Microbial-Physical Synthesis of Fe and Fe₃O₄ Magnetic Nanoparticles Using<i> Aspergillus niger</i> YESM1 and Supercritical Condition of Ethanol

Abstract

Magnetic Fe and Fe 3 O 4 (magnetite) nanoparticles are successfully synthesized using Aspergillus niger YESM 1 and supercritical condition of liquids. Aspergillus niger is used for decomposition of FeSO 4 and FeCl 3 to FeS and Fe 2 O 3 , respectively. The produced particles are exposed to supercritical condition of ethanol for 1 hour at 300°C and pressure of 850 psi. The phase structure and the morphology measurements yield pure iron and major Fe 3 O 4 spherical nanoparticles with average size of 18 and 50 nm, respectively. The crystal size amounts to 9 nm for Fe and 8 nm for Fe 3 O 4 . The magnetic properties are measured to exhibit superparamagnetic- and ferromagnetic-like behaviors for Fe and Fe 3 O 4 nanoparticles, respectively. The saturation magnetization amounts to 112 and 68 emu/g for Fe and Fe 3 O 4 , respectively. The obtained results open new route for using the biophysical method for large-scale production of highly magnetic nanoparticles to be used for biomedical applications.