Influence of a resonant solvatochromic dye on the localized surface plasmon resonance

PHYS 410

Julia M Bingham, julia-bingham@northwestern.edu1, Katherine A. Willets, kallie@northwestern.edu1, Alexander N. Semyonov2, Robert J. Twieg, rtwieg@lci.kent.edu2, and Richard P. Van Duyne, vanduyne@northwestern.edu3. (1) Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208, (2) Department of Chemistry, Kent State University, Kent, OH 44242, (3) Department of Chemistry, Northwestern, 2145 Sheridan Road, Evanston, IL 60208-3113
The extinction maximum, lambda max, of the localized surface plasmon resonance (LSPR) of metallic nanoparticles is highly sensitive to changes in the local environment and is a powerful method for sensing molecules that are close to the nanoparticle. Usually, there is a linear relationship between the change in extinction maximum and the change in the refractive index. In this work, we examined the influence of a solvatochromic chromophore, Nile Red, on the LSPR of the nanoparticle. A solvatochromic dye's electronic absorption is dependent on the solvent environment.

By varying the solvent environment surrounding the Nile Red functionalized Ag nanoparticles, we were changing the refractive index but also changing the coupling between the chromophore (Nile Red) and the LSPR of the nanoparticle. Between these two effects, we observed a nonlinear response of the extinction maximum of the LSPR.

 

PHYS Poster Session - Nanostructured Materials and Nanophotonics
7:30 PM-10:00 PM, Wednesday, April 9, 2008 Morial Convention Center -- Hall A, Poster

Division of Physical Chemistry

The 235th ACS National Meeting, New Orleans, LA, April 6-10, 2008