Post-synthetic modification of a covalent organic framework via a thiol–ene reaction for improving fluorescence detection and removal of cationic crystal violet carcinogenic dye

Based on a thiol–ene reaction, a covalent organic framework containing olefins (COF-A) is modified with 2-mercaptoacetic acid to prepare COF-S-COOH for the first time, which greatly improves the sensing and adsorption capacity for crystal violet.