An official website of the United States government
Here’s how you know
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.
A C. Pipino, John T. Woodward IV, Curtis W. Meuse, Vitalii I. Silin
Abstract
The cavity ring-down technique is used to probe the absolute optical response of the localized surface plasmon resonance (SPR) of a gold nanoparticle distribution to adsorption of trichloroethylene (TCE) and perchloroethylene (PCE) from the gas phase. Extended Mie theory for a coated sphere with a particle-size-dependent dielectric function is used to elucidate size-dispersion effects, the size-dependence of the SPR sensitivity to adsorption, and the kinetics of adsorption. An approximately Gaussian distribution of nanospheres with a mean diameter of 4.5 nm and a standard deviation of 1.1 nm, as determined by atomic force microscopy, is provided by the intrinsic granularity of an ultra-thin, gold film, having a nominal thickness of . 0.18 nm. The cavity ring-down measurements employ a linear resonator with an intra-cavity flow cell, which is formed by a pair of ultra-smooth, fused-silica optical flats at Brewster s angle, where the Au film is present on a single flat. The total system intrinsic loss is dominated by the film extinction, while the angled flats alone contribute only . 5x10-5/flat to the total loss. Based on a relative decay time precision of 0.1 % for ensembles averages of 25 laser shots from a pulsed optical parametric oscillator (OPO), the minimum detectable concentrations of PCE and TCE are found to be 2x10-8 mol/L and 7x10-8 mol/L, respectively, based on a 30 s integration time.
Pipino, A.
, Woodward, J.
, Meuse, C.
and Silin, V.
(2004),
Surface-Plasmon-Resonance-Enhanced Cavity Ring-Down Detection, Journal of Chemical Physics
(Accessed August 14, 2024)