PDF(Pubmed)
Abstract：
Leveraging the fluorescence enhancement effect of the G-triplex (G3)/thioflavin T (ThT) catalyzed by the adjacent double-stranded DNA positioned at the 5\' terminus of the G3, the G3-specific oligonucleotide (G3MB6) was utilized to facilitate the rapid detection of mercury (Hg(II)) through thymine-Hg(II)-thymine (T-Hg(II)-T) interactions. G3MB6 adopted a hairpin structure in which partially complementary strands could be disrupted with the presence of Hg(II). It prompted the formation of double-stranded DNA by T-Hg(II)-T, inducing the unbound single strand of G3MB6 to spontaneously form a parallel G3 structure, producing a solid fluorescence signal by ThT. Conversely, fluorescence was absent without Hg(II), since no double strand and formation of G3 occurred. The fluorescence intensity of G3MB6 exhibited a positive correlation with Hg(II) concentrations from 17.72 to 300 nM (R2 = 0.9954), boasting a notably low quality of limitation (LOQ) of 17.72 nM. Additionally, it demonstrated remarkable selectivity for detecting Hg(II). Upon application to detect Hg(II) in milk samples, the recovery rates went from 100.3% to 103.2%.
摘要：
利用位于G35'末端的相邻双链DNA催化的G-三链体（G3）/硫黄素T（ThT）的荧光增强作用，G3特异性寡核苷酸（G3MB6）用于通过胸腺嘧啶-Hg（II）-胸腺嘧啶（T-Hg（II）-T）相互作用促进汞（Hg（II））的快速检测。G3MB6采用发夹结构，其中部分互补链可以在Hg（II）的存在下被破坏。它促使T-Hg（II）-T形成双链DNA，诱导未结合的G3MB6单链自发形成平行的G3结构，通过ThT产生固体荧光信号。相反，无Hg(II)荧光，因为没有双链和G3的形成发生。G3MB6的荧光强度与Hg(II)浓度在17.72至300nM之间呈正相关(R2=0.9954),其质量限制(LOQ)明显较低，为17.72nM。此外,它显示了检测Hg（II）的显着选择性。在应用于检测牛奶样品中的Hg(II)时，回收率从100.3%上升到103.2%。
