Green Synthesis and Characterization of Monodisperse Gold Nanoparticles Using Aloe Vera Leaf Extract

By using Aloe vera leaf extract as both reducing and stabilizing agents, spherical and small-size gold nanoparticles were successfully synthesized. The method is a simple, straightforward and eco-friendly approach because of absence of toxic reagent and the neutral pH conditions. The synthesized gold nanoparticles were examined by UV-visible absorption spectroscopy (UV-vis), dynamic light scattering (DLS), scanning electron microscope (SEM), transmission electron microscopy (TEM), Fourier transform infrared (FT-IR) and powder X-ray diffraction (XRD). The change of color and the absorbance peak in UV-vis spectroscopy indicate the formation of gold nanoparticles. The XRD results show that the particles are highly crystallined in nature. The TEM and SEM results illustrate the particles are spherical in shape with a narrow distribution from 20 nm to 60 nm. The FT-IR results prove that the gold nanoparticles are capped with extracts, which keeps them from agglomeration and oxidation. The effect of reaction temperature, amount of chloroauric acid solution and extracts was also studied. The results display that these parameters play important roles in the generation of gold nanoparticles.