Metal Nanoparticles for Microscopy and Spectroscopy

Abstract

Metal nanoparticles interact strongly with light due to a resonant response of their free electrons. These 'plasmon' resonances appear as very strong extinction and scattering for particular wavelengths, and result in high enhancements of the local field compared to the incident electric field. In this chapter we introduce the reader to the optical properties of single plasmon particles as well as finite clusters and periodic lattices, and discuss several applications.

Nonfluorescent Optical Probing of Single Molecules and Nanoparticles

“…While SPRs are significant in thin films, localized SPRs (LSPRs) in metal nanoparticles and, more generally, three-dimensional nanostructures have a much stronger and more versatile optical response . The strong plasmonic response is what gives solutions of gold nanoparticles their distinctive red appearancedescribed by Faraday and first explained fully by Gustav Mieand what gives many medieval stained glass windows their color …”

“…When two plasmonic nanoparticles approach each other to distances comparable with the size of the near field, the coupling between the two, which can be thought of as plasmon hybridization, is highly dependent on the distance (see Figure ). This opens the use of a pair of nearby nanoparticles as a plasmonic nanoruler .…”