我们还要感谢小玉苗和Ben威尔逊发展的最内所述的方法。这项工作是由国家科学基金会（DBI 0454324）和国家卫生研究所（R21 EB005183）和ECK NIGMS小灵通NRSA的T32 GM07270。

1。随机的Au纳米粒子阵列的制备 8,10,12,14 <ol><li>首先创建一个模板，是一个随机吸附乳胶球，平均直径454纳米的致密层形成的Au纳米粒子阵列。这是通过首先蒸发20铬纳米粘附层的厚度玻璃盖玻片黄金。 </li><li>聚苯乙烯球暴露镀金基板的混合物，然后自组装单层是1 - 乙基-3 - （3 - dimethylaminopropyl）碳二亚胺盐酸盐（EDC），乳胶球体悬浮液和去离子水。 </li><li>吸附过程是可以持续约一小时，非吸收的领域是用大量清水冲洗带走。 </li><li>形成单层允许空气干燥。 </li><li>最后，20纳米的黄金蒸发乳胶球单层形成随机的黄金纳米粒子阵列。 </li><li>如果SEM是可用的，可以看到金纳米粒子阵列，根据教育统筹局局长，看起来像图1的流程图如图8所示。 </li></ol> 2。生物样品制备9,11 <ol><li>现在显示样品准备，为光学诱捕鼠标细胞核。 </li><li>吖啶橙染料标记3T3老鼠细胞的细胞核，得到的弗雷德哈钦森癌症研究中心的Tewari组。 </li><li> 10％的牛血清白蛋白（BSA）的磷酸盐缓冲液（PBS）被添加到小鼠细胞细胞核中的浓度约1:10（BSA:鼠标细胞核）。 BSA有助于防止粘基材的原子核。 </li><li>使用超声混合的解决方案。 </li><li> 5 UL是我们的解决方案上沉积的铝光栅阵列盖玻片。这是更好地执行这一步显微镜舞台上的铝光栅，使你不必运输样品后的解决办法是存入。 </li><li>两个堆栈的两个1"1"盖玻片用于支持通过查看该样本第五盖玻片。 </li><li>样品放置在显微镜下观看。 </li></ol> 3。诱捕方法<ol><li>通过发送通过蔡司Axio上Imager.D1M的一个35兆瓦的氦氖激光与GFP的修改，以允许为633纳米的激光辐射到达样本的17个过滤器设置配备光学镊子的构造。 </li><li>蔡司LD EC Epiplan - NEOFLUAR 50X的目标是用形象是直径约5微米的细胞核。 </li><li>后样品是根据客观的，重点的黄金纳米粒子阵列或光栅显微镜。 </li><li>直到实现你的愿望陷阱原子核的重点是垂直翻译显微镜。 </li><li>激光对粒子和粒子陷阱当场位置应保持其在激光光斑的位置，甚至当舞台翻译。 </li></ol> 4。代表性的成果: 随机的黄金纳米粒子阵列的程序应存款，可在一个扫描电镜看类似于图1的金纳米粒子的单层。这些电浆镊子创建的捕获力可以由标准的光镊产生的力量的10-20倍。电浆镊子所需的最低强度，实现粒子约束为不同大小的颗粒在图4所示。9,10光栅实现20倍更高的捕集效率的路线和诱捕比黄金纳米点，并可以实现诱捕少17 UW / UM 2（图7）11。 <img alt="图1" src="/files/ftp_upload/3390/3390fig1.jpg" /> 图1 10（一）自组装金纳米粒子形貌的扫描电镜。个别的黄金纳米粒子的直径约450纳米。 （二）纳米粒子的分布稀疏的电浆基板的NSOM的形象，显示了近场辐射。激发激光的波长为633纳米。 （C）（b）中红色正方形的面积高倍镜视野。 （四）电浆基板的散射频谱效率，在624纳米的高峰期。 （E）的吸收效率的电浆基板频谱，显示在668纳米的高峰。 <img alt="图2" src="/files/ftp_upload/3390/3390fig2.jpg" /> 图2 13（一）金微球随机分布在2D域1 × 1 微米 2。每个蓝点代表（A = 60 nm）的纳米微球的中心。观察平面平行随机纳米球阵列的散射场分布在（b） - （E）。由平面波的波长为540 nm的纳米球阵列均匀照明。周围介质的折射率为1.33。 "波拉rization方向沿X轴（横（一））平面波点。事件电场的幅度是假设在计算1。观察平面和纳米球阵列之间的分离是定义为H. B）H =一个 。 C）H = 2A。 D）H =λ。 E）H =2λ。 <img alt="图3" src="/files/ftp_upload/3390/3390fig3.jpg" /> 图3 9定制的荧光显微镜的配置，包括一个绕过激发滤光片和取代分色光束分离器的原理图。这是同时诱捕和荧光成像使用的配置。 <img alt="图4" src="/files/ftp_upload/3390/3390fig4.jpg" /> 图4 10最小的激光强度，保持利用电浆诱捕周围流体的流动速度的函数的陷阱。所有的光信号强度测量样品在显微镜下的目标平面。 （一） - （F）显示为单一的聚苯乙烯微球的直径为7.3，6.3（非球面），5.0，3.9，2.5和1.1微米的测量结果分别。插图显示了相应的颗粒显微图像。所有图像比例尺代表长度在5微米。 <img alt="图5" src="/files/ftp_upload/3390/3390fig5.jpg" /> 图5 10通过拟合线图来源的斜率。 4与粒径电浆诱捕。误差线显示线性拟合的标准偏差。拟合直线的斜率（光的强度阈值和流量之间的比例）图。 4颗粒大小约如本图所示的线性关系，表明优势，尤其是更小的粒子的电浆诱捕。 <img alt="图6" src="/files/ftp_upload/3390/3390fig6.jpg" /> 图6月11日 （一）增强光学诱捕利用一维周期性纳米结构的示意图。入射光是由周期性纳米结构在远场的衍射。 （二）与两个正交极化纳米结构在远场光强度分布。 （二）使用的FDTD模拟得到一个417纳米的铝光栅表面的两个正交偏振的光强度分布。分布在平坦的铝表面强度归。 （c）项和（d）为（c）在350 nm的聚苯乙烯珠和（d）在1微米的聚苯乙烯珠颗粒直接光栅表面对粒子的位置以上的套印潜力。白色圆圈说明粒子的大小。插图显示了相同的粒子的大小作为比较平坦的铝表面以上的诱捕潜力。每个粒子的大小值正常化。对于所有FDTD模拟数字视场为10 × 8微米2。 <img alt="图7" src="/files/ftp_upload/3390/3390fig7.jpg" /> 图7月11日 （一）陷阱效率和最小捕获强度与偏振垂直于光栅线各种大小的聚苯乙烯珠测量。陷阱插图不对称捕集效率转换为一个3.87微米的聚苯乙烯珠垂直与平行光栅规则。实线（大不对称）获得与入射光偏振垂直的光栅，虚线（小不对称）与入射光的偏振平行光栅获得。单位为（PN [MW /微米2] -1）。 （二） - （四）有荧光590 nm的聚苯乙烯珠补漏示范。红色圆圈表示的激光光斑的位置，激光灯太暗可见。起初粒子被困在现场，在更高的功率，电源降低克服阱力的粒子的布朗运动，让粒子逃脱。 （E） - （G）的一个荧光卵巢癌的细胞核补漏示范。启动诱捕所需的最低强度16μW/ 2微米获得使用20X物镜。 <img alt="图8" src="/files/ftp_upload/3390/3390fig8.jpg" /> 图8月14日的帽形的黄金纳米粒子的制备过程:蒸发的Cr和非盟的玻璃盖玻片上薄薄的一层）。 B）暴露1小时领域的聚苯乙烯球悬挂和吸附。 C）拆除非吸附聚苯乙烯球和表面干燥。 D）模板领域上的另一个金层的蒸发。 E）示意图帽状纳米金阵列，其中坳只涵盖模板球顶偏。

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没有利益冲突的声明。

诱捕这些方法的意义是，他们10μW/ 2微米的顺序 10 3 /μW的2微米到某处为了减少光的强度从某处持续诱捕所必需的。 10,11对这些技术的局限性黄金纳米粒子阵列经验暖气，必须克服的问题。为了克服这个问题，一个是电介质材料组成的二维光子晶体结构可以使用。这种结构在理论上可以产生在低光的强度和控制诱捕微型和纳米粒子在精确地控制输入偏振的旋转和位?...

