这项研究是在太平洋西北国家实验室 (4500亿) 进行的, 这是由能源部巴特尔纪念研究所根据合同 No. 管理的。DE-AC05-76RL01830作者衷心感谢美国国务院通过机构间协议 SIAA15AVCVPO10 的关键核查资产基金 (V 基金) 的支持。

1. 材料准备 <ol> <li> 将数 2 in. 硅晶片放入石英载体中, 用于清洗并将硅片放入等离子蚀刻系统中。抽真空室直到它达到至少 75 mTorr。这可能需要几分钟的时间. </li>
	<li> 开始流的 O 2 (30 sccm) 气体, 并允许压力稳定。将蚀刻时间设置为15分钟。一旦室压力已稳定启动射频 (RF) 13.56 兆赫 250 W 等离子体. 
	注: 这一步清洗任何有机污染物的硅片和 functionalizes 表面与羟基 (-OH) 基从而确保亲水性表面. </li>
	<li> 在等待等离子清洗步骤完成时, 从冰箱中取出商业购买的聚苯乙烯纳米 (170 nm 直径、10% 固体、0.5% 十二烷基硫酸钠) (4 和 #176; C)。允许容器加热到室温. </li>
	<li> 短暂涡旋 (1 分钟) 和几种 (35 赫, 1 分钟) 聚苯乙烯纳米, 以尽量减少纳米团聚. </li>
	<li> 进入一个干净的玻璃瓶, 测量1.0 毫升的 170 nm 聚苯乙烯纳米和添加1.0 毫升 H 2 O 获得一个5% 固体胶体悬浮. </li>
	<li> 15 分钟后, 停止 O 2 的流量 , 排出真空室, 并卸下刚清洗过的晶片. </li>
</ol> 2。聚苯乙烯纳米模板的自旋涂层 <ol> <li> 从等离子蚀刻中卸下已清洗的硅片。然后将2的晶片贴在旋转涂布机上。确保它是正确的中心, O 形环是明确的任何碎片。启动真空, 确保晶片牢固地附着在舞台上. </li>
	<li> 设置自旋涂布机的自旋参数。这些参数根据纳米大小的不同而有所不同。对于 5% 170 nm 纳米的解决方案, 将自旋涂布机设置为1步过程, 自旋时间为1分钟, 速度为 3000 rpm, 加速度为 2000 rpm/秒. </li>
	<li> 使用一次性注射器, 从瓶子中提取1毫升的胶体悬浮液。把瓶子放一边采取5和 #181; m 注射器过滤器并且安置它在注射器的末端。按住注射器直到一滴悬浮液清除笔尖。过滤器消除了不良的骨料和微粒, 可以显著降低胶片质量. </li>
	<li> 将足够的悬浮液直接放置在晶片的中心, 这样大约2/3 的表面被覆盖。尽量减少气泡, 因为这些会影响胶片质量。关闭旋转式涂布机盖, 然后按开始。在这一过程中, 可能会看到薄膜对晶片表面的干涉效应纳米组装。这将根据纳米直径的不同而有所不同. </li>
	<li> 在停用真空后卸下自旋涂层晶片。擦拭的碗和盖子的旋转涂布机, 以消除过剩的纳米. </li>
</ol> 3。蚀刻的胶片质量评定和准备工作 <ol> <li> 通过寻找明显的缺陷 (如在自旋涂层过程中可能由微粒引起的条纹或孔), 直观地评估自行组装薄膜的质量. </li>
	<li> 通过在光学显微镜下放置晶片来评估胶片质量。晶粒边界和一些缺陷是正常的。如果晶片有较大的未涂布区域或明显的多层膜, 则需要调整自旋参数以获得更均匀的薄膜。电子显微镜也可以用来评估胶片的质量. </li>
	<li> 使用20X 物镜将光源打开到显微镜上并聚焦到硅片表面。评估在整个晶片的几个点的质量, 以确保均匀. </li>
	<li> 最后的胶片质量检查是使用扫描电子显微镜 (SEM) 在纳米尺度上对纳米自组装进行可视化。利用这种技术, 可以相对快速地对晶片的小部分进行多层、孔洞和晶界/缺陷的评估. </li>
	<li> 一旦获得足够的胶片, 将晶片放入烤箱 (107 和 #176; C) 中2分钟以退火自组装纳米。这有助于鼓励对基体的附着力, 并在蚀刻后产生更好的 nanopatterned 表面. </li>
</ol> 4。蚀刻、金属沉积和光学特性 <ol> <li> 将退火的晶圆加载到等离子体蚀刻中, 并启动泵浦过程. </li>
	<li> 一旦真空室达到至少 75 mTorr, 开始 O 2 (20 sccm) 气体的流量, 等待压力稳定。启动 RF 等离子 (75 W) 的 165s. </li>
	<li> 一旦射频等离子体循环完成, 停止 O 2 的流量 并将腔室排出. </li>
	<li> 基体现在被蚀刻并准备金属沉积。将样品输送到溅射涂布机, 并沉积一层薄薄的 (20 纳米) 金。不同的沉积角度可以用来改变 nanocups 的光学性质。在这种情况下, 金属沉积通常发生在基板上进行. </li>
	<li> 金属沉积后, 基体可以用光学光谱学进行表征。将 microspectrophotometer 聚焦到金属化基体表面, 测量反射光谱。对于170纳米蚀刻纳米阵列, LSPR 是在 615 nm. </li>
	<li> 使用压敏胶带, 轻轻地将胶片与承印物接触。它可能是必要的, 以消除任何气泡, 形成在接口使用镊子. </li>
	<li> 当磁带与基板接触后, 磁带可能会立即剥离, 以从基板表面卸下 nanocups。轻轻剥去胶带, 结果是一个灵活的和保形膜的黄金 nanocups. </li>
</ol>

