Fesenko O. Effects and mechanisms of the enhancement of optical transitions in bioorganic molecules adsorbed on rough metal surface

The first time it was shown a number of factors (type and morphology of rough metal surface, methods of deposition of the molecules, pH, types of molecular groups) influences the enhanced absorption of bioorganic molecules (G, a-Gly, BSA, DNA, p-NBA, complex Eu(DBM)3bath) adsorbed on the nanostructured metal surface. The conditions for preparation of metal surfaces and methods of depositions for obtaining of maximal enhancement factor in IR spectra were determined. On the basis of this experimental data, the technique for detection of small amount of biological molecules (including monolayers) and conformation of macromolecules has been developed. It was concluded that ?-ring structures and the groups with unshared electron pairs are enhanced by the best way. The enhancement more than 100 times is registered for thin layers (close to monolayer) for the cases of regular molecular organization or chemical adsorption on the gold surface. Factor of the enhancement for IR absorption for multilayer films ofthe molecules deposited on gold became less with increasing of the number of molecular layer and reach 2-7 for different molecular moieties.The enhancement could be increased by 3-12 times for the films obtained by thermal vacuum deposition on gold surface in comparison with those for drop deposition from aqueous solution.