Amperometric biosensor for phenols and catechols based on iridium-polyphenol oxidase-modified carbon paste

An amperometric bioelectrode for the quantification of phenols and catechol s based on the incorporation of iridium microparticles and polyphenol oxida se (PPO) within carbon paste matrices, is described. Iridium-doped carbon p aste electrode displays excellent electrocatalytic activity towards the red uction of the enzymatically formed quinone species. Thus, the quantificatio n of the micromolar/submicromolar levels of phenols and catechols can be pe rformed at potentials lower than in the case of bare CPE with much better s ensitivity (around 4-fold higher). The analytical performance as well as th e kinetic parameters for different substrates of clinical, pharmacological and environmental interest, are discussed.