@article{BronderJessingPoghossianetal.2018, author = {Bronder, Thomas and Jessing, Max P. and Poghossian, Arshak and Keusgen, Michael and Sch{\"o}ning, Michael Josef}, title = {Detection of PCR-Amplified Tuberculosis DNA Fragments with Polyelectrolyte-Modified Field-Effect Sensors}, series = {Analytical Chemistry}, volume = {90}, journal = {Analytical Chemistry}, number = {12}, publisher = {ACS Publications}, address = {Washington, DC}, issn = {0003-2700}, doi = {10.1021/acs.analchem.8b01807}, pages = {7747 -- 7753}, year = {2018}, abstract = {Field-effect-based electrolyte-insulator-semiconductor (EIS) sensors were modified with a bilayer of positively charged weak polyelectrolyte (poly(allylamine hydrochloride) (PAH)) and probe single-stranded DNA (ssDNA) and are used for the detection of complementary single-stranded target DNA (cDNA) in different test solutions. The sensing mechanism is based on the detection of the intrinsic molecular charge of target cDNA molecules after the hybridization event between cDNA and immobilized probe ssDNA. The test solutions contain synthetic cDNA oligonucleotides (with a sequence of tuberculosis mycobacteria genome) or PCR-amplified DNA (which origins from a template DNA strand that has been extracted from Mycobacterium avium paratuberculosis-spiked human sputum samples), respectively. Sensor responses up to 41 mV have been measured for the test solutions with DNA, while only small signals of ∼5 mV were detected for solutions without DNA. The lower detection limit of the EIS sensors was ∼0.3 nM, and the sensitivity was ∼7.2 mV/decade. Fluorescence experiments using SybrGreen I fluorescence dye support the electrochemical results.}, language = {en} } @article{KochPoghossianSchoeningetal.2018, author = {Koch, Claudia and Poghossian, Arshak and Sch{\"o}ning, Michael Josef and Wege, Christian}, title = {Penicillin Detection by Tobacco Mosaic Virus-Assisted Colorimetric Biosensors}, series = {Nanotheranostics}, volume = {2}, journal = {Nanotheranostics}, number = {2}, publisher = {Ivyspring}, address = {Sydney}, issn = {2206-7418}, doi = {10.7150/ntno.22114}, pages = {184 -- 196}, year = {2018}, abstract = {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.}, language = {en} } @article{PoghossianJablonskiKochetal.2018, author = {Poghossian, Arshak and Jablonski, Melanie and Koch, Claudia and Bronder, Thomas and Rolka, David and Wege, Christina and Sch{\"o}ning, Michael Josef}, title = {Field-effect biosensor using virus particles as scaffolds for enzyme immobilization}, series = {Biosensors and Bioelectronics}, volume = {110}, journal = {Biosensors and Bioelectronics}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0956-5663}, doi = {10.1016/j.bios.2018.03.036}, pages = {168 -- 174}, year = {2018}, abstract = {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.}, language = {en} } @book{SchoeningPoghossian2018, author = {Sch{\"o}ning, Michael Josef and Poghossian, Arshak}, title = {Label-free biosensing: advanced materials, devices and applications}, publisher = {Springer}, address = {Cham}, isbn = {978-3-319-75219-8}, pages = {xii, 480 Seiten ; Illustrationen, Diagramme}, year = {2018}, language = {en} } @incollection{YoshinobuKrauseMiyamotoetal.2018, author = {Yoshinobu, Tatsuo and Krause, Steffi and Miyamoto, Ko-ichiro and Werner, Frederik and Poghossian, Arshak and Wagner, Torsten and Sch{\"o}ning, Michael Josef}, title = {(Bio-)chemical Sensing and Imaging by LAPS and SPIM}, series = {Label-free biosensing: advanced materials, devices and applications}, booktitle = {Label-free biosensing: advanced materials, devices and applications}, publisher = {Springer}, address = {Cham}, isbn = {978-3-319-75219-8}, pages = {103 -- 132}, year = {2018}, abstract = {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.