Single plasmonic nanoparticle tracking studies of solid supported bilayers with ganglioside lipids.

Single-particle tracking experiments were carried out with gold nanoparticle-labeled solid supported lipid bilayers (SLBs) containing increasing concentrations of ganglioside (GM(1)). The negatively charged nanoparticles electrostatically associate with a small percentage of positively charged lipids (ethyl phosphatidylcholine) in the bilayers. The samples containing no GM(1) show random diffusion in 92% of the particles examined with a diffusion constant of 4.

Gas sensing with high-resolution localized surface plasmon resonance spectroscopy.

We report the first inert gas sensing and characterization studies based on high-resolution localized surface plasmon resonance (HR-LSPR) spectroscopy. HR-LSPR was used to detect the extremely small changes (<3 × 10(-4)) in bulk refractive index when the gas was switched between He(g) and Ar(g) or He(g) and N2(g). We also demonstrate submonolayer sensitivity to adsorbed water from exposure of the sensor to air (40% humidity) versus dry N2(g).

LSPR Imaging: Simultaneous Single Nanoparticle Spectroscopy and Diffusional Dynamics.

A wide-field localized surface plasmon resonance (LSPR) imaging method using a liquid crystal tunable filter (LCTF) is used to measure the scattering spectra of multiple Ag nanoparticles in parallel. This method provides the ability to characterize moving Ag nanoparticles by measuring the scattering spectra of the particles while simultaneously tracking their motion. Consequently, single particle diffusion coefficients can be determined.

Bipolar electrochemical mechanism for the propulsion of catalytic nanomotors in hydrogen peroxide solutions.

Bimetallic nanorods are propelled in aqueous solutions by the catalytic decomposition of hydrogen peroxide to oxygen and water. Several mechanisms (interfacial tension gradients, bubble recoil, viscous Brownian ratchet, self-electrophoresis) have been proposed for the transduction of chemical to mechanical energy in this system. From Tafel plots of anodic and cathodic hydrogen peroxide reactions at various metal (Au, Pt, Rh, Ni, Ru, and Pd) ultramicroelectrodes, we determine the potential at which the anodic and cathodic reaction rates are equal for each metal.