SERS assay of telomerase activity at single-cell level and colon cancer tissues via quadratic signal amplification
SERS assay of telomerase activity at single-cell level and colon cancer tissues via quadratic signal amplification
复制标题
通过二次信号放大对单细胞水平和结肠癌组织的端粒酶活性进行 SERS 测定
DOI：
10.1016/j.bios.2015.10.029
复制
发表时间：
2016-03-15
影响因子：
12.6
通讯作者：
Yang, Ronghua
中科院分区：
文献类型：
--
作者：
Shi, Muling;Zheng, Jing;Yang, Ronghua
端粒酶作为一种重要的生物标志物和治疗靶点，其检测和监测受到了广泛关注。近年来，酶辅助扩增方法为端粒酶活性检测提供了有用的平台，但单步信号扩增仍然阻碍了灵敏度的进一步提高。在此，我们开发了一种二次信号放大策略，用于超灵敏表面增强拉曼散射（SERS）检测端粒酶活性。我们设计的中心思想是使用端粒酶诱导的银纳米颗粒（AgNPs）组装和银离子（Ag+）介导的级联扩增。在我们的方法中，每个端粒酶辅助的DNA序列延伸都可以触发长双链DNA （dsDNA）的形成，使许多AgNPs通过特定的Ag-S键沿着长链组装，形成初级扩增元件。为了进行二次扩增，将每个共轭AgNP溶解在Ag+中，Ag+可以有效诱导4-氨基苯乙硫醇（4-ABT）修饰的金纳米颗粒（AuNPs@4-ABT）发生聚集，形成众多“热点”。通过二次放大，实现了对单个HeLa细胞的检测限制。更重要的是，该方法应用于结肠癌患者的组织中表现出良好的性能，在基于端粒酶的早期癌症诊断的实际应用中具有很大的潜力。为了证明端粒酶抑制剂和端粒酶靶向药物的筛选潜力，我们成功地利用该设计测量了3'-叠氮-3'-脱氧胸腺嘧啶对端粒酶活性的抑制作用。(C) 2015 Elsevier B.V.版权所有
As an important biomarker and therapeutic target, telomerase has attracted extensive attention concerning its detection and monitoring. Recently, enzyme-assisted amplification approaches have provided useful platforms for the telomerase activity detection, however, further improvement in sensitivity is still hindered by the single-step signal amplification. Herein, we develop a quadratic signal amplification strategy for ultrasensitive surface-enhanced Raman scattering (SERS) detection of telomerase activity. The central idea of our design is using telomerase-induced silver nanoparticles (AgNPs) assembly and silver ions (Ag+)-mediated cascade amplification. In our approach, each telomerase-aided DNA sequence extension could trigger the formation of a long double-stranded DNA (dsDNA), making numerous AgNPs assembling along with this long strand through specific Ag-S bond, to form a primary amplification element. For secondary amplification, each conjugated AgNP was dissolved into Ag+, which can effectively induce the 4-aminobenzenethiol (4-ABT) modified gold nanoparticles (AuNPs@4-ABT) to undergo aggregation to form numerous "hot-spots". Through quadratic amplifications, a limit of detection down to single HeLa cell was achieved. More importantly, this method demonstrated good performance when applied to tissues from colon cancer patients, which exhibits great potential in the practical application of telomerase-based cancer diagnosis in early stages. To demonstrate the potential in screening the telomerase inhibitors and telomerase-targeted drugs, the proposed design is successfully employed to measure the inhibition of telomerase activity by 3'-azido-3'-deoxythymidine. (C) 2015 Elsevier B.V. All rights reserved.