Use of Spearmint (Mentha spicata) Leaves in the Biosynthesis of Silver Nanoparticles

This study aimed to synthesize silver nanoparticles using alcoholic extract of spearmint (Mentha spicata) leaves as a reducing agent and to evaluate their antimicrobial properties.Extract concentrations of 2-5% were used in media with varying pHs.Techniques such as UV-vis spectroscopy, FTIR, and DLS were used to characterize the nanoparticles.The formation of silver nanoparticles was verified by the appearance of a plasmon resonance peak at 418 nm with 2% extract and pH 9. DLS analysis showed a size of 16.1 nm for the 2% extract, which decreased to 10.8 nm with increasing concentration.These results demonstrated that alkaline pH and low extract concentrations favor the formation of monodisperse silver nanoparticles, while higher concentrations induce polydispersity.Silver nanoparticles exhibited antimicrobial activity against E. coli, S. aureus (complete inhibition) and C. albicans (inhibition halo), highlighting their potential in biomedical applications.