In this study, we prepared a new ratiometric fluorescent sensor by first encapsulating blue-fluorescent carbon dots (B-CDs) with SiO₂, coupling gold nanoclusters (GSH-AuNCs) to the surface, and finally anchoring a layer of Ag⁺. The presence of UO₂²⁺ caused fluorescence quenching of the ratiometric fluorescent probe when used in aqueous solutions. Furthermore, HOMO–LUMO orbital analysis suggested that the quenching mechanism was mainly attributed to photoinduced electron transfer (PET) between B-CDs@SiO₂@GSH-AuNCs/Ag⁺ and UO₂²⁺. Under optimal conditions, the ratiometric fluorescent probes exhibited excellent selectivity and detected UO₂²⁺ at 37 nmol/L. This new “on–off” ratiometric fluorescent sensor exhibits promising potential for convenient monitoring of UO₂²⁺ levels with ideal recovery in real-world water samples.

_{在这项研究中，我们通过首先用 SiO 2}封装蓝色荧光碳点 (B-CD) ，将金纳米团簇 (GSH-AuNCs) 耦合到表面，最后锚定一层 Ag ⁺，制备了一种新型比例荧光传感器。当在水溶液中使用时， UO ₂ ²⁺的存在导致比例荧光探针的荧光猝灭。此外，HOMO–LUMO轨道分析表明，猝灭机制主要归因于B-CDs@SiO ₂ @GSH-AuNCs/Ag ⁺和UO ₂ ²⁺之间的光诱导电子转移(PET) 。在最佳条件下，比例荧光探针表现出优异的选择性并检测到UO ₂²⁺在 37 nmol/L。这种新的“开-关”比例荧光传感器展示了在现实世界水样中方便地监测 UO ₂ ^{2+水平并实现理想回收率的巨大潜力。}