Monomer sequence influences electron transport in aromatic amide foldamers

Sequence encodes structure and function in biomolecules, but whether monomer order influences electron transport in synthetic foldamers remains incompletely understood. Here, we investigate aromatic amide foldamers built from a peptide-inspired secondary amide and its N-methylated peptoid-inspired analogue. Single molecule conductance measurements reveal that the all-secondary-amide foldamer exhibits a well-defined conductance state (~10-3.8 G0), comparable to the substantially shorter secondary-amide building block (~10-3.7 G0), whereas incorporation of N-methylated units produces lower or less-defined conductance features. Notably, foldamers with identical composition but different sequence arrangements exhibit distinct conductance distributions, demonstrating that sequence order influences electron transport. Displacement and flicker noise analyses indicate compact junction geometries with substantial throughspace contributions, and the all secondary amide foldamer responds most strongly to changes in applied bias and molecular concentration. Computational modeling using molecular dynamics (MD) simulations, density functional theory (DFT), and nonequilibrium Green's function (NEGF)-DFT calculations provide insight into sequencedependent conformational variability. Overall, this work demonstrates that oligomerization can generate electron transport behavior that cannot be inferred directly from isolated monomer properties and establishes monomer order as a design variable for molecular electronics.