Synthesis of Gold Nanoparticles Using Hordeum vulgare Leaf Extract and their Antibacterial Activity

Mohamed M. Sehree, University of Telafer, Nineveh, Iraq;
Shakir Ghazi Gergees, Biology, University of Mosul, Nineveh, Iraq
Pakhshan A. Hassan, Biolog, Salahaddin University, Erbil, Iraq.Follow

Abstract

Plant extracts and gold nanoparticles are promising alternatives for combating antibiotic resistance in light of the increasing bacterial resistance. Leaf extract of barley was used to synthesize gold nanoparticles (AuNPs). Barley gold nanoparticles (BL-AuNPs) were produced by adjusting some reaction parameters. These BL-AuNPs were characterized through employing the UV-visible spectroscopy technique, the scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR), and energy dispersive X-ray spectroscopy (EDX). BL-AuNPs were tested for antibacterial efficacy against two strains of Gram-negative bacteria, clinically isolated and considered as multidrug-resistant pathogens, Acinetobacter baumannii and Salmonella typhi. The antimicrobial efficiency of the compounds was evaluated via diffusion and microdilution assays. UV spectra were used to characterize the extract, providing a peak at 530 nm. The biomolecules associated with the AuNPs conjugated with plant extracts were identified to describe C-H, carbonyl (C-O), carbonyl OH, and C≡C groups based on the FTIR technique. The SEM analysis indicated that barley agglomerates of formed gold nanoparticles ranged in size from 263.2 nm to 214.7 nm. The AFM analysis exhibited that their size was 36.29, and the surface roughness and root mean square were 3.34 and 4.18, respectively. The results of the antibacterial activity of BL-AuNPs showed that A. baumannii and S. typhi strains were not affected at 1 mM of AuNPs, while the free gold nanoparticles showed moderate antibacterial action. The BL-AuNPs exhibited higher antibacterial activity, with inhibition zones ranging from 14 to17 mm for A. baumannii and 10 to18 for S. typhi, compared to AuNPs and barley leaf extract individually, which showed lower antibacterial activity. In conclusion, gold nanoparticles synthesized from the extract of Hordeum vulgare leaves offer a rapid, cost-effective, and eco-friendly method. This green approach yields high quantities without releasing toxic substances. The stability and antibacterial activity of synthesized gold nanoparticles revealed considerable promise for development in biomedical applications. Future studies should include Gram-positive and fungal strains to better evaluate the full antibacterial spectrum and investigate further for outstanding and improved biological uses.

Recommended Citation

Sehree, Mohamed M.; Gergees, Shakir Ghazi; and Hassan, Pakhshan A. (2025) "Synthesis of Gold Nanoparticles Using Hordeum vulgare Leaf Extract and their Antibacterial Activity," Karbala International Journal of Modern Science: Vol. 11 : Iss. 3 , Article 2.
Available at: https://doi.org/10.33640/2405-609X.3409