Template-free synthesis of ZnO/Fe3O4/Carbon magnetic nanocomposite: Nanotubes with hexagonal cross sections and their electrocatalytic property for simultaneous determination of oxymorphone and heroin

Abstract

A new method is introduced to synthesize ZnO/Fe3O4/Carbon magnetic hexagonal nanotubes arrays named ZnO/Fe3O4/C MHNTA using a one-pot synthesis. Scanning electron microscopy (SEM), X-ray powder diffraction (XRD), BET surface area analysis, and energy dispersive X-ray spectroscopy (EDX) are used for the characterization of composition and morphology of Fe3O4/ZnO/C MHNTA, demonstrating its high specific surface area of the synthesized material. The synthesized nanotube possesses hexagonal cross-sections and wall thicknesses of about 25 nm, long lengths of around 1.2 mu m and side lengths of about 100 nm. The mentioned properties provided rapid electron transfer and large electrochemically active surface area and assisted in the discrimination of analytes that reduce or oxidize under the same potentials. The enhanced electrode demonstrated appropriate sensing ability to oxymorphone and heroin after performing fixation of ZnO/Fe3O4/C MHNTA. Kinetic factors charge transfer coefficient, standard heterogeneous electron transfer rate constant and other different electrochemical factors are predicted using voltammetry methods. Low limits of detection (LODs), 3.5 nM and 4.7 nM, and broad liner ranges, 0.01-500.0 mu M are obtained in the case of oxymorphone and heroin, respectively. In addition, the mentioned suggested a suitable potential for profiling of oxymorphone and heroin with appropriate long-term stability, repeatability and reproducibility. The excellent efficiency for the measurement of real samples demonstrated the most significant future perspectives of this sensor. In the last step, the feasible sensing approach is suggested.