Lighting Up Fluorescent Silver Clusters via Target-Catalyzed Hairpin Assembly for Amplified Biosensing.
Lighting Up Fluorescent Silver Clusters via Target-Catalyzed Hairpin Assembly for Amplified Biosensing.
复制标题
通过靶催化发夹组装点亮荧光银簇以实现放大的生物传感。
DOI：
10.1021/acs.langmuir.8b01576
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发表时间：
2019
期刊：
影响因子：
3.9
通讯作者：
Fuan Wang
中科院分区：
文献类型：
--
作者：
Min Pan;Meijuan Liang;Junlin Sun;Xiaoqing Liu;Fuan Wang
恒温无酶核酸电路已被开发用于执行从指令生物计算到放大生物传感的各种功能。催化发夹组装（CHA）是指在一个引发剂的作用下，两个发夹底物交叉打开，由于其设计简单、扩增能力强而受到人们的广泛关注。传统荧光CHA生物传感器的复杂标记和频繁的光漂白仍然是需要解决的挑战。本研究将DNA模板荧光银纳米团簇（DNA-AgNC）的界面和空间敏感特性与CHA电路的高信号放大能力相结合，构建了一种新的无标记无酶恒温CHA点亮AgNC的核酸扩增检测策略。在该策略中，一个多聚鸟嘌呤接枝发夹和另一个AgNC捕获发夹被工程化为组装组成，其在动力学上被阻止在没有靶标的情况下交叉杂交。然而，在目标的存在下，CHA催化的两个功能性发夹的组装连续进行，并伴随着有效的适应AgNC的聚鸟嘌呤延长的dsDNA产物，导致高效的AgNC照明和放大的荧光信号的产生。作为一种简单的混合检测策略，等温无酶CHA介导的AgNCs发光体系（CHA-AgNCs）为DNA的扩增检测提供了一种简便的可视化方法，检测限为20 pM，与某些酶参与的扩增方法相当甚至更好。通过引入由辅助发夹组成的传感模块，通过易于集成的程序，均相CHA-AgNCs系统可以用作通用传感平台，并且容易地适于分析其他生物学重要的分析物，例如microRNA（miRNA）。通过利用CHA的信号放大特性和稳健的AgNCs点亮过程，我们预期CHA点亮AgNCs系统可以为生物医学和生物成像应用提供重要工具，因此在临床诊断和治疗领域应该有很大的希望。
Isothermal enzyme-free nucleic acid circuits have been developed for carrying out diverse functions ranging from dictate biocomputing to amplified biosensing. Catalytic hairpin assembly (CHA), the catalyzed cross-opening of two hairpin substrates by an initiator, has attracted increasing attention because of its facile design and high amplification capacity. The complex labeling and frequent photobleaching of a conventional fluorescent CHA biosensor still remains a challenge that needs to be solved. Herein, we constructed a new label-free and enzyme-free isothermal CHA lighting up AgNCs strategy for amplified nucleic acid assay by integrating the interfacially and spatially sensitive feature of DNA-templated fluorescent silver nanoclusters (DNA-AgNCs) and the high signal amplification capability of the CHA circuit. In this strategy, one polyguanine-grafted hairpin and the other AgNCs-capturing hairpin were engineered as assembly constitutes, which were kinetically impeded from cross-hybridizations without target. However, in the presence of target, the CHA-catalyzed assembly of two functional hairpins was successively progressed and concomitantly accompanied by an efficient accommodation of AgNCs to the polyguanine-elongated dsDNA product, leading to highly efficient AgNCs-lighting up and to the generation of an amplified fluorescence signal. As a simple mix-and-detect strategy, the isothermal enzyme-free CHA-mediated lighting up AgNCs (CHA-AgNCs) system provided a facile visualization way for amplified detection of DNA with a detection limit of 20 pM, which was comparable to or even better than some enzyme-involved amplification methods. The homogeneous CHA-AgNCs system can be used as a general sensing platform and be easily adapted for analyzing other biologically important analytes, for example, microRNA (miRNA), by introducing the sensing module consisting of an auxiliary hairpin through an easy-to-integrate procedure. By taking advantage of the signal amplification features of CHA and the robust AgNCs-lighting up procedure, we anticipate that the CHA-lighting up AgNCs system can provide an important tool for biomedicine and bioimaging applications and thus should hold great promise in clinical diagnoses and treatment fields.