<ol>
	<li>Fang, Y., Sun, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nanoplasmonic+waveguides:+towards+applications+in+integrated+nanophotonic+circuits.">Nanoplasmonic waveguides: towards applications in integrated nanophotonic circuits.</a> Light Sci Appl. 4, e294 (2015).</li><li>Li, J. F., Anema, J. R., Wandlowski, T., Tian, Z. Q. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dielectric+shell+isolated+and+graphene+shell+isolated+nanoparticle+enhanced+Raman+spectroscopies+and+their+applications.">Dielectric shell isolated and graphene shell isolated nanoparticle enhanced Raman spectroscopies and their applications.</a> Chemical Society Reviews. 44 (23), 8399-8409 (2015).</li><li>Wang, L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Large+Area+Plasmonic+Color+Palettes+with+Expanded+Gamut+Using+Colloidal+Self-Assembly.">Large Area Plasmonic Color Palettes with Expanded Gamut Using Colloidal Self-Assembly.</a> ACS Photonics. , (2016).</li><li>Taylor, A. B., Michaux, P., Mohsin, A. S. M., Chon, J. W. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Electron-beam+lithography+of+plasmonic+nanorod+arrays+for+multilayered+optical+storage.">Electron-beam lithography of plasmonic nanorod arrays for multilayered optical storage.</a> Optics Express. 22 (11), 13234-13243 (2014).</li><li>Endo, H., Mochizuki, Y., Tamura, M., Kawai, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fabrication+and+Functionalization+of+Periodically+Aligned+Metallic+Nanocup+Arrays+Using+Colloidal+Lithography+with+a+Sinusoidally+Wrinkled+Substrate.">Fabrication and Functionalization of Periodically Aligned Metallic Nanocup Arrays Using Colloidal Lithography with a Sinusoidally Wrinkled Substrate.</a> Langmuir. 29 (48), 15058-15064 (2013).</li><li>Wang, H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Symmetry+breaking+in+individual+plasmonic+nanoparticles.">Symmetry breaking in individual plasmonic nanoparticles.</a> Proceedings of the National Academy of Sciences. 103 (29), 10856-10860 (2006).</li><li>Wollet, L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Plasmon+hybridization+in+stacked+metallic+nanocups.">Plasmon hybridization in stacked metallic nanocups.</a> Optical Materials Express. 2 (10), 1384-1390 (2012).</li><li>Duempelmann, L., Casari, D., Luu-Dinh, A., Gallinet, B., Novotny, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Color+Rendering+Plasmonic+Aluminum+Substrates+with+Angular+Symmetry+Breaking.">Color Rendering Plasmonic Aluminum Substrates with Angular Symmetry Breaking.</a> ACS Nano. 9 (12), 12383-12391 (2015).</li><li>King, N. S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Angle-+and+Spectral-Dependent+Light+Scattering+from+Plasmonic+Nanocups.">Angle- and Spectral-Dependent Light Scattering from Plasmonic Nanocups.</a> ACS Nano. 5 (9), 7254-7262 (2011).</li><li>Mirin, N. A., Halas, N. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Light-Bending+Nanoparticles.">Light-Bending Nanoparticles.</a> Nano Letters. 9 (3), 1255-1259 (2009).</li><li>Eggleston, M. S., Messer, K., Zhang, L., Yablonovitch, E., Wu, M. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Optical+antenna+enhanced+spontaneous+emission.">Optical antenna enhanced spontaneous emission.</a> Proceedings of the National Academy of Sciences. 112 (6), 1704-1709 (2015).</li><li>Bora, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Plasmonic+black+metals+in+resonant+nanocavities.">Plasmonic black metals in resonant nanocavities.</a> Applied Physics Letters. 102 (25), 251105 (2013).</li><li>Akselrod, G. 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作者没有什么可透露的。

