Key Laboratory of Modern Agricultural Equipment and Technology, Ministry of Education, School of Agricultural Engineering, Jiangsu University, Zhenjiang, Jiangsu 212013, China.
Key Laboratory of Modern Agricultural Equipment and Technology, Ministry of Education, School of Agricultural Engineering, Jiangsu University, Zhenjiang, Jiangsu 212013, China.
J Hazard Mater. 2022 Feb 15;424(Pt B):127480. doi: 10.1016/j.jhazmat.2021.127480. Epub 2021 Oct 12.
Signal amplification provides an effective way to improve detection performance. Herein, an ultrasensitive electrochemiluminescence (ECL) aptasensor for Pb detection was developed based on a dual signal-amplification strategy of the abscission of a quencher and the generation of a G-quadruplex by one-step and simultaneous way. Nitrogen-doped carbon quantum dots linked with complementary DNA (cDNA-NCQDs) at the sensing interface was applied as the quencher of a tris(4,4'-dicarboxylic acid-2,2'-bipyridyl)ruthenium(II) (Ru(dcbpy))/tripropylamine system to minimize the ECL signal due to the intermolecular hydrogen bond-induced energy-transfer process. Upon the addition of Pb, its specific binding with the aptamer triggered the abscission of cDNA-NCQDs, accompanied by the formation of G-quadruplex on the surface of the electrode, both of which amplified the intensity of the light emission. The ECL amplification efficiency induced by the above two mechanisms (78.6%) was valuably greater than that of their sum value (69.3%). This synergistic effect resulted in high detection sensitivity of the ECL aptasensor, which allowed to thereby obtain Pb measurements in the range of 1 fM - 10 nM with an ultra-low detection limit of 0.19 fM. The Pb-mediated synergistic signal-amplification ECL strategy can provide a new approach for integrating various amplification strategies.
信号放大为提高检测性能提供了有效的方法。本文基于一种通过一步和同时的方式切除猝灭剂和生成 G-四链体的双重信号放大策略，开发了一种用于 Pb 检测的超灵敏电化学发光（ECL）适体传感器。在传感界面上，与互补 DNA（cDNA-NCQDs）连接的氮掺杂碳量子点被用作三（4,4'-二羧酸-2,2'-联吡啶）钌（II）（Ru(dcbpy))/三丙胺体系的猝灭剂，以最大限度地减少由于分子间氢键诱导的能量转移过程而导致的 ECL 信号。加入 Pb 后，其与适体的特异性结合触发了 cDNA-NCQDs 的切除，同时在电极表面形成 G-四链体，这两者都放大了发光强度。这两种机制（78.6%）引起的 ECL 放大效率大大高于它们的总和值（69.3%）。这种协同效应导致 ECL 适体传感器具有高检测灵敏度，从而可以在 1 fM-10 nM 的范围内进行 Pb 测量，检测限低至 0.19 fM。这种 Pb 介导的协同信号放大 ECL 策略为整合各种放大策略提供了一种新方法。
