Quantification of the effects of hydrophobicity and mass loading on the effective coverage of surface-immobilized elastin-like peptides

Elastin-like peptides (ELPs) immobilized to solid surfaces have recently gained attention for use in electrochemical applications in 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 (effective surface coverage). In this study, short ELPs with varying hydrophobicity and sequence length were designed for gold attachment, and the effect on the ability of a redox probe to access a gold surface was characterized by cyclic voltammetry. A quantitative model describing the relationship between ELP effective surface coverage as a function of mean hydrophobicity and mass loading was elucidated based on the results, showing the ability to precisely control surface properties by tuning the ELP sequence. This model will be useful for the design of surface-bound ELP sequences that exhibit desired effective surface coverage for electrochemical as well as biomaterial applications.