Hubei Key Laboratory of Pollutant Analysis & Reuse Technology, Department of Chemistry, Hubei Normal University, Huangshi 435002, PR China.
Analyst. 2019 Aug 5;144(16):5003-5009. doi: 10.1039/c9an00898e.
By employment of an aptamer-initiated hybridization chain reaction (HCR) to enhance the enzyme biomineralization of cupric subcarbonate, this work develops a novel colorimetric biosensing method for protein analysis. The HCR product was used to specifically attach a large amount of urease-functionalized gold nanoparticles (Au NPs) for the preparation of a gold nanoprobe. After the sandwich biorecognition reactions, this nanoprobe could be quantitatively captured onto the antibody-functionalized magnetic bead (MB) platform. Then, numerous copper ions would be enriched onto the MB surface through the urease-induced biomineralization of cupric subcarbonate. Based on the complete release of Cu2+ ions for the sensitive copper chromogenic reaction, convenient colorimetric signal transduction was thus achieved for the quantitative analysis of the target analyte of the carcinoembryonic antigen. The HCR product provides a large number of biotin sites for the attachment of Au NP nanotags. The biomineralization reaction of high-content urease loaded onto Au NPs leads to highly efficient Cu2+ enrichment for signal amplification. So this method features excellent performance including a very wide linear range and a low detection limit down to 0.071 pg mL-1. In addition, the satisfactory results of real sample experiments reveal that this method possesses huge potential for practical applications.
通过适体引发的杂交链式反应（HCR）增强亚碳酸铜的酶生物矿化作用，本工作开发了一种用于蛋白质分析的新型比色生物传感方法。HCR 产物被用于特异性地附着大量脲酶功能化的金纳米粒子（Au NPs），以制备金纳米探针。在三明治生物识别反应后，该纳米探针可以定量地捕获到抗体功能化的磁性珠（MB）平台上。然后，通过脲酶诱导的亚碳酸铜的生物矿化作用，将大量的铜离子富集到 MB 表面上。基于 Cu2+离子的完全释放用于敏感的铜显色反应，实现了方便的比色信号转导，从而对癌胚抗原的目标分析物进行定量分析。HCR 产物为 Au NP 纳米标签的附着提供了大量的生物素位点。高含量脲酶负载到 Au NPs 上的生物矿化反应导致高效的 Cu2+富集，用于信号放大。因此，该方法具有非常宽的线性范围和低至 0.071 pg mL-1 的检测限等优异性能。此外，实际样品实验的满意结果表明，该方法具有巨大的实际应用潜力。
