A novel amperometric glucose biosensor based on ternary gold nanoparticles/polypyrrole/reduced graphene oxide nanocomposite

A ternary nanocomposite comprised of dispersed small gold nanoparticles (AuNPs) on the surface of reduced graphene oxide (RGO) was achieved via facile wet-chemical routes by using polypyrrole (PPy) as a linker. Highly dispersed small AuNPs supported on PPy/RGO surface have been evidenced by the TEM and SEM characterization. The composite exhibited excellently electrocatalytic property toward O2 reduction compared with RGO/PPy, RGO and PPy. Based on the oxygen reduction activity and compatibility of the composite, its prospective in biosensing was further exemplified. Upon encapsulation of glucose oxidase via chitosan cross linking, a glucose electrochemical biosensor was constructed. The biosensor manifested a reproducible amperometric response to glucose in a linear range of 0.2-1.2 mM (R = 0.986) with a sensitivity of 123.8 μA mM−1 cm−2. The results indicate that the ternary nanocomposite is promising in biosensor fabrication.