Effect of nanostructured gold surface on the SEIRA spectra of nucleic acid, Albumin, -Glycine and Guanine

Influences of nanostructured gold and colloidal gold surfaces on spectra of DNA, albumin and some of their building blocksα-glycine and guanine in the SEIRA (Surface Enhanced InfraRed Absorption) experiment in reflectance-absorbance mode are presented and discussed. Experimental factor of enhancement for studied samples within 0.1 mkg-0.5 mg (film thickness from 4 nm to 385 nm) was equal to 1.3-20 for different vibrations. A monolayer of albumin on gold substrate was clearly deposited. We have found that plated gold does not practically influence the conformational state of DNA and albumin in comparison with those on CaF2 substrate. Shift in most of the bands on the gold does not exceed 2-3 cm. In contrast, colloidal gold could change the conformation state of DNA, inducing the B to A conformation with elements of Z-form. Nanostructured gold surface influences the vibrational modes of guanine and α-glycine more than those for complex biopolymers. It seems to be connected with donor-acceptor properties of different groups to gold. © Anita Publications. All rights reserved.