Thin-Layer Spectroelectrochemistry on an Aqueous Microdrop

Abstract

Here we report a technique to perform thin layer spectroelectrochemistry using an aqueous microdrop. The chemical systems used to demonstrate the aqueous microdrop technique were an absorption based ionic probe [Fe(CN) 6] 3-/4- and an emission based ionic probe [Ru(bpy) 3] 3+/2+. The ability of the technique to perform semi-infinite linear diffusion spectroelectrochemistry on an aqueous microdrop has been previously demonstrated; in this work we were able to demonstrate spectroelectrochemical behavior consistent with the restricted diffusion in a thin layer cell by reducing the analyte volume and the optical path length. The thin-layer diffusion behavior was illustrated by substantial reduction in peak-to-peak separations of the cyclic voltammograms and the significant decrease in electrolysis time compared to the semi-infinite linear diffusion behavior. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.