References of "Matheis, Katerina"
     in
Bookmark and Share    
See detailElectronic spectroscopy of nucleic acids in the gas phase
Gabelica, Valérie ULg; Rosu, Frédéric ULg; Joly, Laure ULg et al

Conference (2010)

DNA polyanions trapped in a mass spectrometer undergo electron detachment following UV irradiation. Photodetachment is a single-photon process. Its efficiency depends on the nature of the DNA bases, the ... [more ▼]

DNA polyanions trapped in a mass spectrometer undergo electron detachment following UV irradiation. Photodetachment is a single-photon process. Its efficiency depends on the nature of the DNA bases, the ion's charge, and the excitation wavelength. Photodetachment can therefore be used to perform ion spectroscopy experiments, which probe electronic excitation within the initial charge state of the nucleic acids. Ion spectroscopy experiments on trapped nucleic acid cations and anions were performed from 4 to 20 eV using an OPO laser or using synchrotron radiation. Photoelectron spectroscopy experiments were also performed on multiply charged anions to probe direct detachment cross sections and electronic excitations within the final charge. The electronic spectra obtained from photodetachment integral cross sections show several resonances, provided that the photon energy is larger than the electron binding energy. We will also discuss whether the electronic spectra obtained via photodetachment can be used to probe gas phase ion structure. [less ▲]

Detailed reference viewed: 70 (5 ULg)
See detailElectron Photodetachment of DNA Polyanions: Photoelectron Spectroscopy and UV Action Spectroscopy
Gabelica, Valérie ULg; Rosu, Frédéric ULg; De Pauw, Edwin ULg et al

Conference (2008, April 15)

DNA polyanions trapped in a mass spectrometer undergo electron detachment following irradiation with UV light [1-3]. Electron photodetachment is a 1-photon process, and its efficiency depends on: - The ... [more ▼]

DNA polyanions trapped in a mass spectrometer undergo electron detachment following irradiation with UV light [1-3]. Electron photodetachment is a 1-photon process, and its efficiency depends on: - The nature of the DNA bases: guanine-containing strands are the most prone to electron photodetachment, followed by adenine, cytosine, and finally thymine. - The excitation wavelength: electron detachment is maximum around 260 nm, corresponding to base excitation. - The charge of the polyanion: higher charge state ions undergo more efficient electron detachment because of the Coulombic repulsion. Here we will discuss the electron photodetachment mechanism in the light of the most recent experimental results. Because the base-dependence of electron photodetachment efficiency is correlated with the base ionization potential and is maximum at wavelengths corresponding to the base absorption, we initially proposed that electron photodetachment might occur directly from the base, and that the photodetachment yield was correlated with the electron binding energy to the base [2]. Photoelectron spectroscopy experiments were performed on DNA multiply charged anions with varying base composition to probe how the electron binding energies changes with the base composition. Finally, the electron detachment channel was used to perform UV spectroscopy experiments on large DNA polyanions trapped in the gas phase. Gas-phase UV spectra of DNA duplexes and G-quadruplexes containing up to 24 bases (> 7000 Da) will be presented. [1] V. Gabelica, T. Tabarin, R. Antoine, F. Rosu, I. Compagnon, M. Broyer, E. De Pauw, and P. Dugourd, Anal. Chem. 78, 6564 (2006). [2] V. Gabelica, F. Rosu, T. Tabarin, C. Kinet, R. Antoine, M. Broyer, E. De Pauw, and P. Dugourd, J. Am. Chem. Soc. 129, 4706 (2007). [3] V. Gabelica, F. Rosu, E. De Pauw, R. Antoine, T. Tabarin, M. Broyer, and P. Dugourd, J. Am. Soc. Mass Spectrom. 18, 1990 (2007). [less ▲]

Detailed reference viewed: 40 (2 ULg)