LIAD-fs scheme for studies of ultrafast laser interactions with gas phase biomolecules.
| Autor: | Calvert CR; Centre for Plasma Physics, School of Mathematics and Physics, Queen's University Belfast, Northern Ireland., Belshaw L, Duffy MJ, Kelly O, King RB, Smyth AG, Kelly TJ, Costello JT, Timson DJ, Bryan WA, Kierspel T, Rice P, Turcu IC, Cacho CM, Springate E, Williams ID, Greenwood JB |
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| Jazyk: | angličtina |
| Zdroj: | Physical chemistry chemical physics : PCCP [Phys Chem Chem Phys] 2012 May 14; Vol. 14 (18), pp. 6289-97. Date of Electronic Publication: 2012 Feb 09. |
| DOI: | 10.1039/c2cp23840c |
| Abstrakt: | Laser induced acoustic desorption (LIAD) has been used for the first time to study the parent ion production and fragmentation mechanisms of a biological molecule in an intense femtosecond (fs) laser field. The photoacoustic shock wave generated in the analyte substrate (thin Ta foil) has been simulated using the hydrodynamic HYADES code, and the full LIAD process has been experimentally characterised as a function of the desorption UV-laser pulse parameters. Observed neutral plumes of densities >10(9) cm(-3) which are free from solvent or matrix contamination demonstrate the suitability and potential of the source for studying ultrafast dynamics in the gas phase using fs laser pulses. Results obtained with phenylalanine show that through manipulation of fundamental femtosecond laser parameters (such as pulse length, intensity and wavelength), energy deposition within the molecule can be controlled to allow enhancement of parent ion production or generation of characteristic fragmentation patterns. In particular by reducing the pulse length to a timescale equivalent to the fastest vibrational periods in the molecule, we demonstrate how fragmentation of the molecule can be minimised whilst maintaining a high ionisation efficiency. (This journal is © the Owner Societies 2012) |
| Databáze: | MEDLINE |
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