ESR 7: Evangelos Balanikas

UV-induced processes in guanine quadruplexes studied by time-resolved optical spectroscopy: from photon absorption to radical reactivity

Host: Dr. Dimitra Markovitsi

B2: Lasers, Interactions and Dynamics Laboratory

LightDyNAmics Research

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 research 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:

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.
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.
The observed optical spectra will be interpreted by means of quantum chemistry methods.

Scientific Background

Diploma in Applied Mathematical and Physical Sciences at National Technical University of Athens(NTUA) (2012-2017)

Nine month internship and Diploma Thesis preparation in “Ionizing Radiation Dose Enhancement Through the Use of Gold Nanoparticles” Institute of Nuclear & Radiological Sciences & Technology, Energy & Safety, National Centre for Scientific Research “NCSR-Demokritos” (2016-2017).Three months internship at the Institute of Medical Radiation Biology, the University of Duisburg-Essen in Germany (2017)

Scientific Publications

Akos Banyasz, Evangelos Balanikas (ESR7), Lara Martinez-Fernandez, Gérard Baldacchino, Thierry Douki, Roberto Improta, Dimitra Markovitsi (2019) Radicals Generated in Tetramolecular Guanine Quadruplexes by Photoionization: Spectral and Dynamical Features. The Journal of Physical Chemistry B
Evangelos Balanikas (ESR7), Akos Banyasz, Gérard Baldacchino, Dimitra Markovitsi (2019) Populations and Dynamics of Guanine Radicals in DNA strands—Direct versus Indirect Generation. Molecules
Behnaz Behmand, Evangelos Balanikas (ESR7), Lara Martinez-Fernandez, Roberto Improta, Akos Banyasz, Gérard Baldacchino, Dimitra Markovitsi (2020) Potassium Ions Enhance Guanine Radical Generation upon Absorption of Low-Energy Photons by G-Quadruplexes and Modify Their Reactivity. The Journal of Physical Chemistry Letters
Evangelos Balanikas (ESR7), Akos Banyasz, Gérard Baldacchino, Dimitra Markovitsi (2020) Guanine Radicals Generated in Telomeric G-Quadruplexes by Direct Absorption of Low-Energy UV Photons: Effect of Potassium Ions. Molecules
Evangelos Balanikas (ESR7), Akos Banyasz, Thierry Douki, Gérard Baldacchino, Dimitra Markovitsi (2020) Guanine Radicals Induced in DNA by Low-Energy Photoionization. Accounts of Chemical Research
Evangelos Balanikas (ESR7), Lara Martinez-Fernandez, Roberto Improta, Peter Podbevšek, Gérard Baldacchino, Dimitra Markovitsi (2021) The Structural Duality of Nucleobases in Guanine Quadruplexes Controls Their Low-Energy Photoionization. The Journal of Physical Chemistry Letters
Evangelos Balanikas (ESR7), Lara Martinez-Fernandez, Gérard Baldacchino, Dimitra Markovitsi (2021) Electron Holes in G-Quadruplexes: The Role of Adenine Ending Groups. International Journal of Molecular Sciences
Evangelos Balanikas (ESR7), Akos Banyasz, Gérard Baldacchino, Dimitra Markovitsi (2021) Deprotonation Dynamics of Guanine Radical Cations. Photochemistry and Photobiology