TY  - JOUR
A1  - Wagner, Torsten
A1  - Shigiahara, N.
A1  - Miyamoto, K.
A1  - Suzurikawa, J.
A1  - Finger, F.
A1  - Schöning, Michael Josef
A1  - Yoshinobu, T.
T1  - Light-addressable Potentiometric Sensors and Light–addressable Electrodes as a Combined Sensor-and-manipulator Microsystem with High Flexibility
JF  - Procedia Engineering
N2  - This work describes the novel combination of the light-addressable electrode (LAE) and the light-addressable potentiometric sensor (LAPS) into a microsystem set-up. Both the LAE as well as the LAPS shares the principle of addressing the active spot by means of a light beam. This enables both systems to manipulate resp. to detect an analyte with a high spatial resolution. Hence, combining both principles into a single set-up enables the active stimulation e.g., by means of electrolysis and a simultaneous observation e.g., the response of an entrapped biological cell by detection of extracellular pH changes. The work will describe the principles of both technologies and the necessary steps to integrate them into a single set-up. Furthermore, examples of application and operation of such systems will be presented.
Y1  - 2012
U6  - http://dx.doi.org/10.1016/j.proeng.2012.09.290
SN  - 1877-7058
N1  - Part of special issue "26th European Conference on Solid-State Transducers, EUROSENSOR 2012"
IS  - 47
SP  - 890
EP  - 893
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Wagner, Torsten
A1  - Schöning, Michael Josef
T1  - Light-addressable potentiometric sensors (LAPS): recent trends and applications
JF  - Electrochemical sensor analysis / edited by S. Alegret ...
Y1  - 2007
SN  - 978-0-444-53053-0
N1  - Wilson & Wilson's comprehensive analytical chemistry ; 49
SP  - 87
EP  - 128
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Yoshinobu, Tatsuo
A1  - Schöning, Michael Josef
T1  - Light-addressable potentiometric sensors (LAPS) for cell monitoring and biosensing
JF  - Current Opinion in Electrochemistry
Y1  - 2021
U6  - http://dx.doi.org/10.1016/j.coelec.2021.100727
SN  - 2451-9103
IS  - In Press, Journal Pre-proof
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - CHAP
A1  - Wagner, Torsten
A1  - Yoshinobu, T.
A1  - Schöning, Michael Josef
T1  - Light-addressable potentiometric sensor as semiconductor-based sensor platform for (bio-) chemical sensing
T2  - Armenian Journal of Physics
Y1  - 2008
SN  - 1829-1171
SP  - 99
EP  - 103
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  - 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  - http://dx.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  - 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  - http://dx.doi.org/10.1016/j.phmed.2016.03.001
SN  - 2352-4510
VL  - 2016
IS  - 1
SP  - 2
EP  - 7
ER  - 
TY  - JOUR
A1  - Welden, Rene
A1  - Schöning, Michael Josef
A1  - Wagner, Patrick H.
A1  - Wagner, Torsten
T1  - Light-Addressable Electrodes for Dynamic and Flexible Addressing of Biological Systems and Electrochemical Reactions
JF  - Sensors
N2  - In this review article, we are going to present an overview on possible applications of light-addressable electrodes (LAE) as actuator/manipulation devices besides classical electrode structures. For LAEs, the electrode material consists of a semiconductor. Illumination with a light source with the appropiate wavelength leads to the generation of electron-hole pairs which can be utilized for further photoelectrochemical reaction. Due to recent progress in light-projection technologies, highly dynamic and flexible illumination patterns can be generated, opening new possibilities for light-addressable electrodes. A short introduction on semiconductor–electrolyte interfaces with light stimulation is given together with electrode-design approaches. Towards applications, the stimulation of cells with different electrode materials and fabrication designs is explained, followed by analyte-manipulation strategies and spatially resolved photoelectrochemical deposition of different material types.
Y1  - 2020
U6  - http://dx.doi.org/10.3390/s20061680
SN  - 1424-8220
VL  - 20
IS  - 6
PB  - MDPI
CY  - Basel
ER  - 
TY  - JOUR
A1  - Welden, Rene
A1  - Jablonski, Melanie
A1  - Wege, Christina
A1  - Keusgen, Michael
A1  - Wagner, Patrick Hermann
A1  - Wagner, Torsten
A1  - Schöning, Michael Josef
T1  - Light-Addressable Actuator-Sensor Platform for Monitoring and Manipulation of pH Gradients in Microfluidics: A Case Study with the Enzyme Penicillinase
JF  - Biosensors
N2  - The feasibility of light-addressed detection and manipulation of pH gradients inside an electrochemical microfluidic cell was studied. Local pH changes, induced by a light-addressable electrode (LAE), were detected using a light-addressable potentiometric sensor (LAPS) with different measurement modes representing an actuator-sensor system. Biosensor functionality was examined depending on locally induced pH gradients with the help of the model enzyme penicillinase, which had been immobilized in the microfluidic channel. The surface morphology of the LAE and enzyme-functionalized LAPS was studied by scanning electron microscopy. Furthermore, the penicillin sensitivity of the LAPS inside the microfluidic channel was determined with regard to the analyte’s pH influence on the enzymatic reaction rate. In a final experiment, the LAE-controlled pH inhibition of the enzyme activity was monitored by the LAPS.
