TY  - JOUR
A1  - Miyamoto, K.
A1  - Seki, K.
A1  - Wagner, Torsten
A1  - Schöning, Michael Josef
A1  - Yoshinobu, T.
T1  - Enhancement of the spatial resolution of the chemical imaging sensor by a hybrid fiber-optic illumination
JF  - Procedia Engineering
N2  - The chemical imaging sensor, which is based on the principle of the light-addressable potentiometric sensor (LAPS), is a powerful tool to visualize the spatial distribution of chemical species on the sensor surface. The spatial resolution of this sensor depends on the diffusion of photocarriers excited by a modulated light. In this study, a novel hybrid fiber-optic illumination was developed to enhance the spatial resolution. It consists of a modulated light probe to generate a photocurrent signal and a ring of constant light, which suppresses the lateral diffusion of minority carriers excited by the modulated light. It is demonstrated that the spatial resolution was improved from 92 μm to 68 μm.
Y1  - 2014
U6  - http://dx.doi.org/10.1016/j.proeng.2014.11.563
SN  - 1877-7058
N1  - EUROSENSORS 2014 ; European Conference on Solid-State Transducers <28, 2014>
VL  - 87
SP  - 612
EP  - 615
PB  - Elsevier
CY  - Amsterdam
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  - Wagner, Patrick
A1  - Doll, Theodor
A1  - Schöning, Michael Josef
T1  - Engineering of functional interfaces / Patrick Wagner ; Theodor Doll ; Michael J. Schöning (eds.)
JF  - Physica status solidi (A) : Applications and materials science
Y1  - 2014
U6  - http://dx.doi.org/10.1002/pssa.201470241
SN  - 1521-396X (E-Book); 1862-6319 (E-Book); 0031-8965 (Print); 1862-6300 (Print)
VL  - 211
IS  - 6
SP  - 1339
EP  - 1339
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - GEN
A1  - Ingebrandt, Sven
A1  - Wagner, Patrick
A1  - Schöning, Michael Josef
T1  - Engineering of functional interfaces / guest eds. Sven Ingebrandt ; Patrick Wagner ; Michael J. Schöning
T2  - Physica Status Solidi (A)
Y1  - 2013
SN  - 1521-396X (E-Journal); 1862-6319 (E-Journal); 0031-8965 (Print); 1862-6300 (Print)
VL  - Vol. 210
IS  - Iss. 5
SP  - 845
ER  - 
TY  - JOUR
A1  - Bronder, Thomas
A1  - Poghossian, Arshak
A1  - Scheja, S.
A1  - Wu, Chunsheng
A1  - Keusgen, M.
A1  - Schöning, Michael Josef
T1  - Electrostatic Detection of Unlabelled Single- and Double-stranded DNA Using Capacitive Field-effect Devices Functionalized with a Positively Charged Polyelectrolyte Layer
JF  - Procedia Engineering
N2  - Capacitive field-effect electrolyte-insulator-semiconductor sensors consisting of an Al-p-Si-SiO2 structure have been used for the electrical detection of unlabelled single- and double-stranded DNA (dsDNA) molecules by their intrinsic charge. A simple functionalization protocol based on the layer-by-layer (LbL) technique was used to prepare a weak polyelectrolyte/probe-DNA bilayer, followed by the hybridization with complementary target DNA molecules. Due to the flat orientation of the LbL-adsorbed DNA molecules, a high sensor signal has been achieved. In addition, direct label-free detection of in-solution hybridized dsDNA molecules has been studied.
Y1  - 2015
U6  - http://dx.doi.org/10.1016/j.proeng.2015.08.710
SN  - 1877-7058
N1  - Eurosensors 2015
VL  - 120
SP  - 544
EP  - 547
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Murib, M. S.
A1  - Grinsven, B. van
A1  - Grieten, L.
A1  - Janssens, S. D.
A1  - Vermeeren, V.
A1  - Eersels, K.
A1  - Broeders, J.
A1  - Ameloot, M.
A1  - Michiels, L.
A1  - Ceuninck, W. De
A1  - Haenen, K.
