Chemical-structural analysis of wooden painted specimens by clinical multi-slice computed tomography (MSCT) and surface-enhanced Raman scattering (SERS)

The results of Multi-slice X-ray Computed Tomography (MSCT) and Surface-Enhanced Raman Scattering (SERS) study performed on representative organic and inorganic ancient pigments painted on wooden support are presented and discussed. Clear Raman spectra were acquired for organic pigments such as a madder lake, overcoming their fluorescence and weak Raman scattering drawbacks. MSCT Hounsfield Units (HU) measurements show the ability to differentiate the materials, building a volumetric view and, with appropriate algorithms, to segment the layers of the specimen using suitable reconstructions. All these results in combination allowed a complete chemical-physical characterisation of painted pigments on wood samples.