Glucose oxidase electrodes of polyaniline, poly(o-anisidine) and their co-polymer as a biosensor: a comparative study

Polyaniline (PA), poly(o-anisidine) (POA) and their co-polymer poly(aniline-co-o-anisidine) (PA-co-POA) thin films were electropolymerized in solution containing 0.1 M monomer(s) and 1 M H₂SO₄ as a electrolyte by applying sequential linear potential scan rate 50 mV/s between −0.2 and 1.0 V vs. Ag/AgCl electrode on platinum electrode. A simple technique is described for constructing a glucose sensor by the entrapment of glucose oxidase (GOD) in PA, POA and their co-polymer PA-co-POA thin films, which were electrochemically deposited on a platinum plate in phosphate and acetate buffer. The maximum current response was observed for PA, POA, and PA-co-POA GOD electrodes at pH 5.5 and potential 0.60 V (vs. Ag/AgCl). The phosphate buffer gives fast response as compared to acetate buffer in amperometric measurements. PA GOD electrode shows fast response (means time taken for sense the glucose is lees) followed by PA-co-POA and POA GOD electrodes.