In this work, the electrocatalytic oxidation of some dopaminergic drugs such as selegiline (SEL) and pramipexole (PX) was carried out, for the first time with a nickel nanoparticle modified carbon paste electrode (Ni-NP/MCPE) using cyclic voltammetry, chronoamperometry, chronocoulometry, and amperometry methods. At first, nickel nanoparticles were synthesized by a non-aqueous polyol method and then these nanoparticles were mixed with graphite powder to form a modified carbon paste electrode. The as-prepared modified electrode was characterized by using SEM images. The images from the surface of the electrode indicate that these particles were formed uniformly with an average size of 50 nm. In the presence of 0.1 M NaOH, a good redox behavior of the Ni(III)/Ni(II) couple at the surface of the electrode can be observed. SEL and PX were successfully oxidized at the surface of this modified electrode. The electrocatalytic oxidation peak currents of these drugs were linearly dependent on their concentrations. The detection limit, slope, and correlation coefficient were calculated to be 4.0 106, 4.84 102, and 0.9951 for SEL and also 4.5 108, 4.46 102, and 0.9948, respectively, for PX. The proposed sensor exhibited a high sensitivity and good selectivity, and was successfully applied for clinical evaluation of SEL and PX.
