@article{TurekKeusgenPoghossianetal.2008, author = {Turek, M. and Keusgen, M. and Poghossian, Arshak and Mulchandani, A. and Wang, J. and Sch{\"o}ning, Michael Josef}, title = {Enzyme-modified electrolyte-insulator-semiconductor sensors}, series = {Journal of Contemporary Physics. 43 (2008), H. 2}, journal = {Journal of Contemporary Physics. 43 (2008), H. 2}, isbn = {1934-9378}, pages = {82 -- 85}, year = {2008}, language = {en} } @article{KatzPoghossianSchoening2017, author = {Katz, Evgeny and Poghossian, Arshak and Sch{\"o}ning, Michael Josef}, title = {Enzyme-based logic gates and circuits - analytical applications and interfacing with electronics}, series = {Analytical and Bioanalytical Chemistry}, volume = {409}, journal = {Analytical and Bioanalytical Chemistry}, publisher = {Springer}, address = {Berlin}, issn = {1618-2650}, doi = {10.1007/s00216-016-0079-7}, pages = {81 -- 94}, year = {2017}, abstract = {The paper is an overview of enzyme-based logic gates and their short circuits, with specific examples of Boolean AND and OR gates, and concatenated logic gates composed of multi-step enzyme-biocatalyzed reactions. Noise formation in the biocatalytic reactions and its decrease by adding a "filter" system, converting convex to sigmoid response function, are discussed. Despite the fact that the enzyme-based logic gates are primarily considered as components of future biomolecular computing systems, their biosensing applications are promising for immediate practical use. Analytical use of the enzyme logic systems in biomedical and forensic applications is discussed and exemplified with the logic analysis of biomarkers of various injuries, e.g., liver injury, and with analysis of biomarkers characteristic of different ethnicity found in blood samples on a crime scene. Interfacing of enzyme logic systems with modified electrodes and semiconductor devices is discussed, giving particular attention to the interfaces functionalized with signal-responsive materials. Future perspectives in the design of the biomolecular logic systems and their applications are discussed in the conclusion.}, language = {en} } @article{PoghossianKatzSchoening2015, author = {Poghossian, Arshak and Katz, Evgeny and Sch{\"o}ning, Michael Josef}, title = {Enzyme logic AND-Reset and OR-Reset gates based on a field-effect electronic transducer modified with multi-enzyme membrane}, series = {Chemical Communications}, volume = {51}, journal = {Chemical Communications}, publisher = {Royal Society of Chemistry (RSC)}, address = {Cambridge}, doi = {10.1039/C5CC01362C}, pages = {6564 -- 6567}, year = {2015}, abstract = {Capacitive field-effect sensors modified with a multi-enzyme membrane have been applied for an electronic transduction of biochemical signals processed by enzyme-based AND-Reset and OR-Reset logic gates. The local pH change at the sensor surface induced by the enzymatic reaction was used for the activation of the Reset function for the first time.}, language = {en} } @article{ThustSchoeningSchrothetal.1999, author = {Thust, M. and Sch{\"o}ning, Michael Josef and Schroth, P. and Malkoc, {\"U}. and Dicker, C. I. and Steffen, A. and Kordos, P. and L{\"u}th, H.}, title = {Enzyme immobilisation on planar and porous silicon substrates for biosensor applications}, series = {Journal of Molecular Catalysis B: Enzymatic. 7 (1999), H. 1-4}, journal = {Journal of Molecular Catalysis B: Enzymatic. 7 (1999), H. 1-4}, isbn = {1381-1177}, pages = {77 -- 83}, year = {1999}, language = {en} } @article{SchusserBaeckerKrischeretal.2014, author = {Schusser, Sebastian and B{\"a}cker, Matthias and Krischer, M. and Wenzel, L. and Leinhos, Marcel and Poghossian, Arshak and Biselli, Manfred and Wagner, P. and Sch{\"o}ning, Michael Josef}, title = {Enzymatically catalyzed degradation of biodegradable polymers investigated by means of a semiconductor-based field-effect sensor}, series = {Procedia Engineering}, volume = {87}, journal = {Procedia Engineering}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1877-7058}, doi = {10.1016/j.proeng.2014.11.689}, pages = {1314 -- 1317}, year = {2014}, abstract = {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.