Bioinspired Polypeptide Photonic Films with Tunable Structural Color

Abstract

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 photonic films is demonstrated via template microfabrication. Because of the incorporation of l-glutamate (Glu) components, the P­(Cys-co-Glu) co-polypeptide films are endowed with a visual color responsiveness toward pH changes. Additionally, the polypeptide photonic films show on-demand degradability. 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.

4D Direct Laser Writing of Submerged Structural Colors at the Microscale

“…Among them, owing to the good biocompatibility, tunable toughness, high water content and reversible volume change, pH-responsive hydrogel (PRH) has been extensively studied that enables the sensing or display application through the transformation of shape in the solution. [16,17] For instance, Zhu et al developed a pH-responsive device by coating acrylic acid (AAC) and acrylamide (AAm) via in situ copolymerization onto Papilio Paris wings having lamellar structure, which provided the photonic crystals (PCs)-based pH sensor. [18] In addition, Park et al presented a 3D display based on multi-order reflection SCs with P2VP hydrogel.…”

Responsive Structural Colors Derived from Geometrical Deformation of Synthetic Nanomaterials

“…Compared with the opal template, the photonic bandgap of the synthetic inverse opal is smaller, which is determined by the effective refractive index. The color change properties of inverse opals are related to the properties of the polymer itself, such as shape memory polymers, [ 60 ] degradable peptides, [ 104 ] and conductive polymers. [ 76 ] As an important photon pigment, inorganic inverse opal is usually obtained by calcination after filling oxide materials into the PS opal.…”

“…Degradable inverse opals were developed by Tang et al through the ring‐opening polymerization of N ‐carboxyanhydrides (see Figure 3f). [ 104 ] The carboxyl groups in the polymer chains confer the synthesized inverse opals controllable surface wettability. Disulfide bonds confer modifiability of chemical groups in inverse opals.…”

Bioinspired MXene-Based Soft Actuators Exhibiting Angle-Independent Structural Color

“…Furthermore, bioinspired, living, structurally colored soft actuators were reported by assembling engineered cardiomyocyte tissues onto synthetic inverse opal hydrogels, where autonomous shape and color regulation capability was enabled by the cell contraction and elongation in the beating processes of the cardiomyocytes [15]. Compared to chemically colored soft actuators loaded with dyes or pigments [16][17][18][19], physically colored (structurally colored) soft actuators integrated with photonic crystals display brilliant colors that are dynamically tunable by adjusting the lattice constant or refractive index and never fade as long as the periodic structures persist [20][21][22][23][24][25]. However, the structural color of soft actuators reported thus far is dependent on the viewing and light illumination angles, which is one of the critical limitations compared with chemically colored soft actuators.…”