Zhang Li, Bi Xiaoya, Wang Hui, Li Libo, You Tianyan
Key Laboratory of Modern Agricultural Equipment and Technology, Ministry of Education, School of Agricultural Engineering, Jiangsu University, Zhenjiang, Jiangsu, 212013, China.
Department of Environmental Engineering, Henan University of Science and Technology, Luoyang, 471023, China.
Talanta. 2024 Jun 1;273:125843. doi: 10.1016/j.talanta.2024.125843. Epub 2024 Feb 27.
Ligand-protected gold nanoclusters (AuNCs) have become promising nanomaterials in fluorescence (FL) methods for mercury ions (Hg) monitoring, but low FL efficiency hinders their widespread application. Herein, AuNCs/cerium-based metal-organic frameworks (AuNCs/Ce-MOFs) were prepared by loading 6-aza-2-thiothymine-protected AuNCs (ATT-AuNCs) with aggregation-induced emission (AIE) effect on the surface of Ce-MOFs by electrostatic attraction. This strategy improved the FL intensity of AuNCs through two aspects: (i) the AIE effect of ATT-AuNCs and (ii) the confinement effect of Ce-MOFs, which improved the restriction of intramolecular motion (RIM) of ATT-AuNCs. In addition, Ce-MOFs could adsorb and aggregate Hg during detection, which might increase the local concentration. Therefore, based on the high FL signal of AuNCs/Ce-MOFs and enriched Hg, sensitive detection of Hg could be achieved. More importantly, the strong specific recognition between AuNCs and Hg could guarantee selectivity. The developed FL sensor exhibited superior detection performances with a wide linear range of 0.2-500 ng mL and a low detection limit of 0.067 ng mL. Furthermore, the FL sensor used for sensitive and selective detection of Hg in real samples, and the results agreed well with the standard method. In summary, this work proposed an effective and generalized strategy for improving the FL efficiency of AuNCs, which would greatly facilitate their application in pollutant monitoring.
配体保护的金纳米团簇（AuNCs）已成为汞离子（Hg）监测荧光（FL）方法中很有前景的纳米材料，但低荧光效率阻碍了它们的广泛应用。在此，通过静电吸引将具有聚集诱导发光（AIE）效应的6-氮杂-2-硫代胸腺嘧啶保护的金纳米团簇（ATT-AuNCs）负载在铈基金属有机框架（Ce-MOFs）表面，制备了AuNCs/铈基金属有机框架（AuNCs/Ce-MOFs）。该策略从两个方面提高了AuNCs的荧光强度：（i）ATT-AuNCs的AIE效应和（ii）Ce-MOFs的限域效应，这提高了ATT-AuNCs分子内运动受限（RIM）。此外，Ce-MOFs在检测过程中可以吸附和聚集Hg，这可能会增加局部浓度。因此，基于AuNCs/Ce-MOFs的高荧光信号和富集的Hg，可以实现对Hg的灵敏检测。更重要的是，AuNCs与Hg之间的强特异性识别可以保证选择性。所开发的荧光传感器具有优异的检测性能，线性范围宽达0.2 - 500 ng mL，检测限低至0.067 ng mL。此外，该荧光传感器用于实际样品中Hg的灵敏和选择性检测，结果与标准方法吻合良好。总之，这项工作提出了一种有效且通用的提高AuNCs荧光效率的策略，这将极大地促进它们在污染物监测中的应用。