}, language = {en} } @article{MiyamotoSekiWagneretal.2014, author = {Miyamoto, K. and Seki, K. and Wagner, Torsten and Sch{\"o}ning, Michael Josef and Yoshinobu, T.}, title = {Enhancement of the spatial resolution of the chemical imaging sensor by a hybrid fiber-optic illumination}, series = {Procedia Engineering}, volume = {87}, journal = {Procedia Engineering}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1877-7058}, doi = {10.1016/j.proeng.2014.11.563}, pages = {612 -- 615}, year = {2014}, abstract = {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.}, language = {en} } @article{DollWagnerWagneretal.2016, author = {Doll, Theodor and Wagner, Torsten and Wagner, Patrick and Sch{\"o}ning, Michael Josef}, title = {Engineering of functional interfaces / Theodor Doll ; Torsten Wagner ; Patrick Wagner ; Michael J. Sch{\"o}ning (eds.)}, series = {Physica status solidi (a)}, volume = {213}, journal = {Physica status solidi (a)}, number = {6}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1862-6319}, doi = {10.1002/pssa.201670641}, pages = {1393 -- 1394}, year = {2016}, language = {en} } @article{WagnerDollSchoening2014, author = {Wagner, Patrick and Doll, Theodor and Sch{\"o}ning, Michael Josef}, title = {Engineering of functional interfaces / Patrick Wagner ; Theodor Doll ; Michael J. Sch{\"o}ning (eds.)}, series = {Physica status solidi (A) : Applications and materials science}, volume = {211}, journal = {Physica status solidi (A) : Applications and materials science}, number = {6}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1521-396X (E-Book); 1862-6319 (E-Book); 0031-8965 (Print); 1862-6300 (Print)}, doi = {10.1002/pssa.201470241}, pages = {1339 -- 1339}, year = {2014}, language = {en} } @article{BronderPoghossianSchejaetal.2015, author = {Bronder, Thomas and Poghossian, Arshak and Scheja, S. and Wu, Chunsheng and Keusgen, M. and Sch{\"o}ning, Michael Josef}, title = {Electrostatic Detection of Unlabelled Single- and Double-stranded DNA Using Capacitive Field-effect Devices Functionalized with a Positively Charged Polyelectrolyte Layer}, series = {Procedia Engineering}, volume = {120}, journal = {Procedia Engineering}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1877-7058}, doi = {10.1016/j.proeng.2015.08.710}, pages = {544 -- 547}, year = {2015}, abstract = {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.}, language = {en} } @article{MuribGrinsvenGrietenetal.2013, author = {Murib, M. S. and Grinsven, B. van and Grieten, L. and Janssens, S. D. and Vermeeren, V. and Eersels, K. and Broeders, J. and Ameloot, M. and Michiels, L. and Ceuninck, W. De and Haenen, K. and Sch{\"o}ning, Michael Josef and Wagner, Patrick}, title = {Electronic monitoring of chemical DNA denaturation on nanocrystalline diamond electrodes with different molarities and flow rates}, series = {Physica Status Solidi (A). Vol. 210 (2013), iss. 5}, journal = {Physica Status Solidi (A). Vol. 210 (2013), iss. 5}, publisher = {Wiley-VCH}, address = {Berlin}, issn = {0031-8965}, pages = {911 -- 917}, year = {2013}, language = {en} } @article{MorenoiCodinachsKloockSchoeningetal.2008, author = {Moreno i Codinachs, Lia and Kloock, Joachim P. and Sch{\"o}ning, Michael Josef and Baldi, Antoni and Ipatov, Andrey and Bratov, Andrey and Jimenez-Jorquera, Cecilia}, title = {Electronic integrated multisensor tongue applied to grape juice and wine analysis}, series = {Analyst. 133 (2008)}, journal = {Analyst. 