基于门控制电催化效应的分子印迹传感器

以绿麦隆为模板分子,在镍电极表面聚合制得绿麦隆分子印迹膜.洗脱后的分子印迹膜重新吸附不同浓度绿麦隆分子,在印迹膜上形成不同量的印迹孔穴,H2O2通过印迹孔穴在镍电极表面产生电催化氧化,从而形成门控制电催化效应,以此对绿麦隆进行定量分析.研究表明,镍电极对H2O2有较好的催化效果,分子印迹聚合膜中模板分子、功能单体和交联剂的摩尔配比为1∶12∶30,重吸附时间为10 min,测试缓冲液pH=7.2.H2O2的催化电流值与绿麦隆浓度在1.0× 10-4～4.0× 10-7 mol/L范围内呈良好的线性关系;检出限为2.9×10-8 mol/L.将传感器应用于农田水样的检测,其回收率在97％～103％之间.

A Molecularly Imprinting Sensor Based on Gate Controlled Electro-catalyzation

Molecularly imprinted polymer(MIP) was synthesized on the surface of Ni electrode with the template molecules of chlortoluron.After elution,some of the imprinted cavities in MIP can re-bind with chlortoluron molecules.Hydrogen peroxide,which acts as the probe,can enter into the left cavities and are reduced on the Ni electrode surface to form gate controlled electro-reduction .The MIP sensor can be used to detect chlortoluron with high sensitivity due to the highly electrochemically catalytic reduction of H 2 O 2 on the Ni electrode.The mole ratio of template molecules,functional monomer and crosslinking agent in molecular imprinted polymer film was found to be 1∶12∶30,re-adsorption time was 10min and the optimum pH value was 7.2.Chlortoluron could be analyzed in the range of 1.0×10 -4-4.0× 10 -7 mol / L with a detection limit of 2.9×10 -8 mol / L.In addition,the feasibility of the practical applications of the MIP sensor has been demonstrated in the analysis of water samples and showed good recovery,ranging from 97%to 103%.