Advanced Raman Spectroscopy Techniques in Cultural Heritage

This presentation will discuss the recent advances in Raman spectroscopy that are paving ways to novel analytical approaches for improving the knowledge and conservation of art objects.

Cultural Heritage materials are intrinsically complex, and their non-invasive investigation is a major challenge for conservation scientists. Micro-Raman Spectroscopy represents one of the most effective approaches for exploring the molecular composition of their surfaces, due to its high chemical sensitivity and lateral resolution. Over the last few years, Micro Spatially Offset Raman Spectroscopy (Micro-SORS) has emerged as an effective tool for investigating non-invasively compounds located below the surface, for example, in a hidden painted layer, in the preparation layer or in the substrate (i.e. plaster). This is crucial for deeper understanding of the micro-stratified systems, often encountered in paintings or in decayed materials. Moreover, Micro-SORS has been recently coupled with Time-Gated Raman Spectral Multiplexing, enabling fast sub-millimeter resolution molecular depth Raman mapping of both fluorescing and non-fluorescing samples.

The principles of the abovementioned Raman techniques, the existing instrumental modalities, their capabilities and limitations as well as impact in Cultural Heritage will be discussed.