We report the synthesis of Ru@Au nanoparticle involved L-cysteine functionalized reduced graphene oxide (rGO) composites (NSrGO/Ru@AuNPs). The nanocomposites were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). The electrochemical determination of curcumin (CR) has been studied using square wave voltammetry (SWV) on a glassy carbon electrode (GCE) modified with NSrGO/Ru@AuNP composites (NSrGO/Ru@AuNPs/GCE). The effective surface areas (ESAs) of the rGO/GCE and NSrGO/Ru@AuNPs/GCE were calculated to be 347 cm(2) mg(-1) and 1289 cm(2) mg(-1), respectively. These results show that the electrochemical surface area of the NSrGO/Ru@AuNPs/GCE is 3.71 times higher than that of the rGO/GCE. The developed method was also applied successfully for the determination of CR in plasma and the linearity range of CR was 0.001-0.1 nM with a detection limit of 2.0 x 10(-13) M.