基于邻苯二酚-多壁碳纳米管电聚合印迹膜的制备及三聚氰胺测定

Preparation of the electropolymerized catechol imprinted film based on multi walled carbon nanotubes for melamine determination

结合碳纳米材料和分子印迹技术,以邻苯二酚为功能单体,三聚氰胺为目标模板分子,通过电化学聚合法在多壁碳纳米管修饰电极表面制备对目标分子有特异响应的分子印迹电化学传感器。用乙酸的甲醇溶液(8:2,V/V)去除模板分子,选择扫描电镜和原子力显微镜技术对印迹膜表面进行表征。结果表明:均一稳定的邻苯二酚聚合膜显著降低三聚氰胺的响应电位,提高目标分子的选择性和灵敏度。三聚氰胺浓度在0. 5~150μmol/L范围内呈良好的线性关系,检测限为0. 10μmol/L。此传感器可用于牛奶中三聚氰胺的直接测定,加标回收率为93. 0%~102. 0%。

Combined with carbon nanomaterials and molecular imprinted technique,the molecularly imprinted electrochemical sensor(MIES)which having specific response to the melamine was prepared by electrochemical polymerization on the surface of multi-walled carbon nanotubes(MWNTs)modified electrode,using catechol as functional monomer and melamine as the target template molecule.The mixed solution of methanol/acetic acid(8:2,V/V)was used to remove the template molecule.The microsurface of the MIES was characterized by the scanning electron microscopy(SEM)and atomic force microscopy(AFM).The results showed that the stable homogeneous catechol polymerization film significantly reduced the response potential of melamine,and improved the selectivity and sensitivity.The current response showed a good linear relationship to the concentration of melamine in the range of0.5-150μmol/L,with the detection limit of 0.10μmol/L.This sensor could be used for the direct determination of melamine in milk.The standard recoveries ranged from 93.0%to 102.0%.