Supported lipid bilayers, tethered lipid vesicles, and vesicle fusion investigated using gravimetric, plasmonic, and microscopy techniques

Abstract

This article summarizes our most recent contributions to the rapidly growing field of supported lipid assemblies with emphasis on current studies addressing both fundamental and applied aspects of supported lipid bilayer (SLB) and tethered lipid vesicles (TLVs) to be utilized in sensing applications. The new insights obtained from combining the quartz crystal microbalance with dissipation monitoring technique with surface plasmon resonance are described, and we also present recent studies in which nanoplasmonic sensing has been used in studies of SLBs and TLVs. To gain full control over the spatial arrangement of TLVs in both two and three dimensions, we have developed a method for site-selective and sequence-specific sorting of DNA-tagged vesicles to surfaces modified with complementary DNA. The combination of this method with nanoplasmonic sensing formats is covered as well as the possibility of using DNA-modified vesicles for the detection of unlabeled DNA targets on the single-molecule level. Finally, a new method for membrane fusion induced by hybridization of vesicle-anchored DNA is demonstrated, including new results on content mixing obtained with vesicle populations encapsulating short, complementary DNA strands.

Engineering metallic nanostructures for plasmonics and nanophotonics

“…Finally, metallic films can concurrently act as electrodes, presenting opportunities to build a multi-functional sensing platform that combines SPR sensing with electrochemistry and impedance spectroscopy (Hook, 2008; Andersson, 2008; Shan, 2010; Sannomiya, 2010).…”

Convenient synthesis and application of versatile nucleic acid lipid membrane anchors in the assembly and fusion of liposomes

“…16 Furthermore, liposomes can act as nanocontainers for chemical reagents and catalysts, leading to versatile nanoreactors upon fusion. 17 First attempts made by Boxer 18,19 and Höök [20][21][22] have shown earlier the feasibility of liposome fusion mediated by lipid-oligonucleotide conjugates by mimicking the geometry of the natural SNARE complex. 23…”

Nanohole-Based Surface Plasmon Resonance Instruments with Improved Spectral Resolution Quantify a Broad Range of Antibody-Ligand Binding Kinetics

“…16–21 Besides acting as a source of SP waves, nanoholes can concurrently function as nanowells to confine supported lipid bilayer membranes, 22 a scaffold for pore-spanning lipid membranes, 14 nanofluidic channels to transport biomolecules, 23,24 or as electrodes for electrochemical sensing. 25 Integrating these novel functionalities may justify the added cost of nanofabrication and motivates the development of a general-purpose nanoplasmonic sensing platform. Beyond high-throughput fabrication of metallic nanohole arrays, 21,26–28 however, considerable efforts are required to quantify protein binding kinetics accurately and without artifacts, such as optimizing surface modification protocols (immobilization, blocking, and regeneration), microfluidics, low-noise optical measurements, and data analysis.…”