CoO/Co₃O₄ nanoparticles (NPs) were synthesized by using a fresh egg white-assisted combustion method which acts as a new approach for green synthesis of this composite. This method was carried out by the direct heat of cobalt precursor with egg white at low temperature for very short period. In fact, this route is a novel, cheap and appropriate technique yielding nanoparticle-based materials. CoO/Co₃O₄ nanoparticles were characterized by examining the structure and identifying the elements and determining the morphology via XRD, FTIR, SEM, EDS and TEM techniques. The sample magnetic observations were measured through the use of a vibrating sample magnetometer (VSM). The results of XRD, EDS, SEM and TEM confirmed the positive synthesis of the cubic CoO/Co₃O₄ NPs with sponge crystals which proceed. For the as synthesized composite, 57.75 m²/g, 0.0148 cc/g and 10.31 nm were identified to be the S_BET, V_p and ȓ, respectively. The cobalt oxide particles in their nature were polycrystalline, and the crystallite sizes varied from 10 to 20 nm. The magnetic measurement showed that the prepared nanocomposite displays room temperature ferromagnetism with an optimum value, 3.45 emu/g, of saturation magnetization.

Recently, the application of nanotechnology in food sector and the agriculture attract the attention compared to its biomedical application. The aims of the current study was to synthesize and characterize cobalt ferrites nanoparticles [(CoFe2O4) NPs] by combustion method employing glycine as fuels and to evaluate their antimicrobial against pathogenic bacteria and fungi and anti cancer properties against MCF-7 breast cancer cells line. The results indicated that the particles size of the synthesized (CoFe2O4) NPs was 40 nm. These (CoFe2O4) NPs showed potential antibacterial properties against Gram-negative bacteria (Escherichia coli, Salmonella typhi) and Gram-positive bacteria (Staphylococcus aureus, Bacillus cereus) as well as the pathogenic fungi (Aspergillus flavus and Aspergillus ochraceus) in a dose dependent manner with maximum concentration of 1.8 mg/ml. (CoFe2O4) NPs also showed weak antiradical but have cytotoxic effects against MCF-7 breast cancer cells line and succeeded to decrease the cell viability at a concentration of 2 mg/ml. It could be concluded that (CoFe2O4) NPs is a promise candidate as antimicrobial and anticancer agent for food sector and medical application.

Magnesium ferrite (MgFe2O4) nano-particles were synthesized by using both the ceramic method and egg white assisted green synthesis method. The ceramic method carried out at different temperatures while the combustion method achieved at 300 oC for quarter-hour with various amounts of egg white. The green synthesis method was found to be a simple and cost-effective method compared to the ceramic method. Significant effects of the calcination temperatures and concentration of egg white on the observed phases, sizes, lattice parameters and morphological properties of the as-synthesized nanoparticles have been studied. Investigation of the structural and morphological characteristics of the as prepared samples was determined by XRD and SEM techniques, respectively. However, the relative atomic abundance of Mg, Fe and oxygen species present in various solids were determined by the EDX technique. The results display the nanometer size and partially inverse spinel structure of MgFe2O4 studied.