Use of Overoxidised Polypyrrole as a Chromium(VI) Sensor

Abstract
A new Cr(VI) sensor has been developed in this work. The sensor was prepared by coating a layer of polypyrrole on a gold electrode and then oxidising the polymer film by scanning to anodic potentials. This pretreatment procedure decreased the background current usually associated with the electroactivity of the polymer. Determination of Cr(VI) using this sensor was investigated. It was found that Cr(VI) was preconcentrated upon application of an anodic potential (+0.80 V). Detection limits of the order of 10 ppb Cr(VI) were obtained.