High sensitive electrochemical detection of silver nanoparticles based on a MoS2/graphene composite

In this work, MoS2-reduced graphene oxide (rGO) composites were prepared by a simple hydrothermal reaction and characterized by SEM, Raman, XRD, and electrochemical impedance spectroscopy (EIS). The obtained MoS2-rGO/GCE was used for electrochemical investigation of silver nanoparticles (AgNPs) by cyclic voltammetry (CV), differential pulse voltammetry (DPV), and chronocoulometry (CC). It was found that the MoS2-rGO/GCE exhibited good stability and could enhance current response of AgNP electrooxidation effectively. On the basis, a new electrochemical method was developed to detect AgNPs in aqueous solution. The proposed method exhibited satisfactory analytical performance for AgNP detection with the limit of detection (LOD) as 2.63 ng/L and the linear range from 5 to 120 ng/L. The determination assays in water samples by MoS2-rGO/GCE were also discussed. The assay recoveries in water samples were obtained as 94.9-99.4%. That suggested a promising application prospect in environmental analysis.