Electrocatalytic amperometric detection at polymeric cobalt phthalocyanine electrodes

Abstract

Abstract Glassy carbon electrodes modified with a coating of a cobalt phthalocyanine containing polymer offer attractive features for applications as electrocatalytic amperometric sensors following liquid chromatography. These electrodes, which are formed by the anodic electropolymerization of Co‐4,4′,4″,4‴‐tetraaminophthalocyanine, exhibit electrocatalytic properties similar to those of earlier carbon paste electrodes containing Co phthalocyanine monomer added directly to the paste mixture. However, the polymer electrodes also offer increased stability and a compatibility with organic solvents not obtainable with the carbon paste version. The performance of the polymer electrodes is illustrated here for the detection of thiols following reversed‐phase liquid chromatography. Determination of picomole quantities of various thiols is possible at low positive potentials in mobile phases composed of 50% methanol or acetonitrile. Furthermore, the response of the electrodes is extremely stable, with more than 80% of the initial activity retained after 40 hours of continuous use.