Metal Oxides as Possible Faradaic Pseudo-Reference Electrodes

Abstract

Various metal oxides (MOx's), formed either as composites or films, were studied as possible materials for the fabrication of a faradaic pseudo reference electrode ( FPRE ). The basis of the reference was the constant current electrolysis of water to oxygen where the potential depended logarithmically on the current due to the irreversibility of the electrode reaction. It was anticipated, that with judicious choice of the MOx and the current level, that interferences could be minimized in comparison with a reversible, potentiometric reference electrode, particularly for in-vivo application. The properties of Ru02 on Ti substrate or as a composite (graphite/Kel-F), Pt, and Pt particles dispersed in a polymer film on glassy carbon were investigated as possible FPRE. In the case of Pt, the surface of the electrode is assumed to be platinum oxide at anodic potentials.