该协议演示了一种低成本、高效率的浆金 nanocups 周期阵列制作技术。这种技术是特别有利的, 因为它避免了串行自上而下的过程, 如电子束光刻或聚焦离子束铣削。所提出的技术表明, 商业可用的聚合物纳米可以直接自组装的方式作为一个纳米模板的进一步处理。
修改和故障排除:
如果胶片质量较差, 可能需要预纳米溶液。在这里, 我们使用了5...

电的出现与改进的纳米和合成技术一起带来了各种各样的令人兴奋的技术, 如 sub-diffraction 有限的迂回, 增强化学检测和光学传感1 ,2,3。在本协议中, 我们展示了一个可伸缩的和相对低成本的技术, 能够制造 nanopatterned 浆基板使用商业可用的聚合物纳米和蚀刻步骤后, 金属沉积。不像其他制造 nanopatterned 基板的技术, 如电子束光刻机4, 这种技术可以快速有效地扩展到300毫米的硅片, 并以最小的努力, 并使用转移步骤产生灵活和保形薄膜5。
自罗马时代以来, 我们就已经知道, 某些金属, 如金和银, 可以有灿烂的光学性能, 当他们细分化。今天, 我们了解到这些金属粒子在其尺寸接近纳米尺度时表现出一种叫做 "局部表面等离子体共振" (LSPR) 的效应。LSPR 类似于一个驻波, 在金属中发现的弱束缚电子在特定频率的光照亮金属粒子的时候, 会有连贯的振荡。各向异性纳米结构的特殊利益, 因为独特的光学共振可以出现, 由于对称打破6,7,8。
光半 (nanocup) 结构的光照可以激发电偶极子或磁偶极子等离子体模式, 这取决于金属的沉积角度、基体相对入射光的取向以及入射光的偏振度9。Nanocups 通常被认为类似于三维分裂环形谐振器, 其中谐振频率可以近似为 LC 振荡器10,11。谐振频率为聚合物纳米的大小这里使用 (170 毫微米), 沉积的金子的数量 (20 毫微米) 和蚀刻率产生共振频率横跨可见光和接近 IR。
金 nanocups 的光学性能可以通过透射或反射来测量, 这取决于用于自旋涂层的基底。在所提出的协议, 我们选择使用2在. 硅晶片作为基板和执行反射测量后, 金属沉积。测量是使用显微镜耦合的色散光谱仪与卤素光源。我们也成功地使用玻璃基板, 允许在金属沉积后立即进行透射和反射测量。此外, 该技术可以很容易地进行缩放, 并且不限于2。由于高品质单分散聚合物纳米的广泛商业可用性, 简单地从不同大小的纳米开始调整这些结构的光学特性是直接的。
在本协议中, 使用一种称为胶体光刻的方法来制造各向异性半 (或 nanocup) 金纳米结构的技术。胶体光刻采用高度单分散聚合物纳米的自组装, 以快速模式的基板, 可以进一步加工成一个浆基板后溅射涂层一薄层的黄金。同样, 通过在金属沉积过程中倾斜样品基体, 可以调节基体的各向异性。由于所形成的纳米结构的各向异性, 因此产生的构造是极化敏感的。在这里, 我们演示一个特殊的情况, 并进行光学表征和剥离, 以转移到一个透明的, 灵活的薄膜结构。