<table border="1"><tr><td>材料名称</td><td>类型</td><td>公司</td><td>产品编号</td><td>评论</td></tr><tr><td> Axio上成像仪显微镜</td><td> D1M </td><td>蔡司</td><td> D1M </td><td>蔡司Axio上Imager.D1M </td></tr><tr><td>显微镜物镜</td><td> 50x/0.55 </td><td>蔡司</td><td></td><td> LD欧共体Epiplan - NEOFLUAR 50x/0.55高清DIC的</td></tr><tr><td>蔡司显微镜摄像机</td><td> AxioCam MRC </td><td>蔡司</td><td></td><td></td></tr><tr><td>氦氖激光器</td><td> 35兆瓦</td><td>研究光电</td><td></td><td></td></tr><tr><td>可变衰减器</td><td>连续可变ND </td><td> ThorLabs </td><td> NDC - 100C - 4M </td><td>对于调整显微镜强度</td></tr><tr><td>蔡司过滤器集</td><td>过滤器设置＃17 </td><td>蔡司</td><td> 488017-9901-000 </td><td>过滤器设置＃17 </td></tr><tr><td>显微镜载玻片</td><td>厚度为0.5毫米</td><td> VWR </td><td></td><td></td></tr><tr><td> 3T3小鼠细胞的细胞核</td><td></td><td colspan="2">弗雷德哈钦森癌症研究中心</td><td>存储为尽可能冷</td></tr><tr><td>吖啶橙染料</td><td></td><td colspan="2">弗雷德哈钦森癌症研究中心</td><td></td></tr><tr><td>牛血清白蛋白</td><td> 1到10的PBS的口粮</td><td colspan="2">弗雷德哈钦森癌症研究中心</td><td></td></tr><tr><td> 454 nm的聚苯乙烯乳胶球</td><td></td><td> Polysciences，公司</td><td></td><td></td></tr><tr><td>碳二亚胺盐酸盐（EDC） </td><td> 1 - 乙基-3 - （3 - dimethylaminopropyl） </td><td> G - Biosciences公司</td><td> BC25 - 1 </td><td></td></tr><tr><td>金（沉积） </td><td></td><td></td><td></td><td></td></tr><tr><td>反光裁定光栅</td><td></td><td>埃德蒙光学</td><td></td><td></td></tr><tr><td>磷酸盐缓冲液（PBS） </td><td>贝科的磷酸盐缓冲液（D - PBS）（1X） </td><td> Invitrogen公司</td><td> 14190-144 </td><td></td></tr></table>

utilization of plasmonic and photonic crystal nanostructures for enhanced micro- and nanoparticle manipulation

