基于聚硫堇修饰金电极构建无标记电流型免疫传感器检测冈田酸

A tabel-free amperometric immunosensor for okadaic acid detection based on polythionine-modified gold electrodes

在金电极表面利用循环伏安法电聚合修饰聚硫堇(PTh),由于PTh表面具有大量的-NH_(2)官能团,可通过与戊二醛发生席夫碱反应固定抗体,基于抗原-抗体特异性免疫反应的原理,构建一种无标记电流型免疫传感器,实现对冈田酸(OA)的定量检测。用该免疫传感器以方波伏安法(SWV)对OA浓度进行检测,在0.1~100μg/L范围内,免疫反应前后峰值电流差值△i_(p)与OA浓度对数值lgC_(OA)具有良好的线性关系,线性回归方程为△i_(p)=4.1915+2.1679lgC_(OA),线性相关系数R2=0.9578,检测限为18.1 ng/L(S/N=3)。该传感器检测限低、线性工作区间宽、操作简便。

Polythionine(PTh)was modified on the surface of gold electrode by cyclic voltammetry.And the antibodies were immobilized by the Schiff base reaction with glutaraldehyde due to the large number of-NH_(2) functional groups on the surface of PTh.Finally,a label-free amperometric immunosensor was constructed for the quantitative detection of okadaic acid(OA)based on the principle of antigen-antibody specific immune response.The immunosensor was used to detect the OA concentration by square wave voltammetry(SWV).In the range of 0.1~100μg/L,the peak current △i_(p),and OA concentration difference before and after the immune reaction had a linear relationship to lgC_(OA).The linear regression equation is △i_(p),=4.1915+2.1679lgC_(OA) with a linear correlation coeficient R2=0.9578.The detection limit is 18.1 ng/L(S/N=3).The sensor has low detection limit,wide linear working range and simple operation.