Article

Membrane-protein binding measured with solution-phase plasmonic nanocube sensors

1] Howard Hughes Medical Institute, University of California, Berkeley, California, USA. [2] Department of Chemistry, University of California, Berkeley, California, USA. [3] Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA.
Nature Methods (Impact Factor: 32.07). 10/2012; 9(12). DOI: 10.1038/nmeth.2211
Source: PubMed

ABSTRACT

We describe a solution-phase sensor of lipid-protein binding based on localized surface plasmon resonance (LSPR) of silver nanocubes. When silica-coated nanocubes are mixed in a suspension of lipid vesicles, supported membranes spontaneously assemble on their surfaces. Using a standard laboratory spectrophotometer, we calibrated the LSPR peak shift due to protein binding to the membrane surface and then characterized the lipid-binding specificity of a pleckstrin homology domain protein.

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    • "In addition to SPR, plasmonic biosensing can be accomplished by localized surface plasmon resonance (LSPR) and extraordinary optical transmission (EOT). In LSPR, the electric field near metal nanoparticles is amplified resulting in strong scattering spectra ideal for applications in protein biosensing (Anker et al., 2008; Baciu et al., 2008; Wu et al., 2012 ). Unlike SPR, which uses a metallic thin film and prism system, LSPR does not require a complex system in order to couple the light source to the metal dielectric interface (Haes and Van Duyne, 2004). "
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    • "In waveguide interferometer sensors, where the detection signal is typically a change in optical power, an increase in power results in an improved signal-to-noise ratio [18]. In surface plasmon or resonant cavity based sensors, an increase in power corresponds to a narrower resonance linewidth, improving the resolution of the measurement [6]. Therefore, it is critical that the surface functionalization does not decrease the optical power confined within the device. "
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