Fluorescence sensor for nitrofurazone using 4-methyl-7-allyloxynaphtho[1,2-b]pyran-2-ketone as sensing carrier

4-methyl-7-allyloxynaphtho[1,2-b]pyran-2-ketone ( MANPK ), a naphthopyran derivative, was synthesized as a fluorescent carrier for the preparation of an optical chemical sensor for nitrofurazone. To prevent the leakage of the fluorophore, MANPK with a terminal double bond was photo-copolymerized with 2-hydroxypropyl methacrylate on the silanized glass surface. The response of the sensor is based on fluorescence quenching of MANPK by nitrofurazone. The sensor shows sufficient reproducibility, selectivity and a long lifetime. Nitrofurazone can be determined in the range from 6.0 × 10 −6 to 8.0 × 10 −4 M with a detection limit of 4.5 × 10 −6 M at pH 6.0. The sensor has been applied to the direct determination of nitrofurazone in pharmaceutical preparations and urine samples.