Synthesis, chemical characterization and antimicrobial efficacy of chemically synthesized iron oxide nanoparticles (IONPs) against multidrug-resistant bacteria

The discipline of nanobiotechnology has become the most studied field in helping the medical field to develop drugs against multidrug-resistant bacteria. Chemically synthesized iron oxide nanoparticles (IONPs) are produced by various methods alternatives of typical antibiotics. In the present research IONPs were chemically synthesized, characterized and applied against medically important bacteria. Transmission Electron Microscopy (TEM) and Scanning Electron Microscopy (SEM) were used to observe the nanoparticles' morphology, which showed a spherical or quasi-spherical shape with a size range of ± 10 nm. Ultraviolet-visible spectroscopy (UV-Vis) and Fourier Transform Infrared Spectroscopy (FTIR) were used to analyse the functional groups and the elements present in the sample, and Nuclear Magnetic Resonance (NMR), X-Ray Diffraction (XRD) and X-Ray Photoelectron Spectroscopy (XPS) were used to analyse the crystalline structure. Antibacterial activity of the nanoparticles against four pathogenic strains: Pseudomonas aeruginosa (P. aeruginosa-424), Staphylococcus aureus (S. aureus-902), Streptococcus mutans (S. mutans-497), and Escherichia coli (E. coli-443) was investigated by microbiological assays. Concentration-dependent inhibition zones, low minimum inhibitory concentrations (MICs), and notable biofilm damage were among the main methods. Time-kill assays and DNA fragmentation investigations indicated that the chemically synthesised iron oxide nanoparticles have the potential to induce bacterial cell death. Among the species investigated, S. aureus was more sensitive to IONPs, which caused DNA damage. The study highlights how IONPs are a promising candidate for inclusion in antibacterial medications.