There has been an increase in demand for nanocomposite, which has resulted in large-scale manufacturers employing high-energy processes and harmful solvents. Because of this, the need for environmentally benign "green" synthesis processes has grown. Other methods for making nanocomposite include using plants and plant products, bacteria, fungi, yeast, and algae. Green synthesis has minimal toxicity and is safe for human health and the environment compared to other processes, making it the ideal option for creating nanocomposite materials. This work reveals an environmentally friendly synthesis method for magnetic nanocomposites. In particular, they were using an aqueous extract of Artemisia to obtain ZnO/Fe3O4 using cold plasma technology. The magnetic nanocomposite was prepared with different concentrations (0.01, 0.02, and 0.03) of M and (2:8) of the aqueous extract. The structural properties were studied using X-ray diffraction, where the crystal size ranged from 30 to 40 nm, while the surface morphology was studied through the field emission scanning electron microscope, and it was found that the shape of the particles is semi-spherical and within a particle size range of 30 to 60 nm. "Green" magnetic nanocomposites showed low toxicity and high biocompatibility, allowing their application in biomedicine, where magnetic nanocomposites were employed as anti-agents for E. coli and S. aureus using the agar diffusion method. Its high effect on bacterial inhibition was noted when the concentration was increased, as the diameter of inhibition ranged (11-22) mm for E. coli and (15-24) mm for Staphylococcus aureus.
