Underlying Polymorphism: Superhelical Crystallization Induces Architectural and Functional Diversity

Crystallized peptide assemblies have demonstrated useful physicochemical and electromechanical features due to the highly ordered supramolecular packing driven by efficient and extensive non‐covalent interactions. However, the structural polymorphism of the bioinspired self‐assemblies poses challenges for their rational design and scale production as sustainable, eco‐friendly, and tailorable materials for technology applications. Here, it is demonstrated that peptide polymorphic crystallization is a hierarchical process, evolving from initially flexible, twisted nanofibrils bundling to form ribbons, then ripening to robust, plate‐like crystals composed of superhelices, as observed using high‐resolution microscopy and crystallography supported by molecular dynamics simulations and quantum mechanical calculations. The hierarchical process accounts for the known morphological diversity of peptide crystals and provides a mechanism of controllably restricting the assembly to create only specific supramolecular structures as demanded. Especially, the superhelical organization enables high‐efficiency energy transformation, resulting in tremendous photoluminescent, optical waveguiding, and electromechanical energy‐harvesting potential. These findings endorse the feasibility of connecting the bioinspired flexible aggregations and robust crystallizations.