Study of DNA interaction with carbon nanotubes

Structural characterisation of two different forms of carbon - graphite and single-walled carbon nanotubes (SWCNT) has been done with Raman and FTIR spectroscopy. Interaction of nucleic acids with graphite powder and SWCNT was studied with Surface Enhanced Infrared Absorption (SEIRA) spectroscopy. Analysis of DNA-SWCNT complex vibration modes has shown that the numerous structural changes in DNA have been connected with appearance of new sugar and bases conformations, changes in phosphate vibrations and could be interpreted as A-B conformation transition and stabilisation of structure in some DNA fragments. Only very slight graphite influence on DNA structure have been registered. We have proposed the model of DNA interaction with SWCNT based on wrapping of nucleic acid molecules around carbon nanotubes. The similar situation seems to occur in chromosome during DNA assembling by histones

Surface enhanced infrared absorption of nucleic acids on gold substrate

Data on surface enhanced infrared absorption (SEIRA) of nucleic acids deposited on the metal surface have been obtained in the experiment in FTIR reflectance mode. As metal surface, we used Au of 200-500 Е thickness on glass substrate. Roughness of Au was about 50 Е. In our experimental conditions, the enhancement factor of SEIRA was 3 to 5. We obtained different enhancement factors for different vibrations of nucleic acids. Application of this method to tumour nucleic acid gave a possibility to reveal some structural peculiarities of their sugar-phosphate backbone and those after application of anti-cancer drugs