Intrinsic Peroxidase-like Activity of MgFe2O4/PVP nanocomposites and their application in the Colorimetric Detection of H2O2

Abstract

It has been shown that nanoferrites are nanomaterials exhibiting intrinsic enzyme-like activity. Magnesium ferrite nanoparticles (MgFe2O4 NPs) have been effectively used as nanozymes; they have been shown to behave like a peroxidase in the oxidation of 3,3', 3,5'-tetramethylbenzidine (TMB). These materials have been used in various fields, such as biosynthesis, environmental protection, and bioelectronic sensor devices. In this paper, a method for synthesizing an MgFe2O4/PVP nanocomposite and studying it as a peroxidase enzyme mimetic has been described. The resulting nanocomposite has been characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), and FT-IR spectroscopy. The morphology of the MgFe2O4 NP powder has been studied by SEM; it has been shown that the ZnFe2O4–polymer NPs synthesized in the presence of a polymer have a spherical form and a size of 5–10 nm. Since the NPs have a high surface energy, they undergo a rapid interparticle interaction and coarsening and aggregate into spherical structures with a diameter of 80–120 nm. Composition has been determined by EDX with an Mg : Fe ratio of 1 : 2.5. Experimental results have shown that the MgFe2O4/PVP nanocomposites exhibit peroxidase-like activity in a linear range of 0.01–0.16 M. In addition, the color change dependent on hydrogen peroxide concentration can offer a convenient approach to detecting H2O2 both with the naked eye and spectrophotometrically. Therefore, the MgFe2O4/PVP nanocomposites are a promising candidate for the colorimetric detection of H2O2, glucose, ascorbic acid, etc.