New strategies for enhancing the fluorescence emission of metal nanoclusters (MNCs) are very crucial for the highly sensitive sensing of food hazards. In this work, we prepared MNC supraparticles (Sc-CB/AuNCs) by simultaneously introducing cucurbit[7]uril (CB[7]) and Sc³⁺ ions into ATT-AuNCs for the first time. The obtained supraparticles exhibited strong emission enhancement due to synergistic aggregation-induced emission enhancement and restriction of intramolecular motion effects. Notably, the fluorescence of ATT-AuNCs was enhanced by 24-fold due to the combination of CB[7] and Sc³⁺ ions, and the quantum yield reached 69.1%. Moreover, we found that tetracycline (TC) could bind to the Sc-CB/AuNCs through simultaneous host–guest recognition and ionic complexation, which effectively quenched the Sc-CB/AuNCs through the synergy of photoinduced electron transfer and inner filter effect. Based on the above multiple interactions between TC and Sc-CB/AuNCs, an ultrasensitive sensing method for TC was constructed with an LOD of 0.3 nM. Furthermore, a portable fluorescent gel sensor was constructed and successfully used for TC detection in honey samples. The test took only 2 min. This work not only provided a simple and effective fluorescence enhancement strategy for MNCs but also offered a novel sensing strategy, which may largely extend the potential of host–guest recognition-based sensors for food and environmental hazards.

中文翻译：

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基于目标与传感器多重交互的金属纳米团簇超粒子超灵敏传感四环素的制备


增强金属纳米簇 （MNC） 荧光发射的新策略对于食品危害的高度灵敏传感非常重要。在这项工作中，我们首次通过将葫芦[7]脲 （CB[7]） 和 Sc³⁺ 离子同时引入 ATT-AuNCs 中制备了 MNC 超粒子 （Sc-CB/AuNCs）。由于协同聚集诱导的发射增强和分子内运动效应的限制，获得的超粒子表现出强烈的发射增强。值得注意的是，由于 CB[7] 和 Sc³⁺ 离子的组合，ATT-AuNCs 的荧光增强了 24 倍，量子产率达到 69.1%。此外，我们发现四环素 （TC） 可以通过同时主客体识别和离子络合与 Sc-CB/AuNCs 结合，通过光诱导电子转移和内滤效应的协同作用有效地淬灭 Sc-CB/AuNCs。基于上述 TC 与 Sc-CB/AuNCs 之间的多重相互作用，构建了一种 LOD 为 0.3 nM 的 TC 超灵敏传感方法。此外，构建了便携式荧光凝胶传感器，并成功用于蜂蜜样品中的 TC 检测。测试仅用了 2 分钟。这项工作不仅为 MNC 提供了一种简单有效的荧光增强策略，而且还提供了一种新颖的传感策略，这可能在很大程度上扩展基于主客体识别的传感器在食品和环境危害方面的潜力。