Development of a fluorescent probe for cefazolin detection based on solvent-based de-emulsification dispersive liquid–liquid microextraction of silver nanoparticles

A novel, simple, and rapid method has been developed for the fluorimetric determination of trace levels of cefazolin. The method is based on the synthesis of silver nanoparticles (AgNPs) as fluorescent probes using resorcinol as a reducing and capping agent and then their extraction into the 1-octanol by a highly efficient solvent-based de-emulsification dispersive liquid-liquid microextraction technique. The interaction of cefazolin with silver affected the fluorescence intensity of AgNPs in the organic phase that creates a micro-probe fluorimetric detection of this antibiotic at excitation/emission wavelengths of 410/527 nm. Under the established optimum conditions, the linear analytical range was from 0.80 to 12.00 ng mL-1 of cefazolin with a detection limit of 0.55 ng mL-1. The relative standard deviation for ten replicate measurements of 2 and 10 ng mL-1 of cefazolin was 4.18 and 1.88%, respectively. The suggested method was successfully applied to the determination of cefazolin in pharmaceutical formulation, human urine and plasma.