Phenylboronic acid functionalized high-crystallinity fluorescent covalent organic framework act as a sensing platform with dual performance for rifamycin antibiotics and water and adsorbent for rifamycin antibiotics

Phenylboronic acid functionalized high-crystallinity fluorescent covalent organic framework (BA@COF), which can be applied for rifamycin antibiotics and water sensing, and for rifamycin antibiotics adsorption, was synthesized for the first time. To effectively form BA@COF by post-synthetic modification, a fluorescent COF (COF–OMe) was prepared using deep-eutectic solvent as solvent without using catalyst. The BA@COF showed good fluorescence property and adsorption capacity, which owned superior effects in detecting and adsorbing rifampicin, rifapentine, and rifabutin. The results of fluorescence quenching mechanisms showed that internal filtration effect, dynamic quenching, and photoinduced electron transfer were the major mechanisms. Moreover, mainly due to the pore selectivity of BA@COF, hydrogen bonding, and π-π interaction, BA@COF showed good selectivity for three antibiotics. Finally, a dual-function platform based on BA@COF was successfully developed for sensing and adsorbing three antibiotics from various samples. Besides, BA@COF also showed good effect to detect water amount in ethanol (0.1−50%, v/v).