title: A spectroscopic study of mercury vapor adsorption on gold nanoparticle films.
abstract: We have modified the surfaces of glass and Si(100) with 3-aminopropyltrimethoxy silane, a fourth generation amine-terminated poly(amidoamine) dendrimer, and poly(diallydimethyl ammonium chloride) to facilitate adsorption onto colloidal gold particles (average diameter 3, 5, 12, and 22 nm). UV-vis absorption spectroscopy and atomic force microscopy monitored the adsorption process, which is governed by particle diffusion to the surface. The differences in adsorption to the three adhesion layers as a function of pH are discussed. Mercury vapor was exposed to the gold particle films and quantified by X-ray photoelectron spectroscopy and energy-dispersive X-ray spectroscopy. The surface plasmon oscillation of 5-, 12-, and 22-nm particles blue-shifts after exposure to parts-per-million levels of mercury vapor in air. Particle films prepared from the 3-nm gold particles develop a broad peak centered near 530 nm after exposure to mercury vapor. The results demonstrate a novel "litmus" film for mercury vapor.
authors.affiliation: Department of Chemistry, The University of Alabama, 6th Avenue Lloyd Hall, Tuscaloosa, Alabama, 35487, USA.
authors.forename: Todd
authors.initials: T
authors.lastname: Morris
authors.forename: Kathy
authors.initials: K
authors.lastname: Kloepper
authors.forename: Scott
authors.initials: S
authors.lastname: Wilson
authors.forename: Greg
authors.initials: G
authors.lastname: Szulczewski