Nanoporous Pyrene-Based Metal–Organic Frameworks for Fluorescence Screening and Discrimination of Sulfonamide Antibiotics

The presence of antibiotics in aquatic environments has recently raised significant concerns due to their toxic effects as well as the propagation of antibiotic resistances. Thus, efforts are devoted to developing facile screening methods for sulfonamide antibiotics in waters. In this study, we designed a fluorescent array comprising three structurally different pyrene-based luminescent metal–organic framework (LMOF) sensors and applied it in the simultaneous screening of multiple sulfonamides. The pyrene-based LMOFs produced fluorescence quenching responses to sulfonamides via the static quenching mechanism and/or inner filter effect. The array was able to effectively sense and discriminate five structurally similar sulfonamides (sulfamethoxazole, sulfadiazine, sulfapyridine, sulfamerazine, and sulfamethazine), individual sulfonamide at different concentrations, and mixtures of two sulfonamides with various molar ratios. The detection limit of the pyrene-based MOF array for individual sulfonamide was lower than most previously reported fluorescent sensors. It also afforded a fast sulfonamide response (response equilibrium <2 min) owing to the open and uniform nanoporous structures of the LMOF array elements, which allowed a screening speed as fast as approximately 20 min/100 samples. The constructed array exhibited good performance in the discrimination of sulfonamides in real water samples, validating its practicability. This study provides a convenient strategy for the rapid screening of sulfonamide antibiotics in aquatic environments. It also validates the application potential of LMOF array in fluorescence sensing fields.