Green synthesis of silver and gold nanoparticles in Callistemon viminalis extracts and their antimicrobial activities

Bioprocess Biosyst Eng. 2024 Mar 21. doi: 10.1007/s00449-024-02994-6. Online ahead of print.ABSTRACTIn the current study, the bottlebrush [Callistemon viminalis (Sol. ex Gaertn.) G. Don] plant was selected for the green synthesis of silver (Ag) and gold (Au) nanoparticles and to evaluate its antibacterial and antifungal activities. Phytochemical screening of C. viminalis confirmed the presence of alkaloids, anthraquinones, saponins, tannins, betacyanins, phlobatanins, coumarins, terpenoids, steroids, glycosides, and proteins. To characterize the synthesized Ag and Au NPs, UV-Visible spectroscopy, FTIR spectroscopy for functional group identification, field emission scanning electron microscopy (FE-SEM) for particle size, and elemental analysis were performed using EDX. The UV-Visible absorption spectra of the green-synthesized Ag and Au nanoparticles were found to have a maximum absorption band at 420 nm for Ag NPs and 525 nm for Au NPs. FE-SEM analysis of the synthesized NPs revealed a circular shape with a size of 100 nm. Elemental analysis was performed for the synthesis of Ag and Au NPs, which confirmed the purity of the nanoparticles. The greenly synthesized Ag and Au NPs were also evaluated for their anti-bacterial and anti-fungal activities, which exhibited prominent inhibition activities against Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae, Pseudomonas aeruginosa, Candida albicans, C. krusei, Aspergillus sp., and Trichoderma species. The highest zone...
Source: Bioprocess and Biosystems Engineering - Category: Biomedical Engineering Authors: Source Type: research