A1  - Schöning, Michael Josef
A1  - Wagner, Patrick
T1  - Electronic monitoring of chemical DNA denaturation on nanocrystalline diamond electrodes with different molarities and flow rates
JF  - Physica Status Solidi (A). Vol. 210 (2013), iss. 5
Y1  - 2013
SN  - 0031-8965
SP  - 911
EP  - 917
PB  - Wiley-VCH
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Moreno i Codinachs, Lia
A1  - Kloock, Joachim P.
A1  - Schöning, Michael Josef
A1  - Baldi, Antoni
A1  - Ipatov, Andrey
A1  - Bratov, Andrey
A1  - Jimenez-Jorquera, Cecilia
T1  - Electronic integrated multisensor tongue applied to grape juice and wine analysis
JF  - Analyst. 133 (2008)
Y1  - 2008
SN  - 1364-5528
SP  - 1440
EP  - 1448
ER  - 
TY  - JOUR
A1  - Honarvarfard, Elham
A1  - Gamella, Maria
A1  - Channaveerappa, Devika
A1  - Darie, Costel C.
A1  - Poghossian, Arshak
A1  - Schöning, Michael Josef
A1  - Katz, Evgeny
T1  - Electrochemically Stimulated Insulin Release from a Modified Graphene–functionalized Carbon Fiber Electrode
JF  - Electroanalysis
N2  - A graphene-functionalized carbon fiber electrode was modified with adsorbed polyethylenimine to introduce amino functionalities and then with trigonelline and 4-carboxyphenylboronic acid covalently bound to the amino groups. The trigonelline species containing quarterized pyridine groups produced positive charge on the electrode surface regardless of the pH value, while the phenylboronic acid species were neutral below pH 8 and negatively charged above pH 9 (note that their pKa=8.4). The total charge on the monolayer-modified electrode was positive at the neutral pH and negative at pH > 9. Note that 4-carboxyphenylboronic acid was attached to the electrode surface in molar excess to trigonelline, thus allowing the negative charge to dominate on the electrode surface at basic pH. Negatively charged fluorescent dye-labeled insulin (insulin-FITC) was loaded on the modified electrode surface at pH 7.0 due to its electrostatic attraction to the positively charged interface. The local pH in close vicinity to the electrode surface was increased to ca. 9–10 due to consumption of H+ ions upon electrochemical reduction of oxygen proceeding at the potential of −1.0 V (vs. Ag/AgCl) applied on the modified electrode. The process resulted in recharging of the electrode surface to the negative value due to the formation of the negative charge on the phenylboronic acid groups, thus resulting in the electrostatic repulsion of insulin-FITC and stimulating its release from the electrode surface. The insulin release was characterized by fluorescence spectroscopy (using the FITC-labeled insulin), by electrochemical measurements on an iridium oxide, IrOx, electrode and by mass spectrometry. The graphene-functionalized carbon fiber electrode demonstrated significant advantages in the signal-stimulated insulin release comparing with the carbon fiber electrode without the graphene species.
Y1  - 2017
U6  - http://dx.doi.org/10.1002/elan.201700095
SN  - 1521-4109
VL  - 29
IS  - 6
SP  - 1543
EP  - 1553
PB  - Wiley-VCH
CY  - Weinheim
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  - Schöning, Michael Josef
A1  - Glück, O.
A1  - Thust, M.
T1  - Electrochemical methods for the determination of chemical variables in aqueous media
JF  - The measurement, instrumentation, and sensors handbook / ed.-in-chief John G. Webster. In cooperation with IEEE Press
Y1  - 1999
SN  - 0-8493-8347-1
SP  - 1
EP  - 49
PB  - CRC Press
CY  - Boca Raton [u.a.]
ER  - 
TY  - CHAP
A1  - Schöning, Michael Josef
A1  - Poghossian, Arshak
A1  - Glück, Olaf
A1  - Thust, Marion
T1  - Electrochemical methods for the determination of chemical variables in aqueous media
T2  - Measurement, instrumentation, and sensors handbook / ed. by John G. Webster [u.a.] Vol. 2 : Electromagnetic, optical, radiation, chemical, and biomedical measurement
Y1  - 2014
SN  - 978-1-4398-4891-3
SP  - 55-1
EP  - 55-54
PB  - CRC Pr.
CY  - Boca Raton, Fla.
