Lipid assemblies have attracted considerable interest as components in bioanalytical sensors. They provide a native-like environment for the immobilization of membrane proteins and for the study of membrane-related processes. Liposomes are also excellent bioanalytical assay components since selected functionalities can be added to the membrane while their aqueous interior can encapsulate a variety of molecules. This chapter highlights the potential of lipid assemblies in surface-based affinity sensors. It first describes how such sensors are created, providing an overview of lipid immobilization strategies together with a summary of the major transduction techniques used to probe binding at and transport through membrane interfaces. It then reviews the implementation of lipid-based sensors in the study of membrane proteins and membrane-mediated interactions, followed by a discussion of the potential of liposomes as nanoscale labels and as nanoreactors. Finally, it illustrates how external forces can be used to manipulate membrane component for biosensing applications.