The biological functions of biomolecules (proteins, DNA, RNA) are intimately linked to their secondary or tertiary structure. The knowing of biomolecules excited states and the way they de-excite is also of fundamental interest to understand the reactions in which they are engaged and the way they protect its selves from natural light or ionizing radiations (radiotherapy, hadrontherapy).

We investigate these topics using the powerful tools of the gas phase, combining mass spectrometry, infra-red and UV spectroscopy, and leading quantum chemistry calculations.
We are currently developing a new experiment to get both neutral and ionic biomolecules and their complexes directly under vacuum in conditions as close as the ones encountered in solution. It is based on a soft laser desorption source from liquid micordroplets combined to a supersonic expansion of rare gas atoms to insure an efficient vibrational cooling particularly suitable to freeze the systems in the low energy conformers and which provides the optimum conditions to perform well-resolved laser spectroscopy measurement. We also perform experiments in collaboration with several International or French research groups.