Efficient adsorption and sensitive detection of tetracycline antibiotics based on pyrene-functionalized Cu-MOF

Tetracycline antibiotics (TCs) are widely distributed in the environment owing to excessive usage and incomplete metabolic breakdown, posing significant risks to ecosystems and human health. Herein, a bifunctional material, Cu-TATB-PCA, was prepared for simultaneous adsorption and detection of TCs. The material was constructed using Cu-MOF as the structural scaffold, with 1-pyrenecarboxylic acid (PCA) grafted via a postsynthetic ligand exchange (PSE) approach. The incorporated PCA moiety functions as both an active site for enhanced adsorption capacity and a fluorescent reporter for sensitive detection‌. Cu-TATB-PCA demonstrated a remarkable adsorption performance toward TCs, with a maximum adsorption capacity of 520.8 mg/g for oxytetracycline (OTC), 473.9 mg/g for chlortetracycline, and 469.5 mg/g for tetracycline (TC). The high adsorption capacity was mainly attributed to the dominant role of π-π interactions, which worked synergistically with coordination bonds, electrostatic interactions, and hydrogen bonds to collectively contribute to the adsorption process. In addition, Cu-TATB-PCA exhibited a highly sensitive fluorescent response toward TCs due to the mechanism of inner filter effect, which achieved a detection limit of 0.586 μM for TC and 0.776 μM for OTC. The streamlined and efficient material design paradigm paves the way for the development of bifunctional adsorption-detection materials and offers a promising avenue for future research endeavors in this field.