TY  - JOUR
A1  - Siqueira, Jose R.
A1  - Molinnus, Denise
A1  - Beging, Stefan
A1  - Schöning, Michael Josef
T1  - Incorporating a hybrid urease-carbon nanotubes sensitive nanofilm on capacitive field-effect sensors for urea detection
JF  - Analytical chemistry
N2  - The ideal combination among biomolecules and nanomaterials is the key for reaching biosensing units with high sensitivity. The challenge, however, is to find out a stable and sensitive film architecture that can be incorporated on the sensor’s surface. In this paper, we report on the benefits of incorporating a layer-by-layer (LbL) nanofilm of polyamidoamine (PAMAM) dendrimer and carbon nanotubes (CNTs) on capacitive electrolyte-insulator-semiconductor (EIS) field-effect sensors for detecting urea. Three sensor arrangements were studied in order to investigate the adequate film architecture, involving the LbL film with the enzyme urease: (i) urease immobilized directly onto a bare EIS [EIS-urease] sensor; (ii) urease atop the LbL film over the EIS [EIS-(PAMAM/CNT)-urease] sensor; and (iii) urease sandwiched between the LbL film and another CNT layer [EIS-(PAMAM/CNT)-urease-CNT]. The surface morphology of all three urea-based EIS biosensors was investigated by atomic force microscopy (AFM), while the biosensing abilities were studied by means of capacitance–voltage (C/V) and dynamic constant-capacitance (ConCap) measureaments at urea concentrations ranging from 0.1 mM to 100 mM. The EIS-urease and EIS-(PAMAM/CNT)-urease sensors showed similar sensitivity (∼18 mV/decade) and a nonregular signal behavior as the urea concentration increased. On the other hand, the EIS-(PAMAM/CNT)-urease-CNT sensor exhibited a superior output signal performance and higher sensitivity of about 33 mV/decade. The presence of the additional CNT layer was decisive to achieve a urea based EIS sensor with enhanced properties. Such sensitive architecture demonstrates that the incorporation of an adequate hybrid enzyme-nanofilm as sensing unit opens new prospects for biosensing applications using the field-effect sensor platform.
Y1  - 2014
U6  - http://dx.doi.org/10.1021/ac500458s
SN  - 1520-6882 (E-Journal); 0003-2700 (Print); 0096-4484 (Print)
VL  - 86
IS  - 11
SP  - 5370
EP  - 5375
PB  - ACS Publications
CY  - Columbus
ER  - 
TY  - JOUR
A1  - Guo, Yuanyuan
A1  - Seki, Kosuke
A1  - Miyamoto, Ko-ichiro
A1  - Wagner, Torsten
A1  - Schöning, Michael Josef
A1  - Yoshinobu, Tatsuo
T1  - Device simulation of the light-addressable potentiometric sensor with a novel photoexcitation method for a higher spatial resolution
JF  - Procedia Engineering
N2  - A novel photoexcitation method for the light-addressable potentiometric sensor (LAPS) realized a higher spatial resolution of chemical imaging. In this method, a modulated light probe, which generates the alternating photocurrent signal, is surrounded by a ring of constant light, which suppresses the lateral diffusion of photocarriers by enhancing recombination. A device simulation verified that a higher spatial resolution could be obtained by adjusting the gap between the modulated and constant light. It was also found that a higher intensity and a longer wavelength of constant light was more effective. However, there exists a tradeoff between the spatial resolution and the amplitude of the photocurrent, and thus, the signal-to-noise ratio. A tilted incidence of constant light was applied, which could achieve even higher resolution with a smaller loss of photocurrent.
KW  - Light-addressable Potentiometric Sensor
KW  - novel photoexcitation method
KW  - tilted constant illumination
KW  - spatial resolution
Y1  - 2014
U6  - http://dx.doi.org/10.1016/j.proeng.2014.11.369
SN  - 1877-7058
N1  - EUROSENSORS 2014 ; European Conference on Solid-State Transducers <28, 2014>
VL  - 87
SP  - 456
EP  - 459
PB  - Elsevier
CY  - Amsterdam
ER  - 
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  - Bronder, Thomas
A1  - Wu, Chunsheng
A1  - Poghossian, Arshak
A1  - Werner, Frederik
A1  - Keusgen, M.
