Chronoamperometry on ring, ring-recessed and disk electrodes, and their arrays. The sensitive measurement of diffusion coefficients independent of a knowledge of concentration or number of electrons transferred

Abstract

Theory of chronoamperometry on ring-recessed microelectrodes and their arrays is presented. Analysis of the current transients measured at thin rings and their arrays shows that chronoamperometry at such devices is an excellent method of simultaneous measurement of the diffusion coefficient D and the product n[A], where n is the number of electrons transferred and [A] is the concentration of electroactive analyte. A generic, accurate and easy to use method of experimental chronoamperometric data analysis is proposed. It is shown that the method can be applied to the simultaneous measurement of D and n[A] in solution. The method is shown to be applicable to an analysis of data recorded at single disk and ring electrodes as well as arrays of these electrodes even in the case of diffusional non-independence of electrodes in the array.