Welden, MelaniePoghossian, ArshakVahidpour, FarnooshWendlandt, TimKeusgen, MichaelWege, ChristinaSchöning, Michael J.2022-11-092022-11-0920222079-63741823285724http://nbn-resolving.de/urn:nbn:de:bsz:93-opus-ds-125174http://elib.uni-stuttgart.de/handle/11682/12517http://dx.doi.org/10.18419/opus-12498Utilizing an appropriate enzyme immobilization strategy is crucial for designing enzyme-based biosensors. Plant virus-like particles represent ideal nanoscaffolds for an extremely dense and precise immobilization of enzymes, due to their regular shape, high surface-to-volume ratio and high density of surface binding sites. In the present work, tobacco mosaic virus (TMV) particles were applied for the co-immobilization of penicillinase and urease onto the gate surface of a field-effect electrolyte-insulator-semiconductor capacitor (EISCAP) with a p-Si-SiO2-Ta2O5 layer structure for the sequential detection of penicillin and urea. The TMV-assisted bi-enzyme EISCAP biosensor exhibited a high urea and penicillin sensitivity of 54 and 85 mV/dec, respectively, in the concentration range of 0.1–3 mM. For comparison, the characteristics of single-enzyme EISCAP biosensors modified with TMV particles immobilized with either penicillinase or urease were also investigated. The surface morphology of the TMV-modified Ta2O5-gate was analyzed by scanning electron microscopy. Additionally, the bi-enzyme EISCAP was applied to mimic an XOR (Exclusive OR) enzyme logic gate.eninfo:eu-repo/semantics/openAccesshttps://creativecommons.org/licenses/by/4.0/570article2022-02-05