<table><tbody><tr><td>Polystyrene microspheres</td><td>Bangs Laboratories, Inc.</td><td>PS02N</td><td>170 nm &amp;ndash; 580 nm diameter</td></tr><tr><td>Silicon wafers</td><td>El-CAT, Inc.</td><td>3489</td><td>300 mm thick, one side polished [100]</td></tr><tr><td>Adhesive tape</td><td>3M</td><td>Scotch 600</td><td></td></tr><tr><td>Spin coater</td><td>Laurell</td><td>WS-650-23B</td><td></td></tr><tr><td>Plasma etcher</td><td>Nordson March&amp;nbsp;</td><td>AP-600</td><td></td></tr><tr><td>Microspectrophotometer</td><td>CRAIC</td><td>380-PV</td><td></td></tr><tr><td>Sonicator</td><td>VWR</td><td>97043-932</td><td></td></tr><tr><td>Scintillation vials</td><td>Wheaton</td><td>986734</td><td></td></tr><tr><td>5 um syringe filter</td><td>Millex</td><td>SLSV025LS</td><td></td></tr><tr><td>Oxygen gas</td><td>Oxarc</td><td>PO249&amp;nbsp;</td><td>Industrial Grade 99.5% purity</td></tr><tr><td>Vaccum pump</td><td>Kurt J. Lesker</td><td>Edwards 28</td><td></td></tr><tr><td>Disposable syringes</td><td>Air Tite Products Co.</td><td>14-817-25</td><td>1 mL capacity</td></tr><tr><td>Water</td><td>Sigma-Aldrich</td><td>W4502</td><td></td></tr></tbody></table>

fabrication of periodic gold nanocup arrays using colloidal lithography

近年来, 随着研究人员展示了与化学和光学相关的令人兴奋的应用与新的纳米技术相结合, 电的领域发生了爆炸。等离子体是电荷密度振荡的量子, 它借给纳米金属, 如金和银独特的光学特性。特别是, 金和银纳米粒子表现出局部表面等离子体共振-集体电荷密度振荡的表面 nanoparticle-in 的可见光谱。在这里, 我们专注于制作的各向异性浆纳米结构的周期阵列。这些半 (或 nanocup) 结构可以表现出额外的独特的 light-bending 和偏振相关的光学性质, 简单的各向同性纳米材料不能。研究人员对 nanocups 的周期性阵列的制作有兴趣, 例如低成本光学器件、表面增强拉曼散射和篡改指示等。我们提出了一个可伸缩的技术, 基于胶体光刻, 它可以很容易地制造大周期阵列的 nanocups 使用自旋涂层和自行组装商业可用的聚合物纳米。电子显微镜和光学光谱学从可见光到近红外线 (近红外) 进行, 以确认成功的 nanocup 制造。最后, 我们演示了 nanocups 转移到一个灵活的, 保形胶膜。

用 170 nm 直径的聚苯乙烯纳米制备了金 nanocups。退火后2分钟, 在107° c 和蚀刻与 75 W, 20 sccm O2等离子体为 165s, 产生的薄膜的特点是使用 SEM (图 1)。为了评估自旋浇铸薄膜的质量, 可使用光学 microscopy-in 除目视检查外 (图 2)。高质量的电影应该基本上没有瑕疵。即使在高品质的薄膜中, 晶界通常也会被观察到, 但要仔细注意?...

