Abstract
Gold nanoparticles (Au NPs) are widely studied due to the ease of controlled synthesis, facile surface modification, and interesting physical properties. To fully take advantage of the NP properties, self-assembly of colloidal Au NPs into ordered structures is an essential step. Of all self-assembled structures, the two-dimensional (2D) film composed of just a single layer Au NPs is the simplest one. Yet, 2D Au NP monolayers are of key importance for both fundamental studies and numerous applications such as plasmonics, optics, sensors and catalysts. However, the self-assembly of the 2D Au NP monolayers of both microscopic (i.e. 100 nm2) and macroscopic (i.e. > cm2) order is quite challenging. The major contribution of this research is to develop effective methods to self-assemble Au NPs of various sizes into monolayers using a broad range of ligands. Two methods have been developed for this purpose, namely the “drainto-deposit” method and the “three-phase self-assembly” technique. The resultant Au NP monolayers have been found ideal to study the polymer ligand chain configuration indicated by the interparticle space. In addition, the Au NP monolayers serve as promising surface-enhanced Raman spectroscopy (SERS) substrates and are useful to study lithium battery electrolytes.
