title: Localized surface plasmon resonance sensing of lipid-membrane-mediated biorecognition events.
abstract: Supported phospholipid bilayers (SPBs) have emerged as important model systems for studies of the natural cell membrane and its components, which are essential for the integrity and function of cells in all living organisms, and also constitute common targets for therapeutic drugs and in disease diagnosis. However, the preferential occurrence of spontaneous SPB formation on silicon-based substrates, but not on bare noble-metal surfaces, has so far excluded the use of the localized surface plasmon resonance (LSPR) sensing principle for studies of lipid-membrane-mediated biorecognition reactions. This is because the LSPR phenomenon is associated with, and strongly confined to, the interfacial region of nanometric noble-metal particles. This problem has been overcome in this study by a self-assembly process utilizing localized rupture of phospholipid vesicles on silicon dioxide in the bottom of nanometric holes in a thin gold film. The hole-induced localization of the LSPR field to the voids of the holes is demonstrated to provide an extension of the LSPR sensing concept to studies of reactions confined exclusively to SPB-patches supported on SiO2. In particular, we emphasize the possibility of performing label-free studies of lipid-membrane-mediated reaction kinetics, including the compatibility of the assay with array-based reading (approximately 7 x 7 microm2) and detection of signals originating from bound protein in the zeptomole regime.
authors.affiliation: Department of Applied Physics, Chalmers University of Technology, SE-412 96 Göteborg, Sweden.
authors.forename: Andreas
authors.initials: A
authors.lastname: Dahlin
authors.forename: Michael
authors.initials: M
authors.lastname: Zäch
authors.forename: Tomas
authors.initials: T
authors.lastname: Rindzevicius
authors.forename: Mikael
authors.initials: M
authors.lastname: Käll
authors.forename: Duncan S
authors.initials: DS
authors.lastname: Sutherland
authors.forename: Fredrik
authors.initials: F
authors.lastname: Höök
mesh_terms: D000327:Adsorption; D015374:Biosensing Techniques / Q000379:methods*; D001710:Biotin / Q000737:chemistry; D006046:Gold / Q000737:chemistry; D008051:Lipid Bilayers / Q000032:analysis / Q000737:chemistry* / Q000378:metabolism; D008563:Membrane Lipids / Q000032:analysis / Q000737:chemistry* / Q000378:metabolism; D018625:Microscopy, Atomic Force; D012710:Serum Albumin, Bovine / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry; D019265:Spectroscopy, Near-Infrared; D020349:Surface Plasmon Resonance / Q000379:methods*
chemical_list: D008051:Lipid Bilayers; D008563:Membrane Lipids; D012710:Serum Albumin, Bovine; D001710:Biotin; D006046:Gold; D012822:Silicon Dioxide