A new tetraphenylethylene-cyclodextrin (TPE-CD) conjugate with a linkage composed of long triethylene glycol chain and triazole ring on the CD rim has been designed and synthesized. The TPE-CD conjugate exists in a stretched form in DMSO and enhances its fluorescence after addition of a small amount of water due to aggregation-induced emission (AIE) effect. However, in the presence of a large amount of water, the TPE unit will enter the cyclodextrin cavity to form a folded self-inclusion compound. In the self-inclusion compound, not only nitrogen-containing pseudo-crown ether is formed but also arouses photo-induced electron transfer (PET) process from nitrogen atoms of triazole ring to TPE unit and quenches the fluorescence although more aggregation occurs in more water. This is the first finding that TPE-macrocycle conjugate can form pseudo-crown ether and has both the AIE phenomenon and the PET effect. Interestingly, only mercury ion arouses the fluorescence recover of the self-inclusion compound by entering the pseudo-crown ether cavity and blocking the PET process by binding to the nitrogen atoms, while other tested metal ions almost have no effect on the fluorescence. Therefore, the TPE-CD conjugate can be used for the highly selective fluorescence "Turn-On" detection of Hg²⁺.

设计并合成了一种新型四苯基乙烯-环糊精 (TPE-CD) 共轭物，该共轭物由长三甘醇链和 CD 边缘上的三唑环组成。TPE-CD 偶联物在 DMSO 中以拉伸形式存在，由于聚集诱导发射 (AIE) 效应，在添加少量水后会增强其荧光。但在大量水存在的情况下，TPE单元会进入环糊精空腔，形成折叠的自包合化合物。在自包合化合物中，不仅含氮伪形成冠醚，但也会引起从三唑环的氮原子到 TPE 单元的光诱导电子转移 (PET) 过程，并淬灭荧光，尽管在更多的水中会发生更多的聚集。这是首次发现TPE-大环共轭物可以形成假冠醚，同时具有AIE现象和PET效应。有趣的是，只有汞离子通过进入拟冠醚空腔并通过与氮原子结合而阻断PET过程来引起自包合化合物的荧光恢复，而其他被测金属离子对荧光几乎没有影响。^{因此，TPE-CD 偶联物可用于 Hg 2+}的高选择性荧光“开启”检测。