链置换反应触发G-四链体DNA酶双向自组装用于高灵敏均相比色生物传感

Strand Displacement-Triggered Bidirectional Self-Assembly of G-Quadruplexe DNAzymes for Ultrasensitive Homogeneous Colorimetric Biosensing

结合高特异性核酸适配体识别及链置换作用触发杂交链反应,成功实现了大量G-四链体DNA酶活性结构的双向自组装,进一步利用该DNA酶优良的类过氧化物酶性质发展了一种凝血酶(Tb)均相比色生物传感新方法。基于链置换辅助的目标物循环作用以及杂交链反应引起的DNA酶双向自组装信号放大,该方法可在3个数量级线性范围内实现对Tb的高灵敏检测,检测限为0.82 pmol·L^-1。

In combination of the highly specific aptamer-biorecognition with the strand displacement-triggered hybridization chain reaction(HCR),we successfully realized the bidirectional self-assembly of the active structures of a large amount of G-quadruplexe DNAzymes.By further employment of the excellent peroxidase-mimicking property of the formed DNAzymes,we developed a novel thrombin(Tb)homogeneous colorimetric biosensing method.Based on the signal amplifications of the strand displacement-assisted target recycling and the HCR-caused bidirectional self-assembly of DNAzymes,this method can be used for the ultrasensitive detection of Tb in a wide linear range of three orders of magnitude with a detection limit of 0.82 pmol·L^-1.