抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1（PfPMP1）与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员，通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

疟原虫var基因转换速率变化导致抗原变异[英]／Paul H, Robert P, Christodoulou Z, et al//Proc Natl Acad Sci U S A

Surface plasmons are waves that propagate along the surface of a conductor. By altering the structure of a metal's surface, the properties of surface plasmons--in particular their interaction with light--can be tailored, which offers the potential for developing new types of photonic device. This could lead to miniaturized photonic circuits with length scales that are much smaller than those currently achieved. Surface plasmons are being explored for their potential in subwavelength optics, data storage, light generation, microscopy and bio-photonics.

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Surface plasmon subwavelength optics

The emerging field of plasmonics has yielded methods for guiding and localizing light at the nanoscale, well below the scale of the wavelength of light in free space. Now plasmonics researchers are turning their attention to photovoltaics, where design approaches based on plasmonics can be used to improve absorption in photovoltaic devices, permitting a considerable reduction in the physical thickness of solar photovoltaic absorber layers, and yielding new options for solar-cell design. In this review, we survey recent advances at the intersection of plasmonics and photovoltaics and offer an outlook on the future of solar cells based on these principles.

Plasmonics for improved photovoltaic devices

Nanocrystals are fundamental to modern science and technology. Mastery over the shape of a nanocrystal enables control of its properties and enhancement of its usefulness for a given application. Our aim is to present a comprehensive review of current research activities that center on the shape-controlled synthesis of metal nanocrystals. We begin with a brief introduction to nucleation and growth within the context of metal nanocrystal synthesis, followed by a discussion of the possible shapes that a metal nanocrystal might take under different conditions. We then focus on a variety of experimental parameters that have been explored to manipulate the nucleation and growth of metal nanocrystals in solution-phase syntheses in an effort to generate specific shapes. We then elaborate on these approaches by selecting examples in which there is already reasonable understanding for the observed shape control or at least the protocols have proven to be reproducible and controllable. Finally, we highlight a number of applications that have been enabled and/or enhanced by the shape-controlled synthesis of metal nanocrystals. We conclude this article with personal perspectives on the directions toward which future research in this field might take.

Shape‐Controlled Synthesis of Metal Nanocrystals: Simple Chemistry Meets Complex Physics?

The unprecedented ability of nanometallic (that is, plasmonic) structures to concentrate light into deep-subwavelength volumes has propelled their use in a vast array of nanophotonics technologies and research endeavours. Plasmonic light concentrators can elegantly interface diffraction-limited dielectric optical components with nanophotonic structures. Passive and active plasmonic devices provide new pathways to generate, guide, modulate and detect light with structures that are similar in size to state-of-the-art electronic devices. With the ability to produce highly confined optical fields, the conventional rules for light-matter interactions need to be re-examined, and researchers are venturing into new regimes of optical physics. In this review we will discuss the basic concepts behind plasmonics-enabled light concentration and manipulation, make an attempt to capture the wide range of activities and excitement in this area, and speculate on possible future directions.

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Plasmonics for extreme light concentration and manipulation.

Keywords: Nanophotonics ; Plasmonics Reference EPFL-CONF-217139 Record created on 2016-03-07, modified on 2017-05-10

Second harmonic generation from realistic plasmonic nanoantennas and Fano metamolecules

Sub-10 nm gap plasmonic gratings are experimentally studied for second harmonic generation (SHG) and a model is developed to explain the optimum in transmitted SHG, showing the interplay between the grating width and field enhancement.

Surface second harmonic generation from sub-10 nm gap plasmonic gratings

We study the optical forces in plasmonic systems and show how they depend on the metals used in the experiment. The incorporation of plasmonic traps in a microfluidic environment provides new functionalities for lab-on-the-chip applications.

Plasmonic trapping for nanoscale analysis in lab-on-the-chip applications

In this presentation, second harmonic generation from realistic plasmonic nanoantennas and metamolecules will be discussed. The role played by the nanostructure shape and the enhancement of second harmonic generation using Fano resonances will be emphasized.

Second Harmonic Generation from Realistic Plasmonic Nanoantennas and Fano Metamolecules

The material and exact shape of a nanostructure determine its optical response, which is especially strong for plasmonic metals. Unfortunately, only a very few plasmonic metals are available, which limits the spectral range where these strong optical effects can be utilized. Alloying different plasmonic metals can overcome this limitation, at the expense of using a high temperature alloying process, which adversely destroys the nanostructure shape. Here, we develop a low temperature alloying process at only 300°C and fabricate Au-Ag nanostructures with a broad diversity of shapes, aspect ratios and stoichiometries. EDX and XPS analyses confirm the homogeneous alloying through the entire sample. Varying the alloy stoichiometry tunes the optical response of the nanostructure and controls spectral features such as Fano resonances. Binary metasurfaces that combine nanostructures with different stoichiometries are fabricated using multiple-step electron beam lithography, and their optical function as hologram or Fresnel zone plate is demonstrated at the visible wavelength of 532 nm. This low temperature annealing technique provides a versatile and cost-effective way of fabricating complex Au-Ag nanostructures with arbitrary stoichiometry.

Olivier J. F. Martin

Papers

Second harmonic generation from realistic plasmonic nanoantennas and Fano metamolecules

Surface second harmonic generation from sub-10 nm gap plasmonic gratings

Plasmonic trapping for nanoscale analysis in lab-on-the-chip applications

Second Harmonic Generation from Realistic Plasmonic Nanoantennas and Fano Metamolecules

Low temperature annealing method for fabricating alloy nanostructures and metasurfaces: Unlocking a novel degree of freedom