内容详细
  • 王建方教授、Paul Ashby研究员学术交流会
  • 发布时间:2011-08-03 点击次数:1
  • 很高兴邀请到香港中文大学的王建方教授和美国Lawrence Berkeley National Lab

    Paul Ashby研究员来我所访问并作学术报告。学术报告时间是56日,本周五早上

    911点, 地点A718,请大家踊跃参加。

     

    学术报告一:Plasmonic Gold Nanocrystals and Related Nanostructures

     

    Jianfang Wang

     

    Department of Physics, The Chinese University of Hong Kong

     

    Abstract:  The localized plasmon resonances of noble metal nanocrystals

    have found applications in a wide range of areas, such as imaging,

    sensing, nanomedicine (photothermal therapy and controlled drug delivery),

    enhancement of linear and nonlinear optical signals (Raman, fluorescence,

    high-harmonic, solar energy harvesting, two-photon excitation,

    photolithography, and upconversion), optics and optoelectronics

    (subwavelength waveguiding, photoswitching, optical data storage, spasers,

    optical tweezers, and metamaterials), and catalysis. Gold nanocrystals are

    chemically stable, biologically compatible, and exhibit extraordinary

    plasmonic properties. I will describe our synthetic control of the

    plasmonic properties of gold nanocrystals, construction of gold

    nanocrystal-based hybrid nanostructures containing semiconductors or other

    metals. I will also describe our work on the interactions between the

    localized plasmon resonances and the fluorescence process.

     

    学术报告二:Toward Capturing Membrane Protein Dynamics with the Fiber

    Force Probe

     

    Paul Ashby 简介:Paul Ashby started his scientific career at Westmont

    College in California by majoring in chemistry. Subsequently, he went to

    Harvard and joined the group of Charlie Lieber. There he investigated

    intermolecular and surface forces by developing new techniques such as

    Brownian Force Profile Reconstruction and Energy Dissipation Chemical

    Force Microscopy. He then went to the Molecular Foundry at Lawrence

    Berkeley National Lab where, as a postdoc, he continued to probe a variety

    of interfacial chemistry and mechanical properties such as the atmospheric

    chemistry of sea salt aerosols and the influence of extracellular matrix

    elasticity on tissue vitality. Since becoming a staff scientist at the

    Molecular Foundry he has worked to understand membrane protein function by

    imaging the cell surface with high resolution. Today he will share his

    efforts Towards Capturing Membrane Protein Dynamics with the Fiber Force

    Probe.

     

    Abstract Living cells readily deform under the minimum force required to

    perform an AFM measurement precluding the imaging of membrane protein

    complexes.  Attempts to use feedback methods such as Q-control have failed

    to improve the image quality. I will discuss why Q-control does not

    provide an advantage for imaging in solution.1  Instead, the thermal

    force-noise of the cantilever is the principal limitation to reducing

    sample deformation.  Minimizing a cantilever''s cross- section reduces its

    noise significantly and the minimum size of the cantilever is currently

    limited by a conventional deflection detection scheme, which requires a

    large surface area for laser specular reflection. I will present an

    optical deflection detection technique enabling the use of nanowires as

    cantilevers and show that we achieve a force noise in water that is orders

    of magnitude gentler than conventional AFM. This is a significant

    milestone towards non-invasive scanning probe imaging of biological

    processes on the surfaces of vesicles and cell membranes.2 Lastly, I will

    discuss our use of alternative scan algorithms and data processing for

    high-speed imaging and the capture of protein dynamics.