A novel poly(glycine methacrylate-co-3-thienylmethyl methacrylate)-polypyrrole-carbon nanotube-horseradish peroxidase composite film electrode for the detection of phenolic compounds

A novel amperometric biosensor, based on poly(glycine methacrylate-co-3-thienylmethyl methacrylate)-polypyrrole-carbon nanotube {Poly(GMA-co-MTM)/PPy/CNT} composite matrix, was used for the determination of eighteen phenol derivatives. The enzyme, horseradish peroxidase (HRP) was covalently immobilized to this novel composite polymer matrix. The measurement of the phenolic compounds was carried out by the electrode reduction of the generated phenoxy radical, product of the enzymatic reaction, at a fixed voltage of −50 mV. Optimization of the experimental parameters was performed with regard to pH, operational potential and hydrogen peroxide concentration. The differences in sensitivity, linear range, detection limit and response time observed for series of phenolic compounds were discussed. The biosensor gave no response to m-cresol, o-cresol and p-cresol. Poly(GMA-co-MTM)/PPy/CNT/HRP composite film electrode retained 80% of its initial activity after the usage of 700 measurements in one month.