements in blood samples. The sensitivity of the biosensor to other catecholamines such as noradrenaline, dopamine and dobutamine has been studied. Finally, the sensor has been successfully applied for the detection of adrenaline in human blood plasma.
Y1  - 2018
U6  - http://dx.doi.org/10.1002/elan.201800026
SN  - 1521-4109
VL  - 30
IS  - 5
SP  - 937
EP  - 942
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Schöning, Michael Josef
A1  - Poghossian, Arshak
T1  - Detection of charged macromolecules by means of field-effect devices (FEDs): possibilities and limitations
JF  - Electrochemical sensors, biosensors and their biomedical applications / ed. by Xueji Zhang ...
Y1  - 2008
SN  - 978-0-12-373738-0
SP  - 187
EP  - 212
PB  - Elsevier Acad. Press
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Herber, R.
A1  - Ernst, S.
A1  - Buß, G.
A1  - Schöning, Michael Josef
A1  - Baltruschat, H.
T1  - Detection of hydrocarbons in air and water by adsorption on Pt electrodes using continuous impedance measurements
JF  - Proceedings of the Symposium on New Directions in Electroanalytical Chemistry II : [held at the 195th Meeting of the Electrochemical Society in Seattle, Washington on May 3 and 4, 1999] / Physical Electrochemistry, Sensor, and Organic and Biological Electrochemistry Divisions. Ed.: J. Leddy, P. Vanysek, M.D. Porter
Y1  - 1999
SN  - 1-56677-227-3
N1  - Symposium on New Directions in Electroanalytical Chemistry ; (2, 1999, Seattle, Wash.)
SP  - 168
EP  - 177
PB  - Electrochemical Society
CY  - Pennington, NJ
ER  - 
TY  - JOUR
A1  - Oberländer, Jan
A1  - Kirchner, Patrick
A1  - Boyen, Hans-Gerd
A1  - Schöning, Michael Josef
T1  - Detection of hydrogen peroxide vapor by use of manganese(IV) oxide as catalyst for calorimetric gas sensors
JF  - Physica status solidi A: Applications and materials science
N2  - In this work, the catalyst manganese(IV) oxide (MnO2), of calorimetric gas sensors (to monitor the sterilization agent vaporized hydrogen peroxide) has been investigated in more detail. Chemical analyses by means of X-ray-induced photoelectron spectroscopy have been performed to unravel the surface chemistry prior and after exposure to hydrogen peroxide vapor at elevated temperature, as applied in the sterilization processes of beverage cartons. The surface characterization reveals a change in oxidation states of the metal oxide catalyst after exposure to hydrogen peroxide. Additionally, a cleaning effect of the catalyst, which itself is attached to the sensor surface by means of a polymer interlayer, could be observed.
Y1  - 2014
U6  - http://dx.doi.org/10.1002/pssa.201330359
SN  - 1521-396X (E-Journal); 1862-6319 (E-Journal); 0031-8965 (Print); 1862-6300 (Print)
VL  - 211
IS  - 6
SP  - 1372
EP  - 1376
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Kassab, T.
A1  - Han, Y.
A1  - Poghossian, Arshak
A1  - Ingebrandt, S.
A1  - Offenhäusser, A.
A1  - Schöning, Michael Josef
T1  - Detection of layerby-layer adsorbed polyelectrolytes by means of field-effect based capacitive EIS structures
JF  - Biomedizinische Technik. 49 (2004), H. 2
Y1  - 2004
SN  - 0932-4666
SP  - 1034
EP  - 1035
ER  - 
TY  - JOUR
A1  - Emons, H.
A1  - Hüllenkremer, B.
A1  - Schöning, Michael Josef
T1  - Detection of metal ions in aqueous solutions by voltohmmetry
JF  - Fresenius' Journal of Analytical Chemistry. 369 (2001), H. 1
Y1  - 2001
SN  - 0937-0633
SP  - 42
EP  - 46
ER  - 
TY  - JOUR
A1  - Bronder, Thomas
A1  - Jessing, Max P.
A1  - Poghossian, Arshak
A1  - Keusgen, Michael
A1  - Schöning, Michael Josef
T1  - Detection of PCR-Amplified Tuberculosis DNA Fragments with Polyelectrolyte-Modified Field-Effect Sensors
JF  - Analytical Chemistry
N2  - Field-effect-based electrolyte-insulator-semiconductor (EIS) sensors were modified with a bilayer of positively charged weak polyelectrolyte (poly(allylamine hydrochloride) (PAH)) and probe single-stranded DNA (ssDNA) and are used for the detection of complementary single-stranded target DNA (cDNA) in different test solutions. The sensing mechanism is based on the detection of the intrinsic molecular charge of target cDNA molecules after the hybridization event between cDNA and immobilized probe ssDNA. The test solutions contain synthetic cDNA oligonucleotides (with a sequence of tuberculosis mycobacteria genome) or PCR-amplified DNA (which origins from a template DNA strand that has been extracted from Mycobacterium avium paratuberculosis-spiked human sputum samples), respectively. Sensor responses up to 41 mV have been measured for the test solutions with DNA, while only small signals of ∼5 mV were detected for solutions without DNA. The lower detection limit of the EIS sensors was ∼0.3 nM, and the sensitivity was ∼7.2 mV/decade. Fluorescence experiments using SybrGreen I fluorescence dye support the electrochemical results.
