这项工作由海军研究办公室提供的资金得到了支持。 J.丰塔纳承认国家研究理事会博士后院士。

1，自组装配体纳米粒子单层膜作为自组装技术的，宏观的，巯基链烷封端的金纳米球单层膜是如下制作的说明性示例： <ol><li>集中15nm的金纳米球（可商购于许多密度：10 12个粒子/ ml）的水，以10〜13个粒子/ ml。 <ol><li>放置15毫升稀纳米球的水悬浮液中的成的超离心过滤器（100 K标称分子量限度）。 </li><li>离心过滤器/小瓶在4500×g离心2分钟，或直至只有几毫升保持在过滤器室中。 </li></ol></li><li>重悬的纳米球在大约1毫升去离子（DI）水，使得所述纳米颗粒浓度为10 13个粒子/ ml。该悬浮液是稳定的一次再悬浮于DI水中数小时。 <ol><li>验证数密度，并确认哈纳米粒子已经不会合并。稀释的浓缩纳米颗粒悬浮液由1:10回到原来的浓度的一个因素放置0.150毫升悬浮液到一个比色皿（1cm光程长度），并把它添加1.35毫升DI水。 </li><li>放置反应杯插入光谱仪和测量悬浮液和原悬浮液的吸收光谱。比较所述峰值位置和半宽度最大，以确保聚合并没有发生。的吸收峰为两个样本的幅度应该是大致相同的，从而保证了浓缩的样品是通过10倍的密度更大。 </li></ol></li><li>在一个单独的干净20毫升硼硅玻璃小瓶中加入1 ml四氢呋喃（THF）中。 </li><li>添加巯基烷配位体（ 如 5毫升1,6 -己二硫醇和5ml 1 -十二烷硫醇）与十二烷基硫酸钠和摇动溶液混合均匀。应加入足够的配体以覆盖悬浮纳米颗粒的至少整个表面区域。操作excelSS配体提高了速度和反应效率。 </li><li>在通风橱中，倒入含有金纳米球成的THF配位体的小瓶小瓶的内容。 </li><li>迅速拧上盖子，用力摇动小瓶，持续15秒。 </li><li>取下盖子，并设置小瓶倒在通风橱中 ， 图1（a）所示 。根据所使用的配体，金纳米颗粒薄膜的结构域迅速形成在空气-液体界面， 图1（c）所示 。该膜随后将开始翻译了闪烁小瓶的侧面， 图1（d）所示 。几乎所有的纳米颗粒被封端巯基的配位体，从悬浮液中取出，并在1小时内， 图1（e）输送到小瓶的侧面。 </li></ol> 2，转移到单层基板可拆卸<ol><li>要传输影片到可移动玻璃和硅晶片衬底：切底成12.5毫米x25.4毫米面积使用划线笔/轮。 <ol><li>玻璃基板：用干净的丙酮冲洗，其次是异丙醇冲洗，最后用去离子水冲洗。使基板干燥，请继续第2.2节。 </li><li>硅晶片衬底：在通风橱中准备Piranha溶液（3份浓硫酸1份30％过氧化氢 ​​， 注意：氧化剂，腐蚀品）。将15毫升硫酸放入20毫升的玻璃小瓶。这个慢慢加入5毫升30％的过氧化氢 ​​。 