High-Energy Long-Lived Emitting Mixed Excitons in Homopolymeric Adenine-Thymine DNA Duplexes

Molecules

Ignacio Vayá¹  Dimitra Markovitsi²  Thomas Gustavsson² 

[1] Departamento de Química, Instituto de Tecnología Química UPV-CSIC, Universitat Politècnica de València, 46022 Valencia, Spain;Université Paris-Saclay, CEA, CNRS, LIDYL, 91191 Gif-sur-Yvette, France;

关键词: DNA;    intrinsic fluorescence;    time-resolved fluorescence spectroscopy;    excitons;    hypochromism;   

DOI  :  10.3390/molecules27113558

来源: DOAJ

【 摘 要 】

The publication deals with polymeric pA●pT and oligomeric A₂₀●T₂₀ DNA duplexes whose fluorescence is studied by time-correlated single photon counting. It is shown that their emission on the nanosecond timescale is largely dominated by high-energy components peaking at a wavelength shorter than 305 nm. Because of their anisotropy (0.02) and their sensitivity to base stacking, modulated by the duplex size and the ionic strength of the solution, these components are attributed to mixed ππ*/charge transfer excitons. As high-energy long-lived excited states may be responsible for photochemical reactions, their identification via theoretical studies is an important challenge.

【 授权许可】

Unknown