非破坏性的方法来操纵亚微米粒子的位置和方向将基础生物学研究的一个非常有用的工具。也许使用最广泛的物质力量来实现小颗粒的无创性操作已介（DEP）[1]然而，对自己的DEP缺乏通用性和精度，操作时所需的细胞，因为它是传统与固定电极。光镊，利用一个三维电磁场梯度小颗粒施加的力量，实现这一目标所需的通用性和精度。然而，这种方法的主要缺点是需要达到必要的武力来捕获一个粒子的辐射强度高可以破坏生物样品可诱捕和较低的光强度排序的解决方案光电镊子（OET），但OET的有小颗粒的精细操纵限制;。。被DEP的，基于技术，也使该解决方案的财产约束4 5 此视频文章将介绍两种方法，减少光学操纵活细胞所需的辐射强度，还描述了定向控制方法。第一种方法是使用一个随机的黄金纳米粒子（金纳米粒子）阵列，如图1所示样品基板电浆镊子。金纳米粒子阵列转换成本地化的表面等离子体（LSP），包括谐振偶极矩的事件光子辐射和产生的细胞液中的一个大梯度与图案的辐射场。表面等离子体增强诱捕Righini等和我们自己的造型的初步工作表明电浆基板所产生的领域，减少所需的初始强度，提高梯度场的粒子陷阱。6,7,8电浆方法允许罚款由于更高效的光能量转换成机械能和依赖偶极子辐射场的低光信号强度的椭球颗粒与细胞的定向控制。这些领域都显示在图2和图4和5中详细诱捕强度低。电浆镊子的主要问题是，LSP的产生大量的热量和诱捕只有二维。这种热产生对流流动和热泳可以强大到足以驱逐从陷阱的亚微米颗粒。9,10，我们将介绍第二种方法是利用周期性的电介质纳米结构非常有效地散射入射光成衍射模式，如图6所示11，理想的情况下，人会做出这种结构，电介质材料与电浆镊子，以避免相同的加热遇到的问题，但我们的做法镀铝光栅是作为一维周期介质纳米结构。虽然它不是一个半导体，它没有显著暖气经验和有效被困诱捕强度低的小颗粒，如图7所示。对准光栅基板的粒子概念验证的命题，一个2 - D光子晶体可以允许非球面微米大小的粒子的精确旋转10这些光学陷阱的效率增加，由于在纳米结构制作的增强的领域。本文。

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Utilization of Plasmonic and Photonic Crystal Nanostructures for Enhanced Micro- and Nanoparticle Manipulation

电浆镊子和光子晶体纳米结构的光学诱捕微型和纳米粒子的生产效率和方向的控制非常有用的增强。

为增强微型和纳米操纵利用电浆和光子晶体纳米结构

A method to manipulate the position and orientation of submicron particles nondestructively would be an incredibly useful tool for basic biological ...

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JoVE Journal

Bioengineering

12.2K 次观看.  University of Washington. 电浆镊子和光子晶体纳米结构的光学诱捕微型和纳米粒子的生产效率和方向的控制非常有用的增强。

视频: Utilization of Plasmonic and Photonic Crystal Nanostructures for Enhanced Micro- and Nanoparticle Manipulation

Evaluating Plasmonic Transport in Current-carrying Silver Nanowires

Plasmonics is an emerging technology capable of simultaneously transporting a plasmonic signal and an electronic signal on the same information support1,2,3. In this context, metal nanowires are especially desirable for realizing dense routing networks4. A prerequisite to operate such shared nanowire-based platform relies on our ability to electrically contact individual metal nanowires and efficiently excite surface plasmon polaritons5 in this information support. In this article, we describe a protocol to bring electrical terminals to chemically-synthesized silver nanowires6 randomly distributed on a glass substrate7. The positions of the nanowire ends with respect to predefined landmarks are precisely located using standard optical transmission microscopy before encapsulation in an electron-sensitive resist. Trenches representing the electrode layout are subsequently designed by electron-beam lithography. Metal electrodes are then fabricated by thermally evaporating a Cr/Au layer followed by a chemical lift-off. The contacted silver nanowires are finally transferred to a leakage radiation microscope for surface plasmon excitation and characterization8,9. Surface plasmons are launched in the nanowires by focusing a near infrared laser beam on a diffraction-limited spot overlapping one nanowire extremity5,9. For sufficiently large nanowires, the surface plasmon mode leaks into the glass substrate9,10. This leakage radiation is readily detected, imaged, and analyzed in the different conjugate planes in leakage radiation microscopy9,11. The electrical terminals do not affect the plasmon propagation. However, a current-induced morphological deterioration of the nanowire drastically degrades the flow of surface plasmons. The combination of surface plasmon leakage radiation microscopy with a simultaneous analysis of the nanowire electrical transport characteristics reveals the intrinsic limitations of such plasmonic circuitry.

Silver nanowires can simultaneously transport electrons and optical information in the form of surface plasmons. A procedure is described here to realize such a shared circuitry and the limitations at propagating both information carriers are evaluated.

Plasmonics is an emerging technology capable of simultaneously transporting a plasmonic signal and an electronic signal on the same information ...

