Key Laboratory of Luminescence Analysis and Molecular Sensing (Southwest University), Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, P. R. China.
ACS Sens. 2022 Oct 28;7(10):3208-3215. doi: 10.1021/acssensors.2c01832. Epub 2022 Oct 14.
Herein, an exogenous luminophore-free and disposable electrochemiluminescence (ECL) biosensor was established for rapid response of acute myocardial infarction (AMI) using programmable Y-shaped probes (Y-probes) with proximity bivalent recognition. Specifically, the indium tin oxide thin film coated glass electrode (ITO) was modified with urchin-like porous TiO microspheres (pTiO MSs), which could achieve strong and stable ECL in SO solution due to the dual promoting effect of the coreaction accelerator pTiO MSs, exhibiting 2.7-fold higher ECL intensity in comparison with that of bare ITO. Moreover, the Y-probes as bivalent recognition elements containing two kinds of cardiac troponin I (cTnI, a biomarker of AMI) aptamers and a linker labeled with ferrocene (L-Fc) were designed to export a "signal off" mode. When the target cTnI was in the proximity of the Y-probes, the L-Fc was separated from the electrode surface due to the proximity recognition of cTnI and its aptamers, achieving the highly effective recovery of ECL, which allowed for a much more rapid detection of cTnI than the sandwich-type immunoassay. As a proof of concept, an exogenous luminophore-free and disposable ECL platform for rapid and sensitive monitoring of cTnI was obtained and displayed a desired linear range from 100 fg mL to 100 ng mL with a limit of detection (LOD) of 30.1 fg mL, which can be ingeniously expanded as a portable home tester with ECL biosensors developments.
本文建立了一种基于可编程 Y 型探针（Y 探针）近双价识别的外生无荧光素和一次性电化学发光（ECL）生物传感器，用于快速响应急性心肌梗死（AMI）。具体来说，在氧化铟锡（ITO）薄膜涂覆的玻璃电极上修饰了具有仿刺海胆状多孔 TiO 微球（pTiO MSs），由于 pTiO MSs 的核心反应加速剂的双重促进作用，在 SO 溶液中可实现强而稳定的 ECL，与裸 ITO 相比，其 ECL 强度提高了 2.7 倍。此外，Y 探针作为双价识别元件，包含两种心肌肌钙蛋白 I（cTnI，AMI 的生物标志物）适体和一个用二茂铁（L-Fc）标记的连接子，设计为输出“信号关闭”模式。当靶标 cTnI 接近 Y 探针时，由于 cTnI 及其适体的近位识别，L-Fc 从电极表面分离，从而实现 ECL 的高效恢复，这使得比夹心型免疫测定更快速地检测 cTnI。作为概念验证，获得了一种外生无荧光素和一次性 ECL 平台，用于快速灵敏地监测 cTnI，并显示出从 100 fg mL 到 100 ng mL 的期望线性范围，检测限（LOD）为 30.1 fg mL，该平台可以巧妙地扩展为带有 ECL 生物传感器开发的便携式家用测试仪。
