Quantification of Effects of Hydrophobicity and Mass Loading on the Effective Coverage of Surface-Immobilized Elastin-like Peptides for Electrochemical Applications

Abstract

Polypeptide engineering allows for a high degree of control at the molecular level, and thus has emerged as a promising tool for surface modification. Immobilized elastin-like peptides (ELPs), known for their stimuli-responsive behavior, have recently gained attention due to their potential applications in electrochemical sensing as well as bioenabled electrode assembly. Key to the success of these applications is understanding how ELPs impact the access and electron transfer of reacting species to the solid surface. In this study, short ELPs with varying guest residues and sequence length were designed for gold electrode attachment, and the influence on the ability of a redox probe to access a gold surface was characterized by cyclic voltammetry. Based on the results, a quantitative model describing the relationship between ELP effective surface coverage as a function of the mean hydrophobicity and mass loading was elucidated, illustrating the ability to precisely control surface properties by tuning the ELP sequence. This model can be used to design surface-bound ELP sequences design that exhibit desired effective surface coverage for electrochemical applications.