10 Years of Surface-Enhanced Raman Spectroscopy in Art and Archaeology

The identification of organic colorants in works of art has traditionally been one of the most difficult challenges in cultural heritage science. While non-invasive methods such as X-Ray fluorescence spectrometry (XRF), or Raman microscopy are extremely useful for the identification of inorganic pigments, they remain generally unsuitable for the analysis of most organic colorants. The absence of characteristic elemental markers renders XRF essentially useless (with notable exceptions, such as bromine in dibromo indigo tyrian purple -), and the fluorescence of most organic dyes under laser excitation tends to result in poor Raman spectra.