Ministry of Education Key Laboratory of Analysis and Detection for Food Safety, Department of Chemistry, Fuzhou University, Fuzhou 350108, PR China.
Talanta. 2012 Mar 15;91:95-102. doi: 10.1016/j.talanta.2012.01.025. Epub 2012 Jan 18.
A novel redox-active magnetic nanostructure was synthesized by using a wet chemical method for high-efficiency electrochemical immunoassay of carcinoembryonic antigen (CEA, as a model analyte). The nanostructures based on the combination of a magnetic nanocore, a layer of electroactive poly(o-phenylenediamine) (PPD), and a silver metallic shell displayed good adsorption properties for the attachment of anti-CEA antibody selective to CEA. The magnetic nanostructure presented good redox behaviors to facilitate and modulate the way it was integrated into a magnetic carbon paste electrode. The assay was based on a sandwich-type immunoassay protocol by using nanogold-patterned graphene oxide nanoscales (AuNP-GO), conjugated with horseradish peroxidase-labeled anti-CEA, as secondary antibodies and biofunctionalized magnetic nanostructures as immunosensing probes. Under optimal conditions, the nanoparticle-based immunocomposites exhibited good electrochemical responses for the determination of CEA, and allowed the detection of CEA at a concentration as low as 1.0 pg mL(-1) at a signal-to-noise ratio of 3. In addition, the magnetic immunosensing had good reproducibility, and acceptable accuracy, and could be successfully applied for the detection of CEA in the clinical serum specimens. Significantly, by controlling the target biomolecules, this assay can be easily extended for use with other immunosensings, and thus represents a versatile design routine.
一种新型的氧化还原活性磁性纳米结构通过湿化学方法合成，用于高效电化学免疫测定癌胚抗原（CEA，作为模型分析物）。该纳米结构基于磁性纳米核、一层电活性聚邻苯二胺（PPD）和银金属壳的组合，具有良好的吸附性能，可用于附着对 CEA 具有选择性的抗 CEA 抗体。磁性纳米结构表现出良好的氧化还原行为，有助于调节其与磁性碳糊电极集成的方式。该测定基于三明治型免疫测定方案，使用纳米金图案化氧化石墨烯纳米级（AuNP-GO）作为二级抗体，与辣根过氧化物酶标记的抗 CEA 结合，并用作生物功能化磁性纳米结构的免疫传感探针。在最佳条件下，基于纳米颗粒的免疫复合物对 CEA 的测定表现出良好的电化学响应，允许在信噪比为 3 时以低至 1.0 pg mL(-1)的浓度检测 CEA。此外，磁性免疫测定具有良好的重现性和可接受的准确性，可成功应用于临床血清标本中 CEA 的检测。重要的是，通过控制目标生物分子，该测定可以很容易地扩展用于其他免疫测定，因此代表了一种通用的设计常规。
