中文摘要：

构建了测定人血清中甲胎蛋白（AFP）的电化学免疫传感器。此免疫传感器的制备采用恒电位法在膨胀石墨（EG）电极表面合成聚吡咯（PPy）,再以戊二醛（GA）作为交联剂,固定辣根过氧化酶标记的AFP抗体（HRP-anti-AFP）。此免疫传感器在含AFP的溶液中于35℃温育50 min后,再在传感器表面修饰普鲁士蓝（PB）作为电子介体,抗原抗体免疫结合产生的免疫复合物会导致HRP对PB催化氧化的效率降低。在优化条件下,AFP的浓度在0.01～300μg/L范围内呈线性关系,检出限为6.25 pg/mL（S/N=3）。这种基于PPy修饰EG电极的免疫传感器制备简单,灵敏度高且价格低廉,有望成为一次性电化学免疫传感器。

英文摘要：

An electrochemical immunosensor for rapid detection of alphafetoprotein（AFP） was proposed.Polypyrrole（PPy） was firstly synthesized on the surface of expanded graphite（EG） electrode by potentiostatic method,and then horseradish peroxidase（HRP） labeled AFP-antibody（HRP-anti-AFP） was fixed on the immunosensor interface by using glutaraldehyde（GA） as coupling reagent.After incubation of the immunosensor in the solution containing AFP sample at 35 ℃ for 50 min,Prussian blue（PB） was immobilized onto the immunosensor interface as electron mediator.The immune complexes produced by the combination of antibody and antigen reduced the oxidation peak current of PB.Under optimized experimental conditions,AFP was detected in a concentration range from 0.01 to 300 μg/L and a detection limit of 6.25 ng/L（S/N=3） was obtained.Considering its simplicity,high sensitivity and low cost,the immunosensor based on PPy modified EG electrode is feasible to be developed as a disposable electrochemical sensor for clinical purposes.