Fig. 1. (a) UV-Vis-NIR absorption spectrum of an aqueous solution of DOPA melanin (black trace). The colored Gaussian functions illustrate hypothetical, distinct chromophores, some of which can be selectively excited by a given excitation wavelength (black arrow). (b) Synthesis of DOPA melanin from l-DOPA, showing the DHI and DHICA intermediates. Typical structural motifs proposed for eumelanin are shown in (c) and (d): (c) irregular, possibly branched macromolecule, and (d) two-dimensional oligomeric protomolecule (adapted from ref. 59).
