Fluorescence Lifetime Phasor Analysis and Raman
Spectroscopy of Pigmented Organic Binders and Coatings
Used in Artworks

Year: 2022

Authors: Dal Fovo A., Mattana S., Chaban A., Quintero Blabas D., Lagarto J.L., Striova J., Cicchi R., Fontana R.

Autors Affiliation: National Research Council—National Institute of Optics (CNR-INO), Largo E. Fermi 6, 50125 Florence, Italy;

European Laboratory for Non-linear Spectroscopy (LENS), Via Nello Carrara 1, 50019 Sesto Fiorentino, Italy

Abstract: Fluorescence analysis of materials used as binders and coatings in artworks is often
hampered by numerous factors, leading to uncertainties in data interpretation. Fluorescence lifetime
(FL) measurements enable improvement of the specificity with respect to steady-state measurements
by resolving the decay dynamics of the fluorophore emissions. In this work, layers of natural resin, oil,
and wax—in pure form, pigmented, in mixtures, and spread on different substrates—were analyzed
using a compact, portable, fiber-based FL instrument. FL data were processed via the phasor method
and integrated with Raman spectroscopy to obtain complementary chemical information on the
different substances. It was observed that the t-phase of the mixtures is affected by both the pigments
and the dispersing medium, and that the presence of the metal substrate contributes to changes in the
FL of mixtures. The results obtained with our portable FL system combined with Raman spectroscopy
pave the way for a systematic study of a larger number of materials for future in situ applications on
works of art.

Journal/Review: APPLIED SCIENCES-BASEL

Volume: 12      Pages from: 179  to: 191

KeyWords: fluorescence lifetime; Raman spectroscopy; phasor analysis; organic binders; fluorescent
pigments
DOI: https://doi.org/10.3390/app12010179