Ln-MOF based magnetic composite nanosensor for sensitive dual-mode fluorescence/colorimetric detection of fluoroquinolones

Fluoroquinolones are a popular class of antibiotics, which can lead to residues in food and the environment due to their abuse and illegal use. Consequently, this can pose a threat to human health. We hypothesized that a core-shell structured magnetic lanthanide metal–organic framework could serve as an effective dual-mode nanosensor, leveraging its antenna effect and peroxidase (POD)-like activity for the sensitive detection of fluoroquinolones. Herein, a novel Fe₃O₄@EuMOF-based platform was developed to establish a rapid and sensitive fluorescence/colorimetric dual-mode method for detecting fluoroquinolones. The established method demonstrated excellent sensitivity for fluoroquinolones with limit of detections (LODs) of 18.6 nM (fluorescence) and 37.5 nM (colorimetric). Furthermore, this novel method has been successfully applied to detect fluoroquinolones in various food matrix sample with significant recoveries (87.3–107.9 %) and relative standard deviations (RSD) of <8 %. This research provided a sensitive and accurate sensing platform for monitoring fluoroquinolones in various food samples.