Electronic Properties of Amyloid β-Based Peptide Filaments with Different Non-Natural Heterocyclic Side Chains

The incorporation of non-canonical amino acids with aromatic side chains is considered to be a promising way to improve and control the electronic properties of self-assembled peptide nanostructures. In this work, we have studied the influence of aromatic ring heteroatom on the electronic properties of amyloid beta-derived peptide fiber networks. We show that the incorporation of furan instead of thiophene side chains results in only small changes in the resistivity of the peptide network, with a threefold increase in the sheet resistance and a small decrease in the contact resistance. These changes can be explained by a twofold decrease in the diameter of the self-assembled fibers. These characteristics open the way to the use of furan-instead of thiophene-based analogues as non-natural side-chain modifications of peptides for electronic applications; this makes the fibrils more biodegradable and biorenewable.