Nanoscale hydroxyl radical generation from multiphoton ionization of tryptophan

Bisby, RH, Crisostomo, AG, Botchway, SW and Parker, AW 2009, 'Nanoscale hydroxyl radical generation from multiphoton ionization of tryptophan' , Photochemistry and Photobiology, 85 (1) , pp. 353-357.

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Exposure of solutions containing both tryptophan and hydrogen peroxide to a pulsed (~180 fs) laser beam at 750 nm induces luminescence characteristic of 5 hydroxytryptophan. The results indicate that 3-photon excitation of tryptophan results in photoionization within the focal volume of the laser beam. The resulting hydrated electron is scavenged by the hydrogen peroxide to produce the hydroxyl radical. The latter subsequently reacts with tryptophan to form 5-hydroxytryptophan. The involvement of hydroxyl radicals is confirmed by use of ethanol and nitrous oxide as scavengers and their effects on the fluorescence yield in this system. It is postulated that such multiphoton ionization of tryptophanyl residues in cellular proteins may contribute to the photodamage observed during imaging of cells and tissues using multiphoton microscopy.

Item Type: Article
Themes: Subjects / Themes > Q Science > QD Chemistry
Subjects outside of the University Themes
Schools: Schools > School of Environment and Life Sciences
Schools > School of Environment and Life Sciences > Biomedical Research Centre
Journal or Publication Title: Photochemistry and Photobiology
Publisher: Wiley Blackwell Publishing
Refereed: Yes
ISSN: 00318655
Related URLs:
Depositing User: RH Bisby
Date Deposited: 16 Feb 2009 11:11
Last Modified: 15 Feb 2022 15:34

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