133 (2008)}, isbn = {1364-5528}, pages = {1440 -- 1448}, year = {2008}, language = {en} } @article{HonarvarfardGamellaChannaveerappaetal.2017, author = {Honarvarfard, Elham and Gamella, Maria and Channaveerappa, Devika and Darie, Costel C. and Poghossian, Arshak and Sch{\"o}ning, Michael Josef and Katz, Evgeny}, title = {Electrochemically Stimulated Insulin Release from a Modified Graphene-functionalized Carbon Fiber Electrode}, series = {Electroanalysis}, volume = {29}, journal = {Electroanalysis}, number = {6}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1521-4109}, doi = {10.1002/elan.201700095}, pages = {1543 -- 1553}, year = {2017}, abstract = {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.}, language = {en} } @article{BaeckerDellePoghossianetal.2011, author = {B{\"a}cker, Matthias and Delle, L. and Poghossian, Arshak and Biselli, Manfred and Zang, Werner and Wagner, P. and Sch{\"o}ning, Michael Josef}, title = {Electrochemical sensor array for bioprocess monitoring}, series = {Electrochimica Acta (2011)}, volume = {56}, journal = {Electrochimica Acta (2011)}, number = {26}, publisher = {Elsevier}, address = {Amsterdam}, pages = {9673 -- 9678}, year = {2011}, language = {en} } @article{SchoeningGlueckThust1999, author = {Sch{\"o}ning, Michael Josef and Gl{\"u}ck, O. and Thust, M.}, title = {Electrochemical methods for the determination of chemical variables in aqueous media}, series = {The measurement, instrumentation, and sensors handbook / ed.-in-chief John G. Webster. In cooperation with IEEE Press}, journal = {The measurement, instrumentation, and sensors handbook / ed.-in-chief John G. Webster. In cooperation with IEEE Press}, publisher = {CRC Press}, address = {Boca Raton [u.a.]}, isbn = {0-8493-8347-1}, pages = {1 -- 49}, year = {1999}, language = {en} } @article{WeldenSchejaSchoeningetal.2018, author = {Welden, Rene and Scheja, Sabrina and Sch{\"o}ning, Michael Josef and Wagner, Patrick and Wagner, Torsten}, title = {Electrochemical Evaluation of Light-Addressable Electrodes Based on TiO2 for the Integration in Lab-on-Chip Systems}, series = {physica status solidi a : applications and materials sciences}, volume = {215}, journal = {physica status solidi a : applications and materials sciences}, number = {15}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1862-6319}, doi = {10.1002/pssa.201800150}, pages = {Article number 1800150}, year = {2018}, abstract = {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.}, language = {en} } @article{PoghossianWeilCherstvyetal.2013, author = {Poghossian, Arshak and Weil, M. and Cherstvy, A. G. and Sch{\"o}ning, Michael Josef}, title = {Electrical monitoring of polyelectrolyte multilayer formation by means of capacitive field-effect devices}, series = {Analytical and bioanalytical chemistry}, volume = {405}, journal = {Analytical and bioanalytical chemistry}, number = {20}, publisher = {Springer}, address = {Berlin}, issn = {1432-1130 ; 1618-2642}, doi = {10.1007/s00216-013-6951-9}, pages = {6425 -- 6436}, year = {2013}, abstract = {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.}, language = {en} } @article{ArreolaKeusgenSchoening2017, author = {Arreola, Julio and Keusgen, Michael and Sch{\"o}ning, Michael Josef}, title = {Effect of O2 plasma on properties of electrolyte-insulator-semiconductor structures}, series = {physica status solidi a : applications and materials sciences}, volume = {214}, journal = {physica status solidi a : applications and materials sciences}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1862-6319}, doi = {10.1002/pssa.201700025}, pages = {Artikel 1700025}, year = {2017}, abstract = {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.