Utilization of Persea americana (Avocado) oil for the synthesis of gold nanoparticles in sunlight and evaluation of antioxidant and photocatalytic activities

Abstract

Green synthesis of nanoparticles using vegetable oil is growing interest in recent years. In this report, Persea americana (Avocado) oil is used to produce gold nanoparticles (AuNPs) in the presence of direct sunlight. The successful formation of AuNPs was confirmed by various analytical techniques including UV–vis spectroscopy, transmission electron microscopy (TEM), dynamic light scattering (DLS), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). The UV–vis spectra for as-synthesized AuNPs showed λmax = 520 nm, TEM, and DLS analysis depicted the formation of spherical, quasi-spherical, decahedral and triangular shape AuNPs of average size 48.8 ± 24.8 nm. FTIR analysis confirmed the AuNPs were capped with carboxylic acid (COOH) groups of fatty acid in an avocado oil. The prepared AuNPs also showed higher antioxidant activity than avocado oil against 1,1-diphenyl-2-picrylhydrazyl and photocatalytic decomposition of the methylene blue (>84%, 10 mg/L) under real sunlight, without using any reducing agent. The suggested synthetic method via microemulsion approach is clean, cost-effective and convenient in the development of future nanotechnology products.