A novel voltammetric sensor based on palladium nanoparticles/carbon nanofibers/ionic liquid modified carbon paste electrode for sensitive determination of anti-cancer drug pemetrexed

Abstract

In the present study, for the first time, we develop a sensitive voltammetric technique for the determination of pemetrexed using Pd/carbon nanofibers/methyl (trioctyl)ammonium bis(trifluoromethylsulfonyl)imide ([M3OA]+[NTF2]−) ionic liquid modified carbon paste electrode in which Nafion was utilized as binder (CPE/Pd/CNF/[M3OA]+[NTF2]−/Nafion). Composite nanofibers were synthesized by electrospinning method and characterized by SEM, TEM, XRD and FT-IR and the synthesized ionic liquid was also investigated by FT-IR and UV–Vis. Square wave voltammetry (SWV) measurements were performed to investigate the electrochemical oxidation of pemetrexed using the proposed electrode in 0.1 M phosphate buffer solution at pH 6.0. Several parameters such as pH amount, scan rate and the type of supporting electrolyte were studied for pemetrexed oxidation. In addition, selectivity, repeatability, reproducibility and stability were also evaluated. Under optimized conditions, a linear concentration was detected in the range of 1.00–35.0 nM with a detection limit of 0.33 nM by SWV. The proposed sensor was successfully applied for the quantification of pemetrexed in cancerous human plasma, pharmaceutical and health urine samples.