title: Anisotropic metal nanoparticles: Synthesis, assembly, and optical applications.
abstract: This feature article highlights work from the authors' laboratories on the synthesis, assembly, reactivity, and optical applications of metallic nanoparticles of nonspherical shape, especially nanorods. The synthesis is a seed-mediated growth procedure, in which metal salts are reduced initially with a strong reducing agent, in water, to produce approximately 4 nm seed particles. Subsequent reduction of more metal salt with a weak reducing agent, in the presence of structure-directing additives, leads to the controlled formation of nanorods of specified aspect ratio and can also yield other shapes of nanoparticles (stars, tetrapods, blocks, cubes, etc.). Variations in reaction conditions and crystallographic analysis of gold nanorods have led to insight into the growth mechanism of these materials. Assembly of nanorods can be driven by simple evaporation from solution or by rational design with molecular-scale connectors. Short nanorods appear to be more chemically reactive than long nanorods. Finally, optical applications in sensing and imaging, which take advantage of the visible light absorption and scattering properties of the nanorods, are discussed.
authors.affiliation: Department of Chemistry and Biochemistry, University of South Carolina, 631 Sumter Street, Columbia, South Carolina 29208, USA. murphy@mail.chem.sc.edu
authors.forename: Catherine J
authors.initials: CJ
authors.lastname: Murphy
authors.forename: Tapan K
authors.initials: TK
authors.lastname: Sau
authors.forename: Anand M
authors.initials: AM
authors.lastname: Gole
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Orendorff
authors.forename: Jinxin
authors.initials: J
authors.lastname: Gao
authors.forename: Linfeng
authors.initials: L
authors.lastname: Gou
authors.forename: Simona E
authors.initials: SE
authors.lastname: Hunyadi
authors.forename: Tan
authors.initials: T
authors.lastname: Li
mesh_terms: D016880:Anisotropy; D003460:Crystallization; D006046:Gold / Q000737:chemistry; D008027:Light; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D046529:Microscopy, Electron, Transmission; D012542:Scattering, Radiation; D012834:Silver / Q000737:chemistry; D013499:Surface Properties
chemical_list: D012834:Silver; D006046:Gold