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Oxygen tolerance of an implantable polymer/enzyme composite glutamate biosensor displaying polycation-enhanced substrate sensitivity

McMahon, Colm P. and Rocchitta, Gaia and Kirwan, Sarah M. and Killoran, Sarah J. and Serra, Pier A. and Lowry, John P. and O'Neill, Robert D. (2007) Oxygen tolerance of an implantable polymer/enzyme composite glutamate biosensor displaying polycation-enhanced substrate sensitivity. BIOSENSORS & BIOELECTRONICS, 22 (7). pp. 1466-1473. ISSN 0956-5663

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Official URL: http://www.sciencedirect.com/science?_ob=ArticleUR...

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-mu m 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 (similar to 20 nM) compared with the corresponding PEI-free configurations (Pt/GluOx/PPD), without undermining their fast response time (similar to 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. (c) 2006 Elsevier B.V. All rights reserved.

Item Type:Article
Uncontrolled Keywords:glutamate oxidase; polyethyleneimine; PEI; poly(o-phenylenediamine); PPD; Michaelis-Menten; brain monitoring; neurochemistry
Subjects:Biomedical Science > Nanomedicine
ID Code:2197
Deposited By:M T V
Deposited On:17 Dec 2008 15:48
Last Modified:17 Dec 2008 15:48

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