不要盖上瓶盖。要小心;该混合物是高度放热的。有关更多的安全信息19参考。 </li><li>小心地浸没在硅晶片衬底输送到Piranha溶液30分钟，取出，用去离子水清洗，并用氮气干燥。 </li><li>作为一个可选步骤，用于纳米粒子的配体交换和自组装的小瓶可盐化迫使所有的纳米颗粒到玻璃衬底或Si力诚晶圆代替玻璃小瓶的墙壁，否则继续第2.2节。 </li><li>用Piranha溶液（ 注意：氧化剂，腐蚀品）填补了玻璃小瓶，请参阅2.1.2节。 </li><li>允许小瓶中浸泡30分钟。 30分钟后冲洗小瓶用DI水。 </li><li>填写小瓶用丙酮和帽子1％V /六甲基二诉。 </li><li>使密封的小瓶中浸泡24小时，然后用清水冲洗用去离子水和干燥氮气。 </li></ol></li><li>前晃动（1.6节）插入基板到小瓶。拧上盖子，摇晃。 </li><li>摇匀后取下盖子，并使用镊子，定位衬底几乎垂直对瓶壁。 </li><li>用移液管以涂覆该反应混合物到基片上。反应停止时，所有的有机溶剂蒸发或所有纳米颗粒已经从悬浮液中除去。 </li></ol> 3，单层分析<ol><li>估计包装中的单层纳米球的效率迅速地通过观察透射和膜的反射特性。从与白色光源的背后照亮在玻璃基板上的单分子层。用白色光源，均匀的着色膜应观察在传输和反射， 如图2中观察到的金像反射的高密度纳米颗粒单层膜。 </li><li>使用分光光度计（见1.2.2节），从单层量化的宏观吸收光谱， 图4。标准化的吸收光谱，用干净的载玻片。装入单层膜，在玻璃基板上，进入光谱仪的光路，并收集吸收光谱。 注意：该吸收峰应显著红移几百纳米取决于所用的配位体。吸收峰的质量因素应该是可比的稀释悬浮液的值，但仅稍微broadened（ 图4）。如果吸收峰是非常广阔的，或没有很好地定义，那么单层薄膜质量较差可能，继续作进一步鉴定第3.3节。 </li><li>检查使用转印到硅晶片衬底的单层的扫描电子显微镜（SEM）（见2.1.2节）， 如图3中的纳米球的纳米级组织，如果膜是在玻璃基板上的导电带连接到该薄膜的一个角落并良好接地，以扫描电镜基座以防止充电，并允许成像。 </li></ol> 4，有机可溶性纳米粒子高效相转移技术<ol><li>使用该技术，以官能化与巯基配体的纳米颗粒的有效手段，滗从小瓶的底部在反应后剩余的溶液完成后，第1.7节，和干燥的物质在小瓶中的溶液中。 </li><li>添加的有机溶剂（ 如氯仿，甲苯），以重新悬浮以接近100％的粒子的相转移和恢复的纳米颗粒。 </li><li>重复第1.2.1节，以确保在重新悬浮纳米颗粒没有聚集成有机溶剂。如果该吸收峰是板，相对于原悬浮液，超声处理的样品15分钟，以帮助再分散的纳米颗粒， 如图4所示 。 </li></ol>

