Fluorescence turn-on detection of target sequence DNA based on silicon nanodot-mediated quenching
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.
KeywordsSilicon nanodots DNA probe Fluorescent sensor The synthetic target miRNA-27a
This work was supported by the National Natural Science Foundation of China (21475101, 21675119).
Compliance with ethical standards
The study was approved by the Ethical Committee of Wuhan University. Human fluid samples used in this study do not have any identifying information about all the participants that provided written informed consent.
Conflict of interest
The authors declare that they have no conflict of interest.
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