We have developed a new enzyme-free method for target sequence DNA detection based on the dynamic quenching of fluorescent silicon nanodots (SiNDs) toward Cy5-tagged DNA probe. Fascinatingly, the water-soluble SiNDs can quench the fluorescence of cyanine (Cy5) in Cy5-tagged DNA probe in homogeneous solution, and the fluorescence of Cy5-tagged DNA probe can be restored in the presence of target sequence DNA (the synthetic target miRNA-27a). Based on this phenomenon, a SiND-featured fluorescent sensor has been constructed for “turn-on” detection of the synthetic target miRNA-27a for the first time. This newly developed approach possesses the merits of low cost, simple design, and convenient operation since no enzymatic reaction, toxic reagents, or separation procedures are involved. The established method achieves a detection limit of 0.16 nM, and the relative standard deviation of this method is 9% (1 nM, n = 5). The linear range is 0.5–20 nM, and the recoveries in spiked human fluids are in the range of 90–122%. This protocol provides a new tactic in the development of the nonenzymic miRNA biosensors and opens a promising avenue for early diagnosis of miRNA-associated disease.

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我们已经开发出一种新的无酶方法，用于基于对Cy5标签DNA探针的荧光硅纳米点（SiNDs）的动态淬灭来进行目标序列DNA检测。令人着迷的是，水溶性SiND可以在均质溶液中猝灭Cy5标记的DNA探针中的花青（Cy5）荧光，并且可以在目标序列DNA（合成的目标miRNA）存在的情况下恢复Cy5标记的DNA探针的荧光。 -27a）。基于此现象，首次构建了具有SiND功能的荧光传感器，用于“开启”检测合成靶标miRNA-27a。由于不涉及酶促反应，有毒试剂或分离程序，这种新开发的方法具有成本低，设计简单和操作方便的优点。建立的方法实现了0.16 nM的检测限，n  = 5）。线性范围为0.5–20 nM，加标的人体液体中的回收率在90–122％的范围内。该协议为非酶miRNA生物传感器的开发提供了新的策略，并为早期诊断与miRNA相关的疾病开辟了一条有希望的途径。

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