Enhanced Stability of Peptide Nanofibers Coated with a Conformal Layer of Polydopamine

The susceptibility of self‐assembled materials to changes of environmental conditions and mechanical forces often limits their utility for many applications. In this work, the surface of nanofibers formed by β‐sheet peptide self‐assemblies were coated by polydopamine (PDA) deposition. This conformal coating process rendered the nanofiber dimensions and internal π‐stacking chirality impervious to changes in pH, temperature, and physical processing by spin‐coating onto a silicon wafer. Whereas sonication‐induced shearing of the dopamine/naphthalenediimide–dilysine (DA/NDI–KK) composite irreversibly shortened the nanofibers into 100–200 nm segments, the uncoated nanofibers unraveled into single strands upon similar treatment. Additionally, the PDA‐coated nanofibers could be wrapped by an additional layer comprised of a positively charged polyelectrolyte polymer. Protective wrap: The surface of naphthalenediimide–dilysine (NDI–KK) nanofibers formed by β‐sheet peptide self‐assembly were coated by polydopamine (PDA) deposition. This conformal coating process rendered the nanofibers impervious to changes in pH, ionic strength, and temperature.