Abstract

In this study, construction of amperometric glucose biosensor was carried out by immobilizing of glucose oxidase (GOD) on platinum electrode with 0.09 cm2 surface area which coated with polypyrrole (PPy) by cyclic voltammetry technique. Because measured current values in the presence of glucose would be affected from the electrode preparing and working conditions, experimental parameters should be optimized by response surface methodology (RSM). To this, State Ease Design Expert 8.0.7.1. (Serial Number:0021-6578) programe was used. PPy synthesis conditions of pyrrole (Py) monomer concentration and scan rate were optimized according to current response in presence of glucose. Optimal Py monomer concentration and scan rate for PPy synthesis were determined as 10 mM and 50 mV/s, respectively. Immobilization parameters such as concentrations of chitosan, GOD and glutaraldehyde (GAL) also were optimized by RSM as 1.0 %, 4 mg/ml and 0.0625 %, respectively. The digital photos of electrodes at each stage were obtained. All electrodes well characterized in absence and in the presence of glucose by cyclic voltammetry and impedance techniques and it was observed that electrodes were sensitive to glucose molecule. Finally the effect of working pH and applied potential on the current response was investigated by RSM. The highest current response was obsreved when pH of glucose solution and applied potential were 6.0 and 0.8, respectively.