State Key Lab of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, 130022, Jilin, China.
J Fluoresc. 2012 Jan;22(1):43-6. doi: 10.1007/s10895-011-0935-y. Epub 2011 Aug 9.
We develop a novel single fluorophore-labeled double-stranded oligonucleotide (OND) probe for rapid, nanostructure-free, fluorescence-enhanced nucleic acid detection for the first time. We further demonstrate such probe is able to well discriminate single-base mutation in nucleic acid. The design takes advantage of an inherent quenching ability of guanine bases. The short strand of the probe is designed with an end-labeled fluorophore that is placed adjacent to two guanines as the quencher located on the long opposite strand, resulting in great quenching of dye fluorescence. In the presence of a target complementary to the long strand of the probe, a competitive strand-displacement reaction occurs and the long strand forms a more stable duplex with the target, resulting in the two strands of the probe being separated from each other. As a consequence of this displacement, the fluorophore and the quencher are no longer in close proximity and dye fluorescence increases, signaling the presence of target.
我们首次开发了一种新型的单荧光标记双链寡核苷酸（OND）探针，用于快速、无纳米结构、荧光增强的核酸检测。我们进一步证明，这种探针能够很好地区分核酸中的单碱基突变。该设计利用了鸟嘌呤碱基固有的淬灭能力。探针的短链设计有一个末端标记的荧光团，该荧光团放置在两个相邻的鸟嘌呤上，作为位于长链相反链上的淬灭剂，从而大大淬灭染料荧光。在存在与探针长链互补的靶标时，会发生竞争性的链置换反应，长链与靶标形成更稳定的双链，导致探针的两条链彼此分离。由于这种置换，荧光团和淬灭剂不再靠近，染料荧光增加，表明存在靶标。
