Glucose oxidase electrodes of poly(o-anisidine), poly(o-toluidine), and their copolymer as biosensors:: A comparative study

Thin films of poly(o-anisidine) (POA), poly(o-toluidine) (POT), and their copolymer poly(o-anisidine-co-o-toluidine) (POA-co-POT) were electropolymerized in solutions containing 0.1M monomer(s) and 1M H2SO4 as an electrolyte through the application of a sequential linear potential scanning rate of 50 mV/s between -0.2 and 1.0 V versus an Ag/AgCl electrode on a platinum electrode. A simple technique was used to construct glucose sensors through the entrapment of glucose oxidase (GOD) in thin films of POA, POT, and their copolymer POA-co-POT, which were electrochemically deposited on a platinum plate in phosphate and acetate buffers. The maximum current response was observed for POA, POT, and POA-co-POT GOD electrodes at pH 5.5 and at a potential of 0.60 V (vs Ag/AgCl). The phosphate buffer yielded a fast response in comparison with the acetate buffer in amperometric measurements. The POT GOD electrode showed a fast response and was followed by POA-co-POT and POA GOD electrodes. (C) 2004 Wiley Periodicals, Inc.