@article{HuckSchiffelsHerreraetal.2013,
  author    = {Huck, Christina and Schiffels, Johannes and Herrera, Cony N. and Schelden, Maximilian and Selmer, Thorsten and Poghossian, Arshak and Baumann, Marcus and Wagner, Patrick and Sch{\"o}ning, Michael Josef},
  title     = {Metabolic responses of Escherichia coli upon glucose pulses captured by a capacitive field-effect sensor},
  series = {Physica Status Solidi (A)},
  volume    = {210},
  journal   = {Physica Status Solidi (A)},
  number    = {5},
  publisher = {Wiley-VCH},
  address   = {Weinheim},
  issn      = {0031-8965},
  doi       = {10.1002/pssa.201200900},
  pages     = {926 -- 931},
  year      = {2013},
  abstract  = {Living cells are complex biological systems transforming metabolites taken up from the surrounding medium. Monitoring the responses of such cells to certain substrate concentrations is a challenging task and offers possibilities to gain insight into the vitality of a community influenced by the growth environment. Cell-based sensors represent a promising platform for monitoring the metabolic activity and thus, the "welfare" of relevant organisms. In the present study, metabolic responses of the model bacterium Escherichia coli in suspension, layered onto a capacitive field-effect structure, were examined to pulses of glucose in the concentration range between 0.05 and 2 mM. It was found that acidification of the surrounding medium takes place immediately after glucose addition and follows Michaelis-Menten kinetic behavior as a function of the glucose concentration. In future, the presented setup can, therefore, be used to study substrate specificities on the enzymatic level and may as well be used to perform investigations of more complex metabolic responses. Conclusions and perspectives highlighting this system are discussed.},
  language  = {en}
}
@article{IngebrandtHanNakamuraetal.2007,
  author    = {Ingebrandt, S. and Han, Y. and Nakamura, F. and Poghossian, Arshak and Sch{\"o}ning, Michael Josef and Offenh{\"a}usser, A.},
  title     = {Label-free detection of single nucleotide polymorphisms utilizing the differential transfer function of field-effect transistors},
  series = {Biosensors and Bioelectronics. 22 (2007), H. 12},
  journal   = {Biosensors and Bioelectronics. 22 (2007), H. 12},
  isbn      = {0956-5663},
  pages     = {2834 -- 2840},
  year      = {2007},
  language  = {en}
}
@inproceedings{JablonskiKochBronderetal.2017,
  author    = {Jablonski, Melanie and Koch, Claudia and Bronder, Thomas and Poghossian, Arshak and Wege, Christina and Sch{\"o}ning, Michael Josef},
  title     = {Field-Effect Biosensors Modified with Tobacco Mosaic Virus Nanotubes as Enzyme Nanocarrier},
  series = {MDPI Proceeding},
  volume    = {1},
  booktitle = {MDPI Proceeding},
  number    = {4},
  doi       = {10.3390/proceedings1040505},
  pages     = {4},
  year      = {2017},
  language  = {en}
}
@article{JablonskiPoghossianKeusgenetal.2021,
  author    = {Jablonski, Melanie and Poghossian, Arshak and Keusgen, Michael and Wege, Christina and Sch{\"o}ning, Michael Josef},
  title     = {Detection of plant virus particles with a capacitive field-effect sensor},
  series = {Analytical and Bioanalytical Chemistry},
  volume    = {413},
  journal   = {Analytical and Bioanalytical Chemistry},
  publisher = {Springer Nature},
  address   = {Cham},
  issn      = {1618-2650},
  doi       = {10.1007/s00216-021-03448-8},
  pages     = {5669 -- 5678},
  year      = {2021},
  abstract  = {Plant viruses are major contributors to crop losses and induce high economic costs worldwide. For reliable, on-site and early detection of plant viral diseases, portable biosensors are of great interest. In this study, a field-effect SiO2-gate electrolyte-insulator-semiconductor (EIS) sensor was utilized for the label-free electrostatic detection of tobacco mosaic virus (TMV) particles as a model plant pathogen. The capacitive EIS sensor has been characterized regarding its TMV sensitivity by means of constant-capacitance method. The EIS sensor was able to detect biotinylated TMV particles from a solution with a TMV concentration as low as 0.025 nM. A good correlation between the registered EIS sensor signal and the density of adsorbed TMV particles assessed from scanning electron microscopy images of the SiO2-gate chip surface was observed. Additionally, the isoelectric point of the biotinylated TMV particles was determined via zeta potential measurements and the influence of ionic strength of the measurement solution on the TMV-modified EIS sensor signal has been studied.},
