Department of Chemical and Biomolecular Engineering, Case Western Reserve University, Cleveland, OH 44106, USA.
Soft Matter. 2018 May 9;14(18):3528-3535. doi: 10.1039/c8sm00351c.
Control of ionomer thin films on metal surfaces is important for a range of electrodes used in electrochemical applications. Engineered peptides have emerged as powerful tools in electrode assembly because binding sites and peptide structures can be modulated by changing the amino acid sequence. However, no studies have been conducted showing peptides can be engineered to interact with ionomers and metals simultaneously. In this study, we design a single-repeat elastin-like peptide to bind to gold using a cysteine residue, and bind to a perfluorinated sulfonic-acid ionomer called Nafion® using a lysine guest residue. Quartz crystal microbalance with dissipation monitoring and atomic force microscopy are used to show that an elastin-like peptide monolayer attached to gold facilitates the formation of a thin, phase-separated ionomer layer. Dynamic light scattering confirms that the interaction between the peptide with the lysine residue and the ionomer also happens in solution, and circular dichroism shows that the peptides maintain their secondary structures in the presence of ionomer. These results demonstrate that elastin-like peptides are promising tools for ionomer control in electrode engineering.
控制金属表面的离聚物薄膜对于电化学应用中使用的各种电极都很重要。工程肽已成为电极组装中强有力的工具，因为结合位点和肽结构可以通过改变氨基酸序列来调节。然而，目前还没有研究表明可以设计肽同时与离聚物和金属相互作用。在这项研究中，我们设计了一种单一重复的弹性蛋白样肽，使用半胱氨酸残基与金结合，并使用赖氨酸侧链残基与全氟磺酸离聚物 Nafion®结合。利用石英晶体微天平（QCM-D）和原子力显微镜（AFM）证明，附着在金上的弹性蛋白样肽单层有助于形成薄的、相分离的离聚物层。动态光散射（DLS）证实了具有赖氨酸残基的肽与离聚物之间的相互作用也发生在溶液中，圆二色谱（CD）表明在存在离聚物的情况下，肽保持其二级结构。这些结果表明，弹性蛋白样肽是电极工程中控制离聚物的有前途的工具。
