Tb3+-modified covalent organic frameworks-based fluorescence sensor for anthrax biomarker and anionic contaminants

Covalent organic frameworks (COFs) with full π-conjugation can be obtained by tuning the building blocks and covalent bonds. Meanwhile, lanthanide ions (Ln 3+ ) have attracted attention for their unique luminescent properties. In this study, we coordinated Tb ions with COF (TQBQ-COF), thereby constructing a fluorescent sensor for the detection of 2,6-pyridinedicarboxylic acid (DPA) as an anthrax biomarker. The prepared Tb 3+ @TQBQ-COF shows an ultra-low detection limit for DPA (3.58 nM), which is much lower than the required level of DPA for Bacillus anthracis to produce anthrax (60 μM). In addition, the prepared sensors showed good detection performance in detecting anionic pollutants when DPA was used as a photosensitizer. Our work provides a simple method for the detection of DPA.