Dye-encapsulated Zr-based MOFs composites as a sensitive platform for ratiometric luminescent sensing of antibiotics in water

Overuse of antibiotics posed a global threat to human health and the ecological environment. Efficient detection and control of antibiotic pollution demand novel sensory materials. Here, a dual-luminescent material FS@UIO66 was successfully synthesized by encapsulating fluorescent molecules (fluorescein sodium, FS) in UIO66 based on the in-situ encapsulation method. We found that the dual emission peaks of FS@UIO66 at 369 and 515 nm can be sensitively and synchronously quenched by tetracycline (TET). Interestingly, these two peak intensities were switched anisotropically by levofloxacin (LEV), in which the signal at 515 nm was enhanced. Photophysical analysis revealed that there may exist a competition and replenishment mechanism in the sensing processes. The ratiometric fluorescent feature was employed for rapid detection of TET and LEV, with detection limits of 0.2444 μM and 0.2808 μM for TET and LEV, respectively. The superior sensitivity, high selectivity, and excellent recyclability of FS@UIO66 in sensing TET and LEV were demonstrated in this work. In addition, TET and LEV were also successfully detected by FS@UIO66 in water from real water environment. The results indicate that FS@UIO66 composites are favorable for TET and LEV detection, presenting a great sensing platform for antibiotic detection.