Chronocoulometric aptamer based assay for staphylococcal enterotoxin B by target-triggered assembly of nanostructured dendritic nucleic acids on a gold electrode
Chronocoulometric aptamer based assay for staphylococcal enterotoxin B by target-triggered assembly of nanostructured dendritic nucleic acids on a gold electrode
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通过金电极上纳米结构树突状核酸的靶标触发组装，进行基于计时库仑适体的葡萄球菌肠毒素 B 测定
DOI：
10.1007/s00604-019-3236-9
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发表时间：
2019-02-01
影响因子：
5.7
通讯作者：
Xiong, Xiaohui
中科院分区：
文献类型：
--
作者：
Chen, Xiaoye;Liu, Yun;Xiong, Xiaohui
建立了一种快速、灵敏的葡萄球菌肠毒素B（SE B）检测方法。其基于通过整合（a）靶诱导的DNA释放触发与（B）通过杂交链反应的信号放大而形成树突状DNA超结构。适体和触发DNA的部分互补配对形成双链体结构。然后通过金-硫醇化学将捕获的DNA置于金电极表面。在SEB的存在下，适体-靶缀合物被迫形成。由于与SEB的强烈竞争，这导致触发DNA的释放。触发DNA随后与捕获DNA的部分互补序列杂交，以用三个辅助DNA序列（称为H1、H2、H3）触发HCR。最后，树突状DNA超结构结合到hexaamineruthenium（III）阳离子通过静电吸附和组装到修饰的金电极上。这产生了放大的电化学信号，通过计时库仑法测量。在最佳条件下，SEB浓度在5 pg·mL− 1 ~ 100 ng·mL− 1范围内，电荷差与SEB浓度的对数呈线性关系，检出限低至3 pg·mL−1（S/N= 3）。
A rapid and ultrasensitive method is described for the detection of staphylococcal enterotoxin B (SEB). It is based on the formation of a dendritic DNA superstructure by integrating (a) target-induced triggering of DNA release with (b) signal amplification by a hybridization chain reaction. Partially complementary pairing of aptamer and trigger DNA forms a duplex structure. The capture DNA is then placed on the surface of a gold electrode through gold-thiol chemistry. In the presence of SEB, the aptamer-target conjugate is compelled to form. This causes the release of trigger DNA owing to a strong competition with SEB. The trigger DNA is subsequently hybridized with the partial complementary sequences of the capture DNA to trigger HCR with three auxiliary DNA sequances (referred to as H1, H2, H3). Finally, the dendritic DNA superstructure is bound to hexaammineruthenium(III) cation by electrostatic adsorption and assembled onto the modified gold electrode. This produces an amplified electrochemical signal that is measured by chronocoulometry. Under optimal conditions, the charge difference increases linearly with the logarithm of the SEB concentrations in the range from 5 pg·mL−1to 100 ng·mL−1with a detection limit as low as 3 pg·mL−1(at S/N= 3).Graphical abstractAn electrochemical switching strategy is presented for the sensitive detection ofStaphylococcusenterotoxin B based on target-triggered assembly of dendritic nucleic acid nanostructures.