在癌细胞源性外泌体中，微小RNA(miRNA)是重要的癌症生物标志物。本文首次建立了带有增强电化学发光(ECL)和极高稳定性的阳离子化金@发光胺基酚纳米颗粒((+)Au@luminol NPs)，用于对外泌体中miRNA-21的敏感检测。在miRNA-21的存在下，通过使用二戈DNA燃料链(DHP1和DHP2)在金纳米颗粒和ZIF-67金属-有机框架修饰的玻碳电极(AuNP/ZIF-MOF/GCE)上进行了哑铃杂交链式反应(DHCR)。形成的DHCR聚合物带有负电荷，并能电静力吸附大量(+)Au@luminol NPs，产生强烈的ECL信号。将DHCR信号扩增与(+)Au@luminol NPs增强剂相结合，实现了对miRNA-21的敏感检测，其检测限为0.43 fM。此外，该方法成功地应用于健康人群和乳腺癌患者血清样本中miRNA-21的分析，显示了在早期临床诊断中的潜在应用价值。版权所有 © 2023 Elsevier B.V.。保留所有权利。

MicroRNAs (miRNAs) are important cancer biomarkers in cancer cell-derived exosomes. Herein, positively charged Au@luminol nanoparticles ((+)Au@luminol NPs) with enhanced electrochemiluminescence (ECL) and extreme stability were firstly established for the sensitive detection of miRNA-21 in exosome. In the presence of miRNA-21, dumbbell hybridization chain reaction (DHCR) happened at gold nanoparticles and ZIF-67 metal-organic framework modified glass carbon electrode (AuNP/ZIF-MOF/GCE) with the help of dumbbell DNA fuel strands (DHP1 and DHP2). The formed DHCR polymers were negatively charged and could electrostatically adsorb numbers of (+)Au@luminol NPs to produce strong ECL signal. Combing DHCR signal amplification with (+)Au@luminol NPs enhancer, sensitive detection of miRNA-21 realized with a detection limit of 0.43 fM. Moreover, the proposed method was successfully applied for the analysis of miRNA-21 in serum samples of healthy individuals and breast cancer patients, indicating a potential application value in early clinical diagnosis.Copyright © 2023 Elsevier B.V. All rights reserved.