Watch this Scientific Journal Video about Fabrication of Periodic Gold Nanocup Arrays Using Colloidal Lithography at JoVE.com

Fabrication of Periodic Gold Nanocup Arrays Using Colloidal Lithography

我们用胶体光刻技术演示了周期性金 nanocup 阵列的制作, 并讨论了 nanoplasmonic 薄膜的重要性。

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 ...

fabrication-periodic-gold-nanocup-arrays-using-colloidal

Universidad San Sebastian

Research

JoVE Journal

Engineering

7.1K 次观看.  Energy and Environment Directorate. 我们用胶体光刻技术演示了周期性金 nanocup 阵列的制作, 并讨论了 nanoplasmonic 薄膜的重要性。

视频: Fabrication of Periodic Gold Nanocup Arrays Using Colloidal Lithography

A Technique to Functionalize and Self-assemble Macroscopic Nanoparticle-ligand Monolayer Films onto Template-free Substrates

This protocol describes a self-assembly technique to create macroscopic monolayer films composed of ligand-coated nanoparticles1,2. The simple, robust and scalable technique efficiently functionalizes metallic nanoparticles with thiol-ligands in a miscible water/organic solvent mixture allowing for rapid grafting of thiol groups onto the gold nanoparticle surface. The hydrophobic ligands on the nanoparticles then quickly phase separate the nanoparticles from the aqueous based suspension and confine them to the air-fluid interface. This drives the ligand-capped nanoparticles to form monolayer domains at the air-fluid interface.&#160; The use of water-miscible organic solvents is important as it enables the transport of the nanoparticles from the interface onto template-free substrates.&#160; The flow is mediated by a surface tension gradient3,4 and creates macroscopic, high-density, monolayer nanoparticle-ligand films.&#160; This self-assembly technique may be generalized to include the use of particles of different compositions, size, and shape and may lead to an efficient assembly method to produce low-cost, macroscopic, high-density, monolayer nanoparticle films for wide-spread applications.

A simple, robust and scalable technique to functionalize and self-assemble macroscopic nanoparticle-ligand monolayer films onto template-free substrates is described in this protocol.

一种技术，功能化和自组装纳米宏观 - 配体单层膜模板上无基材

This protocol describes a self-assembly technique to create macroscopic monolayer films composed of ligand-coated nanoparticles1,2. The simple, robust and ...

科研

化学

Synthesis, Assembly, and Characterization of Monolayer Protected Gold Nanoparticle Films for Protein Monolayer Electrochemistry

Colloidal gold nanoparticles protected with alkanethiolate ligands called monolayer protected gold clusters (MPCs) are synthesized and subsequently incorporated into film assemblies that serve as adsorption platforms for protein monolayer electrochemistry (PME). PME is utilized as the model system for studying electrochemical properties of redox proteins by confining them to an adsorption platform at a modified electrode, which also serves as a redox partner for electron transfer (ET) reactions. Studies have shown that gold nanoparticle film assemblies of this nature provide for a more homogeneous protein adsorption environment and promote ET without distance dependence compared to the more traditional systems modified with alkanethiol self-assembled monolayers (SAM).1-3 In this paper, MPCs functionalized with hexanethiolate ligands are synthesized using a modified Brust reaction4 and characterized with ultraviolet visible (UV-Vis) spectroscopy, transmission electron microscopy (TEM), and proton (1H) nuclear magnetic resonance (NMR). MPC films are assembled on SAM modified gold electrode interfaces by using a "dip cycle" method of alternating MPC layers and dithiol linking molecules. Film growth at gold electrode is tracked electrochemically by measuring changes to the double layer charging current of the system. Analogous films assembled on silane modified glass slides allow for optical monitoring of film growth and cross-sectional TEM analysis provides an estimated film thickness. During film assembly, manipulation of the MPC ligand protection as well as the interparticle linkage mechanism allow for networked films, that are readily adaptable, to interface with redox protein having different adsorption mechanism. For example, Pseudomonas aeruginosa azurin (AZ) can be adsorbed hydrophobically to dithiol-linked films of hexanethiolate MPCs and cytochrome c (cyt c) can be immobilized electrostatically at a carboxylic acid modified MPC interfacial layer. In this report, we focus on the film protocol for the AZ system exclusively. Investigations involving the adsorption of proteins on MPC modified synthetic platforms could further the understanding of interactions between biomolecules and man-made materials, and consequently aid the development of biosensor schemes, ET modeling systems, and synthetic biocompatible materials.5-8

Alkanethiolate stabilized gold colloids known as monolayer protected clusters (MPCs) are synthesized, characterized, and assembled into thin films as an adsorption interface for protein monolayer electrochemistry of simple redox protein like Pseudomonas aeruginosa azurin (AZ) and cytochrome c (cyt c).

