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Comparisons of platinum, gold, palladium and glassy carbon as electrode materials in the design of biosensors for glutamate
O'Neill, Robert D.; Chang, Seung-Cheol; Lowry, John P.; McNeil, Calum J.
Four electrode materials: Pt, Au, Pd and glassy carbon (GC), were studied to investigate their suitability as substrates in the development of two different classes of glutamate biosensor. Glutamate oxidase cross-linked onto poly(o-phenylenediamine) was chosen as the type 1 biosensor (PPD/GluOx), incorporating PPD as the permselective element to detect H2O2 directly on the electrode surface at relatively high applied potentials. GluOx and horseradish peroxidase/redox polymer modified electrodes (Os2+PVP/HRP/GluOx) that relied on enzyme-catalysed H2O2 detection at lower applied potentials were used as type 2 biosensors. The voltammetric and amperometric responses to the enzyme signal transduction molecule, H2O2, and the archetypal interference species in biological applications, ascorbic acid, were determined on the bare and PPD/GluOx-modified surfaces. The amperometric responses of these electrodes were stable over several days of continuous recording in phosphate buffered saline (pH 7.4). The sensitivity of the type 1 biosensors to H2O2 and glutamate showed parallel trends with low limits of detection and good linearity at low concentrations: Pt>Au∼Pd⪢GC. Type 2 biosensors out-performed the type 1 design for all electrode substrates, except Pt. However, the presence of the permselective PPD membrane in the type 1 biosensors, not feasible in the type 2 design, suggests that Pt/PPD/GluOx might have the best all-round characteristics for glutamate detection in biological media containing interference species such as ascorbic acid. Other points affecting a final choice of substrate should include factors such as mass production issues.
Keyword(s): Poly(1; 2-diaminobenzene); Poly(phenylenediamine); Glutamate oxidase; Horseradish peroxidase; Os2+-polyvinylpyridine; Ascorbic acid; Amperometric detection; Cyclic voltammetry; Hydrogen peroxide
Publication Date:
Type: Journal article
Peer-Reviewed: Yes
Institution: Maynooth University
Citation(s): O'Neill, Robert D. and Chang, Seung-Cheol and Lowry, John P. and McNeil, Calum J. (2004) Comparisons of platinum, gold, palladium and glassy carbon as electrode materials in the design of biosensors for glutamate. Biosensors and Bioelectronics, 19 (11). pp. 1521-1528. ISSN 0956-5663
Publisher(s): Elsevier
File Format(s): other
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First Indexed: 2020-04-02 06:32:59 Last Updated: 2021-07-31 08:01:11