ABSTRACT Metal cations in aqueous solutions at different pHs (1.5, 4.5 and7.2) can be detected using the known inclusion complex H33258@Q8 as a fluorescent probe. Indeed, the fluorescence intensity of H33258 increases rapidly upon increasing the amount of Q[8] up to a Q[8]:H33258 ratio of 2:1, even at pH 1.5. The experimental results reveal that the probe not only exhibited selective recognition of metal cations at different pH but also showed different recognition for metal cations at different pHs. At pH 7.2, the probe responded to quite a variety metal cations, including one of the third main group elements, Al3+, four transition metal cations, Hg2+, Fe3+, Fe2+, and Cr3+ and three lanthanide cations Eu3+, Tm3+ and Yb3+; At pH 4.5, the probe responded to only two transition metal cations, Hg2+ and Fe3+. Unexpectedly, the probe lost its recognition properties at pH 1.5. Graphical Abstract

中文翻译：

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Cucurbit[8]uril-使用荧光传感器改进对不同金属阳离子的识别

摘要 使用已知的包合物 H33258@Q8 作为荧光探针，可以检测不同 pH 值（1.5、4.5 和 7.2）水溶液中的金属阳离子。事实上，当 Q[8] 的量增加到 Q[8]:H33258 的比例为 2:1 时，H33258 的荧光强度会迅速增加，即使在 pH 值为 1.5 时也是如此。实验结果表明，该探针不仅对不同pH下的金属阳离子表现出选择性识别，而且对不同pH下的金属阳离子也表现出不同的识别能力。在 pH 7.2 时，探针对多种金属阳离子有响应，包括第三主族元素之一 Al3+、四种过渡金属阳离子 Hg2+、Fe3+、Fe2+ 和 Cr3+ 以及三种镧系元素阳离子 Eu3+、Tm3+ 和 Yb3+；在 pH 4.5 时，探针仅响应两种过渡金属阳离子 Hg2+ 和 Fe3+。不料，探针在 pH 1.5 时失去其识别特性。图形概要