Sensor synthesis synthesized PbS functionalized with gelatin quantum dots have been considered as novel drugs sensors due to their ultrafine size, photo-stability and excellent fluorescent properties. In this study, a facile method was developed for the preparation of fluorescent water-soluble PbS quantum dots with gelatin sensor. The fluorescence of the PbS quantum dots sensor functionalized with gelatin synthesis is selectively and sensitively enhanced by addition of the Phenylpropanolamine (PPA) drug-induced aggregation of sensor PbS with gelatin. This finding was further used to design a fluorometric method for the determination of (PPA) drug, The reaction is followed fluoremetrically by measuring the absorbance at 335 nm. 2.5×10-2 molL-1 PbS with gelatin sensor, calibration graph in the rang of 0.05 - 10.0 µg L-1 (PPA) drug. The absorbance is linear from 0.05 up to 100.0 µg L−1 in aqueous solution with repeatability (RSD) of 3.5% at a concentration of 10.0 µg L−1 and a detection limit of 2.2 µg L−1 by the fixed-time method of 60 sec. The relative standard deviation for 10.0 µg L-1 (PPA) drug is %95. The applicability of the method was demonstrated by the determination of the (PPA) drug in urine and blood samples تفاصيل المقالة