  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}
}
@article{KarschuckKaulenPoghossianetal.2021,
  author    = {Karschuck, Tobias and Kaulen, Corinna and Poghossian, Arshak and Wagner, Patrick H. and Sch{\"o}ning, Michael Josef},
  title     = {Gold nanoparticle-modified capacitive field-effect sensors: Studying the surface density of nanoparticles and coupling of charged polyelectrolyte macromolecules},
  series = {Electrochemical Science Advances},
  volume    = {2},
  journal   = {Electrochemical Science Advances},
  number    = {5},
  publisher = {Wiley-VCH},
  address   = {Weinheim},
  issn      = {0938-5193},
  doi       = {10.1002/elsa.202100179},
  pages     = {10 Seiten},
  year      = {2021},
  abstract  = {The coupling of ligand-stabilized gold nanoparticles with field-effect devices offers new possibilities for label-free biosensing. In this work, we study the immobilization of aminooctanethiol-stabilized gold nanoparticles (AuAOTs) on the silicon dioxide surface of a capacitive field-effect sensor. The terminal amino group of the AuAOT is well suited for the functionalization with biomolecules. The attachment of the positively-charged AuAOTs on a capacitive field-effect sensor was detected by direct electrical readout using capacitance-voltage and constant capacitance measurements. With a higher particle density on the sensor surface, the measured signal change was correspondingly more pronounced. The results demonstrate the ability of capacitive field-effect sensors for the non-destructive quantitative validation of nanoparticle immobilization. In addition, the electrostatic binding of the polyanion polystyrene sulfonate to the AuAOT-modified sensor surface was studied as a model system for the label-free detection of charged macromolecules. Most likely, this approach can be transferred to the label-free detection of other charged molecules such as enzymes or antibodies.},
  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{KarschuckSchmidtAchtsnichtetal.2023,
  author    = {Karschuck, Tobias and Schmidt, Stefan and Achtsnicht, Stefan and Poghossian, Arshak and Wagner, Patrick and Sch{\"o}ning, Michael Josef},
  title     = {Multiplexing system for automated characterization of a capacitive field-effect sensor array},
  series = {Physica Status Solidi A},
  volume    = {220},
  journal   = {Physica Status Solidi A},
  number    = {22},
  publisher = {Wiley-VCH},
  address   = {Weinheim},
  issn      = {1862-6300 (Print)},
  doi       = {10.1002/pssa.202300265},
  pages     = {7 Seiten},
  year      = {2023},
  abstract  = {In comparison to single-analyte devices, multiplexed systems for a multianalyte detection offer a reduced assay time and sample volume, low cost, and high throughput. Herein, a multiplexing platform for an automated quasi-simultaneous characterization of multiple (up to 16) capacitive field-effect sensors by the capacitive-voltage (C-V) and the constant-capacitance (ConCap) mode is presented. The sensors are mounted in a newly designed multicell arrangement with one common reference electrode and are electrically connected to the impedance analyzer via the base station. A Python script for the automated characterization of the sensors executes the user-defined measurement protocol. The developed multiplexing system is tested for pH measurements and the label-free detection of ligand-stabilized, charged gold nanoparticles.},
  language  = {en}
}
@article{KassabHanPoghossianetal.2004,
  author    = {Kassab, T. and Han, Y. and Poghossian, Arshak and Ingebrandt, S. and Offenh{\"a}usser, A. and Sch{\"o}ning, Michael Josef},
  title     = {Detection of layerby-layer adsorbed polyelectrolytes by means of field-effect based capacitive EIS structures},
  series = {Biomedizinische Technik. 49 (2004), H. 2},
  journal   = {Biomedizinische Technik. 49 (2004), H. 2},
  isbn      = {0932-4666},
  pages     = {1034 -- 1035},
  year      = {2004},
  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}
}