School of Chemistry and Chemical Engineering, University of Chinese Academy of Sciences, 19A YuQuan Road, Beijing 100049, China.
Beijing National Laboratory for Molecular Sciences, Key Laboratory of Colloids and Surfaces, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
Biosens Bioelectron. 2015 Sep 15;71:82-87. doi: 10.1016/j.bios.2015.04.012. Epub 2015 Apr 8.
A label-free electrochemical immunosensor for sensitive detection of α-fetoprotein (AFP) was developed based on graphene/SnO2/Au nanocomposite. The graphene/SnO2/Au nanocomposite modified glassy carbon electrode was used to immobilize α-fetoprotein antibody (anti-AFP) and to construct the immunosensor. Results demonstrated that the peak currents of Ru(NH3)6 decreased due to the interaction between antibody and antigen on the modified electrode. Thus, a label-free immunosensor for the detection of AFP was realized by monitoring the peak current change of Ru(NH3)6. The factors influencing the performance of the immunosensor were investigated in details. Under optimal conditions, the peak currents obtained by DPV decreased linearly with the increasing AFP concentrations in the range from 0.02 to 50 ng mL(-1) with a linear coefficient of 0.9959. This electrochemical immunoassay has a low detection limit of 0.01 ng mL(-1) (S/N=3) and was successfully applied to the determination of AFP in serum samples.
基于石墨烯/SnO2/Au 纳米复合材料，开发了一种用于灵敏检测甲胎蛋白（AFP）的无标记电化学免疫传感器。将石墨烯/SnO2/Au 纳米复合材料修饰的玻碳电极用于固定甲胎蛋白抗体（抗 AFP）并构建免疫传感器。结果表明，由于修饰电极上抗体和抗原之间的相互作用，Ru(NH3)6 的峰电流减小。因此，通过监测Ru(NH3)6的峰电流变化，实现了用于 AFP 检测的无标记免疫传感器。详细研究了影响免疫传感器性能的因素。在最佳条件下，通过 DPV 获得的峰电流随 AFP 浓度在 0.02 至 50 ng mL(-1) 范围内呈线性降低，线性系数为 0.9959。这种电化学免疫分析具有 0.01 ng mL(-1)（S/N=3）的低检测限，并成功应用于血清样品中甲胎蛋白的测定。
