Simultaneous Determination of Benzenediols Isomers Using Copper Nanoparticles/Poly (Glycine)/Graphene Oxide Nanosheets Modified Glassy Carbon Electrode

In this research, a new and suitable electrochemical sensor for simultaneous determination of benzenediols (BD) isomers is fabricated by dripping well-dispersed graphene oxide nanosheets (GONs) and in situ plating of poly glycine (P-Gly)-metal copper nanoparticles at the glassy carbon electrode (GCE), Cu-NPs/P-Gly/GONs/GCE, successively. Besides, the as-prepared modified electrode was characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (EDX), and electrochemical techniques. The proposed electrochemical sensor excellently enhanced the selectivity in the determination of BD isomers by differential pulse voltammetry (DPVs). Compared between the unmodified and modified electrode, unmodified electrode failure to dispel the voltammetric response of BD isomers in a mixture solution, Cu-NPs/P-Gly/GONs/GCE shows larger electrocatalytic activity for the oxidation of hydroquinone (HQ) and catechol (CC) with an enhancement in peak currents and a decrement in peak separation (ΔEp). Consequently, the two isomers can be determined simultaneously. Under the best response experimental, the linear response range was from 3 μM to 200 μM for CC with a detection limit of 1.015 μM and from 2 μM to 300 μM for HQ with a detection limit of 1.067 μM. Further, the suggested sensor was successfully applied for the detection of BD isomers in actual samples.