Aliphatic Polyamine Oxidation Reaction Mechanism at Boron‐doped Microcrystalline and Ultrananocrystalline Diamond Electrodes

The oxidation reaction mechanism of several aliphatic polyamines was studied using diamond electrodes with different doping levels and non‐diamond carbon impurity content. The important roles of surface boron and localized non‐diamond carbon sites in the polyamine oxidation reaction mechanism were confirmed. A well defined oxidation peak was seen for all the amines that was dependent on the onset potential for water discharge. E p ox shifted negative and the i p ox increased with increasing solution pH. i p ox also increased with increasing boron doping level or surface boron site density. FIA‐EC analysis revealed a reproducible response for the aliphatic polyamines in a binary solvent (7/93 %) acetonitrile/borate buffer, pH 11.2. Optimum signal‐to‐background ratios for the aliphatic polyamines were seen at potentials between 650 and 670 mV.