▎ 摘　　要

Herein, we have demonstrated the simultaneous and selective electrochemical determination of dihydroxybenzene isomers at a reduced graphene oxide (RGO) and copper nanoparticles (Cu-NPs) composite modified electrode. The RGO/Cu-NPs composite was prepared by a single-step electrochemical reduction method. The synthesized RGO/Cu-NPs composite was characterized using scanning electron microscopy and elemental analysis. Linear sweep voltammetry was employed for the simultaneous determination of hydroquinone (HQ), catechol (CC) and resorcinol (RC). A well defined and more enhanced oxidation peak response is observed for HQ, CC and RC at the RGO/Cu-NPs composite electrode compared to other modified electrodes, which indicates fast electron transfer from dihydroxybenzene isomers at the RGO/Cu-NPs composite electrode. The composite modified electrode shows high electrocatalytic activity towards the oxidation of HQ, CC and RC. The electrochemical sensor shows a wide linear response in the concentration range of 3 mu M to 350 mu M, 3 to 350 mu M and 12 mu M to 200 mu M for HQ, CC and RC respectively with a detection limit of 0.032 mu M, 0.025 mu M and 0.088 mu M (S/N = 3). In addition, the proposed sensor shows good selectivity and stability along with good precision and consistency. The obtained results clearly demonstrate that the RGO/Cu-NPs composite can be an advanced electrode material for the real time sensing of dihydroxybenzene isomers.