化学
DNA
寡核苷酸
检出限
适体
劈理(地质)
杂交探针
生物物理学
分子生物学
生物化学
A-DNA
色谱法
断裂(地质)
生物
工程类
岩土工程
作者
Haiying Gan,Jie Wu,Huangxian Ju
标识
DOI:10.1016/j.aca.2019.05.013
摘要
A simple proximity hybridization-induced on particle DNA walker was designed for ultrasensitive detection of proteins, for example platelet-derived growth factor (PDGF-BB) secreted by cancer cells, in which the DNA walker was activated by specific target binding and powered by an enzymatic cleavage to produce amplified signal. High-density FAM-labeled hairpin oligonucleotides (FAM-DNA1) were functionalized on AuNPs to construct three-dimensional (3D) DNA tracks. The specific binding of PDGF-BB with two aptamer probes (DNA3 and DNA4) led to the proximity hybridization-induced DNA displacement and the free of DNA walker (DNA2) to perform movement on the 3D tracks by an enzymatic cleavage, resulting in the release of massive FAM-DNA1 fragments from the AuNPs and the generation of fluorescent signal. This DNA walker based sensing strategy could detect PDGF-BB in a concentration range of 4 orders of magnitude with a detection limit down to sub-pM level. The practical applicability of the assay was demonstrated by detecting PDGF-BB secreted from MCF-7 cells with satisfactory results. The proposed DNA walker based assay could conveniently detect PDGF-BB with high sensitivity and good accuracy, along with the good extensibility of the assay, showing promise for practical diagnosis.
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