Self-assembling peptides have become important building blocks for materials design (e.g. hydrogels) and play a crucial role in a range of diseases including Alzheimer and Parkinson. In this context, accessing the nanomechanical properties of ubiquitous β-sheet rich nanofibres (e.g.: amyloids) is key to the formulation of materials and design of therapies. Although the bulk mechanical properties of hydrogels can easily be accessed using common techniques and equipment, the mechanical properties of their constituent fibres, in particular if with radii in the nanometre scale, are more challenging to measure and estimate. In this work we show for the first time how the rapid nanomechanical mapping technique: amplitude modulation-frequency modulation (AM-FM), can be used to determine the heights, Young's moduli and viscosity coefficients of a series of β-sheet peptide nanofibres with high statistical confidence. Our results show how peptide sequence and in particular length, charge and interaction with the substrate affect the viscoelastic properties of the peptide fibres.

自组装肽已成为材料设计（例如水凝胶）的重要组成部分，并在包括阿尔茨海默氏症和帕金森症在内的一系列疾病中发挥关键作用。在这种情况下，获取无处不在的富含 β-折叠的纳米纤维（例如：淀粉样蛋白）的纳米力学特性是材料配方和疗法设计的关键。尽管使用常用技术和设备可以轻松获得水凝胶的整体机械性能，但其组成纤维的机械性能，特别是如果半径为纳米级，测量和估计更具挑战性。在这项工作中，我们首次展示了如何使用快速纳米力学映射技术：调幅-调频 (AM-FM) 来确定高度，Young' 一系列具有高统计置信度的β-折叠肽纳米纤维的模量和粘度系数。我们的结果显示了肽序列，特别是长度、电荷和与底物的相互作用如何影响肽纤维的粘弹性。