Quantitative growth evolution of gold nanoparticles synthesized using aqueous Elaeis guineensis (oil palm) leaves extract

Abstract

Phytosynthesis of gold nanoparticles (AuNPs) have shown the tremendous interest owing to their ecofriendly, simple, cost effective and renewable features. The growth kinetics behavior of plants mediated AuNPs is relatively scarce despite the significant impacts of their morphological structures on their performance in various fields of sciences. Herein, AuNPs were synthesized employing aqueous Elaeisguineensis leaves extract and characterized using TEM, UV–vis spectroscopy and DLS. Ostwald ripening (OR) and Orientation attachment (OA) models were used to investigate the mechanisms leading towards the growth of AuNPs as function of time. The changes in the positions of UV–vis spectra peaks and increasing number of agglomerated particles as function of time detected the ongoing growth process of AuNPs. The experimental results exhibited that the growth of AuNPs was mainly governed by the OA kinetics in initial phase owing to the stable surface adsorption of phenolic compounds, flavonoids, carboxylic acids and amides, impeding the diffusion-controlled growth. Moreover, TEM analysis also confirmed the domination of OA mechanism in early stage through displaying the formation of AuNPs with quasi spherical and elongated morphology. However, the OA growth kinetics was found to be majorly substituted and followed by the OR mechanism in the later period.