DNA and nanophotonics: original methodological approach

Abstract

The aim of the present work is a spectroscopic and thermodynamic study of DNA catalytic properties in the following processes: a) redox; b) formation of interstrand crosslinks; c) performing of photodynamic effects; d) nanoscale resonance radiationless electron excitation energy transfer. The most attention is paid to the latter, as it is truly nanoscale method in its origin. The nanoscale method of laser-induced fluorescence resonance energy transfer (FRET) to donor (acridine orange)-acceptor (ethidium bromide) intercalator pair for quantitative and qualitative study of stability quality DNA double helix in solution in real time is used. The FRET method allows to estimate the concentration of double helix areas with high quality stability applicable for intercalation in DNA after it is subjected to stress effect. It gives the opportunity to compare various types of DNAs with 1) different origins; 2) various degrees of damage; 3) being in various functional states. An alternative model and mechanisms of photodynamic effect on DNA in solutions are proposed. They are based on photoenergy degradation in solutions. The energy activates electrolytic dissociation of water molecules on H3O+ and OH- and acts as a catalyst for hydrolysis reactions of phosphordiester and glycoside linkages.

Keywords

• dna
• nanophotonics
• nanoscale fluorescent probing of stressed dna
• photodynamic effect
• resonance energy transfer