▎ 摘　　要

A hybrid nanostructure of Au-Ag nanorings prepared by decorating the surface of N-doped graphene (NG) was utilized as an electrocatalyst to construct a novel electrochemical sensor. Transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) were used to characterize the as-prepared composites. The Au-Ag nanorings/NG modified electrode exhibited a much better electrochemical response of rutin than that of Au/NG, Ag/NG and NG due to the synergetic catalytic effect between the Au-Ag nanorings and NG. Under optimal conditions, the electrochemical sensor of the Au-Ag nanorings/NG exhibited a wide linear range from 0.05 mu M to 241.2 mu M (S/N = 3) with a low detection limit of 0.01 mu M. In addition, the proposed sensor also displayed good anti-interference ability and long-term stability, which had promising applications in bioassay analysis.