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作者什么都没有透露。

本协议描述了一个单独的“一锅煮”自组装技术来创建使用相转移，相分离和表面张力梯度宏观纳米粒子为配体的单层膜。这种技术的优点在于，它结合了三种自组装工艺成一个单一的，低成本的过程;通过快速有效地相转移纳米颗粒组装的颗粒进入细胞单层在气 - 液界面和运输单层薄膜上无模板基板。 用于创建高密度的单分子膜的最关键要素是使用新合成的柠檬酸盐稳定的?...

宏观的纳米颗粒薄膜的自组装已引起高度重视其从元件5的几何结构和组成决定的独特的性质，并且可能导致大范围的光学，电子和化学应用6-14。自组装等电影上铺配体的金属纳米颗粒必须被包装成高密度，单层。然而几个装配问题需要解决，以推动这类材料的发展。 首先，表面活性剂稳定化的金属纳米颗粒通常是通过在稀悬浮液15的湿化学方法合成。为了防止聚集，并控制在该薄膜中的纳米粒子的粒子间距，纳米粒子需要与配体壳为上限。经过纳米粒子进行了功能化与配体的纳米粒子通常保持在较稀的悬浮液。的技术是那么NEEDED自组装的纳米颗粒成宏观的，高密度，单层膜16，17。 使用巯基化的聚苯乙烯在水-四氢呋喃悬浮Cheng 等人 18相转移金纳米棒。其中，然后重新悬浮于氯仿和一滴放置在空气 - 水界面和纳米棒缓慢蒸发，形成的单层膜。 Bigioni 等 17创造了使用过量的配体和溶剂迅速挥发十二硫醇皑皑的黄金纳米微球的宏观单层，但纳米球需要是相前自组装转移。 一旦单层膜形成，他们通常需要被运送到基底上。 Mayya 等 3只限于纳米微球在水-甲苯接口，并使用表面张力梯度转移他们到无模板基板。同样，约翰逊<e采用表面张力梯度从两种不混溶流体米&gt;等人在过量配体4悬浮的银纳米球，然后翻译的纳米颗粒组成的小瓶的壁上。而组装技术存在解决所有这些问题，需要更有效的技术是必要的，大规模的纳米颗粒薄膜制作的发展提供帮助。 这里我们展示了一个简单的和强大的技术，它结合到一个单一的“一锅煮”的技术，在图1所示的上述三种自组装的问题。一种水混溶的有机溶剂（ 如四氢呋喃，dimeythl亚砜），用于第一快速有效地官能硫醇配位体（ 如巯基烷烃，硫醇-烯，巯基苯酚）到纳米颗粒（ 例如金的纳米球，纳米棒等）。该混合物，然后驱动所述纳米颗粒的自组装成宏观的，高密度，monola揭掉膜在空气 - 液体界面使用相分离。最后，纳米颗粒的单层膜形成到利用表面张力梯度从水/有机溶剂混合物中， 图2和图3无模板基板。

<table border="0" cellpadding="0" cellspacing="0" width="628">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:224px;">1-6 hexanedithiol</td>
			<td style="width:97px;">Sigma</td>
			<td style="width:140px;">H12005-5G</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:224px;">1-dodecanethiol</td>
			<td style="width:97px;">Sigma</td>
			<td style="width:140px;">471364-100ML</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:224px;">20 ml liquid scintillation vials</td>
			<td style="width:97px;">Sigma</td>
			<td style="width:140px;">Z253081-1PAK</td>
			<td></td>
		</tr>
		<tr height="24">
			<td height="24" style="height:25px;width:224px;">acetone</td>
			<td style="width:97px;">Sigma</td>
			<td>650501-1L</td>
			<td></td>
		</tr>
		<tr height="24">
			<td height="24" style="height:24px;width:224px;">amicon ultra-15 centrifugal filter&#160;</td>
			<td style="width:97px;">Millipore</td>
			<td style="width:140px;">100K</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:224px;">centrifuge</td>
			<td style="width:97px;">Sorvall&#160;</td>
			<td style="width:140px;">RC5B</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:224px;">centrifuge&#160;</td>
			<td style="width:97px;">Eppendorf</td>
			<td style="width:140px;">5810R</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:224px;">deionized water&#160;</td>
			<td style="width:97px;">in-house&#39;</td>
			<td style="width:140px;">N/A</td>
			<td></td>
		</tr>
		<tr height="24">
			<td height="24" style="height:25px;width:224px;">glass slides</td>
			<td style="width:97px;">Sigma</td>
			<td style="width:140px;">CLS294875X25-72EA</td>
			<td></td>
		</tr>
		<tr height="24">
			<td height="24" style="height:24px;width:224px;">15 nm gold nanospheres</td>
			<td style="width:97px;">Ted Pella, Inc</td>
			<td style="width:140px;">15703-1</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:224px;">hexamethyldisilazane</td>
			<td style="width:97px;">Sigma</td>
			<td style="width:140px;">52619-50ML</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:224px;">hydrogen peroxide (30%)</td>
			<td style="width:97px;">Sigma</td>
			<td style="width:140px;">216763-100ML</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:224px;">scanning electron microscope</td>
			<td style="width:97px;">Carl Zeiss</td>
			<td style="width:140px;">Model 55</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:224px;">polished silicon wafer</td>
			<td style="width:97px;">Sun Edison</td>
			<td style="width:140px;">N/A</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:224px;">spectrometer</td>
			<td style="width:97px;">OceanOptics</td>
			<td style="width:140px;">USB4000-VIS-NIR</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:224px;">sulfuric acid</td>
			<td style="width:97px;">Fisher</td>
			<td style="width:140px;">A300-212</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:224px;">tetrahydrofuran</td>
			<td style="width:97px;">Sigma</td>
			<td style="width:140px;">401757-100ML</td>
			<td></td>
		</tr>
	</tbody>
</table>

a technique to functionalize and self-assemble macroscopic nanoparticle-ligand monolayer films onto template-free substrates

