A ternary hybrid composed of molybdenum disulfide (MoS2), reduced graphene oxide (rGO) and gold nanoparticles (AuNPs@MoS2-rGO) was prepared and used for voltammetric detection of hydroquinone (HQ), catechol (CC) or resorcinol (RC). The composition and structure of the hybrid were characterized in detail. The electrochemical behaviors of a glassy carbon electrode (GCE) modified with the hybrid towards the oxidation of HQ, CC, and RC were investigated using cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The results revealed 3D MoS2 is active for the catalytic oxidation of these isomers. Additional integration with rGO and AuNPs further improves catalysis due to their synergistic interaction. The enhanced catalysis leads to oxidation of HQ, CC and RC at 0.074 V, 0.178 V, and 0.527 V (vs. Ag/AgCl; by CV) with reduced overpotential (20-100 mV) and 8-fold or 3-fold increased peak current compared to those obtained on MoS2/GCE, or MoS2-rGO/GCE, respectively. Selective detection of one isomer in the presence of the other two was realized by DPV. The linear ranges are 0.1-950 μM, 3-560 μM, and 40-960 μM for HQ, CC, and RC, and the detection limits are 0.04 μM, 0.95 μM, and 14.6 μM, respectively. The sensor also shows good selectivity and displays satisfactory recovery for real sample analysis. Graphical abstract Schematic illustration of the preparation of AuNPs@MoS2-rGO hybrid by hydrothermal growth of MoS2-rGO and subsequent electrodeposition of gold nanoparticles (AuNPs), and its application for selective detection of hydroquinone, catechol and resorcinol by voltammetry.
Keywords: Dihydroxybenzene isomer; Electrochemical sensor; Environment analysis; Gold nanoparticle; Graphene; Molybdenum disulfide.