In present years, the synthesis of iron oxide nanoparticles (IONPs) has established excessive potential in biological applications due to their non-toxic role in biological systems, biocompatibility, and biodegradability. Ongoing research efforts focused on IONPs in the expansion of novel technologies as they can be synthesized with surface modification. Here we have studied the antibacterial effects of IONPs which were synthesized effectively through a green synthesis route by using leaf extract of the Carica papaya plant. The formation of IONPs was confirmed by the color change. The crystallinity of IONPs was determined by XRD and the morphology by using SEM, which showed spherical particles of well-dispersed size. The absorption peak was determined by UV–vis spectroscopy at 390 nm. Average particle size distribution was obtained at 56 nm using PSA.  FL spectroscopy indicated the higher emission wavelength by redshift at 641.6 nm. TGA showed that the IONPs are thermally stable up to 200⁰C with no decomposition. The outcome would pave a way for utilizing IONPs for better biomedical application.

In the present time, Iron oxide magnetic nanoparticles (IOMNPs) have paid considerable attention due to their exclusive applications in terms of surface-to-volume ratio, superparamagnetism, high surface area, biosensor, bio-separation, catalysis, and biomedicine. Our goal was to synthesis iron oxide magnetic nanoparticles by chemical route technique. The preparation method had a very large effect on the size, shape, and surface chemistry of the magnetic nanoparticles including their applications. The iron chloride solution was prepared by mixing deionized water with iron chloride tetrahydrate. The synthesized powder was characterized by XRD, UV-vis, SEM, FT-IR, DLS, FL, and TGA techniques. Moreover, antibacterial activity was evaluated using the synthesized IOMNPs against Escherichia coli (A), Pseudomonas (B), Enterobacter (C), Staphylococcus aureus (D), and Bacillus subtilis (E) in the concentration of 0.1 mg and 0.5 mg. The results showed that Bacillus subtilis possess a higher antibacterial activity at the concentration of 0.5 mg comparing the other bacterial species. The outcome of this work would contribute to the present understanding of the biomedical application with the obtained size, shape, and synthesized method.