这个协议描述了一种自组装技术来建立配体包覆的纳米微粒1,2组成的宏观单层膜。的简单，坚固且可扩展的技术有效地functionalizes金属纳米粒子与巯基配体在一个可混溶的水/有机溶剂混合物中，允许硫醇基团的快速接枝到纳米金表面。从水基悬浮液的纳米颗粒的疏水性配体然后迅速相分离的纳米颗粒，并将其限制到空气 - 液体界面。此驱动器的配位体覆盖的纳米颗粒，形成单层结构域在空气 - 液体界面。使用与水混溶的有机溶剂是重要的，因为它使来自接口的纳米颗粒的运输到无模板基板。该流量由表面张力梯度3,4介导的，并建立宏观的，高密度，单层nanop文章配体膜。此自组装技术可概括为包括使用不同的组成，大小的颗粒，和形状，并可能导致高效率的装配方法，以生产出低成本的，宏观的，高密度的，单层的纳米颗粒薄膜的广泛的应用。

图1（a）所示的金纳米球，巯基链烷配体，四氢呋喃和水的玻璃小瓶中混合后立即悬浮液。的概略的三个主要的自组装阶段，相转移，相分离，和表面张力梯度介导的膜输送示于图1（b）为在靠近所述小瓶的侧面的空气-液体界面的放大图。 上的配位体的硫醇基团的混合，置换的离子性表面活性剂，使微球成为疏水性的，更可混溶的THF后迅速结合到金?...

Watch this Scientific Journal Video about A Technique to Functionalize and Self-assemble Macroscopic Nanoparticle-ligand Monolayer Films onto Template-free Substrates at JoVE.com

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

一个简单，强大和可扩展的技术和功能化自组装纳米宏观 - 配体单层膜模板上的无基材在本协议中所述。

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 ...

a-technique-to-functionalize-self-assemble-macroscopic-nanoparticle

Research

JoVE Journal

Chemistry

10.8K 次观看.  Naval Research Laboratory. 一个简单，强大和可扩展的技术和功能化自组装纳米宏观 - 配体单层膜模板上的无基材在本协议中所述。 

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

Covalent Binding of BMP-2 on Surfaces Using a Self-assembled Monolayer Approach

Bone morphogenetic protein 2 (BMP-2) is a growth factor embedded in the extracellular matrix of bone tissue. BMP-2 acts as trigger of mesenchymal cell differentiation into osteoblasts, thus stimulating healing and de novo bone formation. The clinical use of recombinant human BMP-2 (rhBMP-2) in conjunction with scaffolds has raised recent controversies, based on the mode of presentation and the amount to be delivered. The protocol presented here provides a simple and efficient way to deliver BMP-2 for in vitro studies on cells. We describe how to form a self-assembled monolayer consisting of a heterobifunctional linker, and show the subsequent binding step to obtain covalent immobilization of rhBMP-2. With this approach it is possible to achieve a sustained presentation of BMP-2 while maintaining the biological activity of the protein. In fact, the surface immobilization of BMP-2 allows targeted investigations by preventing unspecific adsorption, while reducing the amount of growth factor and, most notably, hindering uncontrolled release from the surface. Both short- and long-term signaling events triggered by BMP-2 are taking place when cells are exposed to surfaces presenting covalently immobilized rhBMP-2, making this approach suitable for in vitro studies on cell responses to BMP-2 stimulation.

We describe a method for accomplishing efficient immobilization of BMP-2 on surfaces. Our approach is based on the formation of a self-assembled monolayer to achieve the covalent binding of BMP-2 via its free amine residues. This method is a useful tool to study signaling at the cell membrane.

BMP-2的共价结合利用表面上的自组装单层膜法

Bone morphogenetic protein 2 (BMP-2) is a growth factor embedded in the extracellular matrix of bone tissue. BMP-2 acts as trigger of mesenchymal cell ...

