应用吸附法将IgG抗原固定于多壁碳纳米管修饰的玻碳电极表面,制备用于IgG抗体检测的电化学免疫传感器。以辣根过氧化物酶为标记物,对苯二酚为底物,利用辣根过氧化物酶标记IgG抗体与待测IgG抗体竞争电极表面固定的IgG抗原,建立了免疫竞争法检测IgG抗体的高灵敏度电化学分析方法。碳纳米管的大比表面积和电化学催化作用,提高了分子识别物质的固定量和电化学检测的灵敏度。工作电位为+0.030 V(vs.SCE)时,响应电流与IgG抗体浓度在0.30-10μg/mL范围内呈良好的线性关系,检出限为0.11μg/mL。
A highly sensitive amperometric immunosensor for anti-IgG antibody based on a glassy carbon electrode modified with multiwall carbon nanotubes (MWNT) was developed. A MWNT layer formed on a glass carbon electrode was utilized as a sensing platform for the immobilization of IgG antigen and a competitive immunoreaction occurred while analyte anti-IgG antibody and horseradish peroxidase (HRP)-labeled anti-IgG antibody competed for the surface-immobilized IgG antigen binding sites. The catalytic reduction current at t0. 030 V (vs. SCE), which was produced in the reaction of hydroquinone with hydrogen peroxide in the presence of HRP, was linear over a range from 0. 30 to 10 μg/mL anti-IgG antibody with a detection limit of 0. 11 μg/mL.