Hubei Key Laboratory of Pollutant Analysis & Reuse Technology, Department of Chemistry, Hubei Normal University, Huangshi 435002, PR China.
Hubei Key Laboratory of Pollutant Analysis & Reuse Technology, Department of Chemistry, Hubei Normal University, Huangshi 435002, PR China.
Biosens Bioelectron. 2017 Sep 15;95:15-20. doi: 10.1016/j.bios.2017.04.007. Epub 2017 Apr 11.
A thionine (TH)-doped mesoporous silica nanosphere (MSN)/polydopamine (PDA) nanocomposite was synthesized for developing a new signal transduction strategy of electrochemical immunoassay. This nanocomposite was synthesized through one-pot loading of TH and in situ formation of PDA-coating on MSN. After antibody labeling, the obtained nanoprobe was used for the signal tracing of sandwich immunoassay at a magnetic bead-assay platform. Based on the specific capture of the MSN-TH/PDA nanoprobes through sandwich immunoreaction to form a magnetic immunocomplex and the following treatment of the immunocomplex with a NaOH solution, the PDA film coated on MSN was destroyed to release TH tags from the nanoprobe. The released TH was then electrochemically measured at a carbon nanotube (CNT)-modified electrode for the signal transduction of the method. Due to the high loading of TH on the nanoprobe for tag release and effective electrochemical signal enhancement by the electrode modification of CNTs, ultrahigh sensitivity was achieved. Using human IgG as a model analyte, this method showed a wide linear range over four orders of magnitude and a low detection limit of 5.8pg/mL. Additionally, the method has excellent specificity, satisfactory reproducibility and stability as well as acceptable reliability. Due to the simple preparation of the nanoprobe and the low cost, convenient operation of the detection strategy, this nonenzymatic immunoassay method possesses great potentials for practical applications.
一种噻嗪（TH）掺杂介孔硅纳米球（MSN）/聚多巴胺（PDA）纳米复合材料被合成用于开发电化学免疫分析的新信号转导策略。该纳米复合材料通过 TH 的一锅加载和 MSN 上原位形成 PDA 涂层来合成。抗体标记后，所得纳米探针在磁珠分析平台上用于夹心免疫分析的信号跟踪。基于 MSN-TH/PDA 纳米探针通过夹心免疫反应特异性捕获形成磁免疫复合物，以及随后用 NaOH 溶液处理免疫复合物，将 PDA 膜从纳米探针上释放出来。然后通过在碳纳米管（CNT）修饰电极上电化学测量释放的 TH 来进行方法的信号转导。由于纳米探针上用于标记物释放的 TH 高负载和 CNT 电极修饰的有效电化学信号增强，实现了超高灵敏度。用人 IgG 作为模型分析物，该方法在四个数量级范围内显示出宽线性范围和 5.8pg/mL 的低检测限。此外，该方法具有出色的特异性、令人满意的重现性和稳定性以及可接受的可靠性。由于纳米探针的简单制备和检测策略的低成本、方便操作，这种无酶免疫分析方法具有很大的实际应用潜力。