科研

化学

Towards Biomimicking Wood: Fabricated Free-standing Films of Nanocellulose, Lignin, and a Synthetic Polycation

Woody materials are comprised of plant cell walls that contain a layered secondary cell wall composed of structural polymers of polysaccharides and lignin. Layer-by-layer (LbL) assembly process which relies on the assembly of oppositely charged molecules from aqueous solutions was used to build a freestanding composite film of isolated wood polymers of lignin and oxidized nanofibril cellulose (NFC). To facilitate the assembly of these negatively charged polymers, a positively charged polyelectrolyte, poly(diallyldimethylammomium chloride) (PDDA), was used as a linking layer to create this simplified model cell wall. The layered adsorption process was studied quantitatively using quartz crystal microbalance with dissipation monitoring (QCM-D) and ellipsometry. The results showed that layer mass/thickness per adsorbed layer increased as a function of total number of layers. The surface coverage of the adsorbed layers was studied with atomic force microscopy (AFM). Complete coverage of the surface with lignin in all the deposition cycles was found for the system, however, surface coverage by NFC increased with the number of layers. The adsorption process was carried out for 250 cycles (500 bilayers) on a cellulose acetate (CA) substrate. Transparent free-standing LBL assembled nanocomposite films were obtained when the CA substrate was later dissolved in acetone. Scanning electron microscopy (SEM) of the fractured cross-sections showed a lamellar structure, and the thickness per adsorption cycle (PDDA-Lignin-PDDA-NC) was estimated to be 17 nm for two different lignin types used in the study. The data indicates a film with highly controlled architecture where nanocellulose and lignin are spatially deposited on the nanoscale (a polymer-polymer nanocomposites), similar to what is observed in the native cell wall.

The objective of this research was to form synthetic plant cell wall tissue using layer-by-layer assembly of nanocellulose fibrils and isolated lignin assembled from dilute aqueous suspensions.&#160; Surface measurement techniques of quartz crystal microbalance and atomic force microscopy were used to monitor the formation of the polymer-polymer nanocomposite material.

朝仿生学木：纳米纤维素，木质素的装配式自由站立电影和合成聚阳离子

Woody materials are comprised of plant cell walls that contain a layered secondary cell wall composed of structural polymers of polysaccharides and ...

Atomically Defined Templates for Epitaxial Growth of Complex Oxide Thin Films

Atomically defined substrate surfaces are prerequisite for the epitaxial growth of complex oxide thin films. In this protocol, two approaches to obtain such surfaces are described. The first approach is the preparation of single terminated perovskite SrTiO3 (001) and DyScO3 (110) substrates. Wet etching was used to selectively remove one of the two possible surface terminations, while an annealing step was used to increase the smoothness of the surface. The resulting single terminated surfaces allow for the heteroepitaxial growth of perovskite oxide thin films with high crystalline quality and well-defined interfaces between substrate and film. In the second approach, seed layers for epitaxial film growth on arbitrary substrates were created by Langmuir-Blodgett (LB) deposition of nanosheets. As model system Ca2Nb3O10- nanosheets were used, prepared by delamination of their layered parent compound HCa2Nb3O10. A key advantage of creating seed layers with nanosheets is that relatively expensive and size-limited single crystalline substrates can be replaced by virtually any substrate material.

Various procedures are outlined to prepare atomically defined templates for epitaxial growth of complex oxide thin films. Chemical treatments of single crystalline SrTiO3 (001) and DyScO3 (110) substrates were performed to obtain atomically smooth, single terminated surfaces. Ca2 Nb3 O10- nanosheets were used to create atomically defined templates on arbitrary substrates.

原子定义模板复合氧化物薄膜的外延生长

Atomically defined substrate surfaces are prerequisite for the epitaxial growth of complex oxide thin films. In this protocol, two approaches to obtain ...

