Iron oxide nanoparticle synthesis using trigonella and tomato extracts and their antibacterial activity

ABSTRACT

Iron oxide nanoparticles (IONPs) were synthesised by combining the extracts of new plants (trigonella and tomato) with ferric chloride salt (FeCl₃) via a simple chemical method at 200°C for 2 hours. The biomolecules in the extracts play an important part in transforming FeCl₃ to FeO NPs, which demonstrate antibacterial properties. IONPs were characterised via X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), and Fourier-transform infrared spectroscopy (FT-IR). XRD revealed a crystallite size of 17 nm with a body centre cubic (BCC) structure (wüstite) phase for FeO NPs made using trigonella extract. FeO NPs synthesised using tomato extract were 41 nm, and the diffraction peaks revealed a BCC structure phase with excellent crystal quality. FE-SEM images demonstrated that the average grain size of Fe₂O₃ without using any plant extract was approximately 31.36 to 125.5 nm, while for the FeO NPs using tomato extract, it was approximately 48.18 to 77.54 nm, and for trigonella extract, 27.91 to 40.94 nm. In the FT-IR spectra of IONPs with and without plant extract, a strong peak appeared at 699 cm⁻¹ for FeO NPs using trigonella extract and 655 cm⁻¹ using tomato extract. Antibacterial activity of IONPs was determined by growth inhibition zones of the gram-negative bacteria Klebsiellapneumonia and gram-positive bacteria Staphylococcus aureus. The growth inhibition zones for FeO NPs using trigonella extract were 42 and 47 mm, respectively. The zones for FeO NPs using tomato extract were smaller (30 mm and 35 mm, respectively). These NPs may be effective in healing infections caused by these bacteria.

Graphical abstract

KEYWORDS:

• New plant extracts
• iron oxide NPs
• simple chemical method
• antibacterial activity

Acknowledgments

The auther(s) would like to thank Mustansiriayah University (www.uomustansiriyah.edu.iq) Baghdad-Iraq for its support in the present work.

Disclosure statement

No potential conflict of interest was reported by the authors.