Key Laboratory of Analysis and Detection for Food Safety (Ministry of Education & Fujian Province), Department of Chemistry, Fuzhou University, 350108 Fuzhou, PR China.
Biosens Bioelectron. 2011 Oct 15;28(1):174-80. doi: 10.1016/j.bios.2011.07.016. Epub 2011 Jul 19.
A new flow-through electrochemical immunosensor was designed for sensitive detection of alpha-fetoprotein (AFP) in human serum by using nanogold-functionalized magnetic graphene nanosheets as immunosensing probes. Initially, amino functionalized magnetic beads were covalently immobilized on the surface of graphene oxide nanosheets (MGPs), then nanogold particles were adsorbed on the amino groups of the MGPs to construct GoldMag nanocomposites functionalized graphene nanosheets (GMGPs), and then horseradish peroxidase-anti-AFP conjugates (HRP-anti-AFP) were assembled onto the surface of nanogold particles (bio-GMGP). With the aid of an external magnet, the formed bio-GMGPs were attached onto the base electrode in the flow system. With a non-competitive immunoassay format, the injected sample containing AFP antigens was produced transparent immunoaffinity reaction with the immobilized HRP-anti-AFP on the bio-GMGPs. The formed immunocomplex inhibited partly the active center of HRP, and decreased the labeled HRP toward the reduction of H(2)O(2). The performance and factors influencing the performance of the immunosensor were investigated in detail. Under optimal conditions, the electrochemical immunosensor displayed a wide working range of 0.01-200 ng mL(-1) with a low detection limit (LOD) of 1.0 pg mL(-1) AFP (at 3s(B)). Intra- and inter-assay coefficients of variation (CV) were below 10%. In addition, the methodology was validated with real serum samples, receiving a good correlation with the results obtained from commercially available electrochemiluminescence automated analyzer.
一种新型的流通式电化学免疫传感器，通过使用纳米金功能化的磁性石墨烯纳米片作为免疫传感探针，用于灵敏检测人血清中的甲胎蛋白（AFP）。首先，氨基功能化的磁性珠通过共价键固定在氧化石墨烯纳米片（MGPs）的表面，然后纳米金颗粒被吸附在氨基上，以构建纳米金颗粒功能化的磁性石墨烯纳米片（GMGPs），然后辣根过氧化物酶-抗 AFP 偶联物（HRP-anti-AFP）被组装到纳米金颗粒表面（bio-GMGP）。在外磁场的帮助下，形成的 bio-GMGPs 被附着在流动系统中的基底电极上。采用非竞争免疫分析形式，注入的含有 AFP 抗原的样品与固定在 bio-GMGPs 上的 HRP-anti-AFP 发生透明的免疫亲和反应。形成的免疫复合物部分抑制 HRP 的活性中心，减少了标记的 HRP 向 H(2)O(2)的还原。详细研究了免疫传感器的性能和影响性能的因素。在最佳条件下，电化学免疫传感器显示出宽的工作范围为 0.01-200ngmL(-1)，检测限（LOD）低至 1.0pgmL(-1) AFP（在 3s(B)下）。内和间分析的变异系数（CV）低于 10%。此外，该方法通过实际血清样本进行了验证，与市售的电化学发光自动分析仪的结果具有良好的相关性。