单层的合成，装配和表征蛋白质单分子膜的电化学保护的金纳米粒子薄膜

Colloidal gold nanoparticles protected with alkanethiolate ligands called monolayer protected gold clusters (MPCs) are synthesized and subsequently ...

生物工程

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 ...

工程学

Microfabrication of Nanoporous Gold Patterns for Cell-material Interaction Studies

Nanostructured materials with feature sizes in tens of nanometers have enhanced the performance of several technologies, including fuel cells, biosensors, biomedical device coatings, and drug delivery tools. Nanoporous gold (np-Au), produced by a nano-scale self-assembly process, is a relatively new material that exhibits large effective surface area, high electrical conductivity, and catalytic activity. These properties have made np-Au an attractive material to scientific community. Most studies on np-Au employ macro-scale specimens and focus on fundamental science of the material and its catalytic and sensor applications. The macro-scale specimens limit np-Au's potential in miniaturized systems, including biomedical devices. In order to address these issues, we initially describe two different methods to micropattern np-Au thin films on rigid substrates. The first method employs manually-produced stencil masks for creating millimeter-scale np-Au patterns, while the second method uses lift-off photolithography to pattern sub-millimeter-scale patterns. As the np-Au thin films are obtained by sputter-deposition process, they are compatible with conventional microfabrication techniques, thereby amenable to facile integration into microsystems. These systems include electrically-addressable biosensor platforms that benefit from high effective surface area, electrical conductivity, and gold-thiol-based surface bioconjugation. We describe cell culture, immunostaining, and image processing techniques to quantify np-Au's interaction with mammalian cells, which is an important performance parameter for some biosensors. We expect that the techniques illustrated here will assist the integration of np-Au in platforms at various length-scales and in numerous applications, including biosensors, energy storage systems, and catalysts.

We report on techniques to micropattern nanoporous gold thin films via stencil printing and photolithography, as well as methods to culture cells on the microfabricated patterns. In addition, we describe image analysis methods to characterize morphology of the material and the cultured cells using scanning electron and fluorescence microscopy techniques.

细胞物质相互作用研究微细的纳米多孔金模式

Nanostructured materials with feature sizes in tens of nanometers have enhanced the performance of several technologies, including fuel cells, biosensors, ...

Large Area Substrate-Based Nanofabrication of Controllable and Customizable Gold Nanoparticles Via Capped Dewetting

Recent scientific advances in the utilization of metallic nanoparticle for enhanced energy conversion efficiency, improved optical device performance, and high-density data storage have demonstrated the potential benefit of their use in industrial applications. These applications require precise control over nanoparticle size, spacing, and sometimes shape. These requirements have resulted in the use of time and cost intensive processing steps to produce nanoparticles, thus making the transition to industrial application unrealistic. This protocol will resolve this issue by providing a scalable and affordable method for the large-area production of nanoparticle films with improved nanoparticle control compared to the current techniques. In this article, the process will be demonstrated with gold, but other metals can also be used.

This protocol details a novel nano-manufacturing technique that can be used to make controllable and customizable nanoparticle films over large areas based on the self-assembly of dewetting of capped metal films.

大面积地下纳米化的可控、可定制金纳米粒子通过包盖湿法

Recent scientific advances in the utilization of metallic nanoparticle for enhanced energy conversion efficiency, improved optical device performance, and ...