Y1  - 2018
U6  - http://dx.doi.org/10.1021/acs.analchem.8b01807
SN  - 0003-2700
VL  - 90
IS  - 12
SP  - 7747
EP  - 7753
PB  - ACS Publications
CY  - Washington, DC
ER  - 
TY  - JOUR
A1  - Jablonski, Melanie
A1  - Poghossian, Arshak
A1  - Keusgen, Michael
A1  - Wege, Christina
A1  - Schöning, Michael Josef
T1  - Detection of plant virus particles with a capacitive field-effect sensor
JF  - Analytical and Bioanalytical Chemistry
N2  - Plant viruses are major contributors to crop losses and induce high economic costs worldwide. For reliable, on-site and early detection of plant viral diseases, portable biosensors are of great interest. In this study, a field-effect SiO2-gate electrolyte-insulator-semiconductor (EIS) sensor was utilized for the label-free electrostatic detection of tobacco mosaic virus (TMV) particles as a model plant pathogen. The capacitive EIS sensor has been characterized regarding its TMV sensitivity by means of constant-capacitance method. The EIS sensor was able to detect biotinylated TMV particles from a solution with a TMV concentration as low as 0.025 nM. A good correlation between the registered EIS sensor signal and the density of adsorbed TMV particles assessed from scanning electron microscopy images of the SiO2-gate chip surface was observed. Additionally, the isoelectric point of the biotinylated TMV particles was determined via zeta potential measurements and the influence of ionic strength of the measurement solution on the TMV-modified EIS sensor signal has been studied.
KW  - Plant virus
KW  - Capacitive field-effect sensor
KW  - Tobacco mosaic virus (TMV)
KW  - Label-free detection
KW  - Zeta potential
Y1  - 2021
U6  - http://dx.doi.org/10.1007/s00216-021-03448-8
SN  - 1618-2650
N1  - Corresponding authors: Arshak Poghossian & Michael J. Schöning
VL  - 413
SP  - 5669
EP  - 5678
PB  - Springer Nature
CY  - Cham
ER  - 
TY  - JOUR
A1  - Warmer, Johannes
A1  - Wagner, Patrick
A1  - Schöning, Michael Josef
A1  - Kaul, Peter
T1  - Detection of triacetone triperoxide using temperature cycled metal-oxide semiconductor gas sensors
JF  - Physica status solidi (a)
Y1  - 2015
U6  - http://dx.doi.org/10.1002/pssa.201431882
SN  - 1862-6319
VL  - 212
IS  - 6
SP  - 1289
EP  - 1298
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Schopp, Christoph
A1  - Rohrbach, Felix
A1  - Langer, Luc
A1  - Heuermann, Holger
T1  - Detection of welding wire length by active S11 measurement
JF  - IEEE Transactions on Plasma Science
N2  - A novel method to determine the extruded length of a metallic wire for a directed energy deposition (DED) process using a microwave (MW) plasma jet with a straight-through wire feed is presented. The method is based on the relative comparison of the measured frequency response obtained by the large-signal scattering parameter (Hot-S) technique. In the practical working range, repeatability of less than 6% for a nonactive plasma and 9% for the active plasma state is found. Measurements are conducted with a focus on a simple solution to decrease the processing time and reduce the integration time of the process into the existing hardware. It is shown that monitoring a single frequency for magnitude and phase changes is sufficient to achieve good accuracy. A combination of different measurement values to determine the length is possible. The applicability to different diameter of the same material is shown as well as a contact detection of the wire and metallic substrate.
KW  - Circuit simulation
KW  - Hot S-parameter
KW  - Modeling
KW  - Plasma
KW  - Plasma diagnostics
Y1  - 2024
U6  - http://dx.doi.org/10.1109/TPS.2024.3356659
SN  - 0093-3813 (Print)
SN  - 1939-9375 (Online)
IS  - Early Access
SP  - 1
EP  - 6
PB  - IEEE
ER  - 
TY  - JOUR
A1  - Tippkötter, Nils
A1  - Deterding, A.
A1  - Ulber, Roland
T1  - Determination of acetic acid in fermentation broth by gas-diffusion technique
JF  - Engineering in Life Sciences
N2  - Due to the interfering effects of acetic acid in many fermentation processes, a gas-diffusion technique was developed for the online determination of acetic acid. The measurements were accomplished with a flow diffusion analysis (FDA) unit from the TRACE Analytics GmbH, Braunschweig, Germany. The diffusion analysis is based on the UV-absorbance of acetic acid at 205 nm. The measurement was achieved by the separation of an acceptor and a carrier stream (acidified fermentation broth) using a gas permeable polytetrafluoroethylene (PTFE) membrane, whereby broth constituents that would otherwise disturb the UV-measurement of acetic acid, are held back efficiently. Merely, the fermentation by-products, e.g. formic acid, is capable of diffusing through the membrane. While formic acid can disturb the measurement, carbon dioxide does not absorb at 205 nm. The method operates with time-dependent sample enrichment. During the analysis, a small volume of the acceptor stream is stopped for a defined time interval in the acceptor chamber. During this period, the gaseous acetic acid diffuses through the membrane and is enriched in the acceptor chamber. Subsequently after the enrichment, the acceptor stream flows through a UV-detector. The intensity of the signal is proportional to the acetic acid concentration. Online measurements in bioreactors via a sterile filtration probe have been accomplished. A linear calibration in the range of 0.5–5.0 g/L acetic acid with a relative standard deviation of <5 % was obtained. A sampling rate of 8 samples per hour was possible. The system was applied for the determination of acetic acid in E. coli fermentation broth. The instrument is easy to clean, very user-friendly and does not require any toxic or expensive reagents.
