【摘要】 活细胞中低水平miRNA检测的扩增策略对于肿瘤生物标志物的精准检测具有重要意义。因此在本工作中设计了一种在活细胞内利用h-BNNS和四向催化发夹组装（FCHA）技术进行miRNA-21成像的扩增策略。具有低细胞毒性的h-BNNS作为优异的载体和荧光猝灭剂，将修饰有FAM的发夹DNA递送至细胞内。在细胞内miRNA-21的存在下，触发FCHA反应形成十字型DNA结构，以减弱DNA和h-BNNS之间的作用力，同时在一个DNA纳米产物上实现多个荧光信号的标记提高了检测的准确度。这种方法为活细胞内miRNA的超灵敏检测提供了强有力的工具，检测限低至0.5 pmol·L^-1。更多还原

【Abstract】 The amplification strategy of low level miRNA detection in living cells is of great significance for the accurate detection of tumor biomarkers. This work was designed an amplification strategy for miRNA-21 imaging using h-BNNS and four-way catalytic hairpin assembly（FCHA）in living cells. As an excellent carrier and fluorescence quencher, h-BNNS with low cytotoxicity delivers hairpin DNA modified with FAM into cells. In the presence of miRNA-21, the FCHA reaction is triggered to form a cross DNA structure for weakening the force between DNA and h-BNNS. At the same time, the labeling of multiple FAM signal on a DNA nanoproduct improves the detection accuracy. This method provides a powerful tool for the ultrasensitive detection of miRNA in living cells, and the detection limit is as low as 0. 5 pmol · L^-1.更多还原