Calibration of dynamic molecular rule based on plasmon coupling between gold nanoparticles

Physics Department, Biophysics Graduate Program, and Chemistry Department, University of California, Berkeley, California 94720, USA.
Nano Letters (Impact Factor: 12.94). 12/2005; 5(11):2246-52. DOI: 10.1021/nl051592s
Source: PubMed

ABSTRACT Pairs of noble metal nanoparticles can be used to measure distances via the distance dependence of their plasmon coupling. These "plasmon rulers" offer exceptional photostability and brightness; however, the advantages and limitations of this approach remain to be explored. Here we report detailed plasmon peak versus separation calibration curves for 42- and 87-nm-diameter particle pairs, determine their measurement errors, and describe experimental procedures to improve their performance in biology, nanotechnology, and materials sciences.

  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: tA simple method for creating three-dimensional porous wurtzite CdSe films incorporated with plasmonicgold by the electrochemical layer-by-layer assembly was proposed. A prominent enhancement in lightabsorption of CdSe films was attained by the efficient light scattering of gold plasmons as sub-wavelengthantennas and concentrators and the near-field coupling of gold plasmons with the neighboring porousCdSe films. The broadband photocurrent enhancement of Au–CdSe composite systems in the visible lightrange and the local current maximum between 600 and 700 nm suggested the cooperative action ofantenna effects and electromagnetic field enhancement resulting from localized surface plasmon exci-tation of gold. Furthermore, the photoelectrochemical response of porous Au–CdSe composite films washighly tunable with respect to the number of Au–CdSe bilayer. The optimal short-circuit current andopen-circuit potential were obtained in a four-layer Au–CdSe system because the thicker absorber layerwith less porous structure might limit the electrolyte diffusion into the hybrid electrode and impose abarrier for electron tunneling and transferring. The highly versatile and tunable properties of assembledporous Au–CdSe composite films demonstrated their potential application in energy conversion devices.© 2013 Elsevier Ltd. All rights
    Electrochimica Acta 10/2013; 108:680-689. DOI:10.1016/j.electacta.2013.07.019 · 4.09 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Live cell imaging using metallic nanoparticles as tags is an emerging technique to visualize long and highly dynamic processes due to the lack of photobleaching and high photon rate. However, the lack of excited states as compared to fluorescent dyes prevents the use of resonance energy transfer and recently developed super resolution methods to measure distances between objects closer that the resolution limit. In this work, we experimentally demonstrate a technique to determine subdiffraction distances based on the near field coupling of metallic nanoparticles. Due to the symmetry breaking in the scattering cross section, not only distances but also relative orientations can be measured. Gold nanoparticles were prepared on glass in such way that a small fraction of dimers was present. The sample was sequentially illuminated with two wavelengths to separate background from nanoparticle scattering based on their spectral properties. A novel total internal reflection illumination scheme in which the polarization can be rotated was used to further minimize background contributions. In this way, radii, distance and orientation were measured for each individual dimer and their statistical distributions were found to be in agreement with the expected ones. We envision that this technique will allow fast and long term tracking of relative distance and orientation in biological processes.
    01/2011; DOI:10.4279/pip.020010
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Biomolecular motors are central to the function and regulation of all cellular transport systems. The molecular mechanisms by which motors generate force and motion along cytoskeletal filaments have been mostly studied in vitro using a variety of approaches, including several single-molecule techniques. While such studies have revealed significant insights into the chemomechanical transduction mechanisms of motors, important questions remain unanswered as to how motors work in cells. To understand how motor activity is regulated and how motors orchestrate the transport of specific cargoes to the proper subcellular domain requires analysis of motor function in vivo. Many transport processes in cells are believed to be powered by single or very few motor molecules, which makes it essential to track, in real time and with nanometer resolution, individual motors and their associated cargoes and tracks. Here we summarize, contrast, and compare recent methodological advances, many relying on advanced fluorescent labeling, genetic tagging, and imaging techniques, that lay the foundation for groundbreaking approaches and discoveries. In addition, to illustrate the impact and capabilities for these methods, we highlight novel biological findings where appropriate.
    Methods in enzymology 01/2010; 475:81-107. DOI:10.1016/S0076-6879(10)75004-7 · 2.19 Impact Factor


Available from