The leaf extract of O. tenuiflorum was used to synthesize silver nanoparticles (AgNPs) and evaluated for its antioxidant and antibacterial properties. The silver nanoparticle was characterized using the UV-Vis spectrophotometer, SEM, FTIR, and XRD. The total phenolic and total flavonoid contents were determined for both leaf extract and synthesized silver nanoparticles. Antioxidant activities before and after synthesis of silver nanoparticles was assessed by DPPH, ABTS, iron chelating, and NO radical scavenging methods. The antibacterial activity of the leaf extract and AgNP were tested against Escherichia coli and Staphylococcus aureus. Statistical analysis was carried out to establish possible relations between the antioxidant, antibacterial and antioxidant activities. The formation of a dark brown solution mixture confirms the formation of silver nanoparticles at a wavelength of 450 nm. The AgNPs synthesized were spherical, with the size between 14 to 33 nm. Functional groups such as alcohol, aldehyde, nitrile, primary amines, carbonyl, and aromatic groups were confirmed by FTIR and XRD. Total phenol was higher in leaf extract, while total flavonoids were higher in the AgNps. Silver nanoparticles exhibited strong NO scavenging activity while leaf extract showed better ABTS scavenging activity. Silver nanoparticles inhibited E. coli better compared to S. aureus bacteria. It can be coined that the leaf extract of Ocimum tenuiflorum mediated the green synthesis of silver nanoparticles and possess strong antioxidant and antibacterial potentials that can find application in various biomedical areas.
Green synthesis of silver nanoparticles using a Melissa officinalis leaf extract with antibacterial properties