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  - http://dx.doi.org/10.1002/pssa.201800150
SN  - 1862-6319
VL  - 215
IS  - 15
SP  - Article number 1800150
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - CHAP
A1  - Schöning, Michael Josef
A1  - Poghossian, Arshak
A1  - Glück, Olaf
A1  - Thust, Marion
T1  - Electrochemical composition measurement
T2  - Measurement, instrumentation, and sensors handbook: electromagnetic, optical, radiation, chemical, and biomedical measuremen
Y1  - 2014
SN  - 978-1-4398-4891-3
SP  - 55-1
EP  - 55-54
PB  - CRC Pr.
CY  - Boca Raton, Fa.
ET  - 2nd ed.
ER  - 
TY  - JOUR
A1  - Poghossian, Arshak
A1  - Weil, M.
A1  - Cherstvy, A. G.
A1  - Schöning, Michael Josef
T1  - Electrical monitoring of polyelectrolyte multilayer formation by means of capacitive field-effect devices
JF  - Analytical and bioanalytical chemistry
N2  - The semiconductor field-effect platform represents a powerful tool for detecting the adsorption and binding of charged macromolecules with direct electrical readout. In this work, a capacitive electrolyte–insulator–semiconductor (EIS) field-effect sensor consisting of an Al-p-Si-SiO2 structure has been applied for real-time in situ electrical monitoring of the layer-by-layer formation of polyelectrolyte (PE) multilayers (PEM). The PEMs were deposited directly onto the SiO2 surface without any precursor layer or drying procedures. Anionic poly(sodium 4-styrene sulfonate) and cationic weak polyelectrolyte poly(allylamine hydrochloride) have been chosen as a model system. The effect of the ionic strength of the solution, polyelectrolyte concentration, number and polarity of the PE layers on the characteristics of the PEM-modified EIS sensors have been studied by means of capacitance–voltage and constant-capacitance methods. In addition, the thickness, surface morphology, roughness and wettabilityof the PE mono- and multilayers have been characterised by ellipsometry, atomic force microscopy and water contact-angle methods, respectively. To explain potential oscillations on the gate surface and signal behaviour of the capacitive field-effect EIS sensor modified with a PEM, a simplified electrostatic model that takes into account the reduced electrostatic screening of PE charges by mobile ions within the PEM has been proposed and discussed.
Y1  - 2013
U6  - http://dx.doi.org/10.1007/s00216-013-6951-9
SN  - 1432-1130 ; 1618-2642
VL  - 405
IS  - 20
SP  - 6425
EP  - 6436
PB  - Springer
CY  - Berlin
ER  - 
TY  - CHAP
A1  - Weil, M.
A1  - Poghossian, Arshak
A1  - Schöning, Michael Josef
A1  - Cherstvy, A.
T1  - Electrical monitoring of layer-by-layer adsorption of oppositely charged macromolecules by means of capacitive field-effect devices
Y1  - 2012
SN  - 978-3-9813484-2-2
U6  - http://dx.doi.org/10.5162/IMCS2012/P2.5.2
SP  - 1575
EP  - 1578
ER  - 
TY  - JOUR
A1  - Schöning, Michael Josef
A1  - Prämassing, T.
A1  - Beckers, L.
A1  - Zander, W.
T1  - Ein langzeitstabiler pH-Sensor auf Siliziumbasis hergestellt in Dünnschichttechnik mittels Laserablation
JF  - Chemie- und Biosensoren : aktuelle Anwendungen und Entwicklungstrends / 3. Dresdner Sensor-Symposium, 8. - 10. Dezember 1997, Dresden-Radebeul. J. P. Baselt ... (Hg.)
