Preparation of Graphene-Nano Silver Composite Modified Electrode and Its Application for Determination of Rutin

Graphene-nanosilver composites (GR-AgNPs) were prepared by hydrothermal reaction, and then characterized by scanning electron microscopy, infrared absorption spectroscopy and electrochemical impedance spectroscopy. The composites were dropped on the surface of glassy carbon electrode (GCE), and then electrochemical behavior of rutin on the modified electrode was studied by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). As shown by the experimental results, the modified electrode had obvious electrical catalysis on rutin in pH 3.4 of Na₂HPO₄-citric acid buffer solution. Based on these findings, a selective method for determination of rutin by DPV was proposed. Linear relationship between values of oxidation peak current and concentration of rutin was kept in the range of 1.0×10^-7-2.5×10^-5mol·L^-1 with detection limit (3S/N) of 1.0×10^-8mol·L^-1. The proposed method was used in the analysis of samples of commercially available rutin tablets and Fagopyrum tataricum, and values of recovery found were in the ranges of 98.9%-101% and 99.4%-103% respectively. Values of RSDs (n=5) found were in the range of 0.41%-3.6%.