Fluorescence of DNA Duplexes: From Model Helices to Natural DNA

• DOI: 10.1021/jz101122t
• Publication Date: 2010-11-03T12:55:32Z
• Authors: Dimitra Markovitsi; Thomas Gustavsson; Ignacio Vayá
• Keywords: [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry; [CHIM.THEO] Chemical Sciences/Theoretical and/or physical chemistry; 0103 physical sciences; 01 natural sciences

Recent fluorescence studies of DNA duplexes with a simple repetitive base sequence have revealed important collective effects which are very sensitive to conformational disorder. In contrast to the monomeric chromophores, whose fluorescence lifetimes are shorter than 1 ps, the fluorescence decays of duplexes span several decades of time. The occurrence of excitation energy transfer, evidenced by the decay of the fluorescence anisotropy on the femtosecond time scale, is a common feature of all of the examined systems. It is explained by the existence of Franck-Condon exciton states, in line with the Vabsorption spectra. Understanding the nature of the long-lived excited states, whose emission dominates the steady-state fluorescence spectrum of natural DNA, will be one of the challenges for the years to come.