Preparation of a Gold Nanoparticles-Reduced Graphene Oxide Modified Glucose Oxidase Biosensor and Its Amperometric Determination of Glucose in Beverages
An amperometric glucose oxidase(GOx) biosensor based on gold nanoparticles(AuNPs) -reduced graphene oxide(rGO) was fabricated for the detection of glucose in beverages.AuNPs-rGO composite was synthesized by one-pot method with chitosan as reducing and stabilizing agent.It was used as the matrix for GOx immobilization via physical adsorption technique to fabricate the GOx-based biosensor.The biosensor was applied in the amperometric determination of glucose at -0.45 V(vs.Ag/AgCl) in a phosphate buffer (0.1 mol/L，pH 6.0).There was a linear response to glucose in the concentration range of 0.01-0.88 mmol/L,with a sensitivity of 22.54 μA?mmol-1?L?cm-2 and a detection limit of 1.01 μmol/L.The apparent Michaelis-Menten constant was rather small(0.497 mmol/L).The constructed biosensor was successfully applied in the detection of glucose in beverages.