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 and Bioelectronics, 22 (7). pp. 1466-1473. ISSN 0956-5663

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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-μm 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 (∼20 nM) compared with the corresponding PEI-free configurations (Pt/GluOx/PPD), without undermining their fast response time (∼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.

Item Type:	Article
Keywords:	Glutamate oxidase; Polyethyleneimine; PEI; Poly(o-phenylenediamine); PPD; Michaelis–Menten; Brain monitoring; Neurochemistry;
Academic Unit:	Faculty of Science and Engineering > Chemistry
Item ID:	8037
Identification Number:	https://doi.org/10.1016/j.bios.2006.06.027
Depositing User:	John Lowry
Date Deposited:	22 Mar 2017 16:54
Journal or Publication Title:	Biosensors and Bioelectronics
Publisher:	Elsevier
Refereed:	Yes
Funders:	Science Foundation Ireland (SFI)
URI:	http://www.sciencedirect.com
Use Licence:	This item is available under a Creative Commons Attribution Non Commercial Share Alike Licence (CC BY-NC-SA). Details of this licence are available here

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