Supramolecular self-assembled peptide scaffolds for fluorescence enhancement and delayed emission

Luminescent organic materials are increasingly important for applications ranging from bioimaging and sensing to optoelectronics and phototherapy. Their performance depends on controlling excited-state dynamics, yet organic luminophores face intrinsic limitations such as weak spin-orbit coupling, aggregation-induced quenching, and oxygen sensitivity. Conventional strategies such as crystallization, polymer encapsulation, and host-guest assembly can improve fluorescence, thermally activated delayed fluorescence (TADF), and room-temperature phosphorescence (RTP), but often lack biocompatibility, adaptability, or aqueous stability. Peptide-based supramolecular assemblies are emerging as versatile alternatives, offering modularity, biodegradability, and the ability to create ordered nanostructures through hydrogen bonding (H-bonding), π-π stacking, hydrophobic interactions, and electrostatics. These assemblies generate confined and tunable microenvironments that suppress non-radiative losses, stabilize triplet states, and protect excitons from quenching, thereby enabling efficient fluorescence, long-lived RTP, and oxygen-tolerant TADF. In this review, we highlight recent advances in peptide-luminophore co-assemblies that enhance emission efficiency and stability under biological conditions. We discuss molecular design principles, mechanistic insights, and representative examples across fluorescence, RTP, and TADF systems and outline future directions in predictive peptide design, stability engineering, and multifunctional applications. Overall, peptide supramolecular scaffolds show great promise as next-generation platforms for development of efficient and versatile luminescent materials.