SERS OF LANGMUIR-BLODGETT MONOLAYERS - COVERAGE DEPENDENCE

The coverage dependence of surface-enhanced Raman scattering (SERS) and surface-enhanced resonant Raman scattering (SERRS) was studied by using mixed Langmuir-Blodgett (LB) monolayers of tetra-tert-butylvanadylphthalocyanine ((t-Bu)4V0Pc) and arachidic acid. Ag-coated Sn spheres (which provide a broad range of electromagnetic resonances in the visible), Ag, and Au island films were used to enhance the inelastic scattering. LB layers of neat (t-Bu)4VOPc and mixed monolayers with 20 mol % of arachidic acid and with various other molar ratios of arachidic acid:dye as high as 100:1 were prepared to obtain submonolayer dye coverage of the metal surface and to determine the coverage effect of the adsorbed dye on the Raman intensities. © 1990, American Chemical Society. All rights reserved.