Methods for chemical synthesis of colloidal gold

Published data on the chemical synthesis of colloidal gold are summarized and systematized. Attention is focused on the state-of-the-art concepts behind the mechanisms of citrate synthesis and its control parameters, methods for fabrication of ultrafine particles (1 - 5 nm) and the control over the particle spherical shape and size in the range from 10 to 200 nm. The synthesis of gold nanoparticles in organic solvents, in particular, the two-phase Brust Schiffrin method are discussed. The methods for obtaining gold nanoparticles with the use of synthetic and natural biopolymers that can act simultaneously as reducing agents and surface stabilizers (functional agents) are considered. The studies in which important nanomedicine drugs are used as reducing agents and ligands are analyzed.