基于新型聚钙羧酸修饰电极的甲胎蛋白电化学免疫传感器研究

Electrochemical Immunosensor Based on Polycalconcarboxylic Acid Modified Electrode for the Determination of α-Fetoprotein

通过电聚合制得新型聚钙羧酸修饰电极,并用于构建检测甲胎蛋白(AFP)的高灵敏电化学免疫传感器.采用扫描电镜(SEM)和电化学交流阻抗(EIS)观察、表征修饰电极和AFP单克隆抗体(Ab1)固定前后的差异.固定Ab1的电极与一定浓度的AFP、辣根过氧化物酶(HRP)联AFP单克隆抗体(HRP-Ab2)反应,形成夹心型免疫复合物.辣根过氧化物酶催化3,3',5,5'-四甲基联苯胺(TMB)底物产生电流信号,实现AFP浓度的测定.本检测方法灵敏度高,重现性好.

A highly sensitive electrochemical immunosensor based on novel electropolymerized polycalcon- carboxylic acid modified electrode （poly-CCA/GC） has been fabricated for the detection of α-fetoprotein （AFP）. The differences of the poly-CCA/GC electrodes before and after the immobilization of AFP antibody were characterized via scanning electron microscopy （SEM） and electrochemical impedance spectroscopy （EIS）. The immobilization of antibody/antigen/antibody-HRP sandwich was formed on the poly-CCA modi-fied electrode for the determination of special AFP concentrations. The electrochemical signals generated from the HRP which catalyzed the TMB substrate were measured. Experiment results indicated that the developed immunosensor showed a good sensitivity and precision.