Abstract
A surface-adsorbed monolayer of cap-shaped gold particles upon submicrometer-sized polystyrene spheres exhibits pronounced absorption in the visible region. When the surrounding refractive index was altered by immersion in a fluid, the direction of the shift in the absorption spectrum was dependent on the incidence angle of the irradiation. When a thiol molecule, known to adsorb selectively on gold upon polystyrene, was added, the resultant shift in the absorption spectrum’s peak was consistently toward longer wavelengths. Consequently, at certain incidence angles, a change in the refractive index of the surrounding fluid produces no shift, whereas thiol adsorption results in a clear shift, apparently reflecting the different spatial regions in which the refractive index is altered by these two procedures.
© 2002 Optical Society of America
Full Article | PDF ArticleMore Like This
Takayuki Okamoto, Ichirou Yamaguchi, and Tetsushi Kobayashi
Opt. Lett. 25(6) 372-374 (2000)
G. S. Maciel, N. Rakov, and Cid B. de Araújo
Opt. Lett. 27(9) 740-742 (2002)
Thomas A. Germer
Opt. Lett. 27(13) 1159-1161 (2002)