Biosensors were fabricated at neutral pH by sequentially depositing the polycation polyethyleneimine (PEI), the stereoselective enzyme L-glutamate oxidase (GluOx) and the permselective barrier poly-ortho-phenylenediamine (PPD) onto 125-microm diameter Pt wire electrodes (Pt/PEI/GluOx/PPD). These devices were calibrated amperometrically at 0.7 V versus SCE to determine the Michaelis-Menten parameters for enzyme substrate, l-glutamate (Glu) and co-substrate, dioxygen. The presence of PEI produced a 10-fold enhancement in the detection limit for Glu (approximately 20 nM) compared with the corresponding PEI-free configurations (Pt/GluOx/PPD), without undermining their fast response time (approximately 2 s). Most remarkable was the finding that, although some designs of PEI-containing biosensors showed a 10-fold increase in linear region sensitivity to Glu, their oxygen dependence remained low.

Control of the oxygen dependence of an implantable polymer/enzyme composite biosensor for glutamate / Mcmahon, Cp; Rocchitta, Gaia Giovanna Maria; Serra, Pier Andrea; Kirwan, Sm; Lowry, Jp; O'Neill, Rd. - In: ANALYTICAL CHEMISTRY. - ISSN 0003-2700. - 78:7(2006), pp. 2352-2359.

Control of the oxygen dependence of an implantable polymer/enzyme composite biosensor for glutamate

ROCCHITTA, Gaia Giovanna Maria;SERRA, Pier Andrea;
2006

Abstract

Biosensors were fabricated at neutral pH by sequentially depositing the polycation polyethyleneimine (PEI), the stereoselective enzyme L-glutamate oxidase (GluOx) and the permselective barrier poly-ortho-phenylenediamine (PPD) onto 125-microm diameter Pt wire electrodes (Pt/PEI/GluOx/PPD). These devices were calibrated amperometrically at 0.7 V versus SCE to determine the Michaelis-Menten parameters for enzyme substrate, l-glutamate (Glu) and co-substrate, dioxygen. The presence of PEI produced a 10-fold enhancement in the detection limit for Glu (approximately 20 nM) compared with the corresponding PEI-free configurations (Pt/GluOx/PPD), without undermining their fast response time (approximately 2 s). Most remarkable was the finding that, although some designs of PEI-containing biosensors showed a 10-fold increase in linear region sensitivity to Glu, their oxygen dependence remained low.
Control of the oxygen dependence of an implantable polymer/enzyme composite biosensor for glutamate / Mcmahon, Cp; Rocchitta, Gaia Giovanna Maria; Serra, Pier Andrea; Kirwan, Sm; Lowry, Jp; O'Neill, Rd. - In: ANALYTICAL CHEMISTRY. - ISSN 0003-2700. - 78:7(2006), pp. 2352-2359.
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11388/80237
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