Ccorahua R, Noguchi H, Hayamizu Y. Cosolvents Restrain Self-Assembly of a Fibroin-Like Peptide on Graphite.
J Phys Chem B 2021;
125:10893-10899. [PMID:
34559528 DOI:
10.1021/acs.jpcb.1c02594]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Controllable self-assembly of peptides on solid surfaces has been investigated for establishing functional bio/solid interfaces. In this work, we study the influence of organic solvents on the self-assembly of a fibroin-like peptide on a graphite surface. The peptide has been designed by mimicking fibroin proteins to have strong hydrogen bonds among peptides enabling their self-assembly. We have employed cosolvents of water and organic solvents with a wide range of dielectric constants to control peptide self-assembly on the surface. Atomic force microscopy has revealed that the peptides self-assemble into highly ordered monolayer-thick linear structures on graphite after incubation in pure water, where the coverage of peptides on the surface is more than 85%. When methanol is mixed, the peptide coverage becomes zero at a threshold concentration of 30% methanol on graphite and 25% methanol on MoS2. The threshold concentration in ethanol, isopropanol, dimethyl sulfoxide, and acetone varies depending on the dielectric constant with restraining self-assembly of the peptides, and particularly low dielectric-constant protic solvents prevent the peptide self-assembly significantly. The observed phenomena are explained by competitive surface adsorption of the organic solvents and peptides and the solvation effect of the peptide assembly.
Collapse