A Femtoliter Droplet Array for Massively Parallel Protein Synthesis from Single DNA Molecules

Advances in spatial resolution and detection sensitivity of scientific instrumentation make it possible to apply small reactors for biological and chemical research. To meet the demand for high-performance microreactors, we developed a femtoliter droplet array (FemDA) device and exemplified its application in massively parallel cell-free protein synthesis (CFPS) reactions. Over one million uniform droplets were readily generated within a finger-sized area using a two-step oil-sealing protocol. Every droplet was anchored in a femtoliter microchamber composed of a hydrophilic bottom and a hydrophobic sidewall. The hybrid hydrophilic-in-hydrophobic structure and the dedicated sealing oils and surfactants are crucial for stably retaining the femtoliter aqueous solution in the femtoliter space without evaporation loss. The femtoliter configuration and the simple structure of the FemDA device allowed minimal reagent consumption. The uniform dimension of the droplet reactors made large-scale quantitative and time-course measurements convincing and reliable. The FemDA technology correlated the protein yield of the CFPS reaction with the number of DNA molecules in each droplet. We streamlined the procedures about the microfabrication of the device, the formation of the femtoliter droplets, and the acquisition and analysis of the microscopic image data. The detailed protocol with the optimized low running cost makes the FemDA technology accessible to everyone who has standard cleanroom facilities and a conventional fluorescence microscope in their own place.

The overall goal of the protocol is to prepare over one million ordered, uniform, stable, and biocompatible femtoliter droplets on a 1 cm2 planar substrate that can be used for cell-free protein synthesis.

用于从单一DNA分子大规模平行蛋白质合成的Femtoliter滴体阵列

Advances in spatial resolution and detection sensitivity of scientific instrumentation make it possible to apply small reactors for biological and ...

Gold Nanoparticle Synthesis

Gold nanoparticles (Au nanoparticles) that are ~12 nm in diameter were synthesized by rapidly injecting a solution of 150 mg (0.15 mmol) of tetrachloroauric acid in 3.0 g (3.7 mmol, 3.6 mL) of oleylamine (technical grade) and 3.0 mL of toluene into a boiling solution of 5.1 g (6.4 mmol, 8.7 mL) of oleylamine in 147 mL of toluene. While boiling and mixing the reaction solution for 2 hours, the color of the reaction mixture changed from clear, to light yellow, to light pink, and then slowly to dark red. The heat was then turned off, and the solution was allowed to gradually cool down to room temperature for 1 hour. The gold nanoparticles were then collected and separated from the solution using a centrifuge and washed three times; by vortexing and dispersing the gold nanoparticles in 10 mL portions of toluene, and then precipitating the gold nanoparticles by adding 40 mL portions of methanol and spinning them in a centrifuge. The solution was then decanted to remove any remaining byproducts and unreacted starting materials. Drying the gold nanoparticles in a vacuum environment produced a solid black pellet; which could be stored for long periods of time (up to one year) for later use, and then redissolved in organic solvents such as toluene.

A protocol for synthesizing ~12 nm diameter gold nanoparticles (Au nanoparticles) in an organic solvent is presented. The gold nanoparticles are capped with oleylamine ligands to prevent agglomeration. The gold nanoparticles are soluble in organic solvents such as toluene.

金纳米粒子合成

Gold nanoparticles (Au nanoparticles) that are ~12 nm in diameter were synthesized by rapidly injecting a solution of 150 mg (0.15 mmol) of ...

Versatile Technique to Produce a Hierarchical Design in Nanoporous Gold

The potential to generate variable pore sizes, simplistic surface modification, and a breadth of commercial uses in the fields of biosensors, actuators, drug loading and release, and the development of catalysts have unquestionably accelerated the usage of nanoporous gold (NPG)-based nanomaterials in research and development. This article describes the process of the generation of hierarchical bimodal nanoporous gold (hb-NPG) by employing a step-wise procedure involving electrochemical alloying, chemical dealloying techniques, and annealing to create both macro- and mesopores. This is done to improve the utility of NPG by creating a bicontinuous solid/void morphology. The area available for surface modification is enhanced by smaller pores, while molecular transport benefits from the network of larger pores. The bimodal architecture, which is the result of a series of fabrication steps, is visualized using scanning electron microscopy (SEM) as a network of pores that are less than 100 nm in size and connected by ligaments to larger pores that are several hundred nanometers in size. The electrochemically active surface area of the hb-NPG is assessed using cyclic voltammetry (CV), with a focus on the critical roles that both dealloying and annealing play in creating the necessary structure. The adsorption of different proteins is measured by solution depletion technique, revealing the better performance of hb-NPG in terms of protein loading. By changing the surface area to volume ratio, the created hb-NPG electrode offers tremendous potential for biosensor development. The manuscript discusses a scalable method to create hb-NPG surface structures, as they offer a large surface area for the immobilization of small molecules and improved transport pathways for faster reactions.

