The effects of the local dielectric environment on the surface-plasmon resonances of annealed gold-island films as a potential for sensing applications are studied experimentally and modeled theoretically. Gold-island films were annealed at 600 °C to produce spheroidal shape particles that exhibit well-resolved resonances in polarized, angle-resolved, absorption spectra. These resonances are shifted in different amounts by the depolarization effect of the surrounding medium (liquids with various refraction indices). Cross-section calculations based on nonretarded, single-particle, dielectric interaction for these various configurations are presented and are found to be in good agreement with the experimental observations. The results show an interesting potential for biosensing or environmental monitoring applications.
© 1998 Optical Society of America
Original Manuscript: May 15, 1998
Revised Manuscript: July 29, 1998
Published: December 1, 1998
Fabrice Meriaudeau, Todd R. Downey, Ali Passian, Andrew Wig, and Thomas L. Ferrell, "Environment effects on surface-plasmon spectra in gold-island films potential for sensing applications," Appl. Opt. 37, 8030-8037 (1998)