Yongju Jung and Juhyoun Kwak, "Simultaneous Determination of Diffusion Coefficient and Concentration by Chronoamperometry at a Microdisk Electrode," Bull. Korean Chem. Soc., 15 (3), 209 - 213 (1994.03.20.)

Abstract
We propose a new electroanalytical method by which two unknown values among three electrochemical values, i.e. electrode area, diffusion coefficient, and concentration, can be simultaneously obtained by nonlinear regression analysis of a single chronoamperometric faradaic current curve at a microelectrode of disk shape. It is an analytical application of the semi-empirical equation presented by Shoup and Szabo for the chronoamperometric response at a disk electrode. To demonstrate the usefulness and accuracy of this new method, the chronoamperometric current at a platinum disk electrode of 50 mm radius in solutions of Ru(NH3)63+, ferrocene, Fe(CN)63-, and C60, were analyzed.