A1  - Schöning, Michael Josef
T1  - Label-free detection of DNA hybridization with light-addressable potentiometric sensors: comparison of various DNA-immobilization strategies
JF  - Procedia Engineering
N2  - Light-addressable potentiometric sensors (LAPS) consisting of a p-Si-SiO2 and p-Si-SiO2-Au structure, respectively, have been tested for a label-free electrical detection of DNA (deoxyribonucleic acid) hybridization. Three different strategies for immobilizing single-stranded probe DNA (ssDNA) molecules on a LAPS surface have been studied and compared: (a) immobilization of thiol-modified ssDNA on the patterned Au surface via gold-thiol bond, (b) covalent immobilization of amino-modified ssDNA onto the SiO2 surface functionalized with 3-aminopropyltriethoxysilane and (c) layer-by-layer adsorption of negatively charged ssDNA on a positively charged weak polyelectrolyte layer of poly(allylamine hydrochloride).
KW  - LAPS
KW  - lable-free detection
KW  - DNA hybridization
KW  - field-effect sensor
Y1  - 2014
U6  - http://dx.doi.org/10.1016/j.proeng.2014.11.647
SN  - 1877-7058
N1  - EUROSENSORS 2014 ; European Conference on Solid-State Transducers <28, 2014>
VL  - 87
SP  - 755
EP  - 758
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Huck, Christina
A1  - Poghossian, Arshak
A1  - Bäcker, Matthias
A1  - Reisert, Steffen
A1  - Schubert, J.
A1  - Zander, W.
A1  - Begoyan, V. K.
A1  - Buniatyan, V. V.
A1  - Schöning, Michael Josef
T1  - Chemical sensors based on a high-k perovskite oxide of barium strontium titanate
JF  - Procedia Engineering
N2  - High-k perovskite oxide of barium strontium titanate (BST) represents a very attractive multi-functional transducer material for the development of (bio-)chemical sensors for liquids. In this work, BST films have been applied as a sensitive transducer material for a label-free detection of adsorbed charged macromolecules (positively charged polyelectrolytes) and concentration of hydrogen peroxide vapor as well as protection insulator layer for a contactless electrolyte-conductivity sensor. The experimental results of characterization of individual sensors are presented. Special emphasis is devoted towards the development of a capacitively-coupled contactless electrolyte-conductivity sensor.
KW  - barium strontium titanate
KW  - high-k material
KW  - contactless conductivity sensor
KW  - multi-functional material
KW  - hydrogen peroxide
Y1  - 2014
U6  - http://dx.doi.org/10.1016/j.proeng.2014.11.258
SN  - 1877-7058
N1  - EUROSENSORS 2014 ; European Conference on Solid-State Transducers <28, 2014>
VL  - 87
SP  - 28
EP  - 31
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Schusser, Sebastian
A1  - Bäcker, Matthias
A1  - Krischer, M.
A1  - Wenzel, L.
A1  - Leinhos, Marcel
A1  - Poghossian, Arshak
A1  - Biselli, Manfred
A1  - Wagner, P.
A1  - Schöning, Michael Josef
T1  - Enzymatically catalyzed degradation of biodegradable polymers investigated by means of a semiconductor-based field-effect sensor
JF  - Procedia Engineering
N2  - A semiconductor field-effect device has been used for an enzymatically catalyzed degradation of biopolymers for the first time. This novel technique is capable to monitor the degradation process of multiple samples in situ and in real-time. As model system, the degradation of the biopolymer poly(D, L-lactic acid) has been monitored in the degradation medium containing the enzyme lipase from Rhizomucor miehei. The obtained results demonstrate the potential of capacitive field-effect sensors for degradation studies of biodegradable polymers.
