text: Dimitra Markovitsi's areas of research interest include photophysics and photochemistry in the condensed phase, time-resolved optical spectroscopy (absorption, fluorescence), excited states, energy, and charge transfer, charge separation, ionization, radical formation, photodamage, UV-induced primary processes in DNA (excited states, intrinsic fluorescence, electron ejection, oxidative damage) and G-quadruplexes.
  Markovitsi studied the dimensionality of excitation transport in columnar phases. She discussed the effect of orientational disorder on the electronic excited states and introduced a model based on the exciton theory and quantum chemistry computations.
  She published the first studies investigating the effect of structural disorder on the excited states of double helices and guanine quadruplexes. Simultaneously, she explored the behavior of the intrinsic DNA fluorescence from femtoseconds to nanoseconds. She provided evidence of the occurrence of excitation transport between nucleobases and the collective nature of Franck-Condon states. She reported the first spectroscopic investigation on DNA excited states in the UVA region; despite their very poor absorption, such excited states may contribute to the deterioration of the genetic code by solar light, whose UVA intensity is greater than that of UVB and UVC.
  She identified an unanticipated phenomenon: low-energy UV radiation can ionize DNA multimers (but not their monomeric components), generating electron holes in the nucleobases. The latter radical species are precursors of oxidative damage and provide promise for nanodevices based on photoconductivity. She demonstrated that the photoionization of guanine quadruplexes can be adjusted by varying their structural parameters.
  Markovitsi also investigated DNA reaction dynamics on nanosecond to millisecond timescales. This work focuses on the dimerization of nucleobases and the deprotonation and tautomerization of the guanine radical. Her research revealed the anisotropic character of such events, which are highly dependent on the local DNA environment, rendering the conventional models of chemical kinetics inadequate for describing them.
  Markovitsi’s work has been published in collective books, including the “Handbook of Organic Photochemistry and Photobiology.