Controllable biosynthesis of gold nanoparticles by culture medium of baker's yeast

Abstract

A liquid phase method to synthesize gold nanoparticles (NPs) has been studied by reducing tetrachloroauric acid (HAuCl4) with the culture medium of baker's yeast. In general, the reducing substances in the culture medium of the baker's yeast can be divided into two categories: the metabolites and the organizations. Herein the reducing agents are mostly metabolites, along with some other components of the cells that are overlooked in the process of filtering. Different sizes of gold NPs have been obtained by merely varying pH of the medium, with size of the nanoparticles of 5~30 nm. Several characterizations have been carried out to confirm and analyze our products, such as UV-vis spectra, field emission scanning electron microscope (FE-SEM) images, transmission electron microscope (TEM) image, energy dispersive spectrum (EDS) and selected area electron diffraction (SAED) patterns. In the future study, the smaller ones can be treated as a good substitute of the traditional seeds synthesized with some chemical surfactants. Show more