科研

工程学

Synthesis of Immunotargeted Magneto-plasmonic Nanoclusters

Magnetic and plasmonic properties combined in a single nanoparticle provide a synergy that is advantageous in a number of biomedical applications including contrast enhancement in novel magnetomotive imaging modalities, simultaneous capture&#160;and detection of circulating tumor cells (CTCs),&#160;and multimodal molecular imaging combined with photothermal therapy of cancer cells. These applications have stimulated significant interest in development of protocols for synthesis of magneto-plasmonic nanoparticles with optical absorbance in the near-infrared (NIR) region and a strong magnetic moment. Here, we present a novel protocol for synthesis of such hybrid nanoparticles that is based on an oil-in-water microemulsion method. The unique feature of the protocol described herein is synthesis of magneto-plasmonic nanoparticles of various sizes from primary blocks which also have magneto-plasmonic characteristics. This approach yields nanoparticles with a high density of magnetic and plasmonic functionalities which are uniformly distributed throughout the nanoparticle volume. The hybrid nanoparticles can be easily functionalized by attaching antibodies through the Fc moiety leaving the Fab portion that is responsible for antigen binding available for targeting.

Here, we describe a protocol for synthesis of magneto-plasmonic nanoparticles with a strong magnetic moment and a strong near-infrared (NIR) absorbance. The protocol also includes antibody conjugation to the nanoparticles through the Fc moiety for various biomedical applications which require molecular specific targeting.

Immunotargeted的合成磁等离子团簇

Magnetic and plasmonic properties combined in a single nanoparticle provide a synergy that is advantageous in a number of biomedical applications ...

化学

Fabrication and Operation of a Nano-Optical Conveyor Belt

The technique of using focused laser beams to trap and exert forces on small particles has enabled many pivotal discoveries in the nanoscale biological and physical sciences over the past few decades. The progress made in this field invites further study of even smaller systems and at a larger scale, with tools that could be distributed more easily and made more widely available. Unfortunately, the fundamental laws of diffraction limit the minimum size of the focal spot of a laser beam, which makes particles smaller than a half-wavelength in diameter hard to trap and generally prevents an operator from discriminating between particles which are closer together than one half-wavelength. This precludes the optical manipulation of many closely-spaced nanoparticles and&#160;limits the&#160;resolution of optical-mechanical systems. Furthermore, manipulation using focused beams requires beam-forming or steering optics, which can be very bulky and expensive. To address these limitations in the system scalability of conventional optical trapping our lab has devised an alternative technique which utilizes near-field optics to move particles across a chip. Instead of focusing laser beams in the far-field, the optical near field of plasmonic resonators produces the necessary local optical intensity enhancement to overcome the restrictions of diffraction and manipulate particles at higher resolution. Closely-spaced resonators produce strong optical traps which can be addressed to mediate the hand-off of particles from one to the next in a conveyor-belt-like fashion. Here, we describe how to design and produce a conveyor belt using a gold surface patterned with plasmonic C-shaped resonators and how to operate it with polarized laser light to achieve super-resolution nanoparticle manipulation and transport. The nano-optical conveyor belt chip can be produced using lithography techniques and easily packaged and distributed.

The scalability and resolution of conventional optical manipulation techniques are limited by diffraction. We circumvent the diffraction limit and describe a method of optically transporting nanoparticles across a chip using a gold surface patterned with a path of closely spaced C-shaped plasmonic resonators.

一个纳米光输送带的制作和操作

The technique of using focused laser beams to trap and exert forces on small particles has enabled many pivotal discoveries in the nanoscale biological ...

