Fabrication of the Antibiotic Sensor by the Multifunctional Stable Adjustable Luminescent Lanthanide Metal–Organic Frameworks

In recent years, the irrational use of antibiotics has become very widespread. It is necessary to regulate this phenomenon through antibiotic detection. In this work, a series of isomorphic Ln-MOFs (Ln = Tb³⁺ and Eu³⁺) were synthesized from 1,3,5-tri(4-carboxyphenyl)benzene (H₃L) and Ln³⁺ by the solvothermal method for the first time. A series of 1-Eu_xTb_1-x with different luminescence were doped by changing the molar ratio of Tb³⁺ and Eu³⁺. Ln³⁺ forms a 4-connected 2D network structure through self-assembly with fully deprotonated L^3-. It shows good chemical stability in water, and its luminescence is not affected by aqueous solutions with different pH values. 1-Eu demonstrates rapid and sensitive detection capabilities for MDZ and TET with good recyclability and low detection limits (10^-5). In order to increase the practicability of 1-Eu, two portable sensors have been prepared, in which the fluorescent film (Film@1-Eu) has a detection limit of 10^-4, and the sensitivity is only less than 10% of the titration results. A portable fluorescent test paper can reach the detection limit of 14.7 ppm. This study provides a new idea for the application of stable multifunctional materials in the field of fluorescence sensing.