TY - JOUR A1 - Koch, Claudia A1 - Poghossian, Arshak A1 - Schöning, Michael Josef A1 - Wege, Christian T1 - Penicillin Detection by Tobacco Mosaic Virus-Assisted Colorimetric Biosensors JF - Nanotheranostics N2 - The presentation of enzymes on viral scaffolds has beneficial effects such as an increased enzyme loading and a prolonged reusability in comparison to conventional immobilization platforms. Here, we used modified tobacco mosaic virus (TMV) nanorods as enzyme carriers in penicillin G detection for the first time. Penicillinase enzymes were conjugated with streptavidin and coupled to TMV rods by use of a bifunctional biotin-linker. Penicillinase-decorated TMV particles were characterized extensively in halochromic dye-based biosensing. Acidometric analyte detection was performed with bromcresol purple as pH indicator and spectrophotometry. The TMV-assisted sensors exhibited increased enzyme loading and strongly improved reusability, and higher analysis rates compared to layouts without viral adapters. They extended the half-life of the sensors from 4 - 6 days to 5 weeks and thus allowed an at least 8-fold longer use of the sensors. Using a commercial budget-priced penicillinase preparation, a detection limit of 100 µM penicillin was obtained. Initial experiments also indicate that the system may be transferred to label-free detection layouts. Y1 - 2018 U6 - http://dx.doi.org/10.7150/ntno.22114 SN - 2206-7418 VL - 2 IS - 2 SP - 184 EP - 196 PB - Ivyspring CY - Sydney ER - TY - JOUR A1 - Poghossian, Arshak A1 - Jablonski, Melanie A1 - Koch, Claudia A1 - Bronder, Thomas A1 - Rolka, David A1 - Wege, Christina A1 - Schöning, Michael Josef T1 - Field-effect biosensor using virus particles as scaffolds for enzyme immobilization JF - Biosensors and Bioelectronics N2 - A field-effect biosensor employing tobacco mosaic virus (TMV) particles as scaffolds for enzyme immobilization is presented. Nanotubular TMV scaffolds allow a dense immobilization of precisely positioned enzymes with retained activity. To demonstrate feasibility of this new strategy, a penicillin sensor has been developed by coupling a penicillinase with virus particles as a model system. The developed field-effect penicillin biosensor consists of an Al-p-Si-SiO₂-Ta₂O₅-TMV structure and has been electrochemically characterized in buffer solutions containing different concentrations of penicillin G. In addition, the morphology of the biosensor surface with virus particles was characterized by scanning electron microscopy and atomic force microscopy methods. The sensors possessed a high penicillin sensitivity of ~ 92 mV/dec in a nearly-linear range from 0.1 mM to 10 mM, and a low detection limit of about 50 µM. The long-term stability of the penicillin biosensor was periodically tested over a time period of about one year without any significant loss of sensitivity. The biosensor has also been successfully applied for penicillin detection in bovine milk samples. Y1 - 2018 U6 - http://dx.doi.org/10.1016/j.bios.2018.03.036 SN - 0956-5663 VL - 110 SP - 168 EP - 174 PB - Elsevier CY - Amsterdam ER - TY - BOOK A1 - Schöning, Michael Josef A1 - Poghossian, Arshak T1 - Label-free biosensing: advanced materials, devices and applications Y1 - 2018 SN - 978-3-319-75219-8 PB - Springer CY - Cham ER - TY - CHAP A1 - Yoshinobu, Tatsuo A1 - Krause, Steffi A1 - Miyamoto, Ko-ichiro A1 - Werner, Frederik A1 - Poghossian, Arshak A1 - Wagner, Torsten A1 - Schöning, Michael Josef T1 - (Bio-)chemical Sensing and Imaging by LAPS and SPIM T2 - Label-free biosensing: advanced materials, devices and applications N2 - The light-addressable potentiometric sensor (LAPS) and scanning photo-induced impedance microscopy (SPIM) are two closely related methods to visualise the distributions of chemical species and impedance, respectively, at the interface between the sensing surface and the sample solution. They both have the same field-effect structure based on a semiconductor, which allows spatially resolved and label-free measurement of chemical species and impedance in the form of a photocurrent signal generated by a scanning light beam. In this article, the principles and various operation modes of LAPS and SPIM, functionalisation of the sensing surface for measuring various species, LAPS-based chemical imaging and high-resolution sensors based on silicon-on-sapphire substrates are described and discussed, focusing on their technical details and prospective applications. KW - Chemical imaging KW - Field-effect device KW - Light-addressable potentiometric sensor KW - Potentiometry Y1 - 2018 SN - 978-3-319-75219-8 SP - 103 EP - 132 PB - Springer CY - Cham ER - TY - CHAP A1 - Schöning, Michael Josef A1 - Poghossian, Arshak T1 - Enzyme und Biosensorik T2 - Einführung in die Enzymtechnologie N2 - Enzymbasierte Biosensoren finden seit mehr als fünf Jahrzehnten einen prosperierenden Wachstumsmarkt und werden zunehmend auch in biotechnologischen Prozessen eingesetzt. In diesem Kapitel werden, ausgehend vom Sensorbegriff und typischen Kenngrößen für Biosensoren (Abschn. 