Measurement of Scattering Nonlinearities from a Single Plasmonic Nanoparticle

Plasmonics, which are based on the collective oscillation of electrons due to light excitation, involve strongly enhanced local electric fields and thus have potential applications in nonlinear optics, which requires extraordinary optical intensity. One of the most studied nonlinearities in plasmonics is nonlinear absorption, including saturation and reverse saturation behaviors. Although scattering and absorption in nanoparticles are closely correlated by the Mie theory, there has been no report of nonlinearities in plasmonic scattering until very recently. 
Last year, not only saturation, but also reverse saturation of scattering in an isolated plasmonic particle was demonstrated for the first time. The results showed that saturable scattering exhibits clear wavelength dependence, which seems to be directly linked to the localized surface plasmon resonance (LSPR). Combined with the intensity-dependent measurements, the results suggest the possibility of a common mechanism underlying the nonlinear behaviors of scattering and absorption. These nonlinearities of scattering from a single gold nanosphere (GNS) are widely applicable, including in super-resolution microscopy and optical switches. 
In this paper, it is described in detail how to measure nonlinearity of scattering in a single GNP and how to employ the super-resolution technique to enhance the optical imaging resolution based on saturable scattering. This discovery features the first super-resolution microscopy based on nonlinear scattering, which is a novel non-bleaching contrast method that can achieve a resolution as low as l/8 and will potentially be useful in biomedicine and material studies.

Saturable and reverse saturable scattering were discovered in isolated plasmonic particles and adopted as a novel non-bleaching contrast method in super-resolution microscopy. Here the experimental procedures of detecting and extracting nonlinear scattering are explained in detail, as well as how to enhance resolution with the aid of saturated excitation microscopy.

从单电浆纳米粒子散射非线性测量

Plasmonics, which are based on the collective oscillation of electrons due to light excitation, involve strongly enhanced local electric fields and thus ...

Multifunctional Hybrid Fe2O3-Au Nanoparticles for Efficient Plasmonic Heating

One of the most widely used methods for manufacturing colloidal gold nanospherical particles involves the reduction of chloroauric acid (HAuCl4) to neutral gold Au(0) by reducing agents, such as sodium citrate or sodium borohydride. The extension of this method to decorate iron oxide or similar nanoparticles with gold nanoparticles to create multifunctional hybrid Fe2O3-Au nanoparticles is straightforward. This approach yields fairly good control over Au nanoparticle dimensions and loading onto Fe2O3. Additionally, the Au metal size, shape, and loading can easily be tuned by changing experimental parameters (e.g., reactant concentrations, reducing agents, surfactants, etc.). An advantage of this procedure is that the reaction can be done in air or water, and, in principle, is amenable to scaling up. The use of such optically tunable Fe2O3-Au nanoparticles for hyperthermia studies is an attractive option as it capitalizes on plasmonic heating of gold nanoparticles tuned to absorb light strongly in the VIS-NIR region. In addition to its plasmonic effects, nanoscale Au provides a unique surface for interesting chemistries and catalysis. The Fe2O3 material provides additional functionality due to its magnetic property. For example, an external magnetic field could be used to collect and recycle the hybrid Fe2O3-Au nanoparticles after a catalytic experiment, or alternatively, the magnetic Fe2O3 can be used for hyperthermia studies through magnetic heat induction. The photothermal experiment described in this report measures bulk temperature change and nanoparticle solution mass loss as functions of time using infrared thermocouples and a balance, respectively. The ease of sample preparation and the use of readily available equipment are distinct advantages of this technique. A caveat is that these photothermal measurements assess the bulk solution temperature and not the surface of the nanoparticle where the heat is transduced and the temperature is likely to be higher.

Multifunctional Hybrid Fe2O3-Au Nanoparticles for Efficient Plasmonic Heating

We describe the synthesis and properties of multifunctional Fe2O3-Au nanoparticles produced by a wet chemical approach and investigate their photothermal properties using laser irradiation. The composite Fe2O3-Au nanoparticles retain the properties of both materials, creating a multifunctional structure with excellent magnetic and plasmonic properties.

多功能混合铁<sub&gt; 2</sub&gt; 0<sub&gt; 3</sub&gt; -Au纳米粒子高效的电浆暖气

One of the most widely used methods for manufacturing colloidal gold nanospherical particles involves the reduction of chloroauric acid (HAuCl4) to ...

