Abstract：A graphene-modified electrode was prepared with graphene oxide (GO) reduced by electrochemistry on the surface of a glassy carbon electrode (GCE). A linear sweep stripping voltammetry for the determination of trace silver was developed by optimizing the determination conditions such as supporting electrolyte and pH, the amount of modifier, and the accumulation potential and time. In NaAc-HAc buffer solution at pH 4.0, an anodic stripping peak with high sensitivity and good shape appeared at 0.32 V after the soluion containing trace silver was accumulated at -0.10 V for 5 min. The stripping peak current showed a linear relationship with the concentration of Ag+ in the range of 1.0×10-7-4.0×10-5 mol/L with a detection limit of 3.0×10-8 mol/L (S/N=3). The proposed method has been applied to the determination of silver in environmental water samples with satisfactory results, and the average recoveries were between 95% and 107%.
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Deng S Y, Lei J P, Cheng L X, et al. Amplified electrochemiluminescence of quantum dots by electrochemically reduced graphene oxide for nanobiosensing of acetylcholine[J]. Biosensors and Bioelectronics, 2011, 26(11): 4552-4558.
