Catalytic Surfaces for Electroanalysis
Published Online: 15 SEP 2009
Copyright © 2000 John Wiley & Sons, Ltd. All rights reserved.
Encyclopedia of Analytical Chemistry
How to Cite
Cox, J. A. and Kulesza, P. J. 2009. Catalytic Surfaces for Electroanalysis. Encyclopedia of Analytical Chemistry. .
- Published Online: 15 SEP 2009
In this article, electrochemical determinations based on oxidation or reduction processes that require a catalyst to obtain a current proportional to analyte concentration are described. The scope is restricted to cases where the catalyst is immobilized at the electrode surface. In general, oxidation or reduction of a substance at an electrode surface can be the basis of an analytical method as long as the electron-transfer reaction occurs in the potential window between redox of the solvent, supporting electrolyte, and/or the electrode material. The need for a catalyst arises because only a small fraction of solutes that are predicted on the basis of standard potentials to undergo redox in an available potential window are electrolyzed in the absence of a catalyst at a sufficient rate to provide an analytically useful current. As described later, the common mode of promotion of the rate of electron transfer is by mediation. A problem that results when immobilized mediators are used is that the potential at which the current is produced is related to the mediator as well as to the analytes; hence, many practical applications of catalytic surfaces involve electrochemical detection after separation by methods such as high-performance liquid chromatography (HPLC).
- electrochemical catalysis;
- chemically modified electrode;
- pulsed electrochemical detection;
- potentiostatic detection;
- hydrodynamic voltammetry