Direct Electrochemistry of Glucose Oxidase in β-Cyclodextrin Covalently Functionalized Single-Walled Carbon Nanotubes-Cetyltrimethyl Ammonium Bromide Hybrid Film and Its Biosensing

摘要

An unmediated glucose biosensor was prepared by immobilizing glucose oxidase (GOD) into β-cyclodextrin covalently functionalized single-walled carbon nanotubes (β-CD-SWCNTs)/ cetyltrimethyl ammonium bromide (CTAB) composite film modified glassy carbon electrode. Due to the excellent electrical conductivity and biocompatible ability of β-CD-SWCNTs and CTAB, direct electron transfer between GOD and the electrode was facilely achieved with a fast electron transfer rate of 2.111 s~(-1). A pair of well-defined and reversible redox peaks of immobilized GOD was observed, corresponding to the FAD/FADH_2 redox couples at pH 7.0 PBS. In addition, the immobilized GOD in the composite film maintained high biocatalytic activity and the biosensor could be used for the detection of glucose, which exhibited good stability and wide linearity range from 1.87 mM to 12.87 mM glucose with a detection limit of 0.484 mM. These results indicated that β-CD-SWCNTs/CTAB hybrid film is a potential material for the construction of the third generation of related enzyme biosensors.