Presentation day

Tuesday  8:30 AM

 

TITLE

Anisotropic gold nanocrystal growth directed by the interior cavity of a self-assembled peptide nanoarchitechture

 

Abstract

Gold nanocrystals have been attracting great attention due to their unique physical, chemical, and biocompatible properties. From the viewpoint of fabrication of gold nanocrystals under environment-friendly and human-friendky processes, we demonstrated design and synthesis of a betasheet-forming nonapeptide

(RU006: Ac-AIAKAXKIA-NH2, X = L-2-naphthylalanine), and characterization of its self-assembled nanostructure. RU006 formed disk-like nanoarchitectures approximately 100 nm wide and 2.5 nm high and tended to form a network of higher-order assemblies in ultrapure water. Using RU006 as a template molecule, we successfully synthesized ultrathin gold nanoribbons 50-100 nm wide, 2.5 nm high, and microns long without external reductants. Furthermore, we synthesized several RU006 analogs, and examined them in gold nanocrystal synthesis. From the these results, we propose the mechanism of　anisotropic gold nanocrystal growth by peptide templating, as follows: (i) RU006 forms a network by the cooperative association of disk-like assemblies in the presence of AuCl4- ions; (ii) The disk-like assemblies uptake and concentrate AuCl4 - ions within the interior cavity of the network architectures; (iii) AuCl4- ions are reduced slowly by electron transfer from the naphthalene rings to AuIII, resulting in anisotropic gold nanocrystal growth along the template network architectures under ambient conditions [1]. Our approach would be promizing to diversify template architectural morphologies to control morphologies of gold nanocrystals.