Selectivity and sensitivity of ultrathin purine-templated overoxidized polypyrrole film electrodes

Ultrathin overoxidized polypyrrole (OPPy) films templated with adenosine, inosine and adenosine 5′-triphosphate (ATP), grown on glassy carbon (GC), have been characterized. High sensitivity for ruthenium hexaamine, uric acid and adenine at the ultrathin film electrodes indicates that the interactions with the film rather than in-film transport controlled the response of the film electrodes in slow scan voltammetry. The high sensitivity at the film electrodes allowed the analysis of the effect of templating on the probe-film interactions. The results show that templating with purines changes the selectivity and sensitivity of OPPy films. It is demonstrated that templating with ATP, via electrostatic interactions of ATP with the positively charged PPy, has a most significant effect on the response of the OPPy films, and the ATP-templated films show high selectivity to adenine. The sensitivity for adenosine is significantly enhanced at OPPy films considering that the response is not apparent at the bare glassy carbon.