Role of polyphenols in plant-mediated synthesis of gold nanoparticles: identification of active components and their functional mechanism.

In order to learn the active components and their functional mechanism during the plant-mediated synthesis of gold nanoparticles (GNPs), 16 kinds of plants were randomly selected as research objects, and statistical analysis was used to obtain more universal and systematic results. Polyphenols are proved to have the most prominent effect in both reductive and protective capability among all components. The relationship between polyphenols concentration and the protective and reductive capability was further studied in detail. Pyrogallic acid was used as a substitute for polyphenols to elucidate the functional mechanism. The concentration of polyphenols was found to be a critical factor for the preparation of GNPs, and the synergistic competition between phenolic hydroxyl and carbonyl groups caused by the oxidation of polyphenols could affect the particle size and morphology of GNPs. This work can provide excellent guidance for the controllable synthesis of GNPs via the plant-mediated method.