“Carbon dots (CDs) were prepared by hydrothermal method using citric acid and ethylenediamine as precursors, and were successfully integrated into the pore structure of MOF-76 (Tb) using in-situ encapsulation strategy CDs@MOF-76 (Tb) Composite materials. This composite material not only maintains the structural stability of MOF-76 (Tb) framework, but also combines the luminescent properties of CDs and MOF-76 (Tb). After undergoing various environmental tests such as heat treatment, long-term immersion in aqueous solution, 0.0~1.0 mol · L-1 NaCl solution, and pH=3~11, the material exhibits excellent environmental tolerance and demonstrates potential as a fluorescent sensor. In addition, CDs@MOF-76 The (Tb) composite material exhibits high selectivity and sensitivity for detecting Cr (VI) anions (including CrO42- and Cr2O72-) in aqueous environments, with quenching effect constants KSV of 5.01 × 103 L · mol-1 and 1.13 × 104 L · mol-1, respectively, and detection limits (LOD) of 1.06 μ mol · L-1 and 0.47 μ mol · L-1, respectively. Meanwhile, the material can also serve as a ratio fluorescent probe for selective detection of Bi (III) ions, with a KSV of 4.53 × 103 L · mol-1 and a LOD of 1.01 μ mol · L-1. Therefore, CDs@MOF-76 (Tb) composite materials have good anti-interference and cyclic stability for target detection substances, and have broad application prospects in the field of environmental monitoring.”