Colloidal Synthesis of Nanopatch Antennas for Applications in Plasmonics and Nanophotonics

We present a method for colloidal synthesis of silver nanocubes and the use of these in combination with a smooth gold film, to fabricate plasmonic nanoscale patch antennas. This includes a detailed procedure for the fabrication of thin films with a well-controlled thickness over macroscopic areas using layer-by-layer deposition of polyelectrolyte polymers, namely poly(allylamine) hydrochloride (PAH) and polystyrene sulfonate (PSS). These polyelectrolyte spacer layers serve as a dielectric gap in between silver nanocubes and a gold film. By controlling the size of the nanocubes or the gap thickness, the plasmon resonance can be tuned from about 500 nm to 700 nm. Next, we demonstrate how to incorporate organic sulfo-cyanine5 carboxylic acid (Cy5) dye molecules into the dielectric polymer gap region of the nanopatch antennas. Finally, we show greatly enhanced fluorescence of the Cy5 dyes by spectrally matching the plasmon resonance with the excitation energy and the Cy5 absorption peak. The method presented here enables the fabrication of plasmonic nanopatch antennas with well-controlled dimensions utilizing colloidal synthesis and a layer-by-layer dip-coating process with the potential for low cost and large-scale production. These nanopatch antennas hold great promise for practical applications, for example in sensing, ultrafast optoelectronic devices and for high-efficiency photodetectors.

A protocol for the colloidal synthesis of silver nanocubes and fabrication of plasmonic nanoscale patch antennas with sub-10 nm gaps is presented.

在等离子体激元和纳米光子学应用Nanopatch天线的合成胶体

We present a method for colloidal synthesis of silver nanocubes and the use of these in combination with a smooth gold film, to fabricate plasmonic ...

Plasmonic Trapping and Release of Nanoparticles in a Monitoring Environment

Plasmonic tweezers use surface plasmon polaritons to confine polarizable nanoscale objects. Among the various designs of plasmonic tweezers, only a few can observe immobilized particles. Moreover, a limited number of studies have experimentally measured the exertable forces on the particles. The designs can be classified as the protruding nanodisk type or the suppressed nanohole type. For the latter, microscopic observation is extremely challenging. In this paper, a new plasmonic tweezer system is introduced to monitor particles, both in directions parallel and orthogonal to the symmetric axis of a plasmonic nanohole structure. This feature enables us to observe the movement of each particle near the rim of the nanohole. Furthermore, we can quantitatively estimate the maximal trapping forces using a new fluidic channel.

A microchip fabrication process that incorporates plasmonic tweezers is presented here. The microchip enables the imaging of a trapped particle to measure maximal trapping forces.

电浆捕获和纳米粒子的释放在监控环境

Plasmonic tweezers use surface plasmon polaritons to confine polarizable nanoscale objects. Among the various designs of plasmonic tweezers, only a few ...

Fabrication of Periodic Gold Nanocup Arrays Using Colloidal Lithography

Within recent years, the field of plasmonics has exploded as researchers have demonstrated exciting applications related to chemical and optical sensing in combination with new nanofabrication techniques. A plasmon is a quantum of charge density oscillation that lends nanoscale metals such as gold and silver unique optical properties. In particular, gold and silver nanoparticles exhibit localized surface plasmon resonances-collective charge density oscillations on the surface of the nanoparticle-in the visible spectrum. Here, we focus on the fabrication of periodic arrays of anisotropic plasmonic nanostructures. These half-shell (or nanocup) structures can exhibit additional unique light-bending and polarization-dependent optical properties that simple isotropic nanostructures cannot. Researchers are interested in the fabrication of periodic arrays of nanocups for a wide variety of applications such as low-cost optical devices, surface-enhanced Raman scattering, and tamper indication. We present a scalable technique based on colloidal lithography in which it is possible to easily fabricate large periodic arrays of nanocups using spin-coating and self-assembled commercially available polymeric nanospheres. Electron microscopy and optical spectroscopy from the visible to near-infrared (near-IR) was performed to confirm successful nanocup fabrication. We conclude with a demonstration of the transfer of nanocups to a flexible, conformal adhesive film.

We demonstrate the fabrication of periodic gold nanocup arrays using colloidal lithographic techniques and discuss the importance of nanoplasmonic films.

用胶体光刻制备周期性金 Nanocup 阵列

Within recent years, the field of plasmonics has exploded as researchers have demonstrated exciting applications related to chemical and optical sensing ...

