Label-Free and Ultrasensitive Electrochemical DNA Biosensor Based on Urchinlike Carbon Nanotube-Gold Nanoparticle Nanoclusters
Label-Free and Ultrasensitive Electrochemical DNA Biosensor Based on Urchinlike Carbon Nanotube-Gold Nanoparticle Nanoclusters
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DOI：
10.1021/acs.analchem.9b03520
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发表时间：
2020-04-07
影响因子：
7.4
通讯作者：
Wang, Risheng
中科院分区：
文献类型：
--
作者：
Han, Shuo;Liu, Wenyan;Wang, Risheng
纳米材料已被广泛应用于生物传感系统中，用于各种生物靶标的高灵敏度和选择性检测。在这项工作中，一个简单的，无标记的，和超灵敏的电化学DNA生物传感器已被开发，基于"海胆"碳纳米管-金纳米粒子（CNT-AuNP-AuNP）纳米簇，用于信号放大。具体而言，多巴胺（DA）的电化学聚合被用来修饰金电极，用于通过席夫碱反应固定DNA探针。在感测靶核酸时，通过DNA杂交将双DNA（报告子和接头）官能化的AuNP引入到感测系统中。然后，将末端修饰的单壁碳纳米管与DNA（SWCNT-DNA）通过linker-DNA杂交连接到AuNPs表面，形成三维放射状纳米团簇，产生显著的电化学响应。由于CNT-AuNP簇的较大接触表面积和超电子导电性，这种新型设计的3D径向纳米结构表现出对DNA的超灵敏检测，检测限为5.2 fM（线性范围为0.1 pM至10 nM），以及在最佳条件下区分单错配DNA与完全匹配的靶DNA的高选择性。这种生物传感器，它结合了碳纳米管和金纳米粒子的协同性能，代表了一个有前途的信号放大策略，实现灵敏的生物传感器的DNA检测和诊断应用。
Nanomaterials have been extensively utilized in biosensing systems for highly sensitive and selective detection of a variety of biotargets. In this work, a facile, label-free, and ultrasensitive electrochemical DNA biosensor has been developed, based on "urchinlike" carbon nanotube-gold nanoparticle (CNT-AuNP AuNP) nanoclusters, for signal amplification. Specifically, electrochemical polymerization of dopamine (DA) was employed to modify a gold electrode for immobilization of DNA probes through the Schiff base reaction. Upon sensing the target nucleic acid, the dual-DNA (reporter and linker) functionalized AuNPs were introduced into the sensing system via DNA hybridization. Afterward, the end-modified single-wall carbon nanotubes with DNA (SWCNT-DNA) were attached to the surface of the AuNPs through linker-DNA hybridization that formed 3D radial nanoclusters, which generated a remarkable electrochemical response. Because of the larger contact surface area and super electronic conductivity of CNT-AuNP clusters, this novel designed 3D radial nanostructure exhibits an ultrasensitive detection of DNA, with a detection limit of 5.2 fM (a linear range of from 0.1 pM to 10 nM), as well as a high selectivity that discriminates single-mismatched DNA from fully matched target DNA under optimal conditions. This biosensor, which combines the synergistic properties of both CNTs and AuNPs, represents a promising signal amplification strategy for achieving a sensitive biosensor for DNA detection and diagnostic applications.