Zhang Ningzi, Zhang Diwei, Zhao Jing, Xia Zhiguo
The Beijing Municipal Key Laboratory of New Energy Materials and Technologies, School of Materials Sciences and Engineering, University of Science and Technology Beijing, Beijing 100083, China.
Dalton Trans. 2019 May 28;48(20):6794-6799. doi: 10.1039/c9dt01125k. Epub 2019 May 1.
Dye-loaded metal organic frameworks (MOFs) are regarded as one of the most fascinating luminescent materials for selective chemical sensing. Herein, a facile two-step synthesis procedure is reported for the successful encapsulation of fluorescein dye into porous zinc-adenine metal-organic framework (bio-MOF-1) crystals, and thus the aggregation-caused quenching of dye molecules can be eliminated in the confined MOF structure to further create dual emission centers. The as-prepared solid state fluorescein@bio-MOF-1 composite exhibits both the characteristic emissions of the fluorescein dye and bio-MOF-1, and host-guest energy transfer also occurs. Particularly, depending on the variety of the luminescence intensities of different metal ions incorporated in fluorescein@bio-MOF-1, such a host-guest system could be used for high-sensitive sensing of metal cations, especially for the drastic luminescence quenching of Fe ions. The quenching effect coefficient (K) for every metal ion detected is calculated, and the largest K value for Fe ions is determined to be 5072 M. Such an encapsulation strategy can be widely adopted to design new dye@MOF composites with multiple luminescent centers for metal cation sensing.
负载染料的金属有机框架材料（MOFs）被认为是用于选择性化学传感的最具吸引力的发光材料之一。在此，报道了一种简便的两步合成方法，成功地将荧光素染料封装到多孔锌 - 腺嘌呤金属有机框架（bio - MOF - 1）晶体中，从而在受限的MOF结构中消除染料分子的聚集诱导猝灭，进而创建双发射中心。所制备的固态荧光素@bio - MOF - 1复合材料同时展现出荧光素染料和bio - MOF - 1的特征发射，并且还发生了主客体能量转移。特别地，根据掺入荧光素@bio - MOF - 1中的不同金属离子的发光强度变化，这样的主客体系统可用于高灵敏度检测金属阳离子，尤其是对于Fe离子的显著发光猝灭。计算了检测到的每种金属离子的猝灭效应系数（K），确定Fe离子的最大K值为5072 M。这种封装策略可被广泛采用来设计具有多个发光中心的新型染料@MOF复合材料用于金属阳离子传感。
