Nowadays, aggregation-caused quenching (ACQ) of organic molecules in aqueous media seriously restricts their analytical and biomedical applications. In this work, hydrogen bond (H-bond) was utilized to resist the ACQ effect of 2,5,8-triamino-1,3,4,6,7,9,9b-heptaazaphenalene (Melem) as an advanced electrochemiluminescence (ECL) luminophore, whose ECL process was carefully studied in an aqueous K₂S₂O₈ system coupled with electron paramagnetic resonance (EPR) measurements. Notably, the H-bond-induced Melem assemblies (Melem-H) showed 16.6-fold enhancement in the ECL signals as compared to the Melem aggregates (Melem-A), combined by elaborating the enhanced mechanism. On such basis, the effective ECL signal transduction was in situ achieved through the specific recognition of the double-stranded DNA embedded in Melem-H assemblies (Me-dsDNA) with spike protein (SP) of coronavirus disease 2019 (COVID-19). For that, such an ECL biosensor showed a wider linear range (1.0–125.0 pg mL^–1) with a lower limit of detection (LOD) down to 0.45 pg mL^–1, which also displayed acceptable results in analysis of human nasal swab samples. Therefore, the work provides a distinctive insight on addressing the ACQ effect and broadening the application scope of the organic emitter and offers a simple platform for biomedical detection.

中文翻译：

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氢键诱导的 melem 组装体抵抗聚集引起的淬灭，用于 COVID-19 抗原的超灵敏 ECL 检测


如今，有机分子在水性介质中的聚集诱导淬灭 （ACQ） 严重限制了其分析和生物医学应用。在这项工作中，氢键 （H-bond） 被用来抵抗 2,5,8-三氨基-1,3,4,6,7,9,9b-七氮杂苯 （Melem） 作为高级电化学发光 （ECL） 发光团的 ACQ 效应，其 ECL 过程在水性 K₂S₂O₈ 系统中与电子顺磁共振 （EPR） 测量耦合。值得注意的是，H键诱导的 Melem 组装体 （Melem-H） 显示，与 Melem 聚集体 （Melem-A） 相比，ECL 信号增强了 16.6 倍，通过阐述增强机制。在此基础上，通过特异性识别嵌入在 Melem-H 组装体 （Me-dsDNA） 中的双链 DNA 和 2019 冠状病毒病 （COVID-19） 的刺突蛋白 （SP） 来原位实现有效的 ECL 信号转导。为此，这种 ECL 生物传感器显示出更宽的线性范围 （1.0–125.0 pg mL^–1），检测下限 （LOD） 低至 0.45 pg mL^–1，这在人鼻拭子样本的分析中也显示出可接受的结果。因此，这项工作为解决 ACQ 效应和拓宽有机发射器的应用范围提供了独特的见解，并为生物医学检测提供了一个简单的平台。