Gold nanospirals

Abstract

This study used a galvanic displacement reaction for aluminum-gold oxidation–reduction and added surfactants to act as capping agents to control the morphology and size of gold growth. Three surfactants, namely cetyltrimethylammonium bromide, polyvinylpyrrolidone, and poly(ethylene glycol)(12) tridecyl ether, were added to HAuCl₄ (aq.) to create novel gold nanospirals (AuNSs) 200–500 nm in diameter and tens of μm in length. Transmission electron microscopy analysis showed that the AuNSs were face-centered cubic in structure and that growths on the {111} facet were growth twins with mirror symmetry. Used as the base material for surface-enhanced Raman scattering, the structure of the trunk and dendrimers of the AuNSs create numerous hot spots, exhibiting a superior surface enhancement effect.