Two amphiphilic peptides incorporating anthracene as a light-responsive moiety that assemble into 2D-sheets or ribbons are designed. These nanostructures are disassembled upon irradiation with 365 nm light by bimolecular [4 + 4] cycloaddition. The reaction kinetics are depended on peptide preorganization, linking structure to reactivity.

While the assembly of supramolecular peptide nanostructures with diverse functions and morphologies has been extensively studied, the controlled disassembly of these architectures remains less understood. To address this, two short amphiphilic peptides incorporating anthracene as a light-responsive unit and lysine as a pH-sensitive residue are designed. These peptides self-assemble into nanosheets or nanoribbons with distinct secondary structures, which are further tunable by pH through modulation of peptide charge. Upon irradiation at 365 nm, the anthracene moieties undergo a bimolecular [4 + 4] cycloaddition, disrupting the π–π stacking interactions by distorting the planarity of the aromatic units. This photoreaction leads to disassembly of the supramolecular architectures within 10 min. Unlike monomolecular reactions such as photocleavage, the kinetics of this bimolecular photodimerization are significantly influenced by the degree of preorganization within the assemblies. These findings underscore the critical interplay between supramolecular architecture and molecular photochemistry, enabling light-triggered, structure-dependent disassembly of diverse peptide nanostructures.