Conducting polymer based electrochemical sensors: theoretical analysis of current response under steady state conditions

A theoretical analysis describing the steady state response of conducting polymer based amperometric chemical sensors is presented. The processes of substrate transport to the sensor surface, and subsequent substrate reaction at the latter is analyzed in the context of rotating disc voltammetry. Two distinct situations are considered. In the first, the substrate does not partition into the polymer layer, but simply reacts via Butler- Volmer kinetics at the polymer/electrolyte interface. The second situation arises when the substrate partitions into the polymer layer. In this case substrate diffusion through and reaction within the film is analysed.