Ratio fluorescence detection of tetracycline by a Eu³⁺/NH₂-MIL-53(Al) composite

Tetracycline detection has been a great concern because of its overuse and difficulty in degrading. Here, a detection method with ratio fluorescence was developed by synthesizing Eu³⁺ doped nanocomposites with NH₂-MIL-53(Al) nanosheets. After adding tetracycline, the fluorescence intensity at 616 nm characteristic emission peak of Eu³⁺ was sensitized by the antenna effect generated from coordinating Eu³⁺ with tetracycline, but the fluorescence of NH₂-MIL-53(Al) at 433 nm was quenched by the fluorescence resonance energy transfer between the Eu³⁺-tetracycline composition and NH₂-MIL-53(Al). Therefore, the efficient detection of tetracycline was achieved based on this change of ratio fluorescence signal. The experimental results show that Eu³⁺/NH₂-MIL-53(Al) has excellent selectivity, a wider linear range and a lower detection limit for detecting tetracycline. This method can afford favorable ideas for developing advanced chemical and biological sensors.