Study On The Properties Of Gold Nanoparticles Green-synthesized By Myricetin

Gold nanoparticles have been widely used in the field of optical electronics, catalysis, biomedicine and so on, due to the unique physical properties and chemical properties. The traditional synthesis method of gold nanoparticles is mainly chemical. But the stability of gold nanoparticles synthesized by this method is not ideal. Some kinds of surfactants can be used to enhance the stability of gold nanoparticles, but they will be a potential hazard to human body and environment. As the research of green chemistry becomes more and more active, the green preparation of gold nanoparticles has attracted great attention. Biological synthesis of gold nanoparticles employs either microorganisms or plant as reducing agents and capping agents. The method of biosynthesis has the advantages of easy operation, non-toxic and environmental protection. Gold nanoparticles synthesized by biological method have good stability and biocompatibility and expand the application in the field of biomedicine. This paper mainly study the gold nanoparticles synthesized by myricetin(Myr). Myr is a kind of biological component which has outstanding reducing capability and many physiological functions. The morphology and size of gold nanoparticles were characterized by using UV-Vis, TEM, FT-IR, XRD, EDS, SAED. The stability of gold nanoparticles at the different environment and scavenging effect of gold nanoparticles on free radicals were discussed. Main conclusions are as followings:1、Gold nanoparticles synthesized by Myr were spherical or nearly spherical, have good dispersion and uniform size at the optimal conditions that were 4:1 as the mole ratio of nHAuCl4:nMyr,40℃ as the reaction temperature, and one hour as the reaction time. And the surfaces of gold nanoparticles were coated with a layer of biological film. The constitution of it is the oxidation of Myr. Gold nanoparticles were polycrystalline structure with the diameter of nearly 50 nm. The charge of gold nanoparticles was-15.87mV.2、Gold nanoparticles synthesized by Myr have good stability under the different pH values and different concentrations of NaCl, KCl, NaBr, KBr. But gold nanoparticles synthesized by sodium citrate were easy to aggregate in these conditions. So the stability of gold nanoparticles synthesized by Myr is better than those which synthesized by sodium citrate.3、Gold nanoparticles synthesized by Myr have a certain scavenging ability to DPPH free radical, ABTS free radical and hydroxyl radical besides O2- radical. This indicates the gold nanoparticles synthesized by Myr have good antioxidant activity and strong reducing ability. With the increase of concentration of these gold nanoparticles, their antioxidant activity also increased with it. But gold nanoparticles synthesized by sodium citrate cannot eliminate these free radicals. This indicates gold nanoparticles made by sodium citrate have no antioxidant activity.4、Gold nanoparticles synthesized by Myr have better antioxidant activity than gold nanoparticles synthesized by dihydromyricetin(DMY).