Ultrasensitive Electrochemical DNA Biosensor Based on a Label-Free Assembling Strategy Using a Triblock polyA DNA Probe
Ultrasensitive Electrochemical DNA Biosensor Based on a Label-Free Assembling Strategy Using a Triblock polyA DNA Probe
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基于使用三嵌段聚 A DNA 探针的无标记组装策略的超灵敏电化学 DNA 生物传感器
DOI：
10.1021/acs.analchem.9b04757
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发表时间：
2019
影响因子：
7.4
通讯作者：
Liu Gang
中科院分区：
文献类型：
--
作者：
Wang Lele;Wen Yanli;Yang Xue;Xu Li;Liang Wen;Zhu Ying;Wang Lihua;Li Yan;Li Yuan;Ding Min;Ren Shuzhen;Yang Zhenzhou;Lv Min;Zhang Jichao;Ma Kang;Liu Gang
多嵌段DNA探针作为多靶点生物传感器和提高特异性和灵敏度的重要手段，引起了科学界的广泛关注。然而，多嵌段DNA探针的开发高度依赖于有机连接体或纳米材料的化学合成，这限制了其实用性和生物相容性。在这项工作中，我们开发了一种无标记的组装策略，使用三嵌段DNA捕获探针，它连接两个DNA探针与其固有的polyA片段（探针-PolyA-探针，PAP）。中间polyA片段对金电极表面具有高亲和力，从而使我们的生物传感器具有优异的再现性、稳定性和再生性。两个侧翼捕获探针串联共组装在电极表面上，具有一致的空间关系和完全相同的量。当与靶DNA结合时，由于两个捕获探针的强碱基堆积效应，杂交稳定性提高。我们的生物传感器的灵敏度被证明是10 fM，与10 fM至1 nM之间的宽分析范围。我们基于PAP的生物传感器在面对错配的DNA序列时表现出优异的特异性。甚至单核苷酸多态性也可以通过每个探针来区分。我们的生物传感器是通过分析基因组DNA的PCR扩增和不显示的优秀实用性。
Multiblock DNA probe attracted a large amount of scientific attention, for the development of multitarget biosensor and improved specificity/sensitivity. However, the development of multiblock DNA probes highly relied on the chemical synthesis of organic linkers or nanomaterials, which limited their practicability and biological compatibility. In this work, we developed a label-free assembling strategy using a triblock DNA capture probe, which connects two DNA probes with its intrinsic polyA fragment (probe–PolyA–probe, PAP). The middle polyA segment has a high affinity to the gold electrode surface, leading to excellent reproducibility, stability, and regeneration of our biosensor. Two flanking capture probes were tandemly co-assembled on the electrode surface with consistent spatial relationship and exactly the same amount. When combined with the target DNA, the hybridization stability was improved, because of the strong base stacking effect of two capture probes. The sensitivity of our biosensor was proved to be 10 fM, with a wide analysis range between 10 fM to 1 nM. Our PAP-based biosensor showed excellent specificity when facing mismatched DNA sequences. Even single nucleotide polymorphisms can be distinguished by each probe. The excellent practicability of our biosensor was demonstrated by analyzing genomic DNA both with and without PCR amplification.