Melanin

The melanins are a class of functional bio-macromolecule found throughout nature. In humans they serve as our primary photoprotectants and pigment. As a biomolecule class they possess a number of intriguing physico-chemical properties including: broad band monotonic absorbance in the UV and visible; condensed phase electrical and photoconductivity; extremely efficient non-radiative relaxation of photoexcited electronic states (melanins have radiative quantum yields <1%); and free radical scavenging and anti-oxidant behaviour. We focus our attentions primarily on eumelanin (the most prevalent form in humans) which are macromolecules of indolequinones. Our work is motivated by the general desire to better understand how these systems are put together and why they behave like they do, and also by the intriguing suggestion that we may be able to create a new class of bio-inspired high tech organic material.