Synthesis Of Au Micro-Nano Flakes Based On The Biological Molecular Self-Assembly And Ordered Structure

The quantum 2D confinement of electrons recently revealed in graphene nanosheets further inspires to explore 2D metal nanocrystals with intrinsic anisotropic properties and quantum size effect. Among them,2D Au nanocrystals stand out not only due to their unique structure-and environmental-dependent properties, but also due to their rapid development in synthesis approaches and emerging applications in electronics, optics, sensing and biomedicines. The bio-synthesis method has achieved most interesting of researchers because of its nontoxicity in recent years.In this paper we use amyloid fibrils, amino acids and chitin nanofibrils as the reducing agents and capping agents gained the 2D micro-nano gold crystal structure successfully. We have prepared macroscopic gold micro-nano sheet with optimal reaction conditions and fabricated flexible conductive films. We researched small biological molecules-amino acids as reducing agents to prepare 2D gold nanocrystals to explore mechanism of the process. We also prepared gold nanocrystals with chitin nanofibrils as the reducing agent.In summary, single-crystal gold microflak.es with planar area up to and beyond 104 μm2 were prepared at the first time through a facile, one-step, green approach. Flexible conductive composite films with hierarchical structures, metallic conductivity, and golden optical surfaces were fabricated through simply casting an aqueous polyurethane suspension containing single-crystal gold microflakes. We also prepared gold nanocrystals with chitin nanofibrils as the reducing agent. The method has never be reported before. The 2D structure of gold nanosheet has a potential applications in the field of optics devices, electrics sensing and biomedicines.