Amperometric DNA biosensor for Mycobacterium tuberculosis detection using flower-like carbon nanotubes-polyaniline nanohybrid and enzyme-assisted signal amplification strategy
Amperometric DNA biosensor for Mycobacterium tuberculosis detection using flower-like carbon nanotubes-polyaniline nanohybrid and enzyme-assisted signal amplification strategy
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使用花状碳纳米管-聚苯胺纳米杂化物和酶辅助信号放大策略检测结核分枝杆菌的电流DNA生物传感器
DOI：
10.1016/j.bios.2018.08.023
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发表时间：
2018-11-15
影响因子：
12.6
通讯作者：
Bai, Lijuan
中科院分区：
文献类型：
--
作者：
Chen, Yuhan;Guo, Shuliang;Bai, Lijuan
介绍了一种通用的电流型DNA生物传感器，用于快速、超灵敏地检测结核分枝杆菌(MTB)特异的IS6110 DNA序列。令人惊讶的是，当簇状碳纳米管(CNTs)掺杂聚苯胺(PAN)时，得到了具有大比表面积、丰富的活性基团和高效的氧化还原活性的独特的花状结构。因此，我们设计了碳纳米管-聚丙烯腈纳米杂化材料作为新型氧化还原纳米探针和修饰信号探针的纳米载体，形成示踪标记用于电化学信号的产生和放大。此外，还利用功能化的富勒烯(C-60)纳米颗粒(FC60)作为传感平台，加速电子传递，增加捕获探针(CP)的负载量。此外，包括三向DNA连接在内的酶辅助靶循环扩增可以解决靶序列的限制，使该方法适用于其他分析方法。在靶DNA存在的情况下，辅助探针(AP)与靶DNA一起与CP杂交，打开其发夹结构，形成与Nick内切酶结合的Y形连接和识别序列。一旦CP被切割，释放的AP和靶DNA可以与另一个CP杂交，触发下一轮切割，导致大量被切割的CP。将切割后的CP与示踪剂标记杂交后，CNTs-PAN的电化学信号明显增强。基于多重信号放大策略，对结核分枝杆菌靶DNA的检测线性范围为1 fM~10 nM。更重要的是，通用DNA生物传感器对临床标本中结核分枝杆菌的检测也表现出了较高的特异性和灵敏度，为结核分枝杆菌的检测提供了一种实用的工具，并为其他分析方法提供了巨大的潜力。
The authors described a universal amperometric DNA biosensor for rapid and ultrasensitive detection of the specific IS6110 DNA sequence of Mycobacterium tuberculosis (MTB). Surprisingly, when tufted carbon nanotubes (CNTs) doped with polyaniline (PAN), a unique flower-like structure with large surface area, abundant active groups and efficient redox activity was obtained. Accordingly, CNTs-PAN nanohybrid was designed both as novel redox nanoprobe and nanocarrier to decorate signal probe, forming tracer label for the generation and amplification of electrochemical signal. In addition, functionalized fullerene (C-60) nanoparticles (FC60) were employed as sensor platform to accelerate electron transfer and increase the loading of capture probe (CP). Moreover, enzyme-assisted target recycling amplification including three-way DNA junction could resolve the restriction of target sequences and make this method universal for other analytes. In the presence of target DNA, the assistant probe (AP), together with target DNA, could hybridize with CP and open its hairpin structure to form the Y-shaped junction and recognition sequence for nicking endonuclease. Once the CP was cleaved, the released AP and target DNA could hybridize with another CP to trigger the next cycle of cleavage, resulting in a large number of cleaved CP. After hybridization between cleaved CP and tracer label, a significantly enhanced electrochemical signal of CNTs-PAN could be easily read out. Based on the multiple signal amplification strategy, a wide detection linear range from 1 fM to 10 nM was obtained for target DNA of MTB. More importantly, the universal DNA biosensor also showed high specificity and sensitivity for MTB detection in clinical samples, which may provide a pragmatic tool for MTB testing and hold a great potential for other analytes.