Dependence of gold nanoparticle formation on Muntingia calabura and Lagerstroemia speciosa extract amounts

Abstract

Investigating gold nanoparticle formation using plant extract combinations could pave the way for more green synthesis possibilities involving interactive effects of biochemicals. In this study, varying amounts of combined leaf extracts of Muntingia calabura and Lagerstroemia speciosa provide reducing agents capable of producing quasi-spherical gold nanoparticles with average diameter ranging from 30 to 40 nm. These gold nanoparticles generate visible light absorbance peaks at 550 to 559 nm. Gold nanoparticle formation time and peak absorbance wavelength increase with the combined leaf extract amount up to 2.5 vol parts before an eventual decrease is observed for 3 vol parts of extract. Nanoparticle sizes due to 1.5–2.5 vol parts of extract are comparable with each other and are significantly different as compared with nanoparticles produced using 3 vol parts of extract. Based on comparing absorbance spectra before and after two weeks, all the gold nanoparticles were found to be stable for that time period. In conclusion, the combined extract could be used to vary gold nanoparticle size, absorbance, and formation time depending on its amount.