在玻碳电极(GCE)表面固定对H2O2有催化还原活性的富马酸二甲酯联吡啶铜(GCE|CuL);再在GCE|CuL表面修饰一层金磁微粒-壳聚糖复合膜(nanoAu/Fe3O4/Chit),进而固定艾滋病毒(HIV)诊断标志物——包膜糖蛋白(gp160)抗体(antigp160),由此构建了一类快速检测gp160的无试剂安培免疫传感器。当该传感器在含gp160溶液中37℃下温育30min后,传感器表面生成的免疫复合物随gp160浓度的增大而增加,导致CuL对H2O2电催化还原效果降低,催化电流呈现下降趋势。在PBS溶液(pH7.0)和-300mV下,催化电流的降低值ΔIo与gp160浓度在1~400μg/L呈线性关系;检出限为0.5μg/L(3σ)。研制的免疫传感器检测gp160时,一步免疫反应即可得结果,较相同条件下包被gp160抗体的纳米金单分子层修饰电极灵敏度更高,检测范围更宽,有望用于艾滋病人血清标志物gp160快速筛测。
A novel amperometric immunosensor for human immunodefficiency virus (HIV) glyeoprotein 160 (gp160) based on nanoAu/Fe3O4/Chitosan(chit) composite film as immobilization matrix was investigated. Firstly, the complex [ Cu (bpy) 2 (H2O) 12 ( C6H8O4 ) 2 ( CIO4 ) 4 (CuL) was prepared and adsorbed on the surface of glassy carbon electrode (GCE), then nanoAu/Fe3O4/Chitosan composite film was modified on the surface of GCEI CuL and HIV gp160 antibody was furthermore immobilized on the surface to form one gp160 immunosensor(GCEICuL/nanoAu/Fe3O4/Chit/anti gp160). CuL can be employed as an electron transfer mediator for catalytic activity detection of H2O2. After the immunosensor was incubated with HIV gp160 solution at 37℃ for 30 mix, the electron transfer access of CuL to H2O2 is partly inhibited, which led to a linear decrease of the catalytic efficiency to H2O2 by the oxidation of immobilized CuL by H2O2 at -300 mV in pH 7.0 PBS. Under the optimal conditions, the linear range of gp160 by the immunosensor is 1 -400μg/L and the detection limit is 0. 5 μg/L at 3 times noise. The immunosensor shows more sensitivity and accuracy than that only modified by gp160 antibody coated nano Au/chitosan film. This method simplifies the detection system without adding electron transfer media to solution and shortens the analytical time with one-step immunoassay, thus would be valuable for clinical immunoassay for HIV gp160 in AIDs patients' serums