Targeted synthesis of a 3D covalent organic framework with fjh topology exhibiting high photoluminescence: A robust platform for sensitive detection of furantoin

The inappropriate use of antibiotics poses significant risks to both the environment and human health, necessitating the development of accurate and sensitive detection methods. Fluorescence detection, particularly utilizing three-dimensional (3D) covalent organic frameworks (COFs), stands out as a promising avenue. Unlike two-dimensional COFs, 3D COFs can mitigate fluorescence quenching resulting from non-radiative energy loss, primarily attributed to π-π interlayer stacking. In this study, by carefully selecting and designing the building blocks, we synthesized a 3D COF named PyTTA-TTFB-COF with fjh topology and remarkable photoluminescence. This was achieved through the combination of a 4-connected square chromophore, 1,3,6,8-Tetrakis(4-aminophenyl) pyrene, with a 3-connected triangle, 1,3,5-trimethyl-2,4,6-tris(4-formylphenyl) benzene, possessing a specific stereo conformation. Significantly, PyTTA-TTFB-COF exhibits a high photoluminescence quantum yield, notably reaching 60.1% in acetonitrile. Moreover, it displays substantial fluorescence quenching when exposed to furantoin, surpassing the performance observed with other antibiotics. Competitive experiments have confirmed that PyTTA-TTFB-COF can serve as a specific fluorescent probe for the interference-free detection of furantoin.