High-performance ratiometric fluorescence detection and removal of tetracycline in milk based on CDs@ZSM-5:Eu.

Exploring materials with the dual functionality of detecting and removing tetracycline (TC) residues is crucial because of the environmental and health risks posed by antibiotic overuse. This study introduces a dual-emissive luminescent probe, CDs@ZSM-5:Eu, created through a solvent-free method combined with subsequent Euion exchange. The nanocomposite's blue emission, originating from carbon dots (CDs), is quenched by TC via an internal filtering effect, while an antenna effect triggers a strong red fluorescence of a TC-Euchelate. The ratiometric fluorescence changes in CDs@ZSM-5:Eu endow a self-calibrated sensing mechanism for TC, offering a low detection limit of 5.04 nM and a broad detection range of 0.01-50 μM. Demonstrated in real milk samples, the probe exhibits high selectivity and accuracy in detecting TC. The nanocomposite also displayed an impressive TC removal capacity of 238.1 mg g in water, ascribing to the enrichment and electrostatic attraction effects of ZSM-5 toward TC molecules. This research offers a facile strategy for constructing multifunctional zeolite-based hybrids for simultaneous TC detection and removal from aqueous solutions.