Fabrication of transparent composites for non-invasive Surface Enhanced Raman Scattering (SERS) analysis of modern art works

Abstract

Surface Enhanced Raman Scattering (SERS) has become an invaluable tool for the identification of colorants in artworks, due to its enhanced sensitivity and ability to quench fluorescence interference compared to Raman spectroscopy. However, the application of SERS to artwork analysis is still limited by its inherent invasiveness and the need for extraction procedures. In this work non-invasive transparent SERS probes were fabricated by self-assembly of Ag nanoparticles into glass and PDMS surfaces and used for identification of dye content in artistic drawings. SERS measurements were performed directly on the selected analytical surfaces by laser back illumination through the SERS probe. The non-invasiveness of fabricated probes was tested by optical microscopy. It was found that Ag nanoparticle/glass probes left no Ag nanoparticle residue after four consecutive depositions on sacrificial surfaces, whereas Ag nanoparticle/PDMS composites could be deposited and subsequently peeled off the analytical surfaces leaving no contamination traces. The high conformability, flexibility and transparency of Ag nanoparticle/PDMS composites enabled good adhesion to the surface of analyzed artistic drawings and therefore the generation of in situ SERS spectra from artistic drawings. The use of this method allowed identification of main dye components in real artworks comprising a red BIC ballpoint drawing and a Japanese woodblock print.[Figure not available: see fulltext.].