Cephalopod chromatophores contain photosensitizing nanostructures that may facilitate light sensing and signaling in the skin†

Cephalopods can sense and respond to changes in their environment using combinations of pigments, proteins, and/or nanostructures which are sequestered in the stratified optical organs of their dermal tissue. Of these organs, the chromatophore functions as a dynamic optical filter that imparts rapid and adaptive changes to the color and patterns presented in cephalopod skin. Chromatophores contain pigmented granules, but there is very little information available on whether their function extends beyond pigmentation. We examine granule performance within a photovoltaic cell and investigate their light sensing properties. Upon exposure to solar simulated light, photoexcited charge transfer is observed in devices containing the granules, where a photoconversion efficiency up to 0.81 ± 0.14% is recorded. This finding is the first to suggest that these biomaterials function as more than simple colorants; they may also be involved in light sensing and transduction to support adaptive camouflage.