Multi-level assemblies of lead sulphide nanorods

Abstract

A new concept of multi-level assemblies of nanorod-based structures has been proposed,which could give new insight into the construction of nanorod-based complex structuresfrom the bottom up. Multi-level architectures of complex lead sulphide (PbS)nanorod-based structures have been realized by a simple and general amino acid-mediatedapproach. First-level structure (multi-arm horn-like structure), second-level structure(bi-pyramid structure formed by several horn-like structures), and third-levelstructure (multi-pyramid structure formed by several pyramid-like structures) can besynthesized with the assistance of different amino acids: aspartic acid, serine,and histidine, respectively. The amino acids have several functional groups, suchas –NH2 and –COOH, which have strong abilities for coordination with the metal ions, and mightprovide reaction sites by coordinating with metal ions to initiate and then confine theassemblies of the PbS nanorods. This amino acid-mediated method provides a possibility ofstudying the formation and assembly mechanisms from the bottom up and mightopen a door to constructing complex nanorod-based structures at different levels.