A glucose electrochemical sensor based on glucose oxidase immobilized in aminopropyl-magnesium phyllosilicate nanosheets matrix

Abstract

In this work, glucose oxidase (GOD) was immobilized in aminopropyl-magnesium phyllosilicate (AMP) nanosheets matrix to obtain the GOD/AMP composite via an exfoliation-assembly procedure, and a glucose biosensor was constructed by dropping the GOD/AMP composite and nafion film successively onto the glassy carbon electrode surface. The direct electrochemical behavior, the electrocatalytic response to dissolved oxygen and glucose, as well as the ability to detect glucose in real sample were investigated by the methods of cyclic voltammetry and chronoamperometry. The results indicate that the immobilization of GOD in AMP nanosheets matrix maintained the biological activity and facilitated the direct electron transfer of GOD on the glassy carbon electrode surface. The GOD/AMP composite modified electrode show a sensitively response to glucose, with the linear range of 1.0x10-4 to 1.1x10-3 molL-1 and the detection limit of 0.035 mmol L-1. Moreover, the glucose can be detected directly in the real sample of blood serum by this GOD/AMP composite modified electrode.