title: Spectral analysis of induced color change on periodically nanopatterned silk films.
abstract: We demonstrate controllable structural color based on periodic nanopatterned 2D lattices in pure protein films of silk fibroin. We show here periodic lattices in silk fibroin films with feature sizes of hundreds of nanometers that exhibit different colors as a function of varying lattice spacing. Further, when varying the index of refraction contrast between the nanopatterned lattice and its surrounding environment by applying liquids on top of the lattices, colorimetric shifts are observed. The effect is characterized experimentally and theoretically and a simple example of glucose concentration sensing is presented. This is the first example of a functional sensor based on silk fibroin optics.
authors.affiliation: Department of Biomedical Engineering, Tufts University, 4 Colby St, Medford, MA 02155, USA.
authors.forename: Jason J
authors.initials: JJ
authors.lastname: Amsden
authors.forename: Hannah
authors.initials: H
authors.lastname: Perry
authors.forename: Svetlana V
authors.initials: SV
authors.lastname: Boriskina
authors.forename: Ashwin
authors.initials: A
authors.lastname: Gopinath
authors.forename: David L
authors.initials: DL
authors.lastname: Kaplan
authors.forename: Luca
authors.initials: L
authors.lastname: Dal Negro
authors.forename: Fiorenzo G
authors.initials: FG
authors.lastname: Omenetto
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry*; D012831:Bombyx / Q000737:chemistry; D003116:Color; D003124:Colorimetry / Q000379:methods; D005349:Fibroins / Q000737:chemistry*; D005947:Glucose / Q000737:chemistry; D008855:Microscopy, Electron, Scanning / Q000379:methods; D049329:Nanostructures / Q000737:chemistry*; D036103:Nanotechnology / Q000379:methods*; D055095:Optics and Photonics / Q000379:methods; D011108:Polymers / Q000737:chemistry; D047011:Silk / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D001672:Biocompatible Materials; D011108:Polymers; D047011:Silk; D005349:Fibroins; D005947:Glucose