Graphene–polyamidoamine dendrimer–Pt nanoparticles hybrid nanomaterial for the preparation of mediatorless enzyme biosensor

摘要

A novel inorganic–organic hybrid nanomaterial was prepared by anchoring (3-glycidyloxypropyl)trimethoxysilane at the surface of graphene oxide, further cross-linking with polyamidoamine G-4 dendrimer, and final decoration with platinum nanoparticles. A glassy carbon electrode was coated with this hybrid nanomaterial and then used as support for the covalent immobilization of glucose oxidase. This enzyme electrode was employed to construct a mediatorless glucose amperometric biosensor. The resulting biosensor exhibited good electrocatalytical activity for the oxidation of the H_2O_2 produced by the enzyme catalyzed reaction, being able to detect glucose when poised at +400 mV. The biosensor showed a wide linear response to glucose ranging from 10 μM to 8.1 mM, high sensitivity of 24.6 mA/M cm~2 and low detection limit of 0.8 μM. The biosensor was successfully tested for the quantification of glucose in samples of commercial soft drinks.