Highly sensitive ratiometric fluorescent flexible sensor based on multifunctional 4-MU@ZIF-8@PLA-PEG for broad-spectrum antibiotics detection in food safety

Antibiotics play an essential function in treating various diseases. However, their overuse has led to water pollution and food safety issues. This work discusses a highly sensitive ratiometric fluorescent flexible sensor based on multifunctional 4-MU@ZIF-8@PLA-PEG composite film prepared using a low-toxicity, eco-friendly and self-assembly method. The sensor combines the luminescent properties and structural tunability of ZIF-based composites with the processability and flexibility of polymers. The 4-MU@ZIF-8@PLA-PEG sensor can detect tetracycline (TC), oxytetracycline (OTC), chlortetracycline hydrochloride (CTC⋅HCl), and doxycycline hydrochloride (DOX⋅HCl) with dual-emission ratiometric fluorescence, exhibiting a visible color change from blue to yellow, with detection limits of 0.058 nM, 16.806 nM, 2.113 nM and 20.510 nM, respectively. The fluorescence characteristics exhibit excellent linear relationships with TC detection in tap water and milk, and show inhibition rates of 87.27 % and 76.61 % against E. coli and S. aureus . With its antibacterial activity, visual detection, high sensitivity, and short detection time, this sensor has significant potential for detecting antibiotics in aquatic environments and food safety applications.