Ratiometric Fluorescence Thermometry, Quantitative Gossypol Detection, and CO2 Chemical Fixation by a Multipurpose Europium (III) Metal–Organic Framework

A lanthanide-based molecular crystalline material endows metal–organic frameworks (MOFs) with many fascinating applications such as fluorescence detection and CO2 chemical fixation. Herein, we describe and study a multipurpose europium (III) MOF with the formula of Eu2 (TATAB) 2·2. 5H2O·2DMFn (Eu-MOF) (where H3TATAB is 4, 4′, 4″- ( (1, 3, 5-triazine-2, 4, 6-triyl) tris (azanediyl) ) tribenzoic acid ligand) for photoluminescence sensor matrix and CO2 chemical fixation. This Eu-MOF features 1D square channels along the c direction with a pore size of ca. 14. 07 Å × 14. 07 Å, occupied by lattice water and DMF molecules. The obtained Eu-MOF can achieve simultaneous luminescence of the H3TATAB ligand and Eu3+ ions, which can be developed as the sensor matrix for ratiometric fluorescence thermometry. The luminescence of the Eu-MOF demonstrates an obvious color change from red to yellow as temperature rises from 303 to 373 K and the Eu-MOF has a satisfying relative sensitivity of 3. 21% K–1 and a small temperature uncertainty of 0. 0093 K at 333 K. Moreover, sensitive detection of gossypol was achieved with a quenching constant Ksv of 1. 18 × 105 M–1 and a detection limit of 4. 61 μM. A combination of the competitive absorption and photoinduced electron transfer caused by host–guest interactions and strengthened π–π packing effect synergistically between gossypol molecules and the Eu-MOF skeleton realizes the “turn-off” sensing of gossypol. Importantly, the nature of the Eu-MOF allows showing CO2 chemical fixation under mild conditions. Thus, the Eu-MOF can be utilized as a multipurpose material for ratiometric fluorescence thermometry, quantitative gossypol detection, and CO2 chemical fixation.