Phytochemical-capped biogenic gold nanocrystals with chemocatalytic and radical scavenging potential

Abstract

A refined phytosynthetic protocol for the synthesis of gold nanoparticles has been presented in the paper. Nanogold is synthesized using essential oil of leaves of Myristica fragrans. The synthesized nanoparticles have been characterized using UV–vis spectroscopy, TEM, XRD and FTIR. The morphology and dispersity of the particles are found to depend on the quantity of diluted oil used in the synthesis. The gold nanoparticles formed are polydisperse varying in morphology (spheres, pentagons, hexagons), at lower oil concentrations and spherical, monodisperse gold nanoparticles are obtained on increasing the quantity of oil added at 373K. XRD analysis revealed the fcc crystalline structure of the synthesized gold nanoparticles. Detailed analysis of FTIR data leads to the result that tertiary alcohols are responsible for the reduction of gold nanoparticles, and in synergism with other groups they bring about the stabilisation of these metallic nanoparticles. FTIR spectral analysis reports are in accordance with GC–MS analysis results. The synthesized gold nanoparticles are efficient nanocatalysts. The activation energy for the reduction of methylene blue, methyl orange and para-nitrophenol is lowered and their degradation is completed in 10, 7 and 20min, respectively, on the addition of 0.7mL of the synthesized gold colloid. The synthesized gold colloid with homogenous, monodisperse particles is used for catalytic and antioxidation studies. The biogenic gold nanoparticles are found to be potential antioxidants as revealed through their superoxide radical scavenging activity, hydroxyl radical scavenging activity, hydrogen peroxide scavenging activity, NO scavenging activity, DPPH scavenging activity and reducing power activity.