Fluorescent Sensor Based on Stable Cd(II) Metal–Organic Framework for Rapid and Visual Detection of Tetracycline Antibiotics in Water

Antibiotics, widely used in the fields of medicine, animal husbandry, aquaculture, and agriculture, are ubiquitously present in water systems, posing a serious threat to the environment and human health. It is essential to develop a fast, sensitive, and straightforward analytical method for sensing antibiotics in aqueous solution. In this work, a 3D luminescent metal–organic framework (MOF), named Cd-BTDI, has been synthesized, featuring high structural stability in water. Its intense green luminescence with an emission peak at 509 nm is quite stable in aqueous and common organic solvents, providing a good foundation to fabricate a potential chemical sensor. Cd-BTDI exhibits selective and sensitive detection performance for tetracycline (TC) and oxytetracycline (OTC) antibiotics with fast response and good anti-interference. The limits of detection (LODs) for TC and OTC are 0.071 and 0.062 μΜ, respectively. By introducing the commercially available polymer poly(methyl methacrylate), a reusable sensing film can be fabricated for the on-site visual detection of trace tetracycline antibiotics. In addition, Cd-BTDI can detect tetracycline antibiotics in three kinds of typical real water matrices (tap, lake, and river water), showing great potential for practical uses.