Voltammetric behavior of dopamine at a glassy carbon electrode modified with NiFe2O4 magnetic nanoparticles decorated with multiwall carbon nanotubes

• NiFe2O4 magnetic nanoparticles decorated with multiwall carbon nanotube electrode were prepared.
• The modified nanocomposite shows high synergic effect toward dopamine oxidation.
• Dopamine could be measured as low as 0.02 μmol L− 1 with good sensitivity and selectivity.
• The electrode is free from interference of different organic and biological compounds.

Voltammetric behavior of dopamine was studied on a glassy carbon electrode (GCE) modified-NiFe2O4 magnetic nanoparticles decorated with multiwall carbon nanotubes. Impedance spectroscopy and cyclic voltammetry were used to characterize the behavior of dopamine at the surface of modified-GCE. The modified electrode showed a synergic effect toward the oxidation of dopamine. The oxidation peak current is increased linearly with the dopamine concentration (at pH 7.0) in wide dynamic ranges of 0.05–6.0 and 6.0–100 μmol L− 1 with a detection limit of 0.02 μmol L− 1, using differential pulse voltammetry. The selectivity of the method was studied and the results showed that the modified electrode is free from interference of organic compounds especially ascorbic acid, uric acid, cysteine and urea. Its applicability in the determination of dopamine in pharmaceutical, urine samples and human blood serum was also evaluated. The proposed electrochemical sensor has appropriate properties such as high selectivity, low detection limit and wide linear dynamic range when compared with that of the previous reported papers for dopamine detection.