An Impedimetric Sensor Comprising Magnetic Nanoparticles-Graphene Oxide and Carbon Nanotube for the Electrocatalytic Oxidation of Salicylic Acid

An effective and facile electrocatalytic oxidation approach for the determination of salicylic acid (SA) on the surface of Ni-2,3-pyrazine dicarboxylic acid (Ni-PDA)/Fe3O4 magnetic nanoparticles/graphene oxide (GO)/carbon nanotube (CNTs) modified carbon paste electrode was demonstrated in this article. The GO sheets and CNTs were interlinked by ultrafine Fe3O4 nanoparticles forming three dimensional (3D) architectures. The characterization of the nanocomposites was studied by scanning electron microscopy, energy-dispersive X-ray, X-ray diffraction, and wavelength-dispersive X-ray spectroscopy. The electrochemical performance of the Ni-PDA film and the parameters affecting its activity were also investigated by cyclic voltammetry, and electrochemical impedance spectroscopy. The data revealed that the modified electrode present considerable electrocatalytic activity toward SA oxidation. The effects of some parameters such as the different scan rates, pH, and SA concentrations were also evaluated to provide catalysis mechanism for SA oxidation at the surface of modified electrode. Furthermore, impedimetric studies showed that the fabricated electrode as the sensing element has a detection capability of 900 nM allowing the quantitative analysis of SA in the concentration range from 5.00 to 155 A mu M. Remarkable advantages of the prepared modified electrode such as low detection limit, wide linear range of concentration and high sensitivity make it as good sensor for the selective determination of SA. [GRAPHICS]