Fabrication of Large-area Free-standing Ultrathin Polymer Films

This procedure describes a method for the fabrication of large-area and ultrathin free-standing polymer films. Typically, ultrathin films are prepared using either sacrificial layers, which may damage the film or affect its mechanical properties, or they are made on freshly cleaved mica, a substrate that is difficult to scale. Further, the size of ultrathin film is typically limited to a few square millimeters. In this method, we modify a surface with a polyelectrolyte that alters the strength of adhesion between polymer and deposition substrate. The polyelectrolyte can be shown to remain on the wafer using spectroscopy, and a treated wafer can be used to produce multiple films, indicating that at best minimal amounts of the polyelectrolyte are added to the film. The process has thus far been shown to be limited in scalability only by the size of the coating equipment, and is expected to be readily scalable to industrial processes. In this study, the protocol for making the solutions, preparing the deposition surface, and producing the films is described.

We describe a method for the fabrication of large-area (up to 13 cm diameter) and ultrathin (as thin as 8 nm) polymer films. Instead of using a sacrificial interlayer to delaminate the film from its substrate, we use a self-limiting surface treatment suitable for arbitrarily large areas.

大面积的制造自立性的超薄聚合物薄膜

This procedure describes a method for the fabrication of large-area and ultrathin free-standing polymer films.  Typically, ultrathin films are prepared ...

Preparation of Mica and Silicon Substrates for DNA Origami Analysis and Experimentation

The designed nature and controlled, one-pot synthesis of DNA origami provides exciting opportunities in many fields, particularly nanoelectronics. Many of these applications require interaction with and adhesion of DNA nanostructures to a substrate. Due to its atomically flat and easily cleaned nature, mica has been the substrate of choice for DNA origami experiments. However, the practical applications of mica are relatively limited compared to those of semiconductor substrates. For this reason, a straightforward, stable, and repeatable process for DNA origami adhesion on derivatized silicon oxide is presented here. To promote the adhesion of DNA nanostructures to silicon oxide surface, a self-assembled monolayer of 3-aminopropyltriethoxysilane (APTES) is deposited from an aqueous solution that is compatible with many photoresists. The substrate must be cleaned of all organic and metal contaminants using Radio Corporation of America (RCA) cleaning processes and the native oxide layer must be etched to ensure a flat, functionalizable surface. Cleanrooms are equipped with facilities for silicon cleaning, however many components of DNA origami buffers and solutions are often not allowed in them due to contamination concerns. This manuscript describes the set-up and protocol for in-lab, small-scale silicon cleaning for researchers who do not have access to a cleanroom or would like to incorporate processes that could cause contamination of a cleanroom CMOS clean bench. Additionally, variables for regulating coverage are discussed and how to recognize and avoid common sample preparation problems is described.

Reproducible cleaning processes for substrates used in DNA origami research are described, including bench-top RCA cleaning and derivatization of silicon oxide. Protocols for surface preparation, DNA origami deposition, drying parameters, and simple experimental set-ups are illustrated.

对于DNA折纸分析和实验准备云母和硅衬底

The designed nature and controlled, one-pot synthesis of DNA origami provides exciting opportunities in many fields, particularly nanoelectronics. Many of ...

Cooling Rate Dependent Ellipsometry Measurements to Determine the Dynamics of Thin Glassy Films

This report aims to fully describe the experimental technique of using ellipsometry for cooling rate dependent Tg (CR-Tg) experiments. These measurements are simple high-throughput characterization experiments, which can determine the glass transition temperature (Tg), average dynamics, fragility and the expansion coefficient of the super-cooled liquid and glassy states for a variety of glassy materials. This technique allows for these parameters to be measured in a single experiment, while other methods must combine a variety of different techniques to investigate all of these properties. Measurements of dynamics close to Tg are particularly challenging. The advantage of cooling rate dependent Tg measurements over other methods which directly probe bulk and surface relaxation dynamics is that they are relatively quick and simple experiments, which do not utilize fluorophores or other complicated experimental techniques. Furthermore, this technique probes the average dynamics of technologically relevant thin films in temperature and relaxation time (&#964;&#945;) regimes relevant to the glass transition (&#964;&#945; &#62; 100 sec). The limitation to using ellipsometry for cooling rate dependent Tg experiments is that it cannot probe relaxation times relevant to measurements of viscosity (&#964;&#945; &#60;&#60; 1 sec). Other cooling rate dependent Tg measurement techniques, however, can extend the CR-Tg method to faster relaxation times. Furthermore, this technique can be used for any glassy system so long as the integrity of the film remains throughout the experiment.

