纳米金与磁性纳米复合物构建电流型免疫传感器的研究

制备了易于磁性分离、硫堇(Thi)包覆的四氧化三铁(Fe3O4)纳米复合物。通过静电吸附作用,将萘酚(Nafion)、Thi包覆的Fe3O4复合纳米粒子层层修饰到玻碳电极表面,再利用Thi分子中的氨基吸附纳米金,最后固载甲胎蛋白抗体,从而制得灵敏度高、稳定性好的无试剂电流型甲胎蛋白免疫传感器。实验通过透射电子显微镜(TEM)对该复合纳米粒子进行表征,并用循环伏安法考察了电极的电化学特性。结果表明,Fe3O4/Thi复合纳米粒子修饰的电极在实验过程中呈现出良好的氧化还原活性,其检测范围为0.05～20μg/L,检出限为0.03μg/L。

Study of the Amperometric Immunosensor Based on Gold Nanoparticles and Magnetic Nanocomposite

A new reagentless amperometric immunosensor for the detection of α-fetoprotein antibody(anti-AFP) molecule based on Nafion,Fe3O4@ thionine and gold nanoparticles was fabricated.Firstly,Fe3O4@ thionine nanoparticles were prepared by magnetic separation method.Nafion、Fe3O4@ thionine nanoparticles were modified on glassy carbon electrode layer by layer through electrostatic adsorption,then the NH2 of thionine molecules was used to adsorbed the gold nanoparticles.Finally,with function of gold nanoparticles adsorbing AFP antibody,a reagentless amperometric AFP immunosensor with high stability and sensitivity was prepared successfully.Transmission electron microscopy and cyclic voltammetry were used to characterize the composite nanoparticles and the property of the immunosensor.Under the optimal conditions,the immunosensor had a good current response to AFP with a detection range of 0.05-20 μg/L and a detection limit of 0.03 μg/L.