Synthesis and electropolymerization of aminophenylbenzimidazoles, and usage of modified electrode as an enzym free H2O2 sensor

In this study, chemical synthesis of 2-(2-aminophenyl)benzimidazole (2AB), 2-(3- aminophenyl)benzimidazole (3AB) monomers containing aniline and benzimidazole rings was carried out. Polymerization of the monomers in an acetonitrile solution by electrochemical oxidation platinum and on various carbon electrodes. P2AB/AuNP and P2AB were successfully synthesized electrochemically on PGE in acetonitrile for the first time. The coatings were characterized by Scanning Electron Microscopy, X-ray diffraction spectroscopy, Energy dispersive X ray spectroscopy, Surface enhanced Raman spectroscopy, Fouirer Transform Infrared spectroscopy and UV-Vis spectroscopy. A poly(2-aminophenylbenzimidazole)/ gold nanoparticles (P2AB/AuNP) coated disposable pencil graphite electrode (PGE) was fabricated as an enzyme-free sensor for the H2O2 determination. AuNP interacted with P2AB as carrier enhances the electrocatalytic activity towards reduction of H2O2. The analytical performance was evaluated in a 100 mM phosphate buffer solution at pH 6.5 by amperometry. The steady state current vs. H2O2 concentration is linear in the range of 0.06 to 100 mM (R2 = 0.992) with a limit of detection 3.67 × 10−5 M at - 0.8 V and no interference is caused by ascorbic acid, dopamine, uric acid, and glucose. Applicability in samples containing H2O2 was examined by the amperometric analysis in commercially available hair oxidant solution. The results demonstrate that P2AB/AuNPs/PGE has potential applications as a sensing material for quantitative determination of H2O2.