Simultaneous and selective electrochemical determination of dihydroxybenzene isomers at a reduced graphene oxide and copper nanoparticles composite modified glassy carbon electrode

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 μM to 350 μM, 3 to 350 μM and 12 μM to 200 μM for HQ, CC and RC respectively with a detection limit of 0.032 μM, 0.025 μM and 0.088 μM (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.