采用恒电位电沉积氯金酸法、循环伏安电沉积氯金酸法、恒电位电沉积金溶胶法和滴涂金溶胶法在玻碳电极表面修饰纳米金,以亚铁氰化钾为电活性探针,对4种纳米金修饰电极的制备方法分别进行了优化,并对亚铁氰化钾在4种修饰电极表面的电化学响应情况进行了比较,对亚硝酸根在该修饰电极上的电化学行为进行了研究.结果表明:利用恒电位电沉积氯金酸法制备的纳米金修饰电极对亚铁氰化钾具有良好的电催化活性.在最优的试验条件下,亚硝酸根的氧化峰电流与其浓度在1.0×10^-6-1.1×10^-2mol/L范围内呈良好的线性关系,检出限为3.8×10^-7mol/L.运用该电极对水样中的亚硝酸根浓度进行检测,准确度和精密度均较高.
Nano-gold (NG) modified glassy carbon electrodes (NG/GCEs) were prepared by potentio- static electrodeposition of chloroauric acid, cyclic voltammetric electrodeposition of chloroauric acid, potentiostatie electrodeposition of gold colloids, and drop-casting gold colloids, respectively. The preparation methods of four NG/GCEs were optimized based on potassium ferrocyanide as electroactive probe. The electrochemical responses of potassium ferrocyanide on the surface of four NG/GCEs were compared and studied. Furthermore, the electrochemical responses of nitrite on the modified electrode were also in- vestigated. Results showed that the NG/GCE prepared by potentiostatic electrodeposition of chloroaurie acid had excellent electrocatalytic performance to potassium ferrocyanide. The oxidation current of nitrite had good linear relationship with concentration of nitrite in the range of 1.0×10^-6-1.1×10^-2 mol/L with a detection limit of 3.8 × 10^-7mol/L. The proposed method was applied to detect nitrite in water samples with high accuracy and precision.