Voltammetry of Diclofenac at Graphite, Carbon Composites, and Molecularly Imprinted Polymer‐Composite Electrodes

Abstract

The electrochemical behavior of diclofenac (DCF) at graphite electrodes was investigated. The drug is irreversibly oxidized at 0.84 V (pH 1), giving rise to some products, which exhibit two reversible process with formal potential of 0.39 and 0.63 V. Carbon composite electrodes of different nature [polytetrafluoroethylene‐graphite (PTFE‐G), epoxy‐graphite (EG), epoxy‐carbon black (E‐CB)] were also investigated for voltammetric detection of DCF. A similar electrochemical behavior was observed on these electrodes although graphite was preferred over carbon black as conducting phase, and both PTFE and epoxy could act as agglomerant. Electrodes constructed with these materials could be modified with molecularly imprinted polymers (MIPs), and allowed detection of DCF after incubation in an acetonitrile solution of the drug.

Keywords:

• Diclofenac
• Composite electrodes
• Molecular imprinting
• Epoxy‐graphite

Acknowledgments

Authors gratefully acknowledge financial support from the Spanish government: Ministerio de Ciencia y Tecnología, project BQ‐2002‐00261 and Ministerio de Educación y Cultura for a F.P.I. grant to L.F.