Photosensitisation of melanins covalently bound to dyes

Abstract

The effects of binding to melanin of two synthetic dyes, 5-(4,6-dichloro-1,3,5-triazin-2-yl) aminoerythrosin (AE) and 5-(4,6-dichloro-1,3,5-triazin-2-yl) aminofluorescein(AF) in terms of dye fluorescence, dye triplet quantum yield, the rate of photosensitised oxygen consumption and the rate of photosensitised production of melanin free radicals are reported using steady-state fluorescence, laser flash photolysis and e.s.r. techniques. The dyes react as though they are bound near the surface of the polymeric melanin and the results involving singlet oxygen formation and consumption may suggest a melanin site-specific interaction.