Synthesis and characterization of magnetic nanoparticles Zn1-xMgxFe2O4 with partial substitution of Mg2+ (x= 0.0, 0.25, 0.5, 0.75 and 1.0) for adsorption of uremic toxins

Abstract Chronic kidney disease (CKD) is an increasing problem worldwide, usually detected by an increase of uremic toxins in the human bloodstream. In this study, Zn1-xMgxFe2O4 nanoparticles were synthesized and characterized as possible candidates for the adsorption of uremic toxins, such as urea, creatinine, and uric acid. The synthesis of nanoparticles from magnetic oxides of Fe, Zn, and Mg (Zn1-xMgxFe2O4, x = 0.0, 0.25, 0.5, 0.75, and 1.0) was carried out by sol-gel method at a heat treatment temperature of 500 °C for 60 min. The study evaluates the effect of replacing Zn2+ with Mg2+ cations within a zinc ferrite (ZnFe2O4), the crystalline structure, and the magnetic properties of nanoparticles. The synthesized samples were identified as ZnFe2O4 ferrite (JCPDS 22-1012) by X-ray diffraction. By the Vibration Sample Magnetometry technique, it was possible to observe an increase in the saturation magnetization value (Ms), as the content of Mg2+ cations decrease (x ≤ 0.5). The remnant magnetization (0.47–0.91 emu/g) and the coercive field (5–9 Oe) indicate a ferrimagnetic behavior of the synthesized nanoparticles. The samples have a quasi-spherical morphology and a size smaller than 16 nm, as determined by transmission electron microscopy (TEM). The Fourier Transform Infrared (FT-IR) technique showed characteristic absorption bands of the spinel ferrite M − O bonds for the ferrites ZnFe2O4 and Zn0·5Mg0·5Fe2O4. Hemolysis tests of the selected ferrites showed a hemolysis percent of less than 2.0% of cytotoxicity for suspensions of 10 mg of ferrite per milliliter of the aqueous medium. The selected samples of ZnFe2O4 and Zn0·5Mg0·5Fe2O4 were tested as adsorbent materials for uremic toxins removing up to 20% for uric acid, 77% for creatinine, and 85% for urea.