ZnS/AuNPs/ITO修饰电极电化学发光法测定水中痕量铜

Determination of trace copper in water by electrochemiluminescence method using ZnS/AuNPs/ITO modified electrode

针对常规方法测定痕量铜有操作繁琐、灵敏度低等问题,建立了采用ZnS/AuNPs/氧化铟锡(ITO)玻璃电极电化学发光法测定痕量铜的新方法。在ITO玻璃表面,用电化学沉积法沉积AuNPs和ZnS,制备了ZnS/AuNPs/ITO电极。考察了该修饰电极的光、电化学行为,并对制备条件进行了优化。结果表明,Cu2+能够抑制以AuNPs为载体、ZnS为发光物质的修饰电极电化学发光,相对电化学发光值与Cu2+浓度的对数值在1×10-11～5×10-8 mol/L范围内呈线性关系,检出限为0.52×10-11 mol/L。方法用于水样中痕量铜的测定,结果的相对标准偏差(RSD,n=6)不大于1.3%,回收率在97%～105%之间;并与电感耦合等离子体质谱法测定结果基本一致。

During the determination of trace copper by conventional method,there are some problems such as tedious operation and low sensitivity.To solve these problems,a new method for the determination of trace copper by electrochemiluminescence method using ZnS/Gold nanoparticles(AuNPs)/indium tin oxide(ITO)glass electrode was established.AuNPs and ZnS were deposited on ITO glass surface by the electrodeposition method to prepare the ZnS/AuNPs/ITO electrode.The optical and electrochemical behaviors of the modified electrode were investigated,and the preparation conditions were optimized.The results showed that Cu 2+could inhibit the electrochemiluminescence of modified electrode with AuNPs as carrier and ZnS as luminescent material.The relative value of electrochemiluminescence showed linear relationship with the logarithm of Cu 2+concentration in range of 1×10-11-5×10-8.The detection limit of method was 0.52×10-11 mol/L.The proposed method was applied to the determination of trace copper in water samples.The relative standard deviation(RSD,n=6)was not more than 1.3%,and the recoveries were between 97%and 105%.The found results by this method were basically consistent with those obtained by inductively coupled plasma mass spectrometry(ICP-MS).