SURFACE-ENHANCED FLUORESCENCE AND SERRS SPECTRA OF N-OCTADECYL-3,4:9,10-PERYLENETETRACARBOXYLIC MONOANHYDRIDE ON SILVER ISLAND FILMS

Abstract The Langmuir—Blodgett (LB) technique has been used to fabricate monolayers of N -octadecyl-3,4:9,10-perylenetetracarboxylic monoanhydride monoimide (OD-PTCO) on infrared transparent windows, glass and silver island substrates. The long alkyl chain CH 3 (CH 2 ) 17 —PTCO, a perylene derivative with a low quantum yield, was specially synthesized for the study of the electromagnetically surface-enhanced fluorescence (SEF). It is shown that large enhancement factors for SEF (> 10) are obtained for OD-PTCO LB films deposited on silver island films of 6, 10 and 14 nm mass thickness. The three-dimensional images of the silver island films used to produce surface-enhanced spectra were obtained by atomic force microscopy. The delicate interplay between energy transfer and electromagnetic enhancement are illustrated by spectra containing the surface-enhanced resonant Raman scattering and SEF effects in the same spectral region. The infrared and resonance Raman scattering spectra of the bulk and LB films are also reported.