分子印迹共聚物电化学检测木犀草素研究

Electrochemical detection of luteolin based on molecularly imprinted copolymer

采用电化学共聚法,以3,4-乙烯二氧噻吩(EDOT)和对氨基酚(p-AP)为双功能单体制备分子印迹共聚物(MIP),结合响应面法优选MIP制备条件,考察MIP对木犀草素的电催化和识别能力。通过阻抗、计时库伦、SEM和XPS对MIP进行电化学和结构表征。结果表明:最佳制备条件为EDOT与p-AP摩尔浓度比为4:2,聚合范围为0~1.4V,聚合圈数为2圈。MIP对木犀草素的峰电流、电荷转移阻力和有效比表面积分别是非分子印迹聚合物(NIP)的约2.8,0.23和2倍,且MIP具有更高的掺杂率和选择性,故展示出更强电催化和识别能力。所建立含量测定方法线性关系良好(R2=0.994),检测限为0.0418μmol·L-1,测得花生壳中木犀草素含量为0.8658%(RSD=2.264%)。

Molecularly imprinted copolymers were prepared by electrochemical copolymerization using 3,4-ethylenedioxythiophene(EDOT)and p-aminophenol(p-AP)as bi-functional monomers.The preparation conditions of MIP were optimized by response surface method.The electrocatalytic and recognition ability of MIP to luteolin was investigated,and the electrochemical behavior and structure of MIP were characterized by impedance,chronocoulometry,SEM and XPS.The results showed that the optimum preparation conditions were as follows:the molar concentration ratio of EDOT to p-AP was 4:2,the polymerization range was O~1.4V,and the number of polymerization cycles was 2.The peak current to luteolin,charge transfer resistance and effective specific surface area of MIP are about 2.8,0.23 and 2 times that of non-molecular-imprinted polymers(NIP),respectively,and MIP had higher doping rate and selectivity,so it exhibited stronger electrocatalysis and recognition capabilities.The established methods had good the linear relationship with the low detection limit of 0.0418μmol.L^(-1),and the content of luteolin in peanut shell was 0.8658%(RSD%=2.264%).