A new nanoplatform based on reduced graphene oxide decorated with electrochemically generated gold nanoparticles was developed for sensitive and selective determination of nitrazepam. This nanostructure was characterized by Fourier transform infrared spectroscopy, atomic force microscopy, scanning electron microscopy coupled with energy dispersive X-ray spectroscopy and electrochemical methods. The synergic effect of the two nanomaterials gives an electrode platform with a high surface area, good conductivity and excellent catalytic properties. The sensor exhibited a wide linear range (0.5 mu M-400 mu M), low limit of detection (0.166 mu M), excellent sensitivity, good selectivity, and high stability for nitrazepam determination in serum and a pharmaceutical formulation with excellent recovery rates (99%-102.4%).