Phytosynthesis of colloidal nanosilver from Mentha longifolia and Mentha arvensis: Comparative morphological and optical characterization

• Published in: Microscopy research and technique Vol. 83; no. 11; pp. 1299 - 1307
• Main Authors: Javed, Bilal, Mashwani, Zia‐ur‐Rehman
• Format: Journal Article
• Language: English
• Published: Hoboken, USA John Wiley & Sons, Inc 01.11.2020; Wiley Subscription Services, Inc
• Subjects: AFM; Atomic force microscopy; characterization, SEM; DLS; EDX; Energy dispersive X ray spectroscopy; green synthesis; Light scattering; Mentha arvensis; Mentha longifolia; Microscopy; Morphology; Nanoparticles; Optical properties; Photon correlation spectroscopy; Scanning electron microscopy; Silver; spectrophotometry; Spectroscopy; Surface plasmon resonance
• ISSN: 1059-910X; 1097-0029
• DOI: 10.1002/jemt.23518

The present study involves an ecofriendly strategy for the reduction of bulk silver into its nanoforms by using the aqueous extracts of Mentha longifolia leaves (MLL), M. longifolia branches (MLB), and Mentha arvensis (MA). Synthesis of silver nanoparticles (AgNPs) was confirmed initially by observing a change in the color of the reaction mixture followed by measuring the absorbance, and a characteristic surface plasmon resonance band was observed between 400 and 500 nm of the λ of light. Morphological and optical characterization techniques of AgNPs were performed by using UV–visible spectrophotometer, scanning electron microscopy, atomic force microscopy, energy‐dispersive X‐ray spectroscopy (EDX), and dynamic light scattering (DLS) analysis. It was confirmed that the phytosynthesized nanoparticles are anisotropic and nearly spherical having a size smaller than 100 nm while some cubical and prismatic nanostructures were also observed. The average size of a single nanoparticle measured by DLS analysis was reported 10.50 nm, 15.55 nm, and 20.46 nm biofabricated by using MLB, MLL, and MA extract, respectively. The EDX analysis reported the presence of elemental Ag while elemental O was also observed in MLL and MLB AgNPs. The results from these experiments endorse the potential of reported plant species to phytosynthesize AgNPs. The future applications of this work involve the utilization of AgNPs for multiple biological applications. Mentha longifolia and Mentha arvensis aqueous extract resulted in the phytosynthesis of silver nanoparticles. Scanning electron microscopy and atomic force microscopy images revealed that the nanostructures are ≤100 nm and are nearly spherical while some prismatic and cubical nanoforms were also observed. Optical characterization by dynamic light scattering, UV–Vis spectrophotometer, and energy‐dispersive X‐ray spectroscopy confirmed that the silver nanoparticles are monodisperse and are suitable for biomedical applications.