Designing ionic-liquid based practical reference electrode

Abstract

The design of a solid state practical reference electrode, consisting of very simple fabrication steps has been reported. A composite of graphite and poly (methyl methacrylate) [named as plastic chip electrode (PCE)] has been used as a platform for fabrication of these refererence electrodes [the plastic chip reference electrodes (PCRE)]. The bare PCE is coated with silver paint, AgCl mixture on one edge, above which hydrophobic ionic liquid is used as junction. Various compositions of ionic-liquid at junction have been tried and its effect on the electrode potential is studied. The reference electrode has been characterized for its open circuit potential, shelf-life and resusability. The practical application of these prototype reference electrode is tested in potentiometry as well as in voltammetry applications.The performance of PCRE is found to be similar to standard Ag/AgCl reference electrode with 190 mV cathodic potential shift.