Highly sensitive fluorescent quantification of carbendazim by two-dimensional Tb-MOF nanosheets for food safety

Carbendazim (CBZ), a well-known benzimidazole pesticide, is utilized in agriculture to prevent and cure plant diseases caused by fungi. Residual CBZ in food poses serious threat to human health. Herein, a fluorescent two-dimensional terbium-based metal-organic framework (2D Tb-MOF) nanosheet sensor was developed for the rapid and ultrasensitive detection of CBZ. The 2D Tb-MOF nanosheets, prepared with Tb3+ ions and 5-borono-1,3-benzenedicarboxylic acid (BBDC) as the precursors, exhibited excellent optical properties. Upon the addition of CBZ, the fluorescence of Tb-MOF nanosheets was quenched because of the inner filter effect (IFE) and dynamic quenching. The fluorescence sensor offered two linear ranges of 0.06-4 and 4-40 µg/mL with a low detection limit of 17.95 ng/mL. Furthermore, the proposed sensing platform was successfully applied to assay CBZ in apples and tea, and satisfactory results were obtained. This study provides an effective alternative strategy for the qualitative and quantitative determination of CBZ to ensure food safety.