Control of the self-assembly behaviors of charged gold nanoparticles

In this study, the formation mechanism of the self-assembly structures of aqueous gold nanoparticles (NPs) was investigated through deliberately altering the species of ligands, solvent ratios, and especially solvent evaporation conditions. By analyzing UV–vis spectra, transmission electron microscope (TEM) images, and scanning electron microscope (SEM) images, it was found that the self-assembly process was dependent on both the equilibrium of various interparticle interactions in solution and the evaporation rate of solvents. The various interparticle interactions in solution generated an anisotropic interaction for one-dimension (1D) self-assembly, whereas the evaporation rate of solvents determined the specific of 1D derivative structures. Our results demonstrated an efficient protocol for spatial arrays of charged NPs with controllable morphologies.