Free Radical Scavenging and Antioxidant Activity of Silver Nanoparticles Synthesized from Flower Extract of Rhododendron dauricum

Abstract

A simple and efficient eco-friendly approach for the biosynthesis of stable, monodisperse silver nanoparticles (AgNPs) using Rhododendron dauricum flower extract is described. Different reaction parameters (concentration of plant extract, substrate concentration, pH, temperature and reaction time)were optimized to synthesize AgNPs with controlled properties. AgNPs were characterized in terms of synthesis, size distribution (PDI of 0.25), capping functionalities (phenolic compounds) and microscopic evaluation by UV-Visible spectroscopy, dynamic light scattering, Fourier Transform Infrared (FTIR) spectroscopy and Transmission Electron Microscope (TEM). The specific characteristics and loss of organic content (1.81 mg) of the synthesized nanoparticles was measured by Differential Scanning Calorimetry (DSC) and Thermo Gravimetric Analysis (TGA). The results showed the simplistic and feasible approach for obtaining stable aqueous monodispersive AgNPs. Further, the antioxidant activity of AgNPs imparted by plant phenolic components was evaluated using DPPH assay and found to be comparable to standard TROLOX.

Phytoextract-mediated synthesis of zinc oxide nanoparticles using aqueous leaves extract of Ipomoea pes-caprae (L).R.br revealing its biological properties and photocatalytic activity

“…Phytochemical analysis signifies that I. pes-caprae leaves possess enormous bioactive constituents and higher amount of metabolites present. It is well known and also reported in the previous literature that plant-mediated NPs synthesis involves sequential reduction followed by capping with these plant constituents [48]. Previous studies on ZnO nanopellets exhibited significant activity (IC 50 value 11.40 lg/mL) at higher concentration.…”

Plant extract synthesized silver nanoparticles: An ongoing source of novel biocompatible materials

“…The percentage of DPPH quenching effect was found to be increased with increasing concentration of silver nanoparticles from 2.5 to 10 g/mL (Raghunandan et al, 2011b). Interestingly, Mittal et al (2012) have reported that phenolic compounds capped silver nanoparticles (synthesized from the flower extract of Rhododendron dauricum) were found to be potent free radical scavenger than the standard, Trolox. Contrary to this, Dipankar and Murugan (2012) have shown that the antioxidant activity of Iresine herbstii leaf aqueous extract mediated silver nanoparticles was not due to the capping agents adsorbed on their surface but was due to the elemental silver.…”

“…The plant extract synthesized silver nanoparticles have also been investigated for their antioxidant activity (Dipankar and Murugan, 2012;Mittal et al, 2012;Raghunandan et al, 2011b;Subramanian and Suja, 2012). Silver nanoparticles prepared using Trachyspermum copticum seed has scavenged the DPPH free radical five times more effectively than butylated hydroxy anisole (BHA) at the maximum concentration of 10 g/mL.…”

Synthesis of Gold Nanoparticles Using Whole Cells of Geotrichum candidum

“…The biological methods fulfil all the requirements of a process to be green [12]. Synthesis of nanoparticles utilizing biological system such as bacteria, fungi, and several plant extracts have been widely reported in the literature [6,[13][14][15]. Microorganisms are able to produce metal nanomaterials either intra-or extracellularly.…”