Supported lipid bilayers are used as model systems to study interactions of biological membranes with protein or nanoparticles. Supported lipid bilayers have typically been built on hydrophobic metal oxide substrates due to the ease of formation with the vesicle fusion method and wide range of compatible measurement techniques. Recently, a solvent-assisted method of supported lipid bilayer formation—which takes advantage of the self-assembly of a bilayer during the exchange from organic to aqueous media—has allowed expansion of the substrate materials that can be used. We examine the influence of substrate composition (SiO2 vs Au) on the interactions between anionic ligand-coated Au nanoparticles or cytochrome c and zwitterionic supported lipid bilayers. We find that anionic nanoparticles and cytochrome c have higher affinity for bilayers formed on Au relative to those on SiO2 substrates. We examine the substrate-dependence of nanoparticle adsorption with DLVO theory and find that the stronger attractive van der Waals forces and weaker repulsive coulombic forces between nanoparticles and Au substrates vs nanoparticles and SiO2 substrates could be responsible for the change in adsorption observed. Our results indicate that the underlying substrate material influences the degree to which nanoscale analytes interact with supported lipid bilayers. Our findings imply that the lipid bilayer model system should be interpreted together with its support properties and that compositional tuning of the support can be used to refine membrane–analyte interactions.

Influence of substrate composition on nanoparticle and protein interaction with supported lipid bilayers

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.