Plasmon-sampled surface-enhanced spectroscopy

Haynes CL, Van Duyne RP. Plasmon-sampled surface-enhanced Raman excitation spectroscopy. Journal of Physical Chemistry B 2003, 107, 7426-7433. 

Haynes, C. L., and Van Duyne, R. P. (2003). Plasmon-Sampled Surface-Enhanced Raman Excitation Spectroscopy. J. Phys. Chem. B, 107 7426-7433. 

Plasmon-Sampled Surface-Enhanced Raman Excitation Spectroscopy... 

The small cross sections in multiphoton processes are of course a weakness of nonlinear spectroscopy. Especially in microscopy, this problem becomes serious because of the small volume of a sample. By the use of the signal enhancement techniques, however, the disadvantage can be turned into an advantage of back-ground-free selective measurements. For example, the combined use of HRS with the plasmonic enhancement provides us a chemical imaging with nanoscale spatial resolution when a laser-illuminated metal tip is located adjacent to a sample surface, signal enhancement is locally induced near the tip. This spatial resolution is expected to overcome optical diffraction limit. Such tip-enhanced spectroscopy has already been reported in conventional CARS [15]. 

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