Direct electrochemistry of cytochrome c on graphene aerogel/gold nanoparticle hybrid for hydrogen peroxide biosensing

Homogeneously distributed self-assembling graphene aerogel/gold nanoparticles (GA/GNs) hybrid with 3D interconnected pores was fabricated through a simple hydrothermal route. A highly sensitive cytochrome c (Cyt c) sensor based on this GA/GNs hybrid was developed. The porous structure of the GA/GN hybrid favored the high-density immobilization of the enzyme and the penetration of water-soluble molecules, which provided a biocompatible sensing platform for the immobilization of Cyt c. Cyclic voltammetry results indicated that the GA/GN film promoted direct electron transfer between Cyt c and the underlying electrode. The immobilized Cyt c exhibited excellent electrocatalytic activity towards the reduction of H2O2. The fabricated biosensor exhibited fast response and good electrochemical activity for H2O2 with a comparable linear range from 5 μmol · L-1 to 150 μmol · L-1 and low detection limit of 1.75 μmol·L-1. Moreover, the modified electrode displayed rapid response to H2O2 and possessed good stability and reproducibility. These results showed that in situ encapsulation of different nanomaterials into a 3D GA framework can be adopted to fabricate a series of graphene-based 3D porous materials for various applications. Copyright © 2015 American Scientific Publishers All rights reserved.