Bioinspired Thermal-Stable Room-Temperature Phosphorescent Peptides

Room-temperature phosphorescence (RTP) materials exhibit long-lived emission, making them promising for bioimaging, information security, and flexible optoelectronics. Traditional inorganic systems are limited by toxicity and complex synthesis, whereas their organic counterparts often suffer from triplet exciton relaxation and quenching. Inspired by the β-barrel structure of green fluorescent protein, we introduce a "bionic confined structure" strategy using peptides synthesized via N-carboxyanhydride ring-opening polymerization with controllable secondary structures to construct hierarchical confined environments. α-Helical polypeptides exhibit negligible afterglow due to insufficient packing, whereas random coils provide dense confinement with long lifetimes but poor thermal stability. Surprisingly, the α-helix and β-sheet hybrid structure combines rigid backbones and ordered hydrogen bonding, achieving a long lifetime with excellent thermal robustness. This strategy also demonstrates universality across diverse luminophores, enabling multicolor and long-lived RTP. These findings highlight secondary-structure engineering via synthesized peptides as a powerful biomimetic approach for designing efficient, thermally stable, and biocompatible organic RTP materials.