- 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
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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的
Paul Ashby研究员来我所访问并作学术报告。学术报告时间是5月6日,本周五早上
9-11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.
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