Liquid phase determination of isuprel in pharmaceutical and biological samples using a nanostructure modified carbon paste electrode

The electrochemical behavior of isuprel (ISP) on the ionic liquid of 1,3-dipropylimidazolium bromide NiO nanoparticle (NiO/NPs) modified carbon paste electrode (IL/NiO/NPs/CPE) was studied in this paper and further used for ISP detection. ISP showed a diffusion oxidation process on the IL/NiO/NPs/CPE with the oxidation peak potential located at 0.62 V (vs. Ag/AgCl/KCl_sat) in a pH 5.0. Compared with that on the traditional carbon paste electrode, small shift of the oxidation peak potentials appeared but with a great increment of the oxidation peak current on the IL/NiO/NPs/CPE, which was due to the presence of ionic liquid and NiO/NPs in the modified electrode. The diffusion coefficient (D) was also determined using electrochemical approaches. The linear response range and detection limit were found to be 0.4-500 μmol L^{- 1} and 0.1 μmol L^-1, respectively. Other physiological species did not interfere in the determination of ISP at the surface of the proposed sensor in the optimum condition. The proposed sensor was successfully applied for the determination of ISP in real samples.