KW  - microfluidics
KW  - enzyme kinetics
KW  - actuator-sensor system
KW  - light-addressable electrode
KW  - light-addressable potentiometric sensor
Y1  - 2021
U6  - http://dx.doi.org/10.3390/bios11060171
SN  - 2079-6374
N1  - This article belongs to the Special Issue "Selected Papers from the 1st International Electronic Conference on Biosensors (IECB 2020)"
VL  - 11
IS  - 6
PB  - MDPI
CY  - Basel
ER  - 
TY  - CHAP
A1  - Wagner, Torsten
A1  - Yoshinobu, T.
A1  - Otto, R.
A1  - Rao, C.
A1  - Molina, R.
A1  - Schöning, Michael Josef
T1  - Licht-adressierbare potentiometrische Sensorsysteme – Konzepte und Anwendungen
T2  - Sensoren und Mess-Systeme 2006 : Vorträge der 13. ITG/GMA-Fachtagung vom 13. bis 14.3.2006 in Freiburg/Breisgau
Y1  - 2006
SN  - 3-8007-2939-3
SP  - 165
EP  - 168
PB  - VDE Verl.
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Morais, Paulo V.
A1  - Suman, Pedro H.
A1  - Schöning, Michael Josef
A1  - Siqueira Junior, José R.
A1  - Orlandi, Marcelo O.
T1  - Layer-by-layer film based on Sn₃O₄ nanobelts as sensing units to detect heavy metals using a capacitive field-effect sensor platform
JF  - Chemosensors
N2  - Lead and nickel, as heavy metals, are still used in industrial processes, and are classified as “environmental health hazards” due to their toxicity and polluting potential. The detection of heavy metals can prevent environmental pollution at toxic levels that are critical to human health. In this sense, the electrolyte–insulator–semiconductor (EIS) field-effect sensor is an attractive sensing platform concerning the fabrication of reusable and robust sensors to detect such substances. This study is aimed to fabricate a sensing unit on an EIS device based on Sn₃O₄ nanobelts embedded in a polyelectrolyte matrix of polyvinylpyrrolidone (PVP) and polyacrylic acid (PAA) using the layer-by-layer (LbL) technique. The EIS-Sn₃O₄ sensor exhibited enhanced electrochemical performance for detecting Pb²⁺ and Ni²⁺ ions, revealing a higher affinity for Pb²⁺ ions, with sensitivities of ca. 25.8 mV/decade and 2.4 mV/decade, respectively. Such results indicate that Sn₃O₄ nanobelts can contemplate a feasible proof-of-concept capacitive field-effect sensor for heavy metal detection, envisaging other future studies focusing on environmental monitoring.
KW  - Sn₃O₄
KW  - nanobelts
KW  - field-effect sensor
KW  - LbL films
KW  - heavy metals
Y1  - 2023
U6  - http://dx.doi.org/10.3390/chemosensors11080436
SN  - 2227-9040
N1  - This article belongs to the Special Issue The Application of Electrochemical Sensors or Biosensors Based on Nanomaterials
VL  - 11
IS  - 8
PB  - MDPI
CY  - Basel
ER  - 
TY  - JOUR
A1  - Siqueira, Jose R.
A1  - Werner, Frederik
A1  - Bäcker, Matthias
A1  - Poghossian, Arshak
A1  - Zucolotto, Valtencir
A1  - Oliveira, Osvaldo N. Jr.
A1  - Schöning, Michael Josef
T1  - Layer-by-Layer Assembly of Carbon Nanotubes Incorporated in Light-Addressable Potentiometric Sensors
JF  - Journal of Physical Chemistry C. 113 (2009), H. 33
Y1  - 2009
SN  - 1932-7455
SP  - 14765
EP  - 14770
PB  - American Chemical Society
CY  - Washington, DC
ER  - 
TY  - JOUR
A1  - Werner, Frederik
A1  - Miyamoto, Ko-ichiro
A1  - Wagner, Torsten
A1  - Schöning, Michael Josef
A1  - Yoshinobu, Tatsuo
T1  - Lateral resolution enhancement of pulse-driven light-addressable potentiometric sensor
JF  - Sensor and Actuators B: Chemical
N2  - To study chemical and biological processes, spatially resolved determination of the concentrations of one or more analyte species is of distinct interest. With a light-addressable potentiometric sensor (LAPS), chemical images can be created, which visualize the concentration distribution above the sensor plate. One important challenge is to achieve a good lateral resolution in order to detect events that take place in a small and limited region. LAPS utilizes a focused light spot to address the measurement region. By moving this light spot along the semiconductor sensor plate, the concentration distribution can be observed. In this study, we show that utilizing a pulse as light excitation instead of a traditionally used continuously modulated light excitation, the lateral resolution can be improved by a factor of 6 or more.
