Effects of polymer thickness on the potentiometric pH responses of polypyrrole modified glassy carbon electrodes

The potentiometric pH response of electropolymerized polypyrrole modified g lassy carbon electrodes as a function of polymer film thickness was examine d. Electrodes coated with thicker polypyrrole films showed mixed potentiome tric responses toward both cationic and anionic species, while thinner poly pyrrole films (<2 mu m) showed good linear response to pH changes for the p H range between 2 and 12. The possible mechanism for such behavior was disc ussed. (C) 1999 Elsevier Science S.A. All rights reserved.