Surface‐enhanced Raman spectroscopy in art and archaeology

Abstract

Since its introduction in the cultural heritage field, nearly 30 years ago, surface‐enhanced Raman spectroscopy (SERS) has emerged as a promising analytical technique that is particularly suitable for the detection and identification of organic colorants. Its great molecular selectivity and specificity, and unparalleled sensitivity compared to other instrumental methods, have allowed researchers to successfully characterize a wide number of natural dyes and a few synthetic ones in microscopic samples from objects of artistic, historical, and archaeological significance. Continued research over the course of the past decade has led to the construction of comprehensive databases of dyes, whose adsorption and spectral properties have been investigated at length; to the comparative study of the efficiency and performance of various metal substrates; and to the evaluation of several sample treatment methods and ad‐hoc analytical protocols. In addition, recent literature in the field of SERS for art and archaeology has described instrumentation and technique advancements aimed at solving the unique challenges posed by the analysis of irreplaceable objects, namely, quasi non‐destructive sampling, spatial resolution improvement, examination of insoluble compounds, and resolution of dye mixtures. Reviewing the most salient methodological and technological milestones that have traced the history of SERS for cultural heritage to date, the present article is intended as a practical resource for those researchers who would like to undertake systematic characterization of organic colorants from artworks using this powerful technique. Copyright © 2015 John Wiley & Sons, Ltd.

A complete Raman study of common acid red dyes: application to the identification of artistic materials in polychrome prints

“…For this reason, their actual identification on a real work of art by Raman spectroscopy might be prevented by the intrinsic fluorescence of the ink itself; also an additional fluorescent background can arise from the paper support on which the inks are applied. We decided to investigate the possibility to analyze them by SERS, which will help to overcome the fluorescent background and enhance the Raman signal . Because of their high‐water solubility, this class of materials would in theory represent a good candidate for the standard water‐based colloid protocol.…”

Plasmonic colloidal pastes for surface-enhanced Raman spectroscopy (SERS) of historical felt-tip pens

“…18,19 Furthermore, SERS has sensibly expanded the range of measurable materials due to efficient quenching of the molecular uorescence interferences of natural and articial dyes. 20 As a result, many authors have reported successful investigations of lakes and dyestuffs in archaeological textile bers 6,21 and paper and woodblock prints 22 and the identication of dye contents in pastel colors,…”

Sensitive ‘on the fiber’ detection of synthetic organic dyes by laser photoinduced plasmonic Ag nanoparticles

“…The analysis of dyes in cultural heritage applications is nowadays of great interest for several reasons, such as the determination of the provenance and original appearance of the materials, and about the planning of a proper conservation intervention . The analytical method most frequently employed in this type of analysis is based on chromatographic techniques .…”