Y1  - 2008
U6  - http://dx.doi.org/10.1002/elsc.200820227
VL  - 8
IS  - 1, Special Issue: Technical Systems for the Use in Life Sciences
SP  - 62
EP  - 67
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  - Helsper, Christoph
A1  - Fißan, H. J.
A1  - Thielen, H. J.
T1  - Determination of Particle Size Distributions by Means of an Electrostatic Classifier / Fißan, H. J.; Helsper, C. ; Thielen, H. J.
JF  - Journal of Aerosol Science. 14 (1983), H. 3
Y1  - 1983
SN  - 0021-8502
SP  - 354
EP  - 357
ER  - 
TY  - JOUR
A1  - Förster, Arnold
A1  - Tillmann, K.
A1  - Thust, M.
T1  - Determination of segregation, elastic strain and thin-foil relaxation in InxGa-1-x As islands on GaAs(001) by high resolution transmission electron microscopy / K. Tillmann ; A. Thust ; M. Lentzen ... A. Förster ...
JF  - Philosophical magazine / Letters. 74 (1996), H. 5
Y1  - 1996
SN  - 1362-3036
SP  - 309
EP  - 315
ER  - 
TY  - JOUR
A1  - Helsper, Christoph
A1  - Wiedensohler, A.
A1  - Weise, W.
A1  - Lütkemeier, E.
T1  - Determination of the Bipolar Charge Equilibrium in Pure Gases / Wiedensohler, A. ; Weise, W. ; Helsper, C. ; Lütkemeier, E.
JF  - Aerosols : formation and reactivity ; proceedings of the second International Aerosol Conference, 22-26 Sept. 1986, Berlin (West) / Gesellschaft für Aerosolforschung (GAeF) ; American Association for Aerosol Research (AAAR)
Y1  - 1986
N1  - International Aerosol Conference ; (2, 1986, Berlin (West))
SP  - 383
EP  - 386
PB  - Pergamon Press
CY  - Oxford [u.a.]
ER  - 
TY  - JOUR
A1  - Maggakis-Kelemen, Christina
A1  - Biselli, Manfred
A1  - Artmann, Gerhard
T1  - Determination of the elastic shear modulus of cultured human red blood cells
JF  - Biomedizinische Technik. 47 (2002), H. Suppl. 1 Pt. 1
Y1  - 2002
SN  - 0013-5585
N1  - Druckausgabe unter 63 Z 471 vorhanden
SP  - 106
EP  - 109
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  - 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  - Hasan, Istabrak
A1  - Keil, Ludger
A1  - Staat, Manfred
A1  - Wahl, Gerhard
A1  - Bourauel, Christoph
T1  - Determination of the frictional coefficient of the implant-antler interface : experimental approach
JF  - Biomedical Engineering / Biomedizinische Technik
N2  - The similar bone structure of reindeer antler to human bone permits studying the osseointegration of dental implants in the jawbone. As the friction is one of the major factors that have a significant influence on the initial stability of immediately loaded dental implants, it is essential to define the frictional coefficient of the implant-antler interface. In this study, the kinetic frictional forces at the implant-antler interface were measured experimentally using an optomechanical setup and a stepping motor controller under different axial loads and sliding velocities. The corresponding mean values of the static and kinetic frictional coefficients were within the range of 0.5–0.7 and 0.3–0.5, respectively. An increase in the frictional forces with increasing applied axial loads was registered. The measurements showed an evidence of a decrease in the magnitude of the frictional coefficient with increasing sliding velocity. The results of this study provide a considerable assessment to clarify the suitable frictional coefficient to be used in the finite element contact analysis of antler specimens.
Y1  - 2012
SN  - 1862-278X
VL  - 57
IS  - 5
SP  - 359
EP  - 363
PB  - De Gruyter
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Arpshofen, Ingo
A1  - Pool, M. J.
A1  - Sommer, Ferdinand
A1  - Gerling, Ulrich
A1  - Predel, Bruno
A1  - Schultheiss, Emil
T1  - Determination of the integral mixing enthalpies in the Cu-Pd-Si liquid ternary alloy system at 1600 K
JF  - Zeitschrift für Metallkunde : international journal of materials research and advanced techniques. Bd. 74, H. 1
Y1  - 1983
SN  - 0044-3093 ; 0179-4841
SP  - 25
EP  - 32
ER  -