ZnS-MPA quantum dot as a fluorescence quenching nanosensor for sensitive and selective determination of nilotinib in human serum samples

Nilotinib is a second-generation transduction inhibitor for the potential treatment of chronic myelogenous leukemia [1]. From biomedical and pharmaceutical points of view, monitoring drug levels in biological fluid such as plasma, urine, and saliva is essential to assess the drug pharmacokinetic, side effects, and toxicity. Although, by far, there are already some methods for the determination of nilotinib in biological samples mostly based on chromatographic separations [2], but most of these methods suffer from some drawbacks such as high analysis cost and sophisticated instruments.In the present work, a spectrofluorimetric method has been developed for sensitive determination of nilotinib cancer therapy drug in human serum samples. The method is based on the quenching effect of the drug on fluorescence spectra of a ZnS based quantum dot. The ZnS quantum dots were synthesized according to a precipitation method and were further functionalized and stabilized with mercaptopropionic acid (MPA). The synthesized ZnS-MPA quantum dot was utilized to develop a spectrofluorimetric method for determination of the investigated drug at λem=425 (λex=298) under the optimized conditions (pH, 9.5; quantum dot dosage, 150 mg L-1). The calibration curve was linear in the concentration range of 50 to 2500 μg L-1 with a correlation coefficient of 0.9984. The limit of detection was obtained as 20μg L-1 indicating high sensitivity of the method.