Here, we present a protocol for cooling rate dependent ellipsometry experiments, which can determine the glass transition temperature (Tg), average dynamics, fragility and the expansion coefficient of the super-cooled liquid and glass for a variety of glassy materials.

冷却率相关的椭偏仪测量确定薄膜玻膜的动力学

This report aims to fully describe the experimental technique of using ellipsometry for cooling rate dependent Tg (CR-Tg) experiments. These measurements ...

Deacetylation Assays to Unravel the Interplay between Sirtuins (SIRT2) and Specific Protein-substrates

Acetylation has emerged as an important post-translational modification (PTM) regulating a plethora of cellular processes and functions. This is further supported by recent findings in high-resolution mass spectrometry based proteomics showing that many new proteins and sites within these proteins can be acetylated. However the identity of the enzymes regulating these proteins and sites is often unknown. Among these enzymes, sirtuins, which belong to the class III histone lysine deacetylases, have attracted great interest as enzymes regulating the acetylome under different physiological or pathophysiological conditions. Here we describe methods to link SIRT2, the cytoplasmic sirtuin, with its substrates including both in vitro and in vivo deacetylation assays. These assays can be applied in studies focused on other members of the sirtuin family to unravel the specific role of sirtuins and are necessary in order to establish the regulatory interplay of specific deacetylases with their substrates as a first step to better understand the role of protein acetylation. Furthermore, such assays can be used to distinguish functional acetylation sites on a protein from what may be non-regulatory acetylated lysines, as well as to examine the interplay between a deacetylase and its substrate in a physiological context.

Deacetylation Assays to Unravel the Interplay between Sirtuins SIRT2 and Specific Protein-substrates

This protocol describes the required steps to execute in vitro and in vivo deacetylation assays in order to establish the role of proteins as specific deacetylation substrates for sirtuins and further study the role of reversible - lysine acetylation as a post-translational modification.

脱乙酰测定解开蛋白特异底物乙酰化酶之间的Interplay（SIRT2）和

Acetylation has emerged as an important post-translational modification (PTM) regulating a plethora of cellular processes and functions. This is further ...

Capillary Electrophoresis to Monitor Peptide Grafting onto Chitosan Films in Real Time

Free-solution capillary electrophoresis (CE) separates analytes, generally charged compounds in solution through the application of an electric field. Compared to other analytical separation techniques, such as chromatography, CE is cheap, robust and effectively requires no sample preparation (for a number of complex natural matrices or polymeric samples). CE is fast and can be used to follow the evolution of mixtures in real time (e.g., chemical reaction kinetics), as the signals observed for the separated compounds are directly proportional to their quantity in solution.
Here, the efficiency of CE is demonstrated for monitoring the covalent grafting of peptides onto chitosan films for subsequent biomedical applications. Chitosan&#39;s antimicrobial and biocompatible properties make it an attractive material for biomedical applications such as cell growth substrates. Covalently grafting the peptide RGDS (arginine - glycine - aspartic acid - serine) onto the surface of chitosan films aims at improving cell attachment. Historically, chromatography and amino acid analysis have been used to provide a direct measurement of the amount of grafted peptide. However, the fast separation and absence of sample preparation provided by CE enables equally accurate yet real-time monitoring of the peptide grafting process. CE is able to separate and quantify the different components of the reaction mixture: the (non-grafted) peptide and the chemical coupling agents. In this way the use of CE results in improved films for downstream applications.
The chitosan films were characterized through solid-state NMR (nuclear magnetic resonance) spectroscopy. This technique is more time-consuming and cannot be applied in real time, but yields a direct measurement of the peptide and thus validates the CE technique.