KW  - Chemical images
KW  - LAPS
KW  - Light-addressable potentiometric sensor
Y1  - 2017
U6  - http://dx.doi.org/10.1016/j.snb.2017.02.057
SN  - 0925-4005
VL  - 248
SP  - 961
EP  - 965
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Ermolenko, Y. E.
A1  - Yoshinobu, T.
A1  - Mourzina, Y. G.
A1  - Vlasov, Y. G.
A1  - Schöning, Michael Josef
A1  - Iwasaki, H.
T1  - Laserscanned transducer (LSST) as a multisensor system
JF  - Sensors and Actuators B. 103 (2004), H. 1-2
Y1  - 2004
SN  - 0925-4005
SP  - 457
EP  - 462
ER  - 
TY  - JOUR
A1  - Dantism, Shahriar
A1  - Röhlen, Desiree
A1  - Dahmen, Markus
A1  - Wagner, Torsten
A1  - Wagner, Patrick
A1  - Schöning, Michael Josef
T1  - LAPS-based monitoring of metabolic responses of bacterial cultures in a paper fermentation broth
JF  - Sensors and Actuators B: Chemical
N2  - As an alternative renewable energy source, methane production in biogas plants is gaining more and more attention. Biomass in a bioreactor contains different types of microorganisms, which should be considered in terms of process-stability control. Metabolically inactive microorganisms within the fermentation process can lead to undesirable, time-consuming and cost-intensive interventions. Hence, monitoring of the cellular metabolism of bacterial populations in a fermentation broth is crucial to improve the biogas production, operation efficiency, and sustainability. In this work, the extracellular acidification of bacteria in a paper-fermentation broth is monitored after glucose uptake, utilizing a differential light-addressable potentiometric sensor (LAPS) system. The LAPS system is loaded with three different model microorganisms (Escherichia coli, Corynebacterium glutamicum, and Lactobacillus brevis) and the effect of the fermentation broth at different process stages on the metabolism of these bacteria is studied. In this way, different signal patterns related to the metabolic response of microorganisms can be identified. By means of calibration curves after glucose uptake, the overall extracellular acidification of bacterial populations within the fermentation process can be evaluated.
Y1  - 2020
U6  - http://dx.doi.org/10.1016/j.snb.2020.128232
SN  - 0925-4005
VL  - 320
IS  - Art. 128232
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Schöning, Michael Josef
A1  - Kloock, Joachim P.
T1  - Labor für Chemo- und Biosensorik an der FH Aachen, Abt. Jülich – Mehr als nur studieren
JF  - Fachblatt Fachhochschule Aachen (2004)
Y1  - 2004
SN  - 1430-7707
SP  - 18
EP  - 19
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  - CHAP
A1  - Poghossian, Arshak
A1  - Bronder, Thomas
A1  - Wu, Chunsheng
A1  - Schöning, Michael Josef
T1  - Label-free sensing of biomolecules by their intrinsic molecular charge using field-effect devices
T2  - Semiconductor Micro- and Nanoelectonics : Proceedings of the tenth international conference, Yerevan, Armenia, September 11-13
Y1  - 2015
SN  - 978-5-8084-1991-9
SP  - 61
EP  - 63
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  - http://dx.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  - Bronder, Thomas
A1  - Poghossian, Arshak
A1  - Werner, Frederik
A1  - Bäcker, Matthias
A1  - Schöning, Michael Josef
T1  - Label-free electrical detection of DNA with a multi-spot LAPS: First step towards light-addressable DNA chips
JF  - Physica status solidi A : Applications and materials science
N2  - A multi-spot (4 × 4 spots) light-addressable potentiometric sensor (MLAPS) consisting of an Al–p-Si–SiO2 structure has been applied for the label-free electrical detection of DNA (deoxyribonucleic acid) immobilization and hybridization by the intrinsic molecular charge for the first time. Single-stranded probe ssDNA molecules (20 bases) were covalently immobilized onto the silanized SiO2 gate surface. The unspecific adsorption of mismatch ssDNA on the MLAPS gate surface was blocked by bovine serum albumin molecules. To reduce the screening effect and to achieve a high sensor signal, the measurements were performed in a low ionic-strength solution. The photocurrent–voltage (I–V) curves were simultaneously recorded on all 16 spots after each surface functionalization step. Large shifts of I–V curves of 25 mV were registered after the DNA immobilization and hybridization event. In contrast, a small potential shift (∼5 mV) was observed in case of mismatch ssDNA, revealing good specificity of the sensor. The obtained results demonstrate the potential of the MLAPS as promising transducer platform for the multi-spot label-free electrical detection of DNA molecules by their intrinsic molecular charge.
Y1  - 2014
U6  - http://dx.doi.org/10.1002/pssa.201330442
SN  - 1521-396X (E-Journal); 1862-6319 (E-Journal); 0031-8965 (Print); 1862-6300 (Print)
VL  - 211
IS  - 6
SP  - 1423
EP  - 1428
PB  - Wiley-VCH
CY  - Weinheim
ER  -