}, language = {en} } @article{BronderPoghossianJessingetal.2019, author = {Bronder, Thomas and Poghossian, Arshak and Jessing, Max P. and Keusgen, Michael and Sch{\"o}ning, Michael Josef}, title = {Surface regeneration and reusability of label-free DNA biosensors based on weak polyelectrolyte-modified capacitive field-effect structures}, series = {Biosensors and Bioelectronics}, volume = {126}, journal = {Biosensors and Bioelectronics}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0956-5663}, doi = {10.1016/j.bios.2018.11.019}, pages = {510 -- 517}, year = {2019}, language = {en} } @article{PoghossianGeisslerSchoening2019, author = {Poghossian, Arshak and Geissler, Hanno and Sch{\"o}ning, Michael Josef}, title = {Rapid methods and sensors for milk quality monitoring and spoilage detection}, series = {Biosensors and Bioelectronics}, volume = {140}, journal = {Biosensors and Bioelectronics}, number = {Article 111272}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0956-5663}, doi = {10.1016/j.bios.2019.04.040}, year = {2019}, language = {en} } @incollection{SchoeningWagnerPoghossianetal.2018, author = {Sch{\"o}ning, Michael Josef and Wagner, Torsten and Poghossian, Arshak and Miyamoto, K.I. and Werner, C.F. and Krause, S. and Yoshinobu, T.}, title = {Light-addressable potentiometric sensors for (bio-)chemical sensing and imaging}, series = {Encyclopedia of Interfacial Chemistry: Surface Science and Electrochemistry. Vol. 7}, booktitle = {Encyclopedia of Interfacial Chemistry: Surface Science and Electrochemistry. Vol. 7}, publisher = {Elsevier}, address = {Amsterdam}, isbn = {9780128097397}, pages = {295 -- 308}, year = {2018}, language = {en} } @inproceedings{WeldenSeverinsPoghossianetal.2022, author = {Welden, Melanie and Severins, Robin and Poghossian, Arshak and Wege, Christina and Siegert, Petra and Keusgen, Michael and Sch{\"o}ning, Michael Josef}, title = {Studying the immobilization of acetoin reductase with Tobacco mosaic virus particles on capacitive field-effect sensors}, series = {2022 IEEE International Symposium on Olfaction and Electronic Nose (ISOEN)}, booktitle = {2022 IEEE International Symposium on Olfaction and Electronic Nose (ISOEN)}, publisher = {IEEE}, isbn = {978-1-6654-5860-3 (Online)}, doi = {10.1109/ISOEN54820.2022.9789657}, pages = {4 Seiten}, year = {2022}, abstract = {A capacitive electrolyte-insulator-semiconductor (EISCAP) biosensor modified with Tobacco mosaic virus (TMV) particles for the detection of acetoin is presented. The enzyme acetoin reductase (AR) was immobilized on the surface of the EISCAP using TMV particles as nanoscaffolds. The study focused on the optimization of the TMV-assisted AR immobilization on the Ta 2 O 5 -gate EISCAP surface. The TMV-assisted acetoin EISCAPs were electrochemically characterized by means of leakage-current, capacitance-voltage, and constant-capacitance measurements. The TMV-modified transducer surface was studied via scanning electron microscopy.}, language = {en} } @article{SchoeningBronderWuetal.2017, author = {Sch{\"o}ning, Michael Josef and Bronder, Thomas and Wu, Chunsheng and Scheja, Sabrina and Jessing, Max and Metzger-Boddien, Christoph and Keusgen, Michael and Poghossian, Arshak}, title = {Label-Free DNA Detection with Capacitive Field-Effect Devices—Challenges and Opportunities}, series = {Proceedings}, volume = {1}, journal = {Proceedings}, number = {8}, publisher = {MDPI}, address = {Basel}, issn = {2504-3900}, doi = {10.3390/proceedings1080719}, pages = {Artikel 719}, year = {2017}, abstract = {Field-effect EIS (electrolyte-insulator-semiconductor) sensors modified with a positively charged weak polyelectrolyte layer have been applied for the electrical detection of DNA (deoxyribonucleic acid) immobilization and hybridization by the intrinsic molecular charge. The EIS sensors are able to detect the existence of target DNA amplicons in PCR (polymerase chain reaction) samples and thus, can be used as tool for a quick verification of DNA amplification and the successful PCR process. Due to their miniaturized setup, compatibility with advanced micro- and nanotechnologies, and ability to detect biomolecules by their intrinsic molecular charge, those sensors can serve as possible platform for the development of label-free DNA chips. Possible application fields as well as challenges and limitations will be discussed.}, language = {en} }