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 self-assembled 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 polarity-dependent 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.