本文制备了一种基于分子印迹技术的电化学传感器,并成功应用于环境水样中Pb(Ⅱ)的检测。以铅-没食子酸配合物(Pb—Gal)为模板分子,用电聚合邻苯二胺(o-PD)的方法在铂电极上聚合了Pb—Gal分子印迹聚合物膜。根据印迹膜对Pb—Gal的识别作用对Pb(Ⅱ)进行间接测定。以K3[Fe(CN)6]/K4[Fe(CN)6]为探针,利用其氧化还原电流信号变化实现对Pb(Ⅱ)的检测。通过对配合物整体的识别,提高了检测的灵敏度。研究表明,在0.03~30nmol/L范围内,Pb(Ⅱ)浓度的对数值(IgCPb(Ⅱ)与氧化峰电流变化值(△i)呈线性关系,检出限为0.0163nmol/L。
In this paper,we reported a kind of electrochemical sensor based on molecularly imprinted technique,and it has been successfully applied to the determination of lead ion in water samples.With lead-gallic acid complexes as a template molecule,a molecularly imprinted membrane with lead-gallic acid complexes was prepared by electro-polymerization o-phenylenediamine method at a platinum electrode.According to the recognition of molecular imprinting film for lead-gallic acid complexes,we can indirectly detect Pb(Ⅱ).Utilizing potassium ferricyanide solution as a probe,its redox current change was used to detect lead ion.The sensitivity has been improved by identification of the overall complex.There was a good linear relationship between the concentrations of Pb(Ⅱ)in the forms of(lgcPb(Ⅱ))and the current changes(△i).The detection limit was 0.0163nmol/L.