@article{SchollMoraisGabrieletal.2017, author = {Scholl, Fabio and Morais, Paulo and Gabriel, Rayla and Sch{\"o}ning, Michael Josef and Siqueira, Jose Roberto, Jr. and Caseli, Luciano}, title = {Carbon nanotubes arranged as smart interfaces in lipid Langmuir-Blodgett films enhancing the enzymatic properties of penicillinase for biosensing applications}, series = {Applied Materials \& Interfaces}, volume = {9}, journal = {Applied Materials \& Interfaces}, number = {36}, publisher = {ACS}, address = {Washington}, issn = {1944-8252}, doi = {10.1021/acsami.7b08095}, pages = {31054 -- 31066}, year = {2017}, abstract = {In this paper, carbon nanotubes (CNTs) were incorporated in penicillinase-phospholipid Langmuir and Langmuir-Blodgett (LB) films to enhance the enzyme catalytic properties. Adsorption of the penicillinase and CNTs at dimyristoylphosphatidic acid (DMPA) monolayers at the air-water interface was investigated by surface pressure-area isotherms, vibrational spectroscopy, and Brewster angle microscopy. The floating monolayers were transferred to solid supports through the LB technique, forming mixed DMPA-CNTs-PEN films, which were investigated by quartz crystal microbalance, vibrational spectroscopy, and atomic force microscopy. Enzyme activity was studied with UV-vis spectroscopy and the feasibility of the supramolecular device nanostructured as ultrathin films were essayed in a capacitive electrolyte-insulator-semiconductor (EIS) sensor device. The presence of CNTs in the enzyme-lipid LB film not only tuned the catalytic activity of penicillinase but also helped conserve its enzyme activity after weeks, showing increased values of activity. Viability as penicillin sensor was demonstrated with capacitance/voltage and constant capacitance measurements, exhibiting regular and distinctive output signals over all concentrations used in this work. These results may be related not only to the nanostructured system provided by the film, but also to the synergism between the compounds on the active layer, leading to a surface morphology that allowed a fast analyte diffusion because of an adequate molecular accommodation, which also preserved the penicillinase activity. This work therefore demonstrates the feasibility of employing LB films composed of lipids, CNTs, and enzymes as EIS devices for biosensing applications.}, language = {en} } @article{RodriguesMoraisNordietal.2018, author = {Rodrigues, Raul T. and Morais, Paulo V. and Nordi, Cristina S. F. and Sch{\"o}ning, Michael Josef and Siqueira Jr., Jos{\´e} R. and Caseli, Luciano}, title = {Carbon Nanotubes and Algal Polysaccharides To Enhance the Enzymatic Properties of Urease in Lipid Langmuir-Blodgett Films}, series = {Langmuir}, volume = {34}, journal = {Langmuir}, number = {9}, publisher = {ACS Publications}, address = {Washington, DC}, issn = {1520-5827}, doi = {10.1021/acs.langmuir.7b04317}, pages = {3082 -- 3093}, year = {2018}, abstract = {Algal polysaccharides (extracellular polysaccharides) and carbon nanotubes (CNTs) were adsorbed on dioctadecyldimethylammonium bromide Langmuir monolayers to serve as a matrix for the incorporation of urease. The physicochemical properties of the supramolecular system as a monolayer at the air-water interface were investigated by surface pressure-area isotherms, surface potential-area isotherms, interfacial shear rheology, vibrational spectroscopy, and Brewster angle microscopy. The floating monolayers were transferred to hydrophilic solid supports, quartz, mica, or capacitive electrolyte-insulator-semiconductor (EIS) devices, through the Langmuir-Blodgett (LB) technique, forming mixed films, which were investigated by quartz crystal microbalance, fluorescence spectroscopy, and field emission gun scanning electron microscopy. The enzyme activity was studied with UV-vis spectroscopy, and the feasibility of the thin film as a urea sensor was essayed in an EIS sensor device. The presence of CNT in the enzyme-lipid LB film not only tuned the catalytic activity of urease but also helped to conserve its enzyme activity. Viability as a urease sensor was demonstrated with capacitance-voltage and constant capacitance measurements, exhibiting regular and distinctive output signals over all concentrations used in this work. These results are related to the synergism between the compounds on the active layer, leading to a surface morphology that allowed fast analyte diffusion owing to an adequate molecular accommodation, which also preserved the urease activity. This work demonstrates the feasibility of employing LB films composed of lipids, CNT, algal polysaccharides, and enzymes as EIS devices for biosensing applications.