18.1), elektrochemische Enzym-Biosensoren vorgestellt und deren typischen Einsatzgebiete diskutiert (Abschn. 18.2). Ein Blick über den „Tellerrand“ hinaus zeigt alternative Transduktorprinzipien (Abschn. 18.3) und führt abschließend in aktuelle Forschungstrends ein (Abschn. 18.4). Y1 - 2018 SN - 978-3-662-57619-9 U6 - http://dx.doi.org/10.1007/978-3-662-57619-9_18 SP - 323 EP - 347 PB - Springer Spektrum CY - Berlin ER - TY - CHAP A1 - Schöning, Michael Josef A1 - Wagner, Torsten A1 - Poghossian, Arshak A1 - Miyamoto, K.I. A1 - Werner, C.F. A1 - Krause, S. A1 - Yoshinobu, T. T1 - Light-addressable potentiometric sensors for (bio-)chemical sensing and imaging T2 - Encyclopedia of Interfacial Chemistry: Surface Science and Electrochemistry. Vol. 7 Y1 - 2018 SN - 9780128097397 SP - 295 EP - 308 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Bronder, Thomas A1 - Poghossian, Arshak A1 - Jessing, Max P. A1 - Keusgen, Michael A1 - Schöning, Michael Josef T1 - Surface regeneration and reusability of label-free DNA biosensors based on weak polyelectrolyte-modified capacitive field-effect structures JF - Biosensors and Bioelectronics Y1 - 2019 U6 - http://dx.doi.org/10.1016/j.bios.2018.11.019 SN - 0956-5663 VL - 126 SP - 510 EP - 517 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Poghossian, Arshak A1 - Geissler, Hanno A1 - Schöning, Michael Josef T1 - Rapid methods and sensors for milk quality monitoring and spoilage detection JF - Biosensors and Bioelectronics Y1 - 2019 U6 - http://dx.doi.org/10.1016/j.bios.2019.04.040 SN - 0956-5663 VL - 140 IS - Article 111272 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Poghossian, Arshak A1 - Jablonski, Melanie A1 - Molinnus, Denise A1 - Wege, Christina A1 - Schöning, Michael Josef T1 - Field-Effect Sensors for Virus Detection: From Ebola to SARS-CoV-2 and Plant Viral Enhancers JF - Frontiers in Plant Science N2 - Coronavirus disease 2019 (COVID-19) is a novel human infectious disease provoked by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Currently, no specific vaccines or drugs against COVID-19 are available. Therefore, early diagnosis and treatment are essential in order to slow the virus spread and to contain the disease outbreak. Hence, new diagnostic tests and devices for virus detection in clinical samples that are faster, more accurate and reliable, easier and cost-efficient than existing ones are needed. Due to the small sizes, fast response time, label-free operation without the need for expensive and time-consuming labeling steps, the possibility of real-time and multiplexed measurements, robustness and portability (point-of-care and on-site testing), biosensors based on semiconductor field-effect devices (FEDs) are one of the most attractive platforms for an electrical detection of charged biomolecules and bioparticles by their intrinsic charge. In this review, recent advances and key developments in the field of label-free detection of viruses (including plant viruses) with various types of FEDs are presented. In recent years, however, certain plant viruses have also attracted additional interest for biosensor layouts: Their repetitive protein subunits arranged at nanometric spacing can be employed for coupling functional molecules. If used as adapters on sensor chip surfaces, they allow an efficient immobilization of analyte-specific recognition and detector elements such as antibodies and enzymes at highest surface densities. The display on plant viral bionanoparticles may also lead to long-time stabilization of sensor molecules upon repeated uses and has the potential to increase sensor performance substantially, compared to conventional layouts. This has been demonstrated in different proof-of-concept biosensor devices. Therefore, richly available plant viral particles, non-pathogenic for animals or humans, might gain novel importance if applied in receptor layers of FEDs. These perspectives are explained and discussed with regard to future detection strategies for COVID-19 and related viral diseases. Y1 - 2020 U6 - http://dx.doi.org/10.3389/fpls.2020.598103 VL - 11 IS - Article 598103 SP - 1 EP - 14 PB - Frontiers CY - Lausanne ER - TY - JOUR A1 - Poghossian, Arshak A1 - Schöning, Michael Josef T1 - Capacitive field-effect eis chemical sensors and biosensors: A status report JF - Sensors N2 - 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. Y1 - 2020 U6 - http://dx.doi.org/10.3390/s20195639 SN - 1424-8220 VL - 20 IS - 19 PB - MDPI CY - Basel ER -