UV-spectrophotometric Optimization of Temperature, pH, Concentration and Time for Eucalyptus Globulus Capped Silver Nanoparticles Synthesis, their Characterization and Evaluation of Biological Applications.

Morphology (size, shape) and structural variations (bonding pattern, crystallography, and atomic arrangements) have significant impacts on the efficacy of the metallic nanoparticles. Fabrication of these metal nanoparticles through green synthesis using plant extracts has increased attention due to their low cost, less hazardous byproducts, and multiple applications. In present study, Eucalyptus globulus extract was used to synthesize silver nanoparticles (AgNPs). Change of color from light brown to reddish brown and UV-visible spectral peak at 423 nm confirmed the formation of AgNPs. The shifting of FTIR spectra peaks indicated the potential role of the functional groups in extract as capping agents. The DLS evaluated the average size and stability of the nanoparticles while the surface morphology, size and the elemental composition of the AgNPs was established by the FESEM and EDX analysis. The SEM images revealed spherical nanoparticles of size ranging from 40-60 nm. Biogenic AgNPs showed better DPPH radical scavenging activity with IC50 (13.44 ± 0.3) as compared to leaves extract with IC50 (10.57 ± 0.2). The synthesized AgNPs showed higher zones of inhibition (ZOI) by well diffusion method against Escherichia coli, Staphylococcus aureus and Klebsiella pneumoniae. Results of present study highlights the potential benefits of Eucalyptus globulus leaves extract-based AgNPs for various biomedical uses.

Evaluation of biological potential of UV-spectrophotometric, SEM, FTIR, and EDS observed Punica granatum and Plectranthus rugosus extract-coated silver nanoparticles: A comparative study.

Recent developments in the green synthesis of metallic nanoparticles (NPs) using phytoconstituents have attracted the attention of the global scientific community. The present study was designed to synthesize silver NPs (AgNPs) using Punica granatum and Plectranthus rugosus plant extracts. The fabricated AgNPs were characterized using UV-visible spectrophotometry (UV-Vis), Fourier-transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and energy-dispersive x-ray spectroscopy (EDS). The shift in the color of the silver nitrate (AgNO3 ) solution after the addition of P. granatum and P. rugosus extracts indicated the synthesis of AgNPs. The effect of AgNO3 concentrations and pH on the synthesis of AgNPs was also evaluated. The findings of this study suggest that AgNO3 concentration of 1 mM, reaction time of 1 h, and pH of 7 at room temperature were the best suited conditions for the synthesis of AgNPs. According to the FTIR analysis, amidic and carbonyl compounds were primarily responsible for the encapsulation of AgNPs. SEM investigations have shown irregularly shaped geometry with sizes of 35 nm (P. granatum) and 33 nm (P. rugosus) with low agglomeration. The prepared AgNPs exhibited good potential for 2,2-diphenyl-1-picrylhydrazyl radical scavenging, with values of 70% (P. granatum) and 68% (P. rugosus). Hence, we conclude that the leaves of P. granatum and P. rugosus are excellent material for designing of different plant-extracted-conjugated AgNPs for biomedical applications. RESEARCH HIGHLIGHTS: Preparation of the AgNPs using novel plants extracts. P. granatum and P. rugosus extract as reducing, capping, stabilizing, and optimizing agents. Thorough comparative characterization using UV-Vis spectrophotometer, FTIR, SEM, and EDS which is a first of its kind. Comparative antioxidant activity.