Metal nanoclusters (NCs) have attracted much attention due to their unique properties. Silver (Ag) NCs are potential candidates for fluorescence bioimaging, but poor fluorescence of Ag NCs hinders their potential application. Atomic doping provides a feasible route toward improving the brightness of the clusters, but is limited to water-insoluble systems. Herein, we successfully enhance the fluorescence property of water-soluble Ag NCs by doping Au using a reduction method with dihydrolipoic acid as the ligand. Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy proved that Au was successfully doped into Ag NCs by forming bimetallic NCs. The optical properties were analyzed using ultraviolet–visible absorption, photoluminescence, and time-resolved fluorescence spectroscopy. The results indicated that the Ag NCs with 10% Au doping content (AgAu NCs) had an 11-time increase in quantum yield compared to pure Ag NCs. Meanwhile, the sample shows good photostability for 30 min.

中文翻译：

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通过金掺杂增强水溶性银纳米团簇的荧光

金属纳米团簇（NCs）因其独特的性能而备受关注。银（Ag）NCs是荧光生物成像的潜在候选者，但是Ag NCs的荧光差会阻碍其潜在的应用。原子掺杂为提高簇的亮度提供了一条可行的途径，但仅限于水不溶性体系。在这里，我们通过使用二氢硫辛酸作为配体的还原方法掺杂Au来成功增强水溶性Ag NCs的荧光性能。傅里叶变换红外光谱和X射线光电子能谱证明，通过形成双金属NC可以成功地将Au掺杂到Ag NC中。使用紫外可见吸收，光致发光和时间分辨荧光光谱分析光学性质。结果表明，与纯Ag NCs相比，金掺杂量为10％的Ag NCs（AgAu NCs）的量子产率提高了11倍。同时，样品在30分钟内显示出良好的光稳定性。