Surface plasmon enhanced Raman spectroscopy

A method for Raman spectroscopy, comprising:

• providing a metallic film near which a plurality of analyte molecules is disposed, the metallic film being positioned between a first medium on a first side and a second medium on a second side, the second medium being of higher refractive index than the first medium, the second medium being positioned in evanescent communication with said metallic film with respect to radiation of at least one predetermined frequency;
• providing excitation radiation at said at least one predetermined frequency that propagates through said second medium toward said metallic film;
• and
• detecting Raman radiation emitted from said analyte molecules;
• wherein said metallic film comprises lithographically patterned features designed to intensify surface plasmon resonance along said metallic film to promote said emission of said Raman radiation from said analyte molecules.

An apparatus for Raman spectroscopy of a plurality of analyte molecules, comprising:

• a metallic film having an upper surface near which the analyte molecules are disposed;
• means for providing excitation radiation propagating toward a lower surface of the metallic film from therebeneath;
• prismatic means for coupling said incident excitation radiation into surface plasmons on said metallic film;
• and
• means for detecting Raman radiation emitted in a generally upward direction from said analyte molecules;
• wherein said metallic film comprises lithographically patterned features designed to intensify said surface plasmons to promote said emission of said Raman radiation from said analyte molecules.