SYNTHESIS OF GOLD NANOPARTICLES VIA CITRATE REDUCTION AND THEIR CHARACTERIZATION

In this work, colloidal gold nanoparticles (GNPs) were synthesized by the chemical reduction of an acid solution of tetrachloroauric acid (HAuCl4) as a precursor with a base solution of sodium citrate (Na3C6H5O7) as a reducing agent at 80-100℃. In the literature, this method is known as the Turkevich method. UV-Vis spectrometry and Dynamic Light Scattering (DLS) were used to obtain the absorption spectra and the hydrodynamic radii of the prepared gold nanoparticles with their size distribution. The colloidal stability of the samples was obtained via Zeta potential (𝜁) measurements. It was ascertained that the final size of colloidal gold nanoparticles varies with the initial value of the citrate-to-gold molar ratio. Moreover, it is shown that the terminal size of colloidal gold nanoparticles could be reduced significantly at the specific molar ratio.