Geometric Divergence in Nanostructural Fates of Coassembled Peptides Leads to Broadening of Morphology-Based Optoelectronic Property Outcomes.

Sequence-defined hierarchical structure critically governs the function and emergent properties of biomacromolecules. However, introducing functional yet bulky π-conjugated synthetic units imposes geometric constraints that complicate the rational prediction of structuremorphology correlations for engineered biomacromolecules. Here, we report an intriguing coassembly behavior of a sequence-matched peptide pair bearing energy-transporting π-electron donor/acceptor cores (DDD-4T/DDD-PDI). Individually, DDD-4T forms twisted 1-D chiral nanofibers, whereas DDD-PDI assembles into achiral 2-D bundle-like nanostructures. Upon coassembly, heterotypic interactions between a more torsionally compliant donor core and comparatively rigid acceptor core produce hybrid chiral nanostructures distinct from either pristine state. These variations in nanostructure dimensionality and local chirality result in differential photophysical and optoelectronic properties. Thermal annealing and kinetic control of acidification further direct assemblies into alternative local minima, underscoring pathway-dependent supramolecular interactions. Collectively, we present a design principle for bioelectronic materials whereby broadening property-defining morphological fates could be driven by torsional mismatch between supramolecular units.