Integrative self-assembly of covalent organic frameworks and fluorescent molecules for ultrasensitive detection of a nerve agent simulant

共价有机框架和荧光分子的一体化自组装对神经毒模拟物的超灵敏检测

Binding of fluorescent molecules to the porous matrix through noncovalent interactions will synergistically expand their application spectrum. In this regard, we report an integrative self-assembly of molecule 1 with benzothiadizole and 9,9-dihexyl fluorene units, and covalent organic frameworks(COFs) via an emulsion-modulated polymerization process, within which molecules of 1 are able to interact with the scaffolds of COFs through CH-π interactions. Thus the π-πinteractions between the fluorescent molecules are largely suppressed, giving rise to their remarkable monomer-like optical properties. Of particular interest is that, given by the specific interaction between COFs and a nerve agent simulant diethyl chlorophosphite(DCP), these assembled composites show the ability of ultrasensitive detection of DCP with a detection limit of ~40 ppb. Moreover, the present integrative assembly strategy can be extended to encapsulate multiple fluorescent molecules, enabling the assemblies with white light emission. Our results highlight opportunities for the development of highly emissive porous materials by molecular selfassembly of fluorophores and molecular units of COFs.

荧光分子通过非共价键作用载入到多孔矩阵中能够拓展其应用范围.本文报道了利用乳液限域的方法将带有苯并噻二唑和9,9-二己基芴基团的荧光分子1和共价有机框架(Covalent Organic Frameworks, COFs)一体化自组装,使得分子1通过CH-π作用固定在共价有机框架的骨架之上.因此这会极大地抑制荧光分子之间的π-π作用,使其表现出荧光分子单体的光学性质.更有意思的是,共价有机框架和神经毒剂模拟物(DCP)的特殊的作用,使得一体化自组装的复合物能够实现对神经毒剂模拟物高灵敏度的检测(检测限为40 ppb).而且,当前的一体化组装策略能够被拓展用于装载多种不同发射波长的荧光分子来实现白光.我们的结果提供了一种利用荧光探针分子和共价有机框架综合自组装来制备高发光效率多孔材料的新方法.