Assembly and Immobilization of Metal Nanoparticles

Abstract

This paper reviews recent progress of chemical preparation of metal nanoparticles and their assembly formation processes. Various metal and semiconductor nanoparticles have been intensively studied according to their unique properties controlled by their sizes. One predicted that nanoparticles with the diameter in the range of 1-10 nm would display specific electronic structures, which reflect the electronic band structure ("quantum size effect"). For example, some metal nanoparticles in these sizes show photoemission. The melting points of these nanosized metal particles are extremely lower than the bulk. Gold, silver, and copper nanoparticles show their specific absorption, plasmon absorption, which is also used for surface plasmon resonance (SPR). To use their unique properties as materials, not only the control of their structures and sizes but also controlled formation of low dimensional assembly of these nanoparticles are highly important. Ordered assembly of such nanoparticles give their unique and interesting functions, such as sensing, electron tunneling, information stage and so forth. From this viewpoint, we would like to discuss hereafter a couple of fundamental preparation processes of metal nanoparticles and various assemble techniques.