Single-step electrochemical deposition of high performance Au-graphene nanocomposites for nonenzymatic glucose sensing

In this paper, high-quality three-dimensional (3D) nanocomposites (Au nanoparticles anchored on graphene, denoted as Au-gra) were synthesized by a simple electrochemical approach, in which the reduction of Au ions and graphene oxide were achieved with a one-step process. The resulting hybrids were characterized by field-emission scanning electron microscopy (FE-SEM), Raman spectroscopy, X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). It is found that Au nanoparticles have been successfully supported on the surface of graphene, and the nanocomposites uniformly modified on the electrode with 3D porous structures. Based on cyclic voltammetry and amperometric results, Au-gra efficiently catalyzed the oxidation of glucose in neutral media (0.1 M PBS, pH 7.4) and exhibited a rapid response time (about 3 s), a broad linear range (0.1-16 mM), good stability, and sensitivity estimated to be 4.56 μA cm−2 mM−1 (R = 0.992, 285.8 μA cm−2 mM−1 vs. geometric area). The electrochemical experiments were performed at a relatively low detection potential (i.e., 0 V), under which the impact from the oxidation of common interfering species could be effectively limited. These results indicated a great potential of Au-gra in fabricating novel non-enzymatic glucose sensors with high performance.