Fig_4.

(a) Schematic of cholera toxin b subunits (CTX-b) binding to ganglioside GM1 receptors incorporated in lipid membranes. First, a silica shell is coated on a silver surface to promote vesicle rupture. Then, GM1 containing vesicles are injected into microfluidic channels and rupture to form supported lipid bilayers (SLBs). The CTX-b is introduced and binds with GM1. (b) Fluorescence images showing homogeneous SLB formation and different amount of CTX-b binding to various concentration of GM1 in supported lipid bilayers. (c) A line profile of fluorescence intensity across the microfluidic channels. The fluorescence intensity of the SLBs indicates a homogeneous lipid membrane across the channels, while the intensity of CTX-b bound to GM1 increases due to the increase in receptor density.