▎ 摘　　要

Agnuside despite its good properties for the body, can be harmful to the kidneys in extra concentrations. So, its measurement is important. For the first time, we developed a simple, rapid and inexpensive method for the investigation of agnuside electrochemical behavior by designing a gold/reduced graphene oxide/carbon paste electrode (Au/RGO/CPE). The Au/RGO nanocomposite was synthesized through a one-pot in situ reduction of graphene oxide (GO) and HAuCl4 in the presence of sodium citrate and the obtained product was studied by Fourier transform infrared (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX). The anodic oxidation of agnuside has been carried out at a modified carbon paste electrode in 0.1M phosphate buffer solution (pH 6.0) using sensitive differential pulse voltammetry (DPV). Several parameters such as the type and pH of supporting electrolyte and scan rates were optimized. This study reported a good linearity in the range of 0.050-250.0 nM and a low detection limit of 0.016 nM. The relative standard deviations (RSDs) for 10.0 nM and 100.0 nM of agnuside were obtained 3.3% and 1.2%, respectively. The sensor was successfully applied to determine agnuside in Vitex agnus castus fruit and urine sample.