Self-assembly of gold nanorods (NRs) with aspect ratio of similar to 4.6 (1
2 nm in diameter and 50-60 nm in length) has been studied using transmissio
n electron microscopy (TEM). Under appropriate conditions such as nanoparti
cle concentration, solvent evaporation, narrow size distribution, ionic str
ength, and surfactant concentration of the parent solution, gold nanorods a
ssemble into one-, two-, and three-dimensional structures. Some of the thre
e-dimensional assemblies extend to superlattices of NRs. The translation an
d orientation symmetries of the self-assembled structures are determined. T
he factors affecting the formation of the ordered self-assembly are discuss
ed.