Bio-organic adaptive photonic crystals enable supramolecular solvatochromism

Photonic crystals(PCs)exhibit promising structural coloration properties and possess extensive application prospects in diverse optical fields.However,state-of-the-art inorganic or polymeric PCs show limited adaptivity as their configurations are fixed once formed.Herein,bio-organic adaptive PCs are fabricated via drop-casting of amphiphilic guanine-based peptide nucleic acid selfassembled microspheres.The high formation activation energy of up to 81.8 kJ·mol−1 suggests that the self-assembly step dominates the entire process.Therefore,the configurations along with the structural coloration of the supramolecular PCs are sensitive to self-assembly influencing parameters,showing temperature-encoded structural color evolution and solvent polaritydependent solvatochromism.Our findings demonstrate that the supramolecular PCs are adaptive,thus showing promising potential for detection of organic solvents of different polarities in a visual and real-time manner for environmental protection or optical applications.

Rational Design of Biological Crystals with Enhanced Physical Properties by Hydrogen Bonding Interactions

Hydrogen bonds are non-covalent interactions and essential for assembling supermolecules into ordered structures in biological systems,endowing crystals with fascinating physical properties,and inspiring the construction of eco-friendly electromechanical devices.However,the interplay between hydrogen bonding and the physical properties is not fully understood at the molecular level.Herein,we demonstrate that the physical property of biological crystals with double-layer structures could be enhanced by rationally controlling hydrogen bonding interactions between amino and carboxyl groups.Different hydrogen bonding interactions result in various thermal,mechanical,electronic,and piezoelectric properties.In particular,the weak interaction between O and H atoms contributes to low mechanical strength that permits important ion displacement under stress,giving rise to a strong piezoelectric response.This study not only reveals the correlation between the hydrogen bonding and physical properties in double-layer structures of biological crystals but also demonstrates the potential of these crystals as functional biomaterials for high-performance energy-harvesting devices.Theoretical calculations and experimental verifications in this work provide new insights into the rational design of biomaterials with desirable physical properties for bioelectrical devices by modulating intermolecular interactions.