Biomimetic Synthesis Of Gold Nanoparticles By Inorganic Peptide

Recently, the broadening usage and chemical and optical properties of nanogold has gained attentions. The preparation methods which aims at good desperation, size-control and simple process have been explored. Nanogold can be utilized in biological sensor, industrial catalyst, medication and compound material. The formation of biological bone, teeth and shell is controlled by surrounding biological macromolecules. This process (biological mineralization) involves many biological molecules, such as amylose, phosphor grease and protein.The polypeptide sequence MS14 (MHGKTQATSGTIQS) was used to explore a new way of biomimetic preparation of gold nanoparticles and their aggregates. Self-congregation of gold nanoparticles into aggregates in MS14 aqueous solution and self-assembly of gold crystallites onto the designed complex of MS14-PET film (protonated poly(ethylene terephthalate)) proved the specific gold-binding characteristic of the single copy peptide MS14 in vitro. In aqueous solution MS14 could recover Au(III) to Au(0) examined by means of EDX and XPS. Further research suggested that pH of the solution and concentration of Au(III) influenced the morphology and size of the gold nanoparticles formed. In addition, extra reducing agent sodium citrate was introduced into the HAuCl₄-MS14 system and uniformly dispersed nanoparticles under neutral condition were obtained. Finally, we discussed the possible mechanism of this biomimetic synthesis and attempt to produce Au nanoparticles by freezing desiccation, which might have potential applications in Au reclamation and target medicine.