KW  - Field-effect sensor
KW  - enzymatic (bio)degradation
KW  - poly(d, l-lactic acid)
KW  - in-situ monitoring
KW  - impedance spectroscopy
Y1  - 2014
U6  - http://dx.doi.org/10.1016/j.proeng.2014.11.689
SN  - 1877-7058
N1  - EUROSENSORS 2014 ; European Conference on Solid-State Transducers <28, 2014>
VL  - 87
SP  - 1314
EP  - 1317
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Poghossian, Arshak
A1  - Schöning, Michael Josef
T1  - Label-free sensing of biomolecules with field-effect devices for clinical applications
JF  - Electroanalysis
N2  - Among the variety of transducer concepts proposed for label-free detection of biomolecules, the semiconductor field-effect device (FED) is one of the most attractive platforms. As medical techniques continue to progress towards diagnostic and therapies based on biomarkers, the ability of FEDs for a label-free, fast and real-time detection of multiple pathogenic and physiologically relevant molecules with high specificity and sensitivity offers very promising prospects for their application in point-of-care and personalized medicine for an early diagnosis and treatment of diseases. The presented paper reviews recent advances and current trends in research and development of different FEDs for label-free, direct electrical detection of charged biomolecules by their intrinsic molecular charge. The authors are mainly focusing on the detection of the DNA hybridization event, antibody-antigen affinity reaction as well as clinically relevant biomolecules such as cardiac and cancer biomarkers.
Y1  - 2014
U6  - http://dx.doi.org/10.1002/elan.201400073
SN  - 1521-4109 (E-Journal); 1040-0397 (Print)
VL  - 26
IS  - 6
SP  - 1197
EP  - 1213
PB  - Wiley-VCH
CY  - Weinheim
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  - Bohrn, Ulrich
A1  - Stütz, Evamaria
A1  - Fleischer, Maximilian
A1  - Schöning, Michael Josef
A1  - Wagner, Patrick
T1  - Using a cell-based gas biosensor for investigation of adverse effects of acetone vapors in vitro
JF  - Biosensors and Bioelectronics. 40 (2013), H. 1
Y1  - 2013
SN  - 0956-5663
SP  - 393
EP  - 400
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  - Bohrn, Ulrich
A1  - Mucha, Andreas
A1  - Werner, Frederik
A1  - Trattner, Barbara
A1  - Bäcker, Matthias
A1  - Krumbe, Christoph
A1  - Schienle, Meinrad
A1  - Stütz, Evamaria
A1  - Schmitt-Landsiedel, Doris
A1  - Fleischer, Maximilian
A1  - Wagner, Patrick
A1  - Schöning, Michael Josef
T1  - A critical comparison of cell-based sensor systems for the detection of Cr (VI) in aquatic environment
JF  - Sensors and actuators. B: Chemical
Y1  - 2013
SN  - 1873-3077 (E-Journal); 0925-4005 (Print)
VL  - Vol. 182
SP  - 58
EP  - 65
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Kramer, Friederike
A1  - Halamkova, Lenka
A1  - Poghossian, Arshak
A1  - Schöning, Michael Josef
A1  - Katz, Evgeny
A1  - Halamek, Jan
T1  - Biocatalytic analysis of biomarkers for forensic identification of ethnicity between Caucasian and African American
JF  - The analyst. August 2013
Y1  - 2013
SN  - 1364-5528 (E-Journal); 0003-2654 (Print)
VL  - Vol. 138
SP  - 6251
EP  - 6257
PB  - Royal Society of Chemistry
CY  - Cambridge
ER  - 
TY  - JOUR
A1  - Schusser, Sebastian
A1  - Menzel, S.
A1  - Bäcker, Matthias
A1  - Leinhos, Marcel
A1  - Poghossian, Arshak
A1  - Wagner, P.
A1  - Schöning, Michael Josef
T1  - Degradation of thin poly(lactic acid) films: characterization by capacitance-voltage, atomic force microscopy, scanning electron microscopy and contact-angle measurements
JF  - Electrochimica Acta
Y1  - 2013
SN  - 1873-3859 (E-Journal); 0013-4686 (Print)
VL  - Vol. 113
SP  - 779
EP  - 784
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Iken, Heiko
A1  - Ahlborn, K.
A1  - Gerlach, F.
A1  - Vonau, W.
A1  - Zander, W.
A1  - Schubert, J.
