SURFACE-ENHANCED RAMAN-SCATTERING AND SURFACE-PLASMON ABSORPTION OF GLASS-DEPOSITED SILVER-2,2'-BIPYRIDINE FILMS FORMED FROM INTERFACIAL SILVER METAL LIQUID-LIKE FILMS

Surface enhanced Raman scattering (SERS) and surface plasmon absorptio n (SPA) spectra of glass-deposited silver-2,2'-bipyridine (Ag-bpy) fil ms prepared from MELLFs (metal liquid-like films) are reported for the first time. Ag-bpy MELLFs are formed at the interphase between the aq ueous Ag colloid and the dichloromethane solution of bpy and deposited on a microscope glass slide. The interphase transfer of bpy from the organic to the aqueous phase, vigorous shaking, the relatively positiv e surface potential of Ag colloidal particles, and the particular conc entration of bipy (2 x 10(-3) M) in the dichloromethane phase are iden tified as conditions determining formation of the interfacial Ag-bpy M ELLFs. The SPA spectra of the glass-deposited films correspond to thos e of the aggregated Ag colloidal particles. The SERS spectra of the fi lms reveal the presence of two forms of adsorbed bpy. The glass-deposi ted MELLFs are recognized as a novel type of stable SERS-active system as well as new materials with a distinct metal-molecular constitution .