Ultrasensitive colorimetric detection of circulating tumor DNA using hybridization chain reaction and the pivot of triplex DNA.
Ultrasensitive colorimetric detection of circulating tumor DNA using hybridization chain reaction and the pivot of triplex DNA.
复制标题
使用杂交链式反应和三链体 DNA 枢轴对循环肿瘤 DNA 进行超灵敏比色检测
DOI：
10.1038/srep44212
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发表时间：
2017-03-09
影响因子：
4.6
通讯作者：
Ling L
中科院分区：
文献类型：
--
作者：
Li R;Zou L;Luo Y;Zhang M;Ling L
本工作提出了一种用于循环肿瘤DNA（ctDNA）的扩增比色生物传感器，其通过三链体DNA的形成将杂交链反应（HCR）扩增与G-四链体DNA酶活性相关联。在ctDNA存在的情况下，HCR发生。通过三链体DNA和不对称分裂的G-四链体形成的协同作用，所得到的HCR产物被一个序列特异性地识别为包含一个GGG重复序列，另一个序列包含三个GGG重复序列。这种设计利用了HCR的扩增性质和不对称分裂的G-四链体DNA酶的高过氧化物酶样催化活性，其通过三链体DNA形成，在ctDNA存在下产生颜色信号。然而，在没有ctDNA的情况下，没有HCR发生。因此，没有形成三链体DNA和G-四链体结构，产生可忽略的背景。该比色传感平台成功应用于人血浆等复杂生物环境中的ctDNA检测，检测限对应于0.1 pM。本研究明确地使用三链DNA形成为支点，整合核酸扩增和DNA酶，以产生具有低背景的高灵敏度信号。
This work presents an amplified colorimetric biosensor for circulating tumor DNA (ctDNA), which associates the hybridization chain reaction (HCR) amplification with G-Quadruplex DNAzymes activity through triplex DNA formation. In the presence of ctDNA, HCR occurs. The resulting HCR products are specially recognized by one sequence to include one GGG repeat and the other containing three GGG repeats, through the synergetic effect of triplex DNA and asymmetrically split G-Quadruplex forming. Such design takes advantage of the amplification property of HCR and the high peroxidase-like catalytic activity of asymmetrically split G-Quadruplex DNAzymes by means of triplex DNA formation, which produces color signals in the presence of ctDNA. Nevertheless, in the absence of ctDNA, no HCR happens. Thus, no triplex DNA and G-Quadruplex structure is formed, producing a negligible background. The colorimetric sensing platform is successfully applied in complex biological environments such as human blood plasma for ctDNA detection, with a detection limit corresponding to 0.1 pM. This study unambiguously uses triplex DNA forming as the pivot to integrate nucleic acid amplification and DNAzymes for producing a highly sensitive signal with low background.