Fluorescence Aptameric Sensor for Strand Displacement Amplification Detection of Cocaine
Fluorescence Aptameric Sensor for Strand Displacement Amplification Detection of Cocaine
复制标题
用于可卡因链位移扩增检测的荧光适体传感器
DOI：
10.1021/ac902416u
复制
发表时间：
2010-02-15
影响因子：
7.4
通讯作者：
Yu, Ru-Qin
中科院分区：
文献类型：
--
作者：
He, Jing-Lin;Wu, Zai-Sheng;Yu, Ru-Qin
建立了一种基于核酸适体-靶分子相互作用的荧光检测可卡因的新方法。在这里，我们描述了新的探针，发夹探针和单链探针（ss探针），具有两个识别序列的可卡因适体。在可卡因的存在下，两种探针都将与靶标结合形成三重复合物。发夹探针中的构象变化引起发夹结构的打开和与引物的杂交。利用聚合酶和dNTPs，发夹探针的单链结构域的复制触发引物延伸的过程。当发夹探针转化为完全双链形式时，ss探针和可卡因被置换以结合另一个发夹探针并启动新的扩增循环。当SYBR绿色I嵌入到新的DNA双螺旋中时，将观察到荧光信号的产生。新的方案设计允许在封闭管中检测低至2 nM的可卡因，为均相检测提供了一种方便的方法。与以前报道的可卡因适体传感器相比，我们的新方法是高度敏感，选择性和经济。
A new fluorescence method based on aptamer-target interactions has been developed for cocaine detection with target-induced strand displacement. Here we describe new probes, the hairpin-probe and the single strand-probe (ss-probe), that possess two recognition sequences of cocaine aptamer. In the presence of cocaine, both probes would associate with the target to form a tripartite complex. The conformational change in the hairpin-probe causes the opening of a hairpin structure and the hybridization to primer. With polymerase and the dNTPs, the replication of the single-stranded domain of hairpin-probe triggers the process of primer extension. When the hairpin-probe is converted into a fully double-stranded form, the ss-probe and cocaine are displaced to bind another hairpin-probe and initiate new amplification cycles. Fluorescence signal generation would be observed upon SYBR Green I intercalating into the new DNA double helix. The new protocol design permits detection of as low as 2 nM cocaine in a closed tube, offering a convenient approach for a homogeneous assay. Compared with previously reported cocaine aptameric sensors, our new method is highly sensitive, selective, and economical.