电沉积纳米ZnO修饰玻碳电极交流阻抗法测定硫离子

Electrodeposition of nano-ZnO thin film on glassy carbon electrode for impedimetric detection of sulfide

以Zn（NO3）2和KCl为支持解液,在裸玻碳电极（GCE）上电化学沉积一层纳米Zn O薄膜,制备出一种基于纳米Zn O修饰电极（Zn O/GCE）用于检测S2-的电化学传感器。电化学循环伏安法（CV）表明该修饰电极具有大的比表面积及良好导电性能。将Zn O/GCE置于微酸性的Na2S（p H 6.5）溶液中进行富集反应12 min后,可得到恒定的电化学交流阻抗值（Ret）。在最优实验条件下,该制备电极可成功应用于检测不同浓度的Na2S溶液,其ΔRet值与Na2S浓度范围（1.0×10-7～1.0×10-3mol/L）的对数呈良好的线性关系,检出限为6.37×10-8mol/L。制备电极（Zn O/GCE）可应用于实际水样中硫化物的检测。

Nano-ZnO thin film was electro-chemically deposited on glassy carbon electrode （GCE） surface in Zn（NO3）2 and KC1 supporting electrolyte solution, and the obtain modified electrode （ZnO/GCE） was employed as sensor platform for the detection of S2-. Cyclic vohammetry （CV） characterization experiments showed that the modified electrode possessed large surface area and good electrical conductivity. A constant impedance value （Ret） of ZnO/GCE was obtained after it was immersed in Na2S （pH 6.5） solution for 12 rain concentration reaction. Under the optical conditions, the prepared electrode was successfully applied to the determination of Na2S solution with different concentration, and the resulted Ret presented a good linear relationship with the S2- concentration logarithm in the range from 1.0 × 10-7to 1.0 ×10-3 mol/L. Based on 3σ, the detection limit was estimated to be 6.37 × 10-8 mol/L. Satisfactory results were gained for the application to the determination of sulfides in real samples.