Nanoporous gold with a hierarchical and bimodal pore size distribution can be produced by combining electrochemical and chemical dealloying. The composition of the alloy can be monitored via EDS-SEM examination as the dealloying process advances. The material's loading capacity can be determined by studying protein adsorption onto the material.

在纳米多孔金中产生分层设计的多功能技术

The potential to generate variable pore sizes, simplistic surface modification, and a breadth of commercial uses in the fields of biosensors, actuators, ...

Large-area Scanning Probe Nanolithography Facilitated by Automated Alignment and Its Application to Substrate Fabrication for Cell Culture Studies

Scanning probe microscopy has enabled the creation of a variety of methods for the constructive (&#39;additive&#39;) top-down fabrication of nanometer-scale features. Historically, a major drawback of scanning probe lithography has been the intrinsically low throughput of single probe systems. This has been tackled by the use of arrays of multiple probes to enable increased nanolithography throughput. In order to implement such parallelized nanolithography, the accurate alignment of probe arrays with the substrate surface is vital, so that all probes make contact with the surface simultaneously when lithographic patterning begins. This protocol describes the utilization of polymer pen lithography to produce nanometer-scale features over centimeter-sized areas, facilitated by the use of an algorithm for the rapid, accurate, and automated alignment of probe arrays. Here, nanolithography of thiols on gold substrates demonstrates the generation of features with high uniformity. These patterns are then functionalized with fibronectin for use in the context of surface-directed cell morphology studies.

Here we present a protocol for wide-area scanning probe nanolithography enabled by the iterative alignment of probe arrays, as well as the utilization of lithographic patterns for cell-surface interaction studies.

基于自动对准的大面积扫描探针光刻及其在细胞培养研究中的应用

Scanning probe microscopy has enabled the creation of a variety of methods for the constructive (&#39;additive&#39;) top-down fabrication of ...

Fabrication of Gradient Nanopattern by Thermal Nanoimprinting Technique and Screening of the Response of Human Endothelial Colony-forming Cells

Nanotopography can be found in various extracellular matrices (ECMs) around the body and is known to have important regulatory actions upon cellular reactions. However, it is difficult to determine the relation between the size of a nanostructure and the responses of cells owing to the lack of proper screening tools. Here, we show the development of reproducible and cost-effective gradient nanopattern plates for the manipulation of cellular responses. Using anodic aluminum oxide (AAO) as a master mold, gradient nanopattern plates with nanopillars of increasing diameter ranges [120-200&#8239;nm (GP 120/200), 200-280&#8239;nm (GP 200/280), and 280-360&#8239;nm (GP 280/360)] were fabricated by a thermal imprinting technique. These gradient nanopattern plates were designed to mimic the various sizes of nanotopography in the ECM and were used to screen the responses of human endothelial colony-forming cells (hECFCs). In this protocol, we describe the step-by-step procedure of fabricating gradient nanopattern plates for cell engineering, techniques of cultivating hECFCs from human peripheral blood, and culturing hECFCs on nanopattern plates.

Here, we present a protocol for the fabrication of gradient nanopattern plates via thermal nanoimprinting and the method of screening responses of human endothelial progenitor cells to the nanostructures. By using the described technology, it is possible to produce a scaffold that can manipulate cell behavior by physical stimuli.

热 Nanoimprinting 技术制备梯度 Nanopattern 及其对人血管内皮细胞菌落形成的响应筛选

Nanotopography can be found in various extracellular matrices (ECMs) around the body and is known to have important regulatory actions upon cellular ...