Raman spectroscopy advancements in heritage science

Abstract

Micro-Spatially Offset Raman Spectroscopy (micro-SORS) is an advanced Raman technique that allows the non-destructive analysis of inner portions of cultural heritage artefacts, providing insights on their composition in a non-destructive way. The contribution delves into the methodological and technological advancements of micro-SORS at the CNR-ISPC Raman Spectroscopy Laboratory in Milan over the past decade. Developed in 2014, micro-SORS has become a versatile tool for characterizing artefacts from various historical periods and cultural contexts. Significant progress has been made in refining instrumentation and methodology, resulting in high-performance micro-SORS prototypes, including benchtop and portable systems. Key topics focus on investigating layered materials (e.g., paintings and painted objects) and studying the diffusion of conservation treatments and decay products into various substrates. The aim is to obtain information about the materials’ composition, the efficacy of treatments, and the conservation state of the objects under analysis. Additionally, mapping/imaging micro-SORS has been developed to reconstruct the distribution of compounds hidden by opaque layers, such as concealed text in sealed letters. Lastly, this presentation will cover challenges associated with in-situ micro-SORS analysis, including environmental constraints and data interpretation, and will explore strategies for overcoming these.