Solvent-assisted preparation of supported lipid bilayers

The supported lipid bilayer (SLB) platform is a popular cell membrane mimic that is utilized in the chemical, biological, materials science, and medical fields. To date, SLB preparation has proven challenging because of the need for specialized fabrication equipment, domain-specific knowledge about topics relevant to lipid self-assembly, and extensive training in the interfacial science field. Existing methods, such as vesicle fusion, also work with only a narrow range of lipid compositions and material supports. Here, we describe a recently developed simple and versatile protocol to form SLBs. The protocol is simple because it requires minimal sample preparation and only basic microfluidics, making it technically accessible to researchers across different scientific disciplines. The protocol is versatile because it works on a wide range of material supports, such as silicon oxide, gold, and graphene, and is compatible with diverse lipid compositions, including sterols and signaling lipids. The main stages of the procedure involve dissolving a lipid sample in an organic solvent, depositing the lipid solution on a solid support, and replacing the organic solvent with aqueous buffer. In addition, we provide procedures for characterizing the quality of the prepared SLBs and present examples of biofunctionalization procedures. The protocol takes 1-2 h and is broadly useful in various application contexts, including clinical diagnostics, biosensing, and cellular interfaces.