Li Yueyun, Zhang Yihe, Jiang Liping, Chu Paul K, Dong Yunhui, Wei Qin
Beijing Key Laboratory of Materials Utilization of Nonmetallic Minerals and Solid Wastes, National Laboratory of Mineral Materials, School of Materials Science and Technology, China University of Geosciences, Beijing, 100083, P. R. China.
School of Chemical Engineering, Shandong University of Technology, Zibo, 255049, P. R. China.
Sci Rep. 2016 Mar 7;6:22694. doi: 10.1038/srep22694.
A sandwich-type immunosensor is designed and fabricated to detect the human immunoglobulin G (HIgG) using polyaniline and tin dioxide functionalized graphene (GS-SnO2-PAN) as the platform and biotin-functionalized amination magnetic nanoparticles composite (B-Fe3O4@APTES) as the label. GS-SnO2-PAN is used as the sensing agent to capture the primary anti-HIgG (Ab1) and SnO2 reduces the stack of GS. The B-Fe3O4@APTES with a large surface area and excellent biocompatibility captures second antibody (Ab2) efficiently based on the highly selective recognition of streptavidin to biotinylated antibody. The B-Fe3O4@APTES has better electro-catalytic activity in the reduction of hydrogen peroxide (H2O2) and the "biotin-streptavidin-biotin" (B-SA-B) strategy leads to signal amplification. Under optimal conditions, the immunosensor has a wide sensitivity range from 1 pg/L to 10 ng/L and low detection limit of 0.33 pg/L (S/N = 3) for HIgG. The immunosensor has high sensitivity, fast assay rate, as well as good reproducibility, specificity, and stability especially in the quantitative detection of biomolecules in serum samples.
设计并制作了一种三明治型免疫传感器，用于检测人免疫球蛋白G（HIgG），该传感器以聚苯胺和二氧化锡功能化石墨烯（GS-SnO₂-PAN）为平台，以生物素功能化胺化磁性纳米颗粒复合材料（B-Fe₃O₄@APTES）为标记物。GS-SnO₂-PAN用作传感剂以捕获抗人免疫球蛋白G一抗（Ab1），且SnO₂减少了石墨烯的堆叠。具有大表面积和优异生物相容性的B-Fe₃O₄@APTES基于链霉亲和素对生物素化抗体的高度选择性识别，有效地捕获二抗（Ab2）。B-Fe₃O₄@APTES在过氧化氢（H₂O₂）还原反应中具有更好的电催化活性，且“生物素-链霉亲和素-生物素”（B-SA-B）策略可实现信号放大。在最佳条件下，该免疫传感器对HIgG的灵敏度范围为1 pg/L至10 ng/L，检测限低至0.33 pg/L（S/N = 3）。该免疫传感器具有高灵敏度、快速检测速率，以及良好的重现性、特异性和稳定性，尤其适用于血清样本中生物分子的定量检测。
