2,5-巯基-1,3,4-硫代二氮唑自组装金电极测定银(I)

Determination of Ag(Ⅰ) at a gold electrode modified with a self-assembled monolayer of 2,5-dimercapto-1,3,4-thiadiazole

制备了2,5-巯基-1,3,4-硫代二氮唑(DMTD)自组装单分子层修饰金电极,用电化学阻抗谱进行了表征,研究了Ag(I)在该电极上的电化学行为并用差分脉冲阳极溶出伏安法对其进行了测定。结果表明,DMTD/Au电极能显著提高Ag(I)测定的灵敏度和选择性,Ag(I)浓度在9.4×10-7～8.0×10-6mol/L范围内,氧化峰电流与Ag(I)呈现良好的线性关系,检出限为2×10-7 mol/L。该自组装电极可用于水样的测定。

2,5-Dimercapto-1,3,4-thiadiazole（DMTD） self-assembled monolayer on a gold electrode was prepared and characterized by the electrochemical impedance spectroscopic measurements.Electrochemical behaviors of Ag（I） in the self-assembled electrode and determination of Ag（I） by anodic stripping voltammetry were studied.It was found that the DMTD/Au electrode exhibited a significantly increased sensitivity and selectivity for Ag（I）,and the DMTD/Au electrode showed a good linear current response for Ag（I） in the range from 9.4×10-7 mol/L to 8.0×10-6 mol/L by anodic stripping voltammetry with a detection limit of 2×10-7 mol/L.The method was applied to the determination of Ag（I） in water samples with satisfactory results.