The use of the method of enhancement of infrared absorption by rough metallic surface (SEIRA) allows one to increase the probability of infrared transitions and to reveal a series of spectral manifestations of structural features of biological
molecules. We analyzed various experimental techniques which gives a possibility to achieve enhancement in the infrared (IR) spectra. We studied the applicability of the SEIRA techniques for analysis of nucleic acids, lipids, and membranes. Under the conditions of our experiment and according to literature data, there was observed enhancement factor equal to 3-20 for vibrations of various molecular groups. Peculiarity of another optical amplifier, namely, colloidal gold that effectively used for enhancement of signal in JR absorption and Raman scattering, have been studied. We made an attempt
to model the effect of enhancement of electrical field and their frequency dependence for different metal surfaces and obtained that silver, gold and copper are the best.
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