NiS Nanospheres Anchored onto a Graphene Oxide Substrate (NiS@GO) for Efficient Electrochemical Sensing of Trace Amounts of Silver Ions

Abstract Electrochemical analysis is a promising method among all the common analytical technologies reported, due to its considerable sensitivity, inherent portability and low‐cost requirements. To accurately monitor the contamination of heavy metal Ag + , NiS nanospheres anchored onto graphene oxide substrate (NiS@GO) were successfully constructed as a electrochemical sensor, by one‐pot precipitation‐co‐self‐assembly method. Under the optimized conditions, the obtained NiS@GO exhibited a synergistic electrochemical performance for exclusive cyclic‐voltammetry sensing of ultra‐trace Ag + with a nice linear range of 6.67–160×10 −9 mol/L and a low detection limit of 1.76×10 −10 mol/L. When applied for electrochemical detection of Ag + in real environmental water and fruit juice samples, the recoveries were between 95.8 and 102.4 % with relative standard deviations less than 3.4 %. The recognition mechanism for NiS@GO to Ag + was illustrated in detail.