Institute of Physical Chemistry, Zhejiang Normal University, Jinhua, Zhejiang, People's Republic of China.
Anal Chim Acta. 2012 Apr 29;724:86-91. doi: 10.1016/j.aca.2012.02.044. Epub 2012 Mar 5.
Silver nanoclusters (Ag NCs) templated with DNAs have attracted much attention as novel fluorophores because of their convenient emission tunability by the sequence and length of the template DNAs. However, the precise production of Ag NCs in a site-specific manner still remains a challenge to attain highly selective and label-free DNA recognition. Here we exploited the availability of a gap site in DNA duplexes as a new scaffold for the synthesis of Ag NCs. Compared to the commonly used DNA templates for the creation of Ag NCs, the gap site in DNA duplexes was found to facilitate the rapid formation of the fluorescent Ag NCs without sacrifice of their bright emission and excellent stability. We found that fluorescent Ag NCs were highly selectively formed when cytosine faced toward the gap site in DNA duplexes, and they were in situ utilized as readout by signal-on manner for the DNA mutation assays. This base-selective growth of the fluorescent Ag NCs at the gap site would find promising applications in practical detection of single nucleotide polymorphism (SNP) and construction of DNA-based functional sensors with label-free and cost-effective merits.
银纳米簇（Ag NCs）通过 DNA 模板化，由于其序列和长度可以方便地调节发射波长，因此作为新型荧光团引起了广泛关注。然而，以特定方式精确地生产 Ag NCs 仍然是一个挑战，无法实现高度选择性和无标记的 DNA 识别。在这里，我们利用 DNA 双链体中的缺碱基位点作为合成 Ag NCs 的新支架。与通常用于 Ag NCs 合成的 DNA 模板相比，发现 DNA 双链体中的缺碱基位点有利于快速形成荧光 Ag NCs，而不会牺牲其明亮的发射和优异的稳定性。我们发现，当胞嘧啶面对 DNA 双链体中的缺碱基位点时，会高度选择性地形成荧光 Ag NCs，并且它们可以原位用作信号开启方式进行 DNA 突变分析。这种荧光 Ag NCs 在缺碱基位点的碱基选择性生长，有望在实际检测单核苷酸多态性（SNP）和构建具有无标记和经济高效优点的基于 DNA 的功能传感器方面得到应用。
