Impact of Electric Fields on the Nanoscale Behavior of Lipid Monolayers at the Surface of Graphite in Solution

Bi, H.; Wang, X.; Han, X.; Voïtchovsky, K.

Abstract

The nanoscale organization and dynamics of lipid molecules in self-assembled membranes is central to the biological function of cells and in for the technological development synthetic lipid structures as well as in devices such as biosensors.Here we explore the nanoscale molecular arrangement and dynamics of lipids assembled in monolayers at the surface of highly ordered pyrolytic graphite (HOPG), in different ionic solutions and under electrical potentials. Using a combination of atomic force microscopy and fluorescence recovery after photobleaching, we show that HOPG is able to support fully formed and fluid lipid membranes, but mesoscale order and corrugations can be observed depending on the type of lipid considered (DOPC, DOPS, DOTAP) and the ion present (Na+, Ca2+, Cl-). Interfacial solvation forces and ion-specific effects dominate over the electrostatic changes induced by moderate electric fields (1.0 V versus Ag/AgCl reference electrode) with particularly marked effects in the presence of calcium, and for DOPS. Our results provide insights into the interplay between molecular, ionic and electrostatic interactions and the formation of dynamical ordered structures in fluid lipid membranes.

Citation

Bi, H., Wang, X., Han, X., & Voïtchovsky, K. (2018). Impact of Electric Fields on the Nanoscale Behavior of Lipid Monolayers at the Surface of Graphite in Solution. Langmuir, 34(32), 9561-9571. https://doi.org/10.1021/acs.langmuir.8b01631

• Journal Article Type: Article
• Acceptance Date: May 29, 2018
• Online Publication Date: Jul 20, 2018
• Publication Date: Aug 14, 2018
• Deposit Date: Jul 23, 2018
• Publicly Available Date: Jul 20, 2019
• Journal: Langmuir
• Print ISSN: 0743-7463
• Electronic ISSN: 1520-5827
• Publisher: American Chemical Society
• Peer Reviewed: Peer Reviewed
• Volume: 34
• Issue: 32
• Pages: 9561-9571
• DOI: https://doi.org/10.1021/acs.langmuir.8b01631
• Public URL: https://durham-repository.worktribe.com/output/1353737