Rod-like CuO nanoparticles/waste masks carbon modified glassy carbon electrode as a voltammetric nanosensor for the sensitive determination of anti-cancer drug pazopanib in biological and pharmaceutical samples

In the present work, the first voltammetric method is developed for the detection of pazopanib (PZB), a pharmaceutically active ingredient belonging to the tyrosine kinase inhibitor class, using a modified glassy carbon electrode (GCE). Rod-like CuO nanoparticles synthesized by hydrothermal method and finger-like carbon material obtained from hydrothermal carbonization (HTC) of waste masks (M) were used as modification agents. The chemical structure and surface morphology of the synthesized materials were elucidated using various analytical techniques. The results show that carbon material has a core-shell structure, a critical property that increases electrical conductivity. Thus, the effects of both nanoparticles and carbon material on the electrooxidation behavior of pazopanib were investigated and compared. The effect of scan rate, pH, and supporting electrolyte on the voltammetric response of pazopanib was investigated on bare and modified GCE. The possible electrochemical oxidation mechanism was discussed with model drugs on bare GCE. The electrooxidation of PZB was an adsorption-controlled process on modified GCE at pH 7.0 phosphate buffer solution as proved by cyclic voltammetry (CV). All parameters of stripping conditions and square wave voltammetry (SWV) were optimized. The calibration curve was linear in the range of 2.0 x 10-10-1.0 x 10-6 M by adsorptive stripping square wave voltammetry (AdSSWV). The proposed method was used for the quantification of pazopanib in human serum samples and pharmaceutical dosage forms with satisfactory precision and accuracy. The method showed excellent analytical performance at nano- detection levels. Besides, the nanosensor was tested in the presence of some interfering compounds and ions.