Y1  - 1998
SN  - 3-933168-03-1
N1  - Serie Dresdner Beiträge zur Sensorik ; 5
SP  - 99
EP  - 102
PB  - Dresden Univ. Press
CY  - Dresden ; München
ER  - 
TY  - JOUR
A1  - Özsoylu, Dua
A1  - Kizildag, Sefa
A1  - Schöning, Michael Josef
A1  - Wagner, Torsten
T1  - Effect of plasma treatment on the sensor properties of a light‐addressable potentiometric sensor (LAPS)
JF  - physica status solidi a : applications and materials sciences
N2  - A light-addressable potentiometric sensor (LAPS) is a field-effect-based (bio-) chemical sensor, in which a desired sensing area on the sensor surface can be defined by illumination. Light addressability can be used to visualize the concentration and spatial distribution of the target molecules, e.g., H+ ions. This unique feature has great potential for the label-free imaging of the metabolic activity of living organisms. The cultivation of those organisms needs specially tailored surface properties of the sensor. O2 plasma treatment is an attractive and promising tool for rapid surface engineering. However, the potential impacts of the technique are carefully investigated for the sensors that suffer from plasma-induced damage. Herein, a LAPS with a Ta2O5 pH-sensitive surface is successfully patterned by plasma treatment, and its effects are investigated by contact angle and scanning LAPS measurements. The plasma duration of 30 s (30 W) is found to be the threshold value, where excessive wettability begins. Furthermore, this treatment approach causes moderate plasma-induced damage, which can be reduced by thermal annealing (10 min at 300 °C). These findings provide a useful guideline to support future studies, where the LAPS surface is desired to be more hydrophilic by O2 plasma treatment.
Y1  - 2019
U6  - http://dx.doi.org/10.1002/pssa.201900259
SN  - 1862-6319
N1  - Corresponding author: Torsten Wagner
VL  - 216
IS  - 20
PB  - Wiley
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Arreola, Julio
A1  - Keusgen, Michael
A1  - Schöning, Michael Josef
T1  - Effect of O2 plasma on properties of electrolyte-insulator-semiconductor structures
JF  - physica status solidi a : applications and materials sciences
N2  - Prior to immobilization of biomolecules or cells onto biosensor surfaces, the surface must be physically or chemically activated for further functionalization. Organosilanes are a versatile option as they facilitate the immobilization through their terminal groups and also display self-assembly. Incorporating hydroxyl groups is one of the important methods for primary immobilization. This can be done, for example, with oxygen plasma treatment. However, this treatment can affect the performance of the biosensors and this effect is not quite well understood for surface functionalization. In this work, the effect of O2 plasma treatment on EIS sensors was investigated by means of electrochemical characterizations: capacitance–voltage (C–V) and constant capacitance (ConCap) measurements. After O2 plasma treatment, the potential of the EIS sensor dramatically shifts to a more negative value. This was successfully reset by using an annealing process.
KW  - surface functionalization
KW  - O2 plasma
KW  - hydroxylation
KW  - electrolyte-insulator semiconductor sensor (EIS)
KW  - annealing
Y1  - 2017
U6  - http://dx.doi.org/10.1002/pssa.201700025
SN  - 1862-6319
VL  - 214
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - CHAP
A1  - Moreno, Lia
A1  - Dosev, D.
A1  - Bratov, A.
A1  - Dominguez, C.
A1  - Schöning, Michael Josef
A1  - Kloock, Joachim P.
T1  - Effect of electrical properties of the surrounding medium on the response of an interdigitated electrode array with chalcogenide glass film
T2  - XX Eurosensors : 20th anniversary ; Göteborg, Sweden, 17 - 20 September 2006 ; [proceedings]. - Vol. 1
Y1  - 2006
SN  - 978-91-631-9280-7
N1  - Paper number: T1A-P22
SP  - 384
EP  - 385
CY  - Göteborg
ER  - 
TY  - JOUR
A1  - Spelthahn, Heiko
A1  - Schubert, Jürgen
A1  - Schöning, Michael Josef
T1  - Dünnschichtsensoren für die Schwermetallanalytik : Mikroelektroden auf Chalkogenidglasbasis
JF  - GIT Labor-Fachzeitschrift
N2  - Die Detektion von Schadstoffen repräsentiert in der Umweltanalytik eine wichtige Aufgabenstellung. Gerade die Abwasser- bzw. Brauchwasseranalytik sowie die Prozesskontrolle haben einen hohen Stellenwert. Siliziumbasierte Dünnschichtsensoren bieten eine kostengünstige Möglichkeit, „online“-Messungen bzw. Vor-Ort-Messungen zeitnah durchzuführen. In dieser Arbeit wird ein potentiometrisches Sensorarray auf der Basis von Chalkogenidgläsern zur Detektion von Schwermetallen in wässrigen Medien vorgestellt.
Y1  - 2012
IS  - 4
SP  - 285
EP  - 287
PB  - Wiley-VCH
CY  - Weinheim
ER  -