Key Laboratory of Macromolecular Science of Shaanxi Province, Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, School of Chemistry & Chemical Engineering, Shaanxi Normal University, Xi'an 710062, Shaanxi, China.
School of Chemistry & Material Science, Shanxi Normal University, Linfen 041004, Shanxi, China.
ACS Appl Mater Interfaces. 2022 Dec 21;14(50):55997-56006. doi: 10.1021/acsami.2c19916. Epub 2022 Dec 12.
Simple, fast, and sensitive detection of trace water in organic solvents is an urgent requirement for chemical industries. Herein, combining the unusual excited-state intramolecular proton transfer (ESIPT) mechanism with the effective strategy of pore space partition, for the first time, we construct a powerful fluorescent metal-organic framework (SNNU-301) probe with excellent water stability. The SNNU-301 probe shows a remarkable performance for turn-on ESIPT-based fluorescence response to water in nine common organic solvents, exhibiting wide linear ranges, low limit of detection values, and ultrafast response, especially in dimethyl sulfoxide (0-5.2%; 0.011%, v/v; 110 s). The typical ESIPT-sensitive linker 2,5-dihydroxyterephthalate (DHBDC) imparts it with discriminative detection properties via enol-keto tautomerism, and light-responsive triangular tri(pyridin-4-yl)-amine (TPA) realizes pore space partition. The theoretical calculation gives an in-depth explanation about the proton transfer mechanism. Comparative experiments and GCMC simulation provide evidence that the synergy of the ESIPT process and TPA of the framework further boosts its performance effectively. Definitely, this work not only offers a promising candidate with fast detection speed, high sensitivity, excellent universality, and visual observation for the determination of water in organic solvents but also provides valuable guidance for the design of high-performance fluorescent probes.
简单、快速、灵敏地检测有机溶剂中的痕量水是化学工业的迫切需求。在此，我们首次结合异常的激发态分子内质子转移（ESIPT）机制和有效的孔空间分割策略，构建了一种具有优异水稳定性的强大荧光金属-有机骨架（SNNU-301）探针。SNNU-301 探针在九种常见有机溶剂中对水具有基于开启型 ESIPT 的荧光响应的优异性能，表现出宽线性范围、低检测限值和超快响应，特别是在二甲基亚砜中（0-5.2%；0.011%，v/v；110 s）。典型的 ESIPT 敏感连接体 2,5-二羟基对苯二甲酸（DHBDC）通过烯醇-酮互变异构赋予其鉴别检测特性，光响应的三角三（吡啶-4-基）-胺（TPA）实现孔空间分割。理论计算对质子转移机制进行了深入解释。比较实验和 GCMC 模拟提供了证据，证明了框架中 ESIPT 过程和 TPA 的协同作用有效地进一步提高了其性能。这项工作不仅为有机溶剂中水分的快速检测、高灵敏度、优异的通用性和可视化观察提供了一种有前途的候选物，而且为高性能荧光探针的设计提供了有价值的指导。
