Ratiometric upconversion luminescence based nanosensor for the sensitive and selective detection of the antibiotic marbofloxacin

Drug residues in animal and dairy foods are growing at dangerous rate, and the accumulated residual drug samples in the human body lead to serious damage to the human body. The detection of antibiotic residues is of imperative necessity across the world. Herein, we develop polyethyleneimine (PEI) modified upconversion nanoparticles (UCNPs) with good hydrophilicity for ratiometric upconversion luminescence (UCL) sensing of marbofloxacin (MAR) antibiotic. The UCL at 345 and 360 nm of UCNPs@PEI was remarkably quenched by MAR with fast response time of 1 min, while the blue UCL at 450 nm displaying no change as the internal reference. The UCNPs@PEI ratiometric nanoprobe exhibited excellent sensitivity and high selectivity towards MAR in the linear range of 0-80 μmol L −1 with detection limit as low as 0.0084 μmol L −1 . The nanoprobe successfully quantified MAR in milk and chicken meat real samples with good recoveries. The developed UCNPs@PEI ratiometric UCL nanoprobe holds great potential for rapid, sensitive and selective determination of MAR in food samples with convenience and reliability.