Role of Metabolites in Regulating Size Distribution, Structural Stability, Morphology and Biological Performance of Green-Synthesized Silver Nanoparticles via Celtis australis Extract

Abstract

The plant mediated synthetic approach is an environment-friendly and cost-effective process for the preparation of nanomaterials. Herein this study, silver- nanoparticles (Ag-NPs) were fabricated using Celtis australis (C. australis) as capping agent. Synthesis of Ag-NPs was performed using various concentrations of plant extract and precurosr salt solutions labelled as SO-1, SO-2, SO-3 and SO-4. XRD is used for structural and crystallinity analysis of synthesized Ag-NPs and among the products, the one obtained by 40:60 ratio are highly crystalline. The SEM provides information about the morphology and the DLS results shows that the SO-1 has large particle size which might due to the agglomeration of the particles as less repulsion nature is depicted by the zeta potential analysis. Narrow size distribution indicates that particles are uniform size and PdI values show that the samples are monodispersed. FTIR spectrum of Ag-NPs showed the chemical functional groups and gave details about the composition confirmation of synthesized materials. UV-visible spectroscopy of Ag-NPs was used to find the λmax values and band gap energies. The antioxidant capacity of Ag-NPs was observed using a method called ABTS free radical scavenging evaluation and highest activity was found for SO-4 with IC50 value of 39.09 µg/mL. The antibacterial action of Ag-NPs was studied against S. aureus and E. coli by using an agar well diffusion strategy and an increase was seen in the activity with increasing concentration of the samples.