Determination of the Anticancer Drug Sorafenib in Serum by Adsorptive Stripping Differential Pulse Voltammetry Using a Chitosan/Multiwall Carbon Nanotube Modified Glassy Carbon Electrode

Adsorptive stripping differential pulse voltammetry (AdSDPV) was applied to the assay of sorafenib in human serum sample. Cyclic voltammetry at a carbon based screen printed electrode (SPE) permitted to detect the irreversible oxidation of SOR with formation of a new compound reversibly oxidized at a lower potential. Quantitative assays were realized using a chitosan/carboxylic acid functionalized multiwalled carbon nanotube modified glassy carbon electrode in 0.1M phosphate buffer pH 7.0 in the presence of 50% methanol. The AdSDPV method provided two linear responses within the concentration ranges 1 x 10(-8)-8 x 10(- 8) M and 1 x 10(-7)-8 x 10(-7) M in serum with LOQ and LOD of 3.2 x 10(-9) and 9.6 x 10(-10) of lower linear range, respectively. The recovery of sorafenib in spiked serum was 97.5%.