Antibacterial activity of iron oxide nanoparticles synthesized by co-precipitation technology against Bacillus cereus and Klebsiella pneumoniae

Abstract

The present study investigates the synthesis and characterization of iron oxide nanoparticles (Fe3O4-NPs) for their antibacterial potential against Bacillus cereus and Klebsiella pneumonia by modified disc diffusion and broth agar dilution methods. DLS and XRD results revealed the average size of synthesized Fe3O4-NPs as 24 nm while XPS measurement exhibited the spin-orbit peak of Fe 2p3/2 binding energy at 511 eV. Fe3O4-NPs inhibited the growth of K. pneumoniae and B. cereus in both liquid and soild agar media, and displayed 26 mm and 22 mm zone of inhibitions, respectively. MIC of Fe3O4-NPs was found to be 5 μg/mL against these strains. However, MBC for these strains was observed at 40 μg/mL concentration of Fe3O4-NPs for exhibiting 40–50% loss in viable bacterial cells and 80 μg/mL concentration of Fe3O4-NPs acted as bactericidal for causing 90–99% loss in viability. Hence, these nanoparticles can be explored for their additional antimicrobial and biomedical applications.

Keywords

• antibacterial activity
• co-precipitation
• iron oxide nanoparticles
• klebsiella pneumoniae
• physico-chemical characterization