Biogenic nano-scale silver particles by Tephrosia purpurea leaf extract and their inborn antimicrobial activity

• Ag NPs are prepared using T. purpurea leaf extract through green chemistry route.
• XRD and SAED patterns evinces the crystalline nature of the synthesized NPs.
• Ag NPs size is found to vary in the order of SEM > TEM > XRD techniques.
• Biomolecules of the leaf extract are found to play active role in NPs formation.
• Antimicrobial efficacy seems in both bacterial and fungal test pathogens.

In this paper we report the green synthesis of silver nanoparticles (Ag NPs) using Tephrosia purpurea leaf extract. The biomolecules present in the leaf extract are responsible for the formation of Ag NPs and they found to play dual role of both reducing as well as capping agents. The high crystallinity of Ag NPs is evident from bright circular spot array of SAED pattern and diffraction peaks in XRD profile. The synthesized Ag NPs are found to be nearly spherical ones with size approximately ∼20 nm. FTIR spectrum evidences the presence of different functional groups of biomolecules participated in encapsulating Ag NPs and the possible mechanism of Ag NPs formation was also suggested. Appearance of yellow color and surface plasmon resonance (SPR) peak at 425 nm confirms the Ag NPs formation. PL spectra showed decrement in luminescence intensity at higher excitation wavelengths. Antimicrobial activity of Ag NPs showed better inhibitory activity towards Pseudomonas spp. and Penicillium spp. compared to other test pathogens using standard Kirby–Bauer disc diffusion assay.

Figure optionsDownload as PowerPoint slide