Synthesis of gold structures by gold-binding peptide governed by concentration of gold ion and peptide

Although biological synthesis methods for the production of gold structures by microorganisms, plant extracts, proteins, and peptide have recently been introduced, there have been few reports pertaining to controlling their size and morphology. The gold ion and peptide concentrations affected on the size and uniformity of gold plates by a gold-binding peptide Midas-11. The higher concentration of gold ions produced a larger size of gold structures reached 125.5 μm, but an increased amount of Midas-11 produced a smaller size of gold platelets and increased the yield percentage of polygonal gold particles rather than platelets. The mechanisms governing factors controlling the production of gold structures were primarily related to nucleation and growth. These results indicate that the synthesis of gold architectures can be controlled by newly isolated and substituted peptides under different reaction conditions.

Schematic outline of the size, shape, and uniformity changes of gold structures synthesized by Midas-11 peptide as a function of applied conditions, such as pH and gold ion and peptide concentrations.