Table of Contents
Laser Chemistry
Volume 2006, Article ID 82823, 5 pages
http://dx.doi.org/10.1155/2006/82823
Research Article

Assisted Interpretation of Laser-Induced Fluorescence Spectra of Egg-Based Binding Media Using Total Emission Fluorescence Spectroscopy

1Institute of Electronic Structure and Laser, Foundation for Research and Technology-Hellas (IESL-FORTH), P.O. Box 1527, Heraklion 71110, Greece
2Courtauld Institute of Art, Somerset House, Strand, London WC2R 0RN, UK

Received 13 September 2006; Revised 20 October 2006; Accepted 27 October 2006

Academic Editor: Marta Castillejo

Copyright © 2006 Austin Nevin and Demetrios Anglos. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Laser-induced fluorescence (LIF) spectroscopy can provide nondestructive, qualitative analysis of protein-based binding media found in artworks. Fluorescence emissions from proteins in egg yolk and egg white are due to autofluorescent aromatic amino acids as well as other native and age-related fluorophores, but the potential of fluorescence spectroscopy for the differentiation between binding media is dependent on the choice of a suitable excitation wavelength and limited by problems in interpretation. However, a better understanding of emission spectra associated with LIF can be achieved following comparisons with total emission fluorescence spectra where a series of consecutive emission spectra are recorded over a specific range. Results using nanosecond UV laser sources for LIF of egg-based binding media are presented which are rationalised following comparisons with total emission spectra. Specifically, fluorescence is assigned to tryptophan and oxidation products of amino acids; in the case of egg yolk, fatty-acid polymerisation and age-related degradation products account for the formation of fluorophores.