Abstract A novel, rapid and ultrasensitive ratiometric and colorimetric fluorescence method was developed using bovine serum albumin protected gold/silver bimetallic nanoclusters (BSA-Au/Ag NCs) as fluorescent sensor for mercury (Hg) detection. The fluorescence sensor which was synthesized by one-pot approach shows dual-emissions at 470 nm (Ag NCs) and 630 nm (Au NCs) under a single excitation at 390 nm. In the presence of Hg2+, the red fluorescence of Au NCs was quenched while the fluorescence of Ag NCs almost unchanged, which exhibited a ratiometric fluorescence response and an obvious fluorescence color change toward Hg2+. The selective quenching mechanism may be due to the formation of gold amalgam bonds between Hg2+ (4f145d10) and Au+ (4f145d10). A limit of detection (LOD) of 2.2 μg L−1 and a relative standard deviation (RSD, n = 7) of 0.7% at a concentration of 50 μg L−1 of Hg2+ were obtained when using a commercial fluorescence spectrophotometer as the detector. In visual detection, as low as 10 μg L−1 of Hg2+ can be easily discriminated from the blank with the naked eye. The proposed method retains several unique advantages, including simplicity, rapidity, ease of usage and high-sensitively.

中文翻译：

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一锅法合成牛血清白蛋白保护的金/银双金属纳米团簇，用于汞的比率和视觉检测

摘要 使用牛血清白蛋白保护的金/银双金属纳米团簇 (BSA-Au/Ag NCs) 作为汞 (Hg) 检测的荧光传感器，开发了一种新型、快速和超灵敏的比率和比色荧光方法。通过一锅法合成的荧光传感器在 390 nm 的单次激发下显示出 470 nm (Ag NCs) 和 630 nm (Au NCs) 的双发射。在 Hg2+ 存在下，Au NCs 的红色荧光被淬灭，而 Ag NCs 的荧光几乎没有变化，呈现出比例荧光响应和明显的荧光颜色向 Hg2+ 变化。选择性淬灭机制可能是由于在 Hg2+ (4f145d10) 和 Au+ (4f145d10) 之间形成了金汞合金键。检测限 (LOD) 为 2.2 μg L−1，相对标准偏差 (RSD，n = 7) 为 0。当使用商业荧光分光光度计作为检测器时，在 50 μg L-1 的浓度下获得了 7% 的 Hg2+。在视觉检测中，低至 10 μg L-1 的 Hg2+ 可以很容易地从空白中用肉眼辨别出来。所提出的方法保留了几个独特的优点，包括简单、快速、易于使用和高灵敏度。