Eumelanin biopolymer synthetized from L-DOPA has been characterized by Raman and Surface Enhanced
Raman Spectroscopy (SERS). Although Raman spectra of eumelanin were scarcely resolved, SERS measurements of this
biopolymer on nanostructured gold substrate, provided a large enhancement of vibrational peaks related to functional
groups adherent to the substrate, so that well resolved vibrational spectra were obtained. The SERS peaks correspond to
vibrational modes related to the monomeric units of eumelanin. So, SERS spectra can be used to identify the monomeric
content of eumelanin and resolve the presence of vibrational modes which have been calculated and predicted according
to different theoretical models and previously observed in vibrational spectra of single monomeric units.