Concatenated Catalytic Hairpin Assembly/Hyperbranched Hybridization Chain Reaction Based Enzyme-Free Signal Amplification for the Sensitive Photoelectrochemical Detection of Human Telomerase RNA
Concatenated Catalytic Hairpin Assembly/Hyperbranched Hybridization Chain Reaction Based Enzyme-Free Signal Amplification for the Sensitive Photoelectrochemical Detection of Human Telomerase RNA
复制标题
基于串联催化发夹组装/超支化杂交链式反应的无酶信号放大，用于人端粒酶 RNA 的灵敏光电化学检测
DOI：
10.1021/acs.analchem.8b05610
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发表时间：
2019-03-05
影响因子：
7.4
通讯作者：
Zhu, Jun-Jie
中科院分区：
文献类型：
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作者：
Chu, Yanxin;Deng, An-Ping;Zhu, Jun-Jie
人类端粒酶RNA （hTR）是端粒DNA重复序列合成的模板，是癌症诊断的重要生物标志物，在肿瘤细胞中被发现过表达7倍。在此，我们提出了一种用于hTR检测的光电化学（PEC）生物传感器，并结合了一种基于催化发夹组装（CHA）和超支化杂交链反应（HB-HCR）级联的新型扩增策略。在电极表面，硫代发夹探针通过Cd-S键固定在沉积的CdS纳米颗粒上。在目标hTR存在的情况下，CHA反应被触发，而triggerl的暴露可以进一步引发HB-HCR反应，形成丰富的含有树突状DNA结构的hemin/ g -四重体DNAzymes。DNAzymes随后在PEC电极表面催化H2O2沉淀4-氯-1-萘酚（4-CN），有效抑制了光电流输出。因此，光电流响应的变化与hTR浓度的对数值在200 ~ 20.0 nM范围内呈线性正相关，检测限（LOD）为17.0 fM。CHA/HB-HCR的LOD比CHA/线性分支HCR （CHA/LB-HCR）低约8.8倍，比CHA低547倍。结合DNA纳米技术的高信号放大能力，成功构建了稳定、可重复、选择性强的聚乙二醇生物传感器，并将其应用于hTR检测中。
Human telomerase RNA (hTR), an important biomarker for cancer diagnosis, is the template for the synthesis of telomeric DNA repeats and is found to be 7-fold overexpressed in tumor cells. Herein, we present a photoelectrochemical (PEC) biosensor for hTR detection coupled with a novel amplification strategy based on cascades of catalytic hairpin assembly (CHA) and hyperbranched hybridization chain reaction (HB-HCR). At the electrode surface, thiolated hairpin 1 probes were immobilized on deposited CdS nanoparticles via a Cd-S bond. In the presence of target hTR, a CHA reaction was triggered and the exposing of triggerl could further initiate an HB-HCR reaction to form abundant hemin/G-quadruplex DNAzymes containing dendritic DNA structure. The DNAzymes' catalytic precipitation of 4-chloro-1-naphthol (4-CN) by H2O2 subsequently took place on the surface of the PEC electrode and efficiently suppressed the photocurrent output. Therefore, the change of photocurrent response had a positive linear relationship with logarithmic value of hTR concentration varying from 200 fM to 20.0 nM with a limit of detection (LOD) of 17.0 fM. The LOD for CHA/HB-HCR was about 8.8-fold lower than that of CHA/linear-branched HCR (CHA/LB-HCR) and 547-fold lower than that of CHA. By coupling the feature of high signal amplification capacity for DNA nanotechnology, a prominently stable, reproducible, and selective PEC biosensor was successfully constructed and applied in hTR detection.