A recycled Tb-MOF fluorescent sensing material for highly sensitive and selective detection of tetracycline in milk

A novel three-dimensional terbium metal–organic framework (Tb-MOF) sensing material has been synthesized by hydrothermal method and applied in fluorescent detection of tetracycline (TC) in milk. The sensing material could emit strong green fluorescence with a long fluorescence lifetime (906.48 ± 1.49 μs), which could be sensitively and selectively quenched by TC aqueous solution. Meanwhile, it had the characteristics of fast response (2 min), low detection limit (184 nmol/L), wide linear range (0–100 and 100–244 μmol/L) and recyclable luminescence sensing during TC detection. The luminescence quenching mechanism was mainly derived from the inner-filter effect and energy transfer from ligand to Tb3+ ion. Furthermore, satisfactory recoveries of 93.5–104.2% were obtained in TC spiked raw milk and pasteurized milk samples, suggesting the potential application of Tb-MOF in the detection of TC in food engineering.