Ag/AgI quasi-reference microelectrodes

Miniaturization of conventional Ag/AgCl macroscopic electrodes for their integration in chemical microsensors has given rise to several troubles that have reduced the durability and reliability of the reference potential. In this work, Ag/AgI quasi-reference microelectrodes are proposed as an alternative to Ag/AgCl electrodes in order to improve their stability and durability. The fabrication process of the developed samples has been defined in the silicon planar technology field. Silver layer electrodeposition and iodation parameters have been specially studied in order to optimize these fabrication processes. Ag and AgI layers composition, grain size and porosity have been analysed by SEM and EDAX techniques. Additionally, voltage measurements between developed quasi-reference microelectrodes and a commercial SCE macroelectrode have been obtained to determine the former stability.