Chapter 6: The Essential Role of Electrode Materials in ECL Applications

Electrochemiluminescence (ECL) is a phenomenon that occurs in the proximity of the electrode surface, since the radicals involved in the formation of the light-emitting excited states are generated after an electrochemical stimulus. The choice of the electrode material is crucial for the light generation, because it influences the kinetic of the heterogeneous electron transfer reaction. For this reason, the deep understanding of the whole ECL system, of the relative target application under development, is of fundamental importance for the proper choice of the electrode material. In the present chapter, different electrode materials are reported for different ECL applications, ranging from noble gold electrodes, through transparent electrodes for ECL and microscopy techniques combination, to carbon-based electrodes, which present fast kinetics for coreactant oxidation. Their electrochemical behaviour and their ECL efficiencies have been reported mainly with [Ru(bpy)3]2+/TPrA coreactant system in “oxidative-reduction” mechanism, but other coreactants have been used, such as peroxydisulfate and benzoyl peroxide in “reductive-oxidation” mechanism. A comprehensive and exhaustive electrochemical study of the above-written materials will be presented in the next pages.