Self-assembled graphene platelet-glucose oxidase nanostructures for glucose biosensing.

Graphene platelet-glucose oxidase (GP-GOD) nanostructures have been prepared through self-assembly of GOD and chitosan (CS) functionalized GPs by electrostatic attraction in aqueous solution. The stable aqueous dispersion of GPs was prepared by chemical reduction of graphene oxide with the use of CS as a reducing and stabilizing agent. UV-vis spectroscopy, X-ray diffraction, transmission electron microscopy, scanning electron microscopy and X-ray photoelectron spectroscopy were used to characterize the resulting GPs and GP-GOD nanostructures. Furthermore, a glucose biosensor was constructed by deposition of the resultant GP-GOD on the surface of glassy carbon electrode. It was found that the resulting biosensor exhibits good response to glucose. The linear detection range is estimated to be from 2 to 22 mM (r=0.9987), and the detection limit is estimated to be 20 μM at a signal-to-noise ratio of 3.