Free solution capillary electrophoresis is a fast, cheap and robust analytical method that enables the quantitative monitoring of chemical reactions in real time. Its utility for rapid, convenient and precise analysis is demonstrated here through analysis of covalent peptide grafting onto chitosan films for improved cell adhesion.

毛细管电泳监视肽接枝壳聚糖膜实时

Free-solution capillary electrophoresis (CE) separates analytes, generally charged compounds in solution through the application of an electric field. ...

Reactive Vapor Deposition of Conjugated Polymer Films on Arbitrary Substrates

We demonstrate a method of conformally coating conjugated polymers on arbitrary substrates using a custom-designed, low-pressure reaction chamber. Conductive polymers, poly(3,4-ethylenedioxythiophene) (PEDOT) and poly(3,4-propylenedioxythiophene) (PProDOT), and a semiconducting polymer, poly(thieno[3,2-b]thiophene) (PTT), were deposited on unconventional highly-disordered and textured substrates with high surface areas, such as paper, towels and fabrics. This reported deposition chamber is an improvement of previous vapor reactors because our system can accommodate both volatile and nonvolatile monomers, such as 3,4-propylenedioxythiophene and thieno[3,2-b]thiophene. Utilization of both solid and liquid oxidants are also demonstrated. One limitation of this method is that it lacks sophisticated in situ thickness monitors. Polymer coatings made by the commonly used solution-based coating methods, such as spin-coating and surface grafting, are often not uniform or susceptible to mechanical degradation. This reported vapor phase deposition method overcomes those drawbacks and is a strong alternative to common solution-based coating methods. Notably, polymer films coated by the reported method are uniform and conformal on rough surfaces, even at a micrometer scale. This feature allows for future application of vapor deposited polymers in electronics devices on flexible and highly textured substrates.

This paper presents a protocol for reactive vapor deposition of poly(3,4-ethylenedioxythiophene), poly(3,4-propylenedioxythiophene), and poly(thieno[3,2-b]thiophene) films on glass slides and rough substrates, such as textiles and paper.

任意基底上共轭聚合物薄膜的反应气相沉积

We demonstrate a method of conformally coating conjugated polymers on arbitrary substrates using a custom-designed, low-pressure reaction chamber. ...

Solution-Processed "Silver-Bismuth-Iodine" Ternary Thin Films for Lead-Free Photovoltaic Absorbers

Bismuth-based hybrid perovskites are regarded as promising photo-active semiconductors for environment-friendly and air-stable solar cell applications. However, poor surface morphologies and relatively high bandgap energies have limited their potential. Silver-bismuth-iodine (Ag-Bi-I) is a promising semiconductor for optoelectronic devices. Therefore, we demonstrate the fabrication of Ag-Bi-I ternary thin films using material solution processing. The resulting thin films exhibit controlled surface morphologies and optical bandgaps according to their thermal annealing temperatures. In addition, it has been reported that Ag-Bi-I ternary systems crystallize to AgBi2I7, Ag2BiI5, etc. according to the ratio of the precursor chemicals. The solution-processed AgBi2I7 thin films exhibit a cubic-phase crystal structure, dense, pinhole-free surface morphologies with grains ranging in size from 200 to 800 nm, and an indirect bandgap of 1.87 eV. The resultant AgBi2I7 thin films show good air stability and energy band diagrams, as well as surface morphologies and optical bandgaps suitable for lead-free and air-stable single-junction solar cells. Very recently, a solar cell with 4.3% power conversion efficiency was obtained by optimizing the Ag-Bi-I crystal compositions and solar cell device architectures.

Solution-Processed &quot;Silver-Bismuth-Iodine&quot; Ternary Thin Films for Lead-Free Photovoltaic Absorbers

Herein, we present detailed protocols for solution-processed silver-bismuth-iodine (Ag-Bi-I) ternary semiconductor thin films fabricated on TiO2-coated transparent electrodes and their potential application as air-stable and lead-free optoelectronic devices.

无铅光伏吸收剂的溶液处理 "银铋碘" 三元薄膜

Bismuth-based hybrid perovskites are regarded as promising photo-active semiconductors for environment-friendly and air-stable solar cell applications. ...