Preparation of amperometric glucose biosensor by means of electropolymerisation of polyaniline onto graphite

Abstract

In this study, an amperometric glucose biosensor with immobilization of glucose oxidase enzyme on electrochemically polymerized polyaniline film onto graphite surface has been prepared. The immobilization of the enzyme glucose oxidase has been accomplished via the physical entrapment technique. Electropolymerization of aniline onto the suface of the graphite was carried out by cyclic voltammetry (potential range of -0.4V to 1.2V, scan rate 100mV/sec, 10 cycles) by using standard calomel electrode (SCE) as reference and platinum wire as counter. Characterization of the PANi/Graphite was carried out with the aid of cyclic voltammetry in 1M HCl, obtaining three couple of peaks from which the two pair were distinct, having proved the electro-activity of the PANi film. The enzyme was potentiostatically immobilized onto the surface from 0.1M phosphate buffer of pH 6.0 with 200U/mL glucose oxidase (GOx) enzyme. The amperometric response was studied by using hydrodynamic amperometric mode. Determination of glucose was carried out by the measurement of amperometric response obtained during the reduction of enzymatically produced hydrogen peroxide at - 0.4 V vs calomel electrode and platinum wire as counter in phosphate buffer of pH 6.0. Biosensor was found to be responsive within the concentration range of 0.01ML

-1 -0.1ML -1 . All experiments were carried out at room temperature.