Comparative Kinetics of Supported Lipid Bilayer Formation on Silica Coated Vertically Oriented Highly Curved Nanowires and Planar Silica Surfaces

Supported lipid bilayers (SLBs), formed via lipid vesicle adsorption on highly curved silica surfaces, are widely used in biosensor applications and as models for curved cell membranes. However, SLB formation is often hindered on convex structures with radii comparable to the vesicles. In this study, lightguiding semiconductor nanowires (NWs), engineered for fluorescence signal enhancement, were used to compare the kinetics of SLB formation on vertically oriented NWs and planar silica surfaces. Time resolved fluorescence microscopy with single-molecule sensitivity revealed that while vesicle adsorption rates were similar on both surfaces lateral expansion of the SLB was up to three times faster on NWs than on the planar control. This accelerated expansion is attributed to lower energy penalties when SLBs spread along the cylindrical NWs compared with a planar surface, accompanied by accelerated SLB expansion driven by the merging of the SLB with excess lipids from vesicles accumulated on the NWs.