Highly Selective and Sensitive Turn-Off-On Fluorescent Probes for Sensing Al3+ Ions Designed by Regulating the Excited-State Intramolecular Proton Transfer Process in Metal-Organic Frameworks
Highly Selective and Sensitive Turn-Off-On Fluorescent Probes for Sensing Al3+ Ions Designed by Regulating the Excited-State Intramolecular Proton Transfer Process in Metal-Organic Frameworks
复制标题
通过调节金属有机骨架中激发态分子内质子转移过程设计的高选择性和高灵敏度可关闭荧光探针，用于传感 Al3 离子
DOI：
10.1021/acsami.8b20410
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发表时间：
2019-03-27
影响因子：
9.5
通讯作者：
Zhai, Quan-Guo
中科院分区：
文献类型：
--
作者：
Li, Yong-Peng;Zhu, Xiao-Han;Zhai, Quan-Guo
本工作提出了基于激发态分子内质子转移（ESIPT）的高性能金属有机骨架（MOF）铝离子荧光探针的概念。基于ESIPT荧光机理，通过逐步调节有机连接基团上的羟基，构建了新型的镁-有机骨架（Mg-MOF）铝离子荧光探针。首次观察到相邻羟基和羧基之间的分子内氢键的数量可以有效地调节ESIPT过程并导致可调谐的荧光传感性能。与精心设计的多孔和阴离子框架一起，修饰有一对分子内氢键的Mg-TPP-DHBDC探针通过不寻常的关闭（0 - 1.2 μ M）和开启（4.2 - 15 μ M）发光传感机制对Al 3+表现出超高的定量荧光响应。值得注意的是，28 nM的检测限值代表了迄今为止所有报道的基于MOF的Al 3+荧光传感器中的最低记录。得益于独特的关-开ESIPT荧光检测过程，Mg-TPP-DHBDC MOF传感器与其他16种常见金属离子（包括Ga3+、In3+、Fe3+、Cr3+、Ca2+和Mg2+）相比表现出单一的Al3+检测。令人印象深刻的是，这种Al 3+选择性传感过程甚至可以通过可重复使用的MOF试纸实现，通过肉眼检测。总的来说，定量Al 3+检测，以及非凡的灵敏度，选择性，快速响应和良好的可重复使用性，强烈支持我们基于ESIPT的荧光MOF Al 3+探针的概念，并使Mg-TPP-DHBDC成为最强大的Al 3+荧光传感器之一。
The concept of high-performance excited-state intramolecular proton transfer (ESIPT)-based fluorescent metal-organic framework (MOF) probes for Al3+ is proposed in this work. By regulating the hydroxyl groups on the organic linker step by step, new fluorescent magnesium-organic framework (Mg-MOF) probes for Al3+ ions were established based on the ESIPT fluorescence mechanism. It is observed for the first time that the number of intramolecular hydrogen bonds between adjacent hydroxyl and carboxyl groups can effectively adjust the ESIPT process and lead to tunable fluorescence sensing performance. Together with the well-designed porous and anionic framework, the Mg-TPP-DHBDC probe decorating with a pair of intramolecular hydrogen bonds exhibits extra-high quantitative fluorescence response to Al3+ through an unusual turn-off (0-1.2 mu M) and turn-on (4.2-15 mu M) luminescence sensing mechanism. Notably, the 28 nM limit of detection value represents the lowest record among all reported MOF-based Al3+ fluorescent sensors up to now. Benefited from the unique turn-off-on ESIPT fluorescence detection process, the Mg-TPP-DHBDC MOF sensor exhibits single Al3+ detection compared with other 16 common metal ions including Ga3+, In3+, Fe3+, Cr3+, Ca2+, and Mg2+. Impressively, such an Al3+ selective sensing process can even be fulfilled by the reusable MOF test paper detected by naked eyes. Overall, the quantitative Al3+ detection, together with the extraordinary sensitivity, selectivity, fast response, and good reusability, strongly supports our concept of ESIPT-based fluorescent MOF Al3+ probes and makes Mg-TPP-DHBDC one of the most powerful Al3+ fluorescent sensors.