Alkyl-Nitrile Adlayers as Probes of Plasmonically Induced Electric Fields.

ABSTRACT: Vibrational Stark shifts observed from mercaptoalkyl monolayers on surface enhanced Raman (SERS) active materials are reported to provide a direct measurement of the local electric field around plasmonic nanostructures. Adlayers of CN^-, p-mercaptobenzonitrile, and n-mercaptobutylnitrile were adsorbed to a heterogeneous nanostructured Ag surface. The frequency of the CN moiety was observed to shift in a correlated fashion with the SERS intensity. These shifts are attributed to a vibrational Stark shift arising from rectification of the optical field, which gives rise to a DC potential on the surface. All three molecules showed CN Stark shifts on the plasmonic surfaces. P-mercaptobenzonitrile is observed to be a well-behaved probe of the electric field, providing a narrow spectral

SUBMITTER: Kwasnieski DT 

PROVIDER: S-EPMC4511604 | biostudies-literature | 2015 Aug

REPOSITORIES: biostudies-literature