Location-specific nanoplasmonic sensing of biomolecular binding to lipid membranes with negative curvature

Abstract

The biochemical processes of cell membranes are sensitive to the geometry of the lipid bilayer. We show how plasmonic "nanowells" provide label-free real-time analysis of molecules on membranes with detection of preferential binding at negative curvature. It is demonstrated that norovirus accumulate in invaginations due to multivalent interactions with glycosphingolipids.

Fabrication and Characterization of Plasmonic Nanopores with Cavities in the Solid Support

“…Since these nanostructures should be particularly useful for studying phenomena associated with nanoscale geometry [9] it is important to visualize the shape of the cavities in SiO 2 underneath Au. A combined focused ion beam (FIB) and SEM was used to perform cross-sections (Figure 2b) and thus reveal the structure of the cavities (Figure 2c).…”

“…All binding was performed in PBS buffer and the data, i.e., centroid shift for both peak and dip [9], is presented in Figure 6. All binding was irreversible, i.e., the molecules remained on the surface (the signal did not decrease) upon rinsing.…”

“…Yet, nanostructures may provide other interesting benefits, which will never be achieved with planar surface techniques, such as the possibility to investigate how surface topography influences biomolecular binding. Plasmonic nanopores have been especially useful for this purpose by generating regions with negative curvature [9]. It is particularly interesting to liberate a volume underneath the metal film to create cavities with controlled curvature and dimensions.…”

“…The refractive index sensitivities of the plasmonic resonances and characteristic shifts upon molecular binding are reported. The possibility to perform location-specific detection [9] by proper spectral analysis is evaluated. Finally, possible applications of these nanostructured sensors are discussed.…”

Nanohole Array-Directed Trapping of Mammalian Mitochondria Enabling Single Organelle Analysis

“…19 They have also been utilized for on-chip detection and analysis of complex bioparticles such as exosomes, 20 viruses, 21 and virus-like particles. 22, 23 However, these platforms have also primarily relied on non-directional capture of molecules and particles, though some examples have spatially-heterogeneous surface chemistry for selective capture of particles. Nanoholes fabricated in free-standing silicon nitride (Si 3 N 4 ) films have been shown to be efficient at directing the flow of solution through them, which can be used for directed trapping of particles suspended in solution.…”