Efficient Detection of Antibiotics in Water by a Macrocyclic Metal–Organic Framework with Different Response Modes

The efficient detection of multiple antibiotics in aqueous environments holds significant importance. Herein, a Zn(II)-based macrocyclic metal–organic framework (FCS-6) was constructed and employed as an ultrasensitive chemical sensor for antibiotics detection. FCS-6 demonstrates excellent structural stability and exhibits distinct fluorescence responses in simulated antibiotic-contaminated wastewater. Specifically, the fluorescence of FCS-6 could be selectively enhanced by norfloxacin (NFX) and ciprofloxacin (CFX), while being quenched by nitrofurantoin (NFT). Notably, FCS-6 displayed excellent detection ability, with limits of detection (LOD) of 1.9, 4.7, and 10.1 ppm for NFX, CFX, and NFT, respectively. Mechanism studies demonstrated that the fluorescence variation of FCS-6 toward NFX, CFX, and NFT could be attributed to specific molecular recognition and electron transfer processes between FCS-6 and the antibiotics. This study provides a reference for the rational design and synthesis of MOF-based multiresponsive fluorescent sensors and offers more possibilities for the ultrasensitive detection of antibiotics in water.