Isolating Surface-Enhanced Raman Scattering Hot Spots Using Multiphoton Lithography

摘要

Molecular adsorption sites on macroscopic surface-enhanced Raman scattering (SERS) substrates exhibit a high variance in Raman enhancement factors. As a direct consequence of this broad distribution, molecules adsorbed to the extremely small fraction of sites of extraordinary SERS enhancement (>10~9) contribute a large percentage of the total Raman signal measured. Random site adsorption over this distribution poses a problem for reliably measuring SERS signals from a number of molecules that form less than a monolayer of surface coverage. In this Communication, we present a method for isolating hot spots on large area (>25 mm~2) SERS substrates.