Synthesis and Applications of Triangular Gold Nanoplates

Colloidal metal nanoparticles are emerging as key materials because of their localized surface plasmon resonance (LSPR) property and the enormous applications in catalysis, plasmonics, sensing, and photonics. Anisotropic nanoparticles have attracted increasing attention due to the novel and unusual chemical and physical behavior along with the decreased symmetry. In the case of the anisotropic nanoparticles, triangular gold nanoplates stand out owing to their unique shape and excellent LSPR properties, which is of great significance to develop a new generation of photonic and electronic devices. However, compared with the spherical nanoparticles, the controllable synthesis of triangular gold nanoplates is much more difficult. Therefore, numerous efforts have been put into their controlled synthesis and a variety of methods have been developed successfully, providing opportunities for the better use of this new material. In this review, we highlight the synthetic achievements, the shape-directing mechanism and separation methods of triangular gold nanoplates. We also address the recent breakthroughs of Au triangular structures in constructing anisotropic superlattices and taking advantage of their enhanced electromagnetic field for single-molecular fluorescence detection and surface-enhanced Raman scattering. Finally, with the development of the self-assembly technology, we believe that Au triangular nanoplates are powerful building blocks for the bottom-up materials engineering and it will play a more important role in chemistry, materials and other fields.