| Autor: |
Jessop AL; School of Mathematics, Statistics, Chemistry and Physics, Murdoch University , Perth, Western Australia 6150, Australia., Pirih P; Department of Chemistry and Physics of Materials, University of Salzburg , Salzburg 5020, Austria., Wang L; Department of Chemistry and Physics of Materials, University of Salzburg , Salzburg 5020, Austria., Patel NH; Marine Biological Laboratory, University of Chicago , Woods Hole, MA 02543, USA., Clode PL; Centre for Microscopy, Characterisation and Analysis, University of Western Australia , Perth, Western Australia 6009, Australia.; School of Biological Sciences, University of Western Australia , Perth, Western Australia 6009, Australia., Schröder-Turk GE; School of Mathematics, Statistics, Chemistry and Physics, Murdoch University , Perth, Western Australia 6150, Australia.; Research School of Physics, The Australian National University , Canberra, Australian Capital Territory 2601, Australia., Wilts BD; Department of Chemistry and Physics of Materials, University of Salzburg , Salzburg 5020, Austria. |
| Abstrakt: |
Biophotonic nanostructures in butterfly wing scales remain fascinating examples of biological functional materials, with intriguing open questions with regard to formation and evolutionary function. One particularly interesting butterfly species, Erora opisena (Lycaenidae: Theclinae), develops wing scales that contain three-dimensional photonic crystals that closely resemble a single gyroid geometry. Unlike most other gyroid-forming butterflies, E. opisena develops discrete gyroid crystallites with a pronounced size gradient hinting at a developmental sequence frozen in time. Here, we present a novel application of a hyperspectral (wavelength-resolved) microscopy technique to investigate the ultrastructural organization of these gyroid crystallites in dry, adult wing scales. We show that reflectance corresponds to crystallite size, where larger crystallites reflect green wavelengths more intensely; this relationship could be used to infer size from the optical signal. We further successfully resolve the red-shifted reflectance signal from wing scales immersed in refractive index liquids with varying refractive index, including values similar to water or cytosol. Such photonic crystals with lower refractive index contrast may be similar to the hypothesized nanostructural forms in the developing butterfly scales. The ability to resolve these fainter signals hints at the potential of this facile light microscopy method for in vivo analysis of nanostructure formation in developing butterflies. |
