Key Laboratory of Luminescence Analysis and Molecular Sensing (Southwest University), Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University, Chongqing, 400715, PR China.
Key Laboratory of Luminescence Analysis and Molecular Sensing (Southwest University), Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University, Chongqing, 400715, PR China.
Biosens Bioelectron. 2023 Oct 1;237:115539. doi: 10.1016/j.bios.2023.115539. Epub 2023 Jul 20.
Constructing mono-luminophor-based electrochemiluminescence (ECL) ratio system is a great challenge due to the limitations of the luminescent species with dual-signal-output, luminescence efficiency and coreactant. This work developed carboxyl-functionalized poly[9,9-bis(3'-(N,N-dimethylamino) propyl)-2,7-fluorene]-alt-2,7-(9,9 dioctylfluorene)] nanoparticles(PFN NPs) as dual-emitting luminophors, which can synchronously output strong cathodic and anodic ECL signals without any exogenous coreactants. The inherent molecular structure enabled efficient intramolecular electron transfer between tertiary amine groups and backbone of PFN to generate strong cathodic and anodic ECL emission. Particularly, H in aqueous solution played an irreplaceable role for cathodic ECL emission. The silver nanoparticles (AgNPs) were developed as signal regulator because of their excellent hydrogen evolution reaction (HER) activity, which significantly quenched the cathodic signal while kept the anodic signal unchanged. The dual-emitting PFN NPs cleverly integrated signal regulator AgNPs and bicyclic strand displacement amplification (SDA) to construct a coreactant-free mono-luminophor-based ratiometric ECL sensing for SARS-CoV-2 RdRp gene assay. The strong dual-emitting of PFN NPs and excellent quenching effect of AgNPs on cathodic emission endowed the biosensor with a high detection sensitivity, and the detection limit was as low as 39 aM for RdRp gene. The unique dual-emitting properties of PFN NPs open up a new path to construct coreactant-free mono-luminophor-based ECL ratio platform, and excellent HER activity of AgNPs offers some new thoughts for realizing ECL signal changes.
构建基于单发光体的电化学发光（ECL）比率系统是一个巨大的挑战，因为具有双信号输出、发光效率和共反应物的发光体有限。本工作开发了羧基功能化的聚[9,9-双（3'-(N,N-二甲基氨基)丙基）-2,7-芴]-交替-2,7-(9,9 二辛基芴)]纳米粒子（PFN NPs）作为双发射发光体，无需任何外源共反应物即可同步输出强的阴极和阳极 ECL 信号。固有分子结构使三级胺基团和 PFN 骨架之间能够发生有效的分子内电子转移，从而产生强的阴极和阳极 ECL 发射。特别是，H 在水溶液中对阴极 ECL 发射起着不可替代的作用。银纳米粒子（AgNPs）由于其出色的析氢反应（HER）活性而被开发为信号调节剂，它可以显著猝灭阴极信号而保持阳极信号不变。双发射 PFN NPs 巧妙地集成了信号调节剂 AgNPs 和双环链置换扩增（SDA），构建了无共反应物的单发光体比率型 ECL 传感，用于 SARS-CoV-2 RdRp 基因分析。PFN NPs 的强双发射和 AgNPs 对阴极发射的出色猝灭效应赋予了该生物传感器高的检测灵敏度，对 RdRp 基因的检测限低至 39 aM。PFN NPs 的独特双发射特性为构建无共反应物的单发光体 ECL 比率平台开辟了新途径，AgNPs 的出色 HER 活性为实现 ECL 信号变化提供了新的思路。
