Surface-enhanced fluorescence and SERRS spectra of N-octadecyl-3,4:9,10-perylenetetracarboxylic monoanhydride on silver island films

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 CH3-(CP2)(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 lame 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. (C) 1997 Elsevier Science B.V.