Dual-emission ratiometric fluorescence sensor based on CeO2 quantum dots for the rapid detection of norfloxacin

The misuse and overuse of antibiotics brings serious pollution to the environment. Norfloxacin (NOR), one of the broad-spectrum antibiotics, is extensively used in treatment of human and animal diseases, which results in the continuous accumulation in the environment. Therefore, it is significance to develop a simple and efficient method for detecting norfloxacin. In this study, cerium dioxide quantum dots (CeO2 QDs) with the characteristics of uniform size and excellent fluorescence emission property were synthesized by using the sol-gel method. A fast and ultrasensitive dual-emission ratiometric fluorescent sensor based on the CeO2 QDs fluorescence was fabricated for the determination of norfloxacin, with a wide linear range (1.00-1000 nM), low detection limit of 0.65 nM, and fast response time (60 s). Furthermore, this ratiometric sensor has been applied for the determination of norfloxacin in environmental water samples with the recovery ranging from 95.54% to 101.04%, and the relative standard deviation 1.09% to 2.94%. these results are consistent with the results analyzed by the high-performance liquid chromatography (HPLC). Therefore, this as-presented sensor has a potential application in the determination of norfloxacin in environmental water samples.