Organic Solvent-Mediator for Controlling Self-Assembly of Peptides on 2D Materials

摘要

The controllable nanoscale self-assembly of biomolecules, such as peptides, on 2D materials is an important issue in establishing functional bio/solid interfaces for biosensors. So far, we established method to control the self-assembly by applying electrochemical bias and designing new sequence of peptides. Herein, we evaluated a method to control the self-assembly process of Y(GA)4Y peptide (Y4Y) by employing methanol (MeOH) as mediator. A MeOH-mediated self-assemoly of Y4Y was undergone at concentrations ranging from 0% to 50% of MeOH, showing that the threshold of self-assembly is 25% for graphene and 20% for MoS_2, with a peptide coverage of ~50% for both (Fig. 1a-b). Higher concentrations of MeOH resulted in no peptide assembly, thus evidencing the effect of MeOH in controlling the coverage of Y4Y structure over both substrates graphene and MoS_2. An additional experiment of post-incubation (PI) was carried out to prove the stability of the assembled structure formed by both initial water-mediated assembly and MeOH-mediated assembly. The figure 1c shows the AFM images of Y4Y before and after PI, demonstrating that after an initial water-mediated incubation, the assembly is easily destroyed in a MeOH-mediated PI. However, when Y4Y is initially incubated with 10%MeOH, the assembled structure remains stable to up 20%MeOH-mediated PI, indicating a distinct formed self-assembled structure. These results unveil promising properties of MeOH as self-assembly mediator on 2D materials.