Regeneration of an electropolymerised polypyrrole layer for the amperometric detection of ammonia

During recent years, attempts have been undertaken to utilise electrochemically polymerised pyrrole for amperometric detection of ammonia. However, these attempts suffer from gradual decrease of sensitivity of the polypyrrole layer with increasing ammonia exposure, and trials to regenerate the polypyrrole failed until now. In this communication, we present recovery of polypyrrole sensitivity by treatment with perchloric acid and subsequent oxidation. Consequently, a higher durability of polypyrrole-based ammonia sensors could be achieved.