Green synthesis of silver nanoparticles using extracts of Allium rotundum l, Falcaria vulgaris Bernh, and Ferulago angulate Boiss, and their antimicrobial effects in vitro

Green chemistry is a safe and cost-effective method for producing metal nanoparticles. This study aimed to investigate the green synthesis of silver nanoparticles using extracts of Allium rotundum l, Falcaria vulgaris Bernh, and Ferulago angulate Boiss, and their antimicrobial effects. Aerial parts of Allium rotundum l., Falcaria vulgaris Bernh. and Ferulago angulate Boiss. were used for the synthesis of silver nanoparticles (Ag NPs). Ag NPs were characterized by UV-vis spectrophotometer, X-ray diffractometer (XRD), and Transmission electron microscopy (TEM). The formation and stability of the reduced silver nanoparticles were checked by UV-vis spectrophotometer analysis. The average particle diameter of silver nanoparticles was calculated from the XRD pattern according to the Scherrer's equation. The antimicrobial, synergistic effects of synthesized nanoparticles and ethanolic extracts of plants were studied alone and in combination with Pseudomonas aeruginosa PAO1 and Staphylococcus aureus ATCC 25923 using disk diffusion method and the diameter of the zone of inhibition compared to the Tetracycline, Kanamycin, and Cefpirome. The minimum inhibitory concentration (MIC) of bacteria was determined using micro broth dilution. The XRD spectroscopy of synthesized nanoparticles showed the face center cubic structure. Also, TEM showed the formation of silver nanoparticles with an average size of 20.5 nm. The diameter of the inhibition zone of synthesized silver nanoparticles in the MIC of the mixture of plant extracts and silver nanoparticles was 21, and 25 (mm) for P. aeruginosa, and S. aureus, respectively. Obtained results showed that the bio-synthesized silver nanoparticles have an antibacterial effect on both P. aeruginosa and S. aureus.