以G-三链体/硫黄素T为探针非标记荧光法检测DNA

Label-free fluorescence method for DNA detection using G-triplex/thioflavin T as signal probes

为了获得一种简单、灵敏、低成本的DNA检测方法,提出了一种非标记荧光定量检测DNA的方法。信号探针(Signal DNA)和封闭探针(Block DNA)通过部分杂交形成双链DNA结构。所形成的双链DNA结构与靶标DNA作用,释放出一段富G的DNA序列;此富G的DNA序列可形成G-三链体(G-triplex,G3),可结合硫黄素T(ThT)形成G3/ThT复合物,产生强的荧光信号。通过测定体系中荧光的强度,实现对目标DNA的定量检测,检出限为21 nmol/L。该方法不需要标记荧光染料,成本低,操作简单,灵敏高,在DNA定量检测领域有良好的应用前景。

In order to obtain a simple,sensitive and low-cost DNA detection method,a label-free fluorescence method for DNA detection is proposed.The signal DNA probe and the block DNA probe form a double-stranded DNA structure by partial hybridization.The formed double-stranded DNA structure interacts with the target DNA to release a G-rich DNA sequence.This G-rich DNA sequence can form G-triplex(G3),which can bind with thioflavin T(ThT)to form G3/ThT complex to produce strong fluorescent emission.Quantitative detection of target DNA can be achieved by measuring the intensity of fluorescence in the system.The detection limit of this method is 21 nM.This method does not need to label fluorescent dyes,featuring low cost,simple operation and high sensitivity,showing a good application prospect in the field of DNA quantitative detection.