Fluctuation of nucleic acid expression and ultrasensitive and specific detection of these variations in expression is a crucial subject in molecular medicine and clinical theranostics. A novel DNAzyme-coupled branched hybridization chain reaction (b-HCR) assay is reported for efficient signal-amplified detection of miRNA in this study. This assay was composed of a translator (T) hybridized with miR-21 to initiate the first HCR by hairpin 1 (H₁) and hairpin 2 (H₂). The primary HCR provided a backbone chain for numerous branches budding through hairpin 3 (H₃) and hairpin 4 (H₄) assembles. In the presence of hemin, the G-rich domains embedded in H1 and H4 produce an active G-quadruplex DNAzyme upon exposure to a target that could catalyze the oxidation of colorless substrate to colored product. The present approach has the potential to be used for quantitative detection of miR-21 with a sensitivity and a dynamic range of 1 pM and 1 pM to 1 nM, respectively.

核酸表达的波动以及这些表达差异的超灵敏和特异性检测是分子医学和临床治疗学中的关键课题。这项研究中报道了一种新颖的DNA酶偶联的分支杂交链反应（b-HCR）检测方法，可用于miRNA的有效信号放大检测。该测定法由与miR-21杂交的翻译器（T）组成，通过发夹1（H ₁）和发夹2（H ₂）启动第一个HCR 。主要HCR为发夹3（H ₃）和发夹4（H ₄）萌芽的许多分支提供了主链。）组装。在存在血红素的情况下，嵌入到H1和H4中的富含G的结构域在暴露于可催化无色底物氧化为有色产物的靶标时产生活性G-四链体DNA酶。本方法具有用于灵敏度和动态范围分别为1 pM和1 pM至1 nM的miR-21定量检测的潜力。