A1  - Schöning, Michael Josef
T1  - Development of redox glasses and subsequent processing by means of pulsed laser deposition for realizing silicon-based thin-film sensors
JF  - Electrochimica acta
Y1  - 2013
SN  - 1873-3859 (E-Journal); 0013-4686 (Print)
SP  - Available online 30.8.2013
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Reisert, Steffen
A1  - Geissler, Hanno
A1  - Flörke, Rudolf
A1  - Weiler, Christian
A1  - Wagner, Patrick
A1  - Schöning, Michael Josef
T1  - Characterisation of aseptic sterilisation processes using an electronic nose
JF  - International journal of nanotechnology
Y1  - 2013
SN  - 1475-7435 (Print) 7141-8151 (Online)
VL  - Vol. 10
IS  - No. 5-7
SP  - 470
EP  - 484
PB  - Inderscience Enterprises
CY  - Genève
ER  - 
TY  - JOUR
A1  - Miyamoto, Ko-ichiro
A1  - Hirayama, Yuji
A1  - Wagner, Torsten
A1  - Schöning, Michael Josef
A1  - Yoshinobu, Tatsuo
T1  - Visualization of enzymatic reaction in a microfluidic channel using chemical imaging sensor
JF  - Electrochimica acta
Y1  - 2013
SN  - 1873-3859 (E-Journal); 0013-4686 (Print)
SP  - Publ. online
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Bäcker, Matthias
A1  - Schusser, Sebastian
A1  - Poghossian, Arshak
A1  - Schöning, Michael Josef
T1  - Degradationsverhalten bioabbaubarer Polymere : siliziumbasierte Sensorik zur Überwachung
JF  - GIT Labor-Fachzeitschrift
Y1  - 2013
SN  - 0016-3538
SP  - 32
EP  - 33
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Buniatyan, V.
A1  - Huck, Christina
A1  - Poghossian, Arshak
A1  - Aroutiounian, V. M.
A1  - Schöning, Michael Josef
T1  - BaxSr1-x TiO3/pc-Si heterojunction capacitance
JF  - Armenian journal of physics
Y1  - 2013
SN  - 1829-1171
VL  - 6
IS  - 4
SP  - 188
EP  - 197
PB  - National Academy of Sciences of Armenia
CY  - Yerevan
ER  - 
TY  - JOUR
A1  - Buniatyan, V.
A1  - Huck, Christina
A1  - Poghossian, Arshak
A1  - Aroutiounian, V. M.
A1  - Schöning, Michael Josef
T1  - BaxSr1-x TiO3/pc-Si heterojunction
JF  - Armenian journal of physics
Y1  - 2013
SN  - 1829-1171
VL  - 6
IS  - 4
SP  - 177
EP  - 187
PB  - National Academy of Sciences of Armenia
CY  - Yerevan
ER  - 
TY  - JOUR
A1  - Reisert, Steffen
A1  - Schneider, Benno
A1  - Geissler, Hanno
A1  - Gompel, Matthias van
A1  - Wagner, Patrick
A1  - Schöning, Michael Josef
T1  - Multi-sensor chip for the investigation of different types of metal oxides for the detection of H2O2 in the ppm range
JF  - physica status solidi (a)
N2  - In this work, a multi-sensor chip for the investigation of the sensing properties of different types of metal oxides towards hydrogen peroxide in the ppm range is presented. The fabrication process and physical characterization of the multi-sensor chip are described. Pure SnO2 and WO3 as well as Pd- and Pt-doped SnO2 films are characterized in terms of their sensitivity to H2O2. The sensing films have been prepared by drop-coating of water-dispensed nano-powders. A physical characterization, including scanning electron microscopy and X-ray diffraction analysis of the deposited metal-oxide films, was done. From the measurements in hydrogen peroxide atmosphere, it could be shown, that all of the tested metal oxide films are suitable for the detection of H2O2 in the ppm range. The highest sensitivity and reproducibility was achieved using Pt-doped SnO2.

Calibration plot of a SnO2, WO3, Pt-, and Pd-doped SnO2 gas sensor for H2O2 concentrations in the ppm range.
Y1  - 2013
SN  - 1862-6319
VL  - 210
IS  - 5
SP  - 898
EP  - 904
PB  - Wiley
CY  - Weinheim
ER  -