Raman spectroscopy and SERS: recent advances in cultural heritage diagnostics and the potential use of anisotropic metal nanostructures

Raman and Surface-Enhanced Raman Spectroscopies (SERS) are among the foremost non-destructive techniques for material characterization in cultural heritage research. SERS, in particular, stands out for its remarkable signal enhancement and ability to mitigate fluorescence interference, making it a valuable tool embraced by researchers across the field. Central to this enhancement are metallic nanostructures, with their effects finely tuned by variations in shape, size, and metal type. Anisotropic nanostructures—such as nanostars, nanoflowers, and nanocubes—are especially compelling due to their capacity to amplify SERS hotspots and intensify plasmonic bands, positioning them at the frontier of scientific interest. Nevertheless, the application of anisotropic nanostructures in cultural heritage SERS analyses remains relatively untapped, with only a few recent studies venturing into this promising area. This review provides a focused overview of metal nanostructure properties, highlighting the unique benefits that anisotropic designs offer in advancing SERS analyses for cultural heritage materials.