Single-Molecule Detection with Lightguiding Nanowires: Determination of Protein Concentration and Diffusivity in Supported Lipid Bilayers
| Autor: | Fredrik Höök, Vladimir P. Zhdanov, Björn Agnarsson, Damiano Verardo, Heiner Linke |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
Cholera Toxin
Materials science Light Lipid Bilayers Nanowire Bioengineering 02 engineering and technology G(M1) Ganglioside Thermal diffusivity Microscopy Molecule Nanotechnology General Materials Science Lipid bilayer business.industry Nanowires Mechanical Engineering Cell Membrane General Chemistry 021001 nanoscience & nanotechnology Condensed Matter Physics Single Molecule Imaging Membrane Semiconductor Microscopy Fluorescence Semiconductors Chemical physics 0210 nano-technology business Biosensor Protein Binding |
| Zdroj: | Nano letters. 19(9) |
| ISSN: | 1530-6992 |
| Popis: | Determining the surface concentration and diffusivity of cell-membrane-bound molecules is central to the understanding of numerous important biochemical processes taking place at cell membranes. Here we use the high aspect ratio and lightguiding properties of semiconductor nanowires (NWs) to detect the presence of single freely diffusing proteins bound to a lipid bilayer covering the NW surface. Simultaneous observation of light-emission dynamics of hundreds of individual NWs occurring on the time scale of only a few seconds is interpreted using analytical models and employed to determine both surface concentration and diffusivity of cholera toxin subunit B (CTxB) bound to GM1 gangliosides in supported lipid bilayer (SLB) at surface concentrations down to below one CTxB per μm2. In particular, a decrease in diffusivity was observed with increasing GM1 content in the SLB, suggesting increasing multivalent binding of CTxB to GM1. The lightguiding capability of the NWs makes the method compatible with conventional epifluorescence microscopy, and it is shown to work well for both photostable and photosensitive dyes. These features make the concept an interesting complement to existing techniques for studying the diffusivity of low-abundance cell-membrane-bound molecules, expanding the rapidly growing use of semiconductor NWs in various bioanalytical sensor applications and live cell studies. |
| Databáze: | OpenAIRE |
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