Abstract Fluorescent DNA-stabilized Ag nanoclusters (DNA/Ag NCs) plays significant roles in biochemical detections due to their high fluorescence quantum yield, high stability and good biocompatibility. In this paper, two guanine-enhanced fluorescence DNA-stabilized silver nanoclusters were designed to study the effect of guanine coating degree on silver nanoclusters fluorescence and their interactions with small biological molecules. The results indicated that the degree of guanine coating had a slight influence on the fluorescence of the two DNA/Ag NCs, however, the two DNA/Ag NCs had different fluorescence response when interacting with different small biological molecules. The fluorescence of the DNA/Ag NCs wrapped in the guanine-rich strand could be quenched by small biomolecules such as ascorbic acid, dopamine and cysteine, while the fluorescence of the DNA/Ag NCs approached to the guanine-rich strand could only be quenched by dopamine and cysteine. Based on this interesting phenomenon, an analytical method for recognition of ascorbic acid, dopamine and cysteine from other small biological molecules can be established by measuring the fluorescence change of DNA/Ag NCs and a method for selective detection of ascorbic acid in the absence of dopamine and cysteines can be achieved by combining the two DNA/Ag NCs probe.

中文翻译：

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用于识别不同小生物分子的鸟嘌呤增强 DNA 杂交中稳定的荧光银纳米团簇

摘要 荧光DNA稳定的银纳米团簇（DNA/Ag NCs）由于其高荧光量子产率、高稳定性和良好的生物相容性在生化检测中发挥着重要作用。本文设计了两种鸟嘌呤增强荧光DNA稳定的银纳米团簇，研究了鸟嘌呤包覆度对银纳米团簇荧光及其与生物小分子相互作用的影响。结果表明，鸟嘌呤包被的程度对两种DNA/Ag NCs的荧光有轻微影响，但两种DNA/Ag NCs在与不同的生物小分子相互作用时具有不同的荧光响应。包裹在富含鸟嘌呤的链中的 DNA/Ag NCs 的荧光可以被抗坏血酸、多巴胺和半胱氨酸等小生物分子淬灭，而接近富含鸟嘌呤的链的 DNA/Ag NCs 的荧光只能被多巴胺和半胱氨酸淬灭。基于这一有趣的现象，可以通过测量DNA/Ag NCs的荧光变化建立一种从其他生物小分子中识别抗坏血酸、多巴胺和半胱氨酸的分析方法，以及一种在没有多巴胺的情况下选择性检测抗坏血酸的方法和半胱氨酸可以通过结合两个 DNA/Ag NCs 探针来实现。