an ultrasensitive electrochemical sensor for direct determination of anticancer drug dacarbazine based on multiwall carbon nanotube-modified carbon paste electrode and application in pharmaceutical sample

A simple and ultrasensitive sensor based on carbon paste electrode (cpe) modified by multiwall carbon nanotube (mwcnt) was developed for the electrochemical determination of anticancer drug dacarbazine (dac). the electrochemical behavior of dac was studied in 0.1 m phosphate buffer solution (pbs) using cyclic voltammetry (cv) while differential pulse voltammetry (dpv) was used for quantification. compared with the unmodified carbon paste electrode, the modified electrode facilitates the electron transfer of dac, since it notably increases the oxidation peak current of dac. the electronic transfer property of the mwcnt carbon paste electrode was characterized by electrochemical impedance spectroscopy (eis). also, morphology of the electrode was characterized by scanning electron microscopy (sem). under optimized conditions, the modified electrode exhibited a linear response over the concentration ranging from 0.4 to 40 nm and 40–2500 nm dac, with a detection limit of 0.12 nm. the proposed sensor exhibited a high sensitivity, good stability and was successfully applied for dac determination in pharmaceutical sample, with good percentage recovery. in addition, to evaluate precision and accuracy of dpv method, high-performance liquid chromatography (hplc) method was used.