Steering attosecond electron dynamics in biomolecules with UV-XUV LIGHT pulses (DFM.AD005.030)

Area tematica

Scienze fisiche e tecnologie della materia

Area progettuale

Struttura responsabile del progetto di ricerca

Istituto di fotonica e nanotecnologie (IFN)

Responsabile di progetto

FRANCESCA CALEGARI
Telefono: 02/23996055
E-mail: francesca.calegari@polimi.it

Abstract

One of the challenges facing science is to understand the chemical origin of DNA damage-induced mutations. Upon exposure to UV light, DNA nucleobases become electronically excited. This process potentially favors mutagenic miscoding of the DNA sequence. Within this context, a prominent question still needs to be addressed: which is the role of the electron dynamics in the photo-induced chemical changes that occur in our own biological molecules?
The main target of STARLIGHT is to study with unprecedented temporal resolution (few- femtoseconds/attoseconds) the electron dynamics occurring in UV photoexcited biomolecules. I will mainly consider aromatic complexes including DNA nucleobases (and ultimately DNA) with the aim of tracking in real time the electron dynamics preceding structural changes potentially leading to damage. The proposed research is based on a bottom-up approach: it allows one to understand the physical origin of a variety of light-driven processes occurring in more complex biological systems of crucial importance in photochemistry and photobiology, with tremendous prospects in phototherapy.

Obiettivi

The main goal of the project is to study the UV-light-induced electron dynamics in biomolecules on an ultrafast time scale by using few-cycle UV pulses in combination with attosecond XUV pulses. Particular attention will be devoted to DNA nucleobases (and ultimately DNA) with the aim of tracking in real time the electron dynamics preceding structural changes potentially leading to damage. With the final goal of steering the electronic motion in biomolecules, circularly polarized UV light pulses will be used to induce electronic currents in cyclic molecules with increasing complexity from benzene to porphyrins.
The two main tasks of STARLIGHT are:
1)Study and control electronic excitation leading to structural changes responsible for mutations of DNA.
2)Steer the electronic motion in aromatic compounds with creation of ring currents.
Intermediate steps has to be done to achieve the two above mentioned tasks:
a)Development of a UV pump - XUV attosecond probe beam-line with high photon-flux.
b)Development of a few-cycle UV source for UV pump - UV probe experiments.
c)Study of the electron dynamics in biomolecular subunits.
d)Control of the electron dynamics in cyclic biomolecules.

Data inizio attività

01/04/2015

Parole chiave

Atomic, molecular physics, Lasers, ultra-short lasers and laser physics, Physical chemistry of biological systems

Ultimo aggiornamento: 19/05/2024