}, language = {en} } @article{HuckPoghossianBaeckeretal.2014, author = {Huck, Christina and Poghossian, Arshak and B{\"a}cker, Matthias and Chaudhuri, S. and Zander, W. and Schubert, J. and Begoyan, V. K. and Buniatyan, V. V. and Wagner, P. and Sch{\"o}ning, Michael Josef}, title = {Capacitively coupled electrolyte-conductivity sensor based on high-k material of barium strontium titanate}, series = {Sensors and actuators. B: Chemical}, journal = {Sensors and actuators. B: Chemical}, number = {198}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1873-3077 (E-Journal); 0925-4005 (Print)}, doi = {10.1016/j.snb.2014.02.103}, pages = {102 -- 109}, year = {2014}, language = {en} } @article{KarschuckPoghossianSeretal.2024, author = {Karschuck, Tobias and Poghossian, Arshak and Ser, Joey and Tsokolakyan, Astghik and Achtsnicht, Stefan and Wagner, Patrick and Sch{\"o}ning, Michael Josef}, title = {Capacitive model of enzyme-modified field-effect biosensors: Impact of enzyme coverage}, series = {Sensors and Actuators B: Chemical}, volume = {408}, journal = {Sensors and Actuators B: Chemical}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0925-4005 (Print)}, doi = {10.1016/j.snb.2024.135530}, pages = {12 Seiten}, year = {2024}, abstract = {Electrolyte-insulator-semiconductor capacitors (EISCAP) belong to field-effect sensors having an attractive transducer architecture for constructing various biochemical sensors. In this study, a capacitive model of enzyme-modified EISCAPs has been developed and the impact of the surface coverage of immobilized enzymes on its capacitance-voltage and constant-capacitance characteristics was studied theoretically and experimentally. The used multicell arrangement enables a multiplexed electrochemical characterization of up to sixteen EISCAPs. Different enzyme coverages have been achieved by means of parallel electrical connection of bare and enzyme-covered single EISCAPs in diverse combinations. As predicted by the model, with increasing the enzyme coverage, both the shift of capacitance-voltage curves and the amplitude of the constant-capacitance signal increase, resulting in an enhancement of analyte sensitivity of the EISCAP biosensor. In addition, the capability of the multicell arrangement with multi-enzyme covered EISCAPs for sequentially detecting multianalytes (penicillin and urea) utilizing the enzymes penicillinase and urease has been experimentally demonstrated and discussed.}, language = {en} } @article{SchoeningKurowskiThustetal.2000, author = {Sch{\"o}ning, Michael Josef and Kurowski, A. and Thust, M. and Kordos, P. and Schultze, J. W. and L{\"u}th, H.}, title = {Capacitive microsensors for biochemical sensing on porous silicon technology}, series = {Sensors and Actuators B. 64 (2000), H. 1-3}, journal = {Sensors and Actuators B. 64 (2000), H. 1-3}, isbn = {0925-4005}, pages = {59 -- 64}, year = {2000}, language = {en} } @article{SchoeningThustKordosetal.2000, author = {Sch{\"o}ning, Michael Josef and Thust, M. and Kordos, P. and Schultze, J.W. and L{\"u}th, H.}, title = {Capacitive microsensors for biochemical sensing based on porous silicon technology}, series = {Transducers '99 : proceedings of the Tenth International Conference on Solid-State Sensors and Actuators ; 7 - 10 June, 1999, Sendai, Japan / ed.: S. Middelhoek}, journal = {Transducers '99 : proceedings of the Tenth International Conference on Solid-State Sensors and Actuators ; 7 - 10 June, 1999, Sendai, Japan / ed.: S. Middelhoek}, publisher = {Elsevier}, address = {Amsterdam [u.a.]}, pages = {1184 -- 1187}, year = {2000}, language = {en} } @article{JablonskiMuenstermannNorketal.2021, author = {Jablonski, Melanie and M{\"u}nstermann, Felix and Nork, Jasmina and Molinnus, Denise and Muschallik, Lukas and Bongaerts, Johannes and Wagner, Torsten and Keusgen, Michael and Siegert, Petra and Sch{\"o}ning, Michael Josef}, title = {Capacitive field-effect biosensor applied for the detection of acetoin in alcoholic beverages and fermentation broths}, series = {physica status solidi (a) applications and materials science}, volume = {218}, journal = {physica status solidi (a) applications and materials science}, number = {13}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1862-6319}, doi = {10.1002/pssa.202000765}, pages = {7 Seiten}, year = {2021}, abstract = {An acetoin biosensor based on a capacitive electrolyte-insulator-semiconductor (EIS) structure modified with the enzyme acetoin reductase, also known as butane-2,3-diol dehydrogenase (Bacillus clausii DSM 8716ᵀ), is applied for acetoin detection in beer, red wine, and fermentation broth samples for the first time. The EIS sensor consists of an Al/p-Si/SiO₂/Ta₂O₅ layer structure with immobilized acetoin reductase on top of the Ta₂O₅ transducer layer by means of crosslinking via glutaraldehyde. The unmodified and enzyme-modified sensors are electrochemically characterized by means of leakage current, capacitance-voltage, and constant capacitance methods, respectively.}, language = {en} } @article{BuniatyanMatirosyanAbouzaretal.2009, author = {Buniatyan, Vahe V. and Matirosyan, N. and Abouzar, Maryam H. and Schubert, J. and Zander, W. and Gevorgian, S. and Sch{\"o}ning, Michael Josef and Poghossian, Arshak}, title = {Capacitive field-effect pH sensor based on an electrolyte-ferroelectric-insulator-semiconductor structure}, series = {SENSOR 2009 : : 14th International Conference on Sensors, Technologies, Electronics and Applications; N{\"u}rnberg, Germany, 26 - 28 May 2009; proceedings; [part of] Sensor + Test Conference 2009 / AMA, Fachverband f{\"u}r Sensorik e.V}, journal = {SENSOR 2009 : : 14th International Conference on Sensors, Technologies, Electronics and Applications; N{\"u}rnberg, Germany, 26 - 28 May 2009; proceedings; [part of] Sensor + Test Conference 2009 / AMA, Fachverband f{\"u}r Sensorik e.V}, publisher = {AMA Service}, address = {Wunstorf}, isbn = {9783981099355}, pages = {317 -- 322}, year = {2009}, language = {en} } @article{PoghossianSchoening2020, author = {Poghossian, Arshak and Sch{\"o}ning, Michael Josef}, title = {Capacitive field-effect eis chemical sensors and biosensors: A status report}, series = {Sensors}, volume = {20}, journal = {Sensors}, number = {19}, publisher = {MDPI}, address = {Basel}, issn = {1424-8220}, doi = {10.3390/s20195639}, pages = {Artikel 5639}, year = {2020}, abstract = {Electrolyte-insulator-semiconductor (EIS) field-effect sensors belong to a new generation of electronic chips for biochemical sensing, enabling a direct electronic readout. The review gives an overview on recent advances and current trends in the research and development of chemical sensors and biosensors based on the capacitive field-effect EIS structure—the simplest field-effect device, which represents a biochemically sensitive capacitor. Fundamental concepts, physicochemical phenomena underlying the transduction mechanism and application of capacitive EIS sensors for the detection of pH, ion concentrations, and enzymatic reactions, as well as the label-free detection of charged molecules (nucleic acids, proteins, and polyelectrolytes) and nanoparticles, are presented and discussed.}, language = {en} } @article{JablonskiPoghossianSeverinetal.2021, author = {Jablonski, Melanie and Poghossian, Arshak and Severin, Robin and Keusgen, Michael and Wege, Christian and Sch{\"o}ning, Michael Josef}, title = {Capacitive Field-Effect Biosensor Studying Adsorption of Tobacco Mosaic Virus Particles}, series = {Micromachines}, volume = {12}, journal = {Micromachines}, number = {1}, publisher = {MDPI}, address = {Basel}, doi = {10.3390/mi12010057}, pages = {Artikel 57}, year = {2021}, abstract = {Plant virus-like particles, and in particular, tobacco mosaic virus (TMV) particles, are increasingly being used in nano- and biotechnology as well as for biochemical sensing purposes as nanoscaffolds for the high-density immobilization of receptor molecules. The sensitive parameters of TMV-assisted biosensors depend, among others, on the density of adsorbed TMV particles on the sensor surface, which is affected by both the adsorption conditions and surface properties of the sensor. In this work, Ta₂O₅-gate field-effect capacitive sensors have been applied for the label-free electrical detection of TMV adsorption. The impact of the TMV concentration on both the sensor signal and the density of TMV particles adsorbed onto the Ta₂O₅-gate surface has been studied systematically by means of field-effect and scanning electron microscopy methods. In addition, the surface density of TMV particles loaded under different incubation times has been investigated. Finally, the field-effect sensor also demonstrates the label-free detection of penicillinase immobilization as model bioreceptor on TMV particles.}, language = {en} }