A Versatile Luminescent Ga-Organic Framework with Multi-Emission Centers as a Blue LED and Fluorescent Probe for Low-Temperature Detection and Selective Fe3+ Sensing

The development and utilization of 3p-block based MOFs as fluorescent materials has attracted significant attention in recent years. Herein, we have successfully constructed a versatile luminescent Ga-MOF (SNNU-63) with a 3d10 configuration and a large ligand twist configuration. Interestingly, the as-synthesized Ga-MOF exhibits excellent luminescence property and a good material for blue light-emitting diode (LED). At 80 K, this Ga-MOF shows multi-emission centers at 381, 462, and 494 nm. As a ratiometric thermometer, this Ga-MOF exhibits an excellent temperature sensing property with high relative sensitivity (Sm = 2.60 % K−1 at 110 K). The fluorescence intensity ratio I381/I494 shows a very good fit for the Boltzmann results (80–240 K). Moreover, the luminescent Ga-MOF exhibits an excellent selective detection of Fe3+ over other metal ions in aqueous an medium, and the limit of detection (LOD) towards Fe3+ ions is calculated to be 1.227 × 10−4 M. This work presents a versatile luminescent Ga-MOF material as a blue LED and fluorescent probe for low-temperature and selective Fe3+ sensing.