Membrane protein biosensing with plasmonic nanopore arrays and pore-spanning lipid membranes

Integration of solid-state biosensors and lipid bilayer membranes is important for membrane protein research and drug discovery. In these sensors, it is critical that the solid-state sensing material does not have adverse effects on the conformation or functionality of membrane-bound molecules. In this work, pore-spanning lipid membranes are formed over an array of periodic nanopores in free-standing gold films for surface plasmon resonance (SPR) kinetic binding assays. The ability to perform kinetic assays with a transmembrane protein is demonstrated with alpha-hemolysin (alpha-HL). The incorporation of alpha-HL into the membrane followed by specific antibody binding (anti-alpha-HL) red-shifts the plasmon resonance of the gold nanopore array, which is optically monitored in real time. Subsequent fluorescence imaging reveals that the antibodies primarily bind in nanopore regions, indicating that alpha-HL incorporation preferentially occurs into areas of pore-spanning lipid membranes.