Photodeposition of Pd onto Colloidal Au Nanorods by Surface Plasmon Excitation

A protocol is described to photocatalytically guide Pd deposition onto Au nanorods (AuNR) using surface plasmon resonance (SPR). Excited plasmonic hot electrons upon SPR irradiation drive reductive deposition of Pd on colloidal AuNR in the presence of [PdCl4]2-. Plasmon-driven reduction of secondary metals potentiates covalent, sub-wavelength deposition at targeted locations coinciding with electric field &#8220;hot-spots&#8221; of the plasmonic substrate using an external field (e.g., laser). The process described herein details a solution-phase deposition of a catalytically-active noble metal (Pd) from a transition metal halide salt (H2PdCl4) onto aqueously-suspended, anisotropic plasmonic structures (AuNR). The solution-phase process is amenable to making other bimetallic architectures. Transmission UV-vis monitoring of the photochemical reaction, coupled with ex situ XPS and statistical TEM analysis, provide immediate experimental feedback to evaluate properties of the bimetallic structures as they evolve during the photocatalytic reaction. Resonant plasmon irradiation of AuNR in the presence of [PdCl4]2- creates a thin, covalently-bound Pd0 shell without any significant dampening effect on its plasmonic behavior in this representative experiment/batch. Overall, plasmonic photodeposition offers an alternative route for high-volume, economical synthesis of optoelectronic materials with sub-5 nm features (e.g., heterometallic photocatalysts or optoelectronic interconnects).

A protocol for anisotropic photodeposition of Pd onto aqueously-suspended Au nanorods via localized surface plasmon excitation is presented.

通过表面等离子体激发将 Pd 光沉积到胶体 Au 纳米棒上

A protocol is described to photocatalytically guide Pd deposition onto Au nanorods (AuNR) using surface plasmon resonance (SPR). Excited plasmonic hot ...

Preparation of Silver-Palladium Alloyed Nanoparticles for Plasmonic Catalysis under Visible-Light Illumination

Localized surface plasmon resonance (LSPR) in plasmonic nanoparticles (NPs) can accelerate and control the selectivity of a variety of molecular transformations. This opens possibilities for the use of visible or near-IR light as a sustainable input to drive and control reactions when plasmonic nanoparticles supporting LSPR excitation in these ranges are employed as catalysts. Unfortunately, this is not the case for several catalytic metals such as palladium (Pd). One strategy to overcome this limitation is to employ bimetallic NPs containing plasmonic and catalytic metals. In this case, the LSPR excitation in the plasmonic metal can contribute to accelerate and control transformations driven by the catalytic component. The method reported herein focuses on the synthesis of bimetallic silver-palladium (Ag-Pd) NPs supported on ZrO2 (Ag-Pd/ZrO2) that acts as a plasmonic-catalytic system. The NPs were prepared by co-impregnation of corresponding metal precursors on the ZrO2 support followed by simultaneous reduction leading to the formation of bimetallic NPs directly on the ZrO2 support. The Ag-Pd/ZrO2 NPs were then used as plasmonic catalysts for the reduction of nitrobenzene under 425 nm illumination by LED lamps. Using gas chromatography (GC), the conversion and selectivity of the reduction reaction under the dark and light irradiation conditions can be monitored, demonstrating the enhanced catalytic performance and control over selectivity under LSPR excitation after alloying non-plasmonic Pd with plasmonic metal Ag. This technique can be adapted to a wide range of molecular transformations and NPs compositions, making it useful for the characterization of the plasmonic catalytic activity of different types of catalysis in terms of conversion and selectivity.

Presented here is a protocol for the synthesis of silver-palladium (Ag-Pd) alloy nanoparticles (NPs) supported on ZrO2 (Ag-Pd/ZrO2). This system allows for harvesting energy from visible light irradiation to accelerate and control molecular transformations. This is illustrated by nitrobenzene reduction under light irradiation catalyzed by Ag-Pd/ZrO2 NPs.

为增强微型和纳米操纵利用电浆和光子晶体纳米结构

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