Processus photo-induits dans des G-quadruplexes

par Evangelos Balanikas

Projet de thèse en Chimie

Sous la direction de Dimitra Markovitsi et de Gérard Baldacchino.

Thèses en préparation à université Paris-Saclay , dans le cadre de École doctorale Sciences chimiques : molécules, matériaux, instrumentation et biosystèmes (Orsay, Essonne ; 2015-....) , en partenariat avec Laboratoire Interactions, Dynamique et Lasers (laboratoire) , DICO (equipe de recherche) et de Université Paris-Sud (établissement de préparation de la thèse) depuis le 17-09-2018 .


  • Résumé

    Guanine Quadruplexes (G4) are four-stranded structures formed by guanine rich DNA sequences. They have been correlated with the oxidative damage which perturbs biological functions. In addition, G4 structures are studied in respect to their applications in molecular electronics and nanotechnologies. The objective of the thesis is to study the generation and the reactivity of guanine radicals (including electron holes, important in charge transport) induced by absorption low energy UV radiation by G4. The investigation will involve the use of several experimental and computational techniques: o The electrons ejected by photo-ionization and the resulting base radicals will be studied by time-resolved absorption spectroscopy and time-resolved circular dichroism, from nanoseconds to milliseconds. o The dynamics of the excited states, expected to play a role in the photo-ionization process, will be studied by fluorescence spectroscopy, from femtoseconds to nanoseconds. o The observed optical spectra will be interpreted by means of quantum chemistry methods. o The reaction products resulting from UV-induced radicals will be identified using analytical methods.

  • Titre traduit

    Photo-induced processes in G-quadruplxes


  • Résumé

    Guanine Quadruplexes (G4) are four-stranded structures formed by guanine rich DNA sequences. They have been correlated with the oxidative damage which perturbs biological functions. In addition, G4 structures are studied in respect to their applications in molecular electronics and nanotechnologies. The objective of the thesis is to study the generation and the reactivity of guanine radicals (including electron holes, important in charge transport) induced by absorption low energy UV radiation by G4. The investigation will involve the use of several experimental and computational techniques: o The electrons ejected by photo-ionization and the resulting base radicals will be studied by time-resolved absorption spectroscopy and time-resolved circular dichroism, from nanoseconds to milliseconds. o The dynamics of the excited states, expected to play a role in the photo-ionization process, will be studied by fluorescence spectroscopy, from femtoseconds to nanoseconds. o The observed optical spectra will be interpreted by means of quantum chemistry methods. o The reaction products resulting from UV-induced radicals will be identified using analytical methods.