Cosolvent-Modulated Supramolecular Chirality Unveils Pronounced Piezoelectric Response in Peptide-Based Nanomaterials.

Peptide-based functional biomaterials have attracted widespread interest due to their inherent biocompatibility, biodegradability, and structural tunability. Among functional biomaterials, piezoelectric materials are particularly valuable for developing self-powered biodevices in biomedical applications. However, peptide-based piezoresponsive systems remain largely underexplored. In this study, we present a chromophore-conjugated peptide (PEP-A) that self-assembles into nanomaterials exhibiting either piezo-active or inactive states, with the functional behaviour closely linked to their chiroptical properties under different solvent conditions. Through a comprehensive investigation involving spectroscopy, microscopy, and atomistic simulations, we uncover how cosolvent-induced modulation of the self-assembly process co-governs chiroptical and piezoelectric properties. Interestingly, PEP-A forms elongated nanofibers in pure water that are both chiroptically and piezoelectrically inactive. However, the introduction of a minimal amount of cosolvent (1% DMSO or 1% DMF) triggers the emergence of supramolecular chirality alongside a significant piezoresponse, revealing a direct correlation between macroscopic chirality and piezoelectric functionality. Our findings highlight how subtle changes in the assembly environment can drive profound shifts in material properties, offering a powerful strategy to design responsive piezoelectric biomaterials. This study provides a novel approach to designing next-generation, responsive, peptide-based piezoelectric biomaterials for biomedical and bioelectronic applications.