Direct phoxim sensing based on fluorescent metal-organic framework of Nu-1000 induced FRET

Abstract

To control and on-site evaluate the contamination of organophosphorus pesticides, one direct sensing approach based on spontaneous fluorescence resonance energy transfer (FRET) was developed in this study. The luminescent metal-organic frameworks (LMOFs), a novel achievement of MOFs, could provide adjustable adsorption capacity and fluorescence index to scientific analysis was first employed to evaluate phoxim molecules in vegetables and fruits. Through the π-π recognition and FRET sensing between phoxim molecules and skeleton of Nu-1000 LMOFs probes, an ultra-low detection limit of 1.65 pg/L in the range of 5×10−7 to 5×10−3 mg/mL (R2=0.998) was achieved in the presence of phoxim. Such simple and accurate LMOFs- FRET-based sensing strategy could offer valuable reference for developing sensitive FRET sensors and/or on-site evaluation approaches in the areas of food quality control and food safety.