5.1 INTRODUCTION

Solid electrodes have been a mainstay in electroanalytical chemistry for nearly five decades now (1). For a solid material to function as an electrochemical electrode, it must possess several characteristics: electrical conductivity, chemical and electrochemical stability over a wide range of conditions, rapid electron transfer for a wide variety of redox systems, and reproducible electrical, microstructural, and chemical properties. Table 5.1 lists some desirable electrode properties for materials used in electroanalytical measurements. A challenge with making high-quality electroanalytical measurements is reproducibly controlling the electrode's physicochemical properties in such a way as to achieve a low background current and a rapid rate of electron transfer for the target analyte. Electrodes exhibiting these properties are referred to as being "active" or in an "activated state". Activation is accomplished by a process known as electrode pretreatment, which involves conditioning the surface morphology, microstructure, and chemistry in a manner that promotes low background current and rapid reaction kinetics (both electron and proton transfer) with a redox analyte dissolved in solution or confined to the surface.

Electrochemical reactions...