Physical properties and antibacterial activity of green-iron oxide nanoparticles synthesize with chia seeds

This study examined the use of chia seed extract as a reducing agent to produce iron oxide nanoparticles (NPs) in an environmentally-friendly manner (green-iron oxide NPs). The synthesis of the iron oxide NPs was verified using X-ray diffraction (XRD), Raman spectroscopy, Fourier transform infrared (FTIR) spectroscopy, field emission scanning electron microscopy (FESEM), energy dispersive X-ray (EDX) spectroscopy, and ultraviolet-visible spectroscopy (UV-Vis). The XRD analysis verified the formation of iron oxide NPs at different phases; haematite (alpha-Fe2O3), maghemite (gamma-Fe2O3), and magnetite (Fe3O4); as well as average crystalline sizes of 14.76 nm at all the crystalline peaks. Meanwhile, Raman spectroscopy analysis was conducted and confirmed the results of the XRD analysis. The FTIR analysis discovered absorption bands at 468, 601, 775, and 810 cm(-1), which confirmed that the NPs formed were iron oxide NPs, while the FESEM images revealed imperfect spherical NPs with average grain sizes of 27.228 nm. The EDX analysis verified the composition of the elements while the UV-Vis spectrum indicated a broad absorption band between 315 - 458 nm, with a peak at 250 nm. Lastly, the antibacterial activity of the green-iron oxide NPs was more effective against gram-positive Staphylococcus aureus (S. aureus) than gram-negative Escherichia coli (E. coli).