Direct Electrochemistry and Electrocatalysis Behaviors of Glucose Oxidase Based on Hyaluronic Acid-Carbon Nanotubes-Ionic Liquid Composite Film

摘要

Multi-walled carbon nanotubes(MWNTs)were dispersed in the ionic liquid[BMIM][BF4]to form a uniform black suspension.Based on it,a novel glucose oxidase(GOx)-hyaluronic(HA)-[BMIM][BF4]-MWNTs/C-CE modified electrode was fabricated.UV-vis spectroscopy confirmed that GOx immobilized in the composite film retained its native structure.The experimental results of EIS indicated MWNTs,[BMIM][BF4]and HA were successfully immobilized on the surface of GCE and[BMIM][BF4]-MWNTs could obviously improve the diffusion of ferricyanide toward the electrode surface.The experimental results of CV showed that a pair of well-defined and quasi-reversible peaks of GOx at the modified electrode was exhibited,and the redox reaction of GOx at the modified electrode was surface-confined and quasi-reversible electrochemical process.The average surface coverage of GOx and the apparent Michaelis-Menten constant were 8.5×10-9mol/cm2 and 9.8 mmol/L,respectively.The cathodic peak current of GOx and the glucose concentration showed linear relationship in the range from 0.1 to 2.0mmol/L with a detection limit of 0.03 mmol/L(SIN=3).As a result,the method presented here could be easily extended to immobilize and obtain the direct electrochemistry of other redox enzymes or proteins.