Bioinspired Polypeptide Photonic Films with Tunable Structural Color

We report a new synthetic strategy of combining N-carboxyanhydride (NCA) chemistry and photonic crystals for the fabrication of polypeptide structural color films. Driven by surface-initiated ring-opening polymerization, the di-NCA derivative of L-cystine (Cys) is introduced to replicate the functionalized colloidal crystal templates and construct freestanding P(Cys)films with tunable structural color. Furthermore, the feasibility of preparing patterned polypeptide photonicfilms is demonstrated via templatemicrofabrication. Because of the incorporation ofL-glutamate (Glu) components, the P(Cys-co-Glu) co-polypeptidefilms areendowed with a visual color responsiveness toward pH changes. Additionally, the polypeptide photonic films show on-demanddegradability. Given the large family of amino acid building blocks, this powerful and versatile approach paves the way for chemical derivatization of multifunctional peptide-based optical platforms

Automated summary

We present a new synthetic strategy that combines N-carboxyanhydride (NCA) chemistry and photonic crystals for the fabrication of polypeptide structural color films. Through surface-initiated ring-opening polymerization, a di-NCA derivative of L-cystine (Cys) is utilized to replicate functionalized colloidal crystal templates and create freestanding P(Cys) films with adjustable structural color. The feasibility of producing patterned polypeptide photonic films is demonstrated through template microfabrication. The introduction of L-glutamate (Glu) components enables the P(Cys-co-Glu) copolypeptide films to exhibit visual color responsiveness to pH changes. Additionally, the polypeptide photonic films possess on-demand degradability.