  A double nanohole in a metal film was used to trap nanoparticles (20 nm
diameter) and simultaneously record their Raman spectrum using the trapping
laser as the excitation source. This allowed for the identification of
characteristic Stokes lines for titania and polystyrene nanoparticles, showing
the capability for material identification of nanoparticles once trapped.
Increased Raman signal is observed for the trapping of multiple nanoparticles.
This system combines the benefits of nanoparticle isolation and manipulation
with unique identification.