}, language = {en} } @article{SpelthahnSchubertSchoening2012, author = {Spelthahn, Heiko and Schubert, J{\"u}rgen and Sch{\"o}ning, Michael Josef}, title = {D{\"u}nnschichtsensoren f{\"u}r die Schwermetallanalytik}, series = {GIT : Labor-Fachzeitschrift}, volume = {56}, journal = {GIT : Labor-Fachzeitschrift}, number = {4}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {0016-3538}, pages = {285 -- 287}, year = {2012}, abstract = {Die Detektion von Schadstoffen repr{\"a}sentiert in der Umweltanalytik eine wichtige Aufgabenstellung. Gerade die Abwasser- bzw. Brauchwasseranalytik sowie die Prozesskontrolle haben einen hohen Stellenwert. Siliziumbasierte D{\"u}nnschichtsensoren bieten eine kosteng{\"u}nstige M{\"o}glichkeit, „online"-Messungen bzw. Vor-Ort-Messungen zeitnah durchzuf{\"u}hren. In dieser Arbeit wird ein potentiometrisches Sensorarray auf der Basis von Chalkogenidgl{\"a}sern zur Detektion von Schwermetallen in w{\"a}ssrigen Medien vorgestellt.}, language = {en} } @article{SchoeningWangKrauseetal.2002, author = {Sch{\"o}ning, Michael Josef and Wang, Josepf and Krause, Robin and Block, Kirstin and Musameh, Mustafa and Mulchandani, Ashok and Mulchandani, Priti and Chen, Wilfred}, title = {Dual amperometric-potentiometric biosensor detection system for monitoring organophosphorus neurotoxins}, series = {Analyica Chimica Acta. 469 (2002), H. 2}, journal = {Analyica Chimica Acta. 469 (2002), H. 2}, isbn = {0378-4304}, pages = {197 -- 203}, year = {2002}, language = {en} } @article{BronderPoghossianSchejaetal.2015, author = {Bronder, Thomas and Poghossian, Arshak and Scheja, Sabrina and Wu, Chunsheng and Keusgen, Michael and Mewes, Dieter and Sch{\"o}ning, Michael Josef}, title = {DNA Immobilization and Hybridization Detection by the Intrinsic Molecular Charge Using Capacitive Field-Effect Sensors Modified with a Charged Weak Polyelectrolyte Layer}, series = {Applied Materials \& Interfaces}, volume = {36}, journal = {Applied Materials \& Interfaces}, number = {7}, publisher = {American Chemical Society}, address = {Washington, DC}, doi = {10.1021/acsami.5b05146}, pages = {20068 -- 20075}, year = {2015}, abstract = {Miniaturized setup, compatibility with advanced micro- and nanotechnologies, and ability to detect biomolecules by their intrinsic molecular charge favor the semiconductor field-effect platform as one of the most attractive approaches for the development of label-free DNA chips. In this work, a capacitive field-effect EIS (electrolyte-insulator-semiconductor) sensor covered with a layer-by-layer prepared, positively charged weak polyelectrolyte layer of PAH (poly(allylamine hydrochloride)) was used for the label-free electrical detection of DNA (deoxyribonucleic acid) immobilization and hybridization. The negatively charged probe single-stranded DNA (ssDNA) molecules were electrostatically adsorbed onto the positively charged PAH layer, resulting in a preferentially flat orientation of the ssDNA molecules within the Debye length, thus yielding a reduced charge-screening effect and a higher sensor signal. Each sensor-surface modification step (PAH adsorption, probe ssDNA immobilization, hybridization with complementary target DNA (cDNA), reducing an unspecific adsorption by a blocking agent, incubation with noncomplementary DNA (ncDNA) solution) was monitored by means of capacitance-voltage and constant-capacitance measurements. In addition, the surface morphology of the PAH layer was studied by atomic force microscopy and contact-angle measurements. High hybridization signals of 34 and 43 mV were recorded in low-ionic strength solutions of 10 and 1 mM, respectively. In contrast, a small signal of 4 mV was recorded in the case of unspecific adsorption of fully mismatched ncDNA. The density of probe ssDNA and dsDNA molecules as well as the hybridization efficiency was estimated using the experimentally measured DNA immobilization and hybridization signals and a simplified double-layer capacitor model. The results of field-effect experiments were supported by fluorescence measurements, verifying the DNA-immobilization and hybridization event.}, language = {en} }