【摘要】 免疫亲和反应引起的导电性的改变比较微弱 ,难以进行电检测。通过采用纳米金修饰羊抗兔IgG ,以及免疫反应 ,形成抗原 -抗体 -纳米金复合体 ,该复合体有序聚集成量子点阵列 ,改变了电荷输运途径并提高导电性 ,实现免疫反应的电检测。采用纤维素薄膜作为固相载体 ,以夹心结构实现免疫渗滤 ,用双环金电极进行交流阻抗谱检测。工作频率为 2 0Hz～ 1MHz。实验结果表明 ,导电性不受游离纳米金粒子影响 ,随着纳米金生物复合体的密度增加而增高。IgG的检测下限可达到 10ng/mL ,工作频率为 10 0Hz时具有最高的灵敏度。最后 ,通过掺杂实验表明 ,掺杂的Ag离子增加低频时的导电性 ,使交流阻抗谱趋于平坦。更多还原

【Abstract】 It is difficult to detect the conductivity alteration of immunoreactions. For this problem, gold nanoparticles was employed to functionalize anti-IgG and the antigen-antibody-nanogold complex formed by immunoreactions. The complex aggregated to quantum dots array, followed by enhancement of charge transfer efficiency and improvement of conductivity. So that, the binding of antigen/antibody, could be detected by electronic methods. With the cellulose film as solid phase, the holed plastics-cellulose-electrode structure was designed for immunofiltration. AC impedance spectrum was measured by the double-ring gold electrode over a frequency range of 20 Hz～1 MHz. The results reveal that conductivity is not devoted by isolated gold nanoparticles, but increased with density of nanogold complex. The limitation of detection for IgG is 10 ng/mL, and the optimized frequency is around 100 Hz. At last, the dope experiment shows that Ag +can improve conductivity of complex in low frequency and make the spectrum more flat.更多还原