Infrared microscopy and surface-enhanced Raman scattering of Ag colloid-2,2 '-bipyridine film

A new methodology of IR spectral investigation of SERS-active surfaces was developed. IR microscopy in reflectance mode was employed for IR spectral m apping of a sample of Ag colloid-2,2'-bipyridine (bpy) film deposited on a substrate consisting of an 100 nm Au layer sputtered onto a glass slide. LR spectra obtained from the film itself as well as from the yellow microcrys tals observed in the boundary region of deposited film are consistent with the LR spectra of the crystals of a synthetically prepared [Ag(bpy)(2)]NO3 obtained by the same technique. The structure of the synthetically prepared complex was elucidated by X-ray diffraction. On the basis of the compariso n between the IR and SERS spectral data, the time evolution of the SERS sig nal of adsorbed bpy is attributed to spectral changes induced by illuminati on of the sample by 514.5 nm in the course of SERS spectral measurement. (C ) 1999 Elsevier Science B.V. All rights reserved.