Supramolecular engineering of amyloid-inspired tripeptide assemblies enabling tunable piezoelectricity.

Rational molecular design of short peptides represents an effective strategy for modulating supramolecular architectures and piezoelectricity of peptide assemblies. However, the impact of peptide sequence and side chain chemistry on the piezoelectric properties of assemblies remains largely unexplored. Diphenylalanine (FF), the core recognition motif of β-amyloid protein, has emerged as an excellent molecular building block for fabricating piezoelectric materials due to its easily modifiable structure and exceptional electromechanical properties. Here, we systematically investigate the effect of peptide sequence and side chain variation on the supramolecular stacking and piezoelectric properties of FF-inspired tripeptide assemblies. Crystal structures reveal that variations in molecular structures induce distinct secondary structures and supramolecular assembly modes, producing tunable piezoelectric coefficients confirmed by density functional theory calculations. Notably, IFF assemblies exhibit a maximum piezoelectric coefficient of 57.1 pC/N, representing the highest predicted value among oligopeptide supramolecular materials. The IFF assemblies-based piezoelectric nanogenerator generates an open-circuit voltage of 2.3 V under 70 N force, maintaining excellent mechanical durability over 10,000 press-release cycles. This work presents a promising strategy for regulating the piezoelectricity of peptide supramolecular assemblies, establishing rational design principles for advancing the development of high-performance peptide-based piezoelectric biomaterials.