No 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 ex-hibited a synergistic electrochemical performance for exclusive cyclic-voltammetry sensing of ultra-trace Ag + with a nice linear range of 6.67-160 × 10 À 9 mol/L and a low detection limit of 1.76 × 10 À 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.