基于纳米金/壳聚糖掺杂碳纳米管修饰金电极非标记免疫传感器的研究

Study on Label-free Immunosensor Based on Gold Nanoparticles/Chitosan Incorporating Carbon Nanotubes Composite Membrane Modified Gold Electrode

应用吸附法将羊抗人IgG抗体直接固定于纳米金（GNPs）/壳聚糖（Chit）掺杂碳纳米管（CNTs）修饰的金电极表面,制备了用于人IgG抗原检测的非标记电化学免疫传感器。利用循环伏安法和交流阻抗研究了修饰电极表面的电化学特性,用差分脉冲伏安法研究了测试底液的pH值对免疫传感器性能的影响。实验表明,在含不同浓度人IgG的PBS溶液（pH7.0）中,免疫传感器的响应电流与人IgG的质量浓度在0.05~455μg/L范围内呈良好的线性关系,相关系数（r2）为0.991 1,其检出限（S/N=3）为0.01μg/L。与传统方法相比,该免疫传感器无需信号放大试剂,具有制备简单、灵敏度高、稳定性好等特点。

A highly sensitive label-free electrochemical immunosensor was developed for the determination of human IgG based on a gold electrode modified with GNPs and carbon nanotubes（CNTs） incorporated with chitosan composite and the IgG antibody was directly absorbed on the modified electrode surface.The electrochemical behaviors of the modified electrode were investigated by cyclic voltammetry（CV） and AC impedance.The influence of electrolyte pH on immunosensor was studied by differential pulse voltammetry（DPV）.A good linearity was obtained between response current and concentration of human IgG antigen in the range of 0.05-455 μg/L,with a correlation coefficient（r2） of 0.991 1.The detection limit（S/N=3） was 0.01 μg/L.Compared with the traditional methods,the immunosensor exhibited the advantages of simple preparation,high sensitivity and long-term stability without any consumption of reagent for signal amplification.