ABSTRACT
Spectroelectrochemistry has proven to be a very powerful technique for the study of redox processes in terms of its ability to provide optical data that is complementary in nature to standard current or potential measurements [1, 2]. Absorbance spectroelectrochemistry suffers from the disadvantage of poor sensitivity, however, limiting its use in the characterization of thin (monolayer) films. Recently, spectroelectrochemistry has been performed at the surface of an integrated optical waveguide (IOW) to allow for the ultrasensitive characterization of redox behavior in thin film materials at monolayer surface coverage or less [3-5]. This review focuses on the development and use of the electroactive integrated optical waveguide (the EA-IOW), a multilayer, step-index, single-mode IOW that possesses a transparent metal oxide film as the top layer that functions as a working electrode [5]. With the EA-IOW, changes in absorbance at the surface of this electrode can be monitored with a sensitivity of up to 4000 times that of a single-pass transmission spectroelectrochemical experiment.
