Synthesis of Fe3O4@copper(II) imidazolate nanoparticles: Catalytic activity of modified graphite screen printed electrode for the determination of levodopa in presence of melatonin

Abstract

Abstract This work reports a simple route for the synthesis of Fe3O4@copper(II) imidazolate nanoparticles (Fe3O4@Cu(Im)2 NPs). The synthesized Fe3O4@Cu(Im)2 NPs were characterized by energy dispersive X‐ray analysis (EDX), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermo-gravimetric analysis (TGA), X-ray diffraction (XRD), and Brunauer-Emmett-Teller (BET) techniques. Levodopa was successfully detected by a sensitive and facile electrochemical sensor fabricated based on the graphite screen printed electrode modified with Fe3O4@Cu(Im)2 nano-particles (NPs) (Fe3O4@Cu(Im)2/GSPE). The electrochemical response features of the modified electrode towards levodopa was examined by cyclic voltammetry (CV), differential pulse voltammetry (DPV) and chronoamperometry (CHA). Electrochemical sensor response for the target analyte ameliorated considerably after modification with Fe3O4@Cu(Im)2 NPs as compared to the ones achieved with the use of a bare GSPE; levodopa is detectable in range from 1.0 to 300.0\xa0µM with the limit of detection being 0.24\xa0μM under optimal conditions. Moreover, this modified electrode could determine levodopa in the presence of melatonin by DPV. The Fe3O4@Cu(Im)2/GSPE presented satisfactory results for stability and repeatability. The applicability of the sensor was evaluated by detecting levodopa in spiked human urine and melatonin tablet samples and good recoveries were obtained from different spiked samples.