(162h) Thermal Tuning of Aqueous Peptide Conformations for Tailored Binding Energetics and 2D Surface Assembly

Understanding and controlling the interactions, dynamics and assembly structure of biomolecules at atomically flat inorganic solid interfaces is critical for the development of biomimetic bio-hybrid interfaces with applications to biosensing and bioelectronic devices. One promising candidate for tailoring interfacial structure are combinatorically selected solid-binding dodecapeptides, as many of them spontaneously form long-range ordered assemblies on two-dimensional solid surface, such as graphene, MoS₂, and BN. The conformation of the solid-binding peptide is dynamic in solution and depends on the solution conditions, such as pH, temperature, and salt concentration. As self-assembly of biomolecules relies heavily on the molecular conformation of the monomer, we show that it is possible to direct the formation of the equilibrium assembly structure at the solid interface by controlling the labile conformation of the peptides in aqueous solution via an environmental selection process. As elucidated by structural kinetic analyses, molecular dynamics simulations and a scanning probe energetic analysis (dubbed Intrinsic Friction Analysis), our results demonstrate that (i) Peptide-graphite binding can be tuned via thermal selection of specific conformational states, (ii) The resulting assembly structure is specific to the most prominent peptide solution conformations, and, (iii) That the thermally selected conformation persists throughout the assembly process. Collectively, results led to the rational redesign of a peptide sequence with predetermined binding and assembly characteristics. The environmental processing of biomolecules may allow for the bottom-up fabrication of active bio-nano interfaces for multifarious applications from bioelectronic devices, biosensors, biomolecular fuel cells, to logic elements. The research was supported by NSF-DMREF program through the grant DMR-1629071 as part of the Materials Genome Initiative.