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Catalytic Surfaces for Electroanalysis

Electroanalytical Methods

  1. James A. Cox1,
  2. Pawel J. Kulesza2

Published Online: 15 SEP 2009

DOI: 10.1002/9780470027318.a9075

Encyclopedia of Analytical Chemistry

Encyclopedia of Analytical Chemistry

How to Cite

Cox, J. A. and Kulesza, P. J. 2009. Catalytic Surfaces for Electroanalysis. Encyclopedia of Analytical Chemistry. .

Author Information

  1. 1

    Miami University, Oxford, OH, USA

  2. 2

    University of Warsaw, Warsaw, Poland

Publication History

  1. Published Online: 15 SEP 2009

Abstract

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).

Keywords:

  • electrochemical catalysis;
  • mediation;
  • chemically modified electrode;
  • pulsed electrochemical detection;
  • potentiostatic detection;
  • hydrodynamic voltammetry