我们感谢教授太平绅士斯帕茨（生物物理化学系，海德堡大学以及新材料和生物系统学系，马克斯普朗克研究所的智能系统，斯图加特）对他的鼎力支持。从马克斯 - 普朗克协会与德意志研究联合会（DFG SFB/TR79到EAC-A）的财政支持也大大承认。

1。 11-Mercaptoundecanoyl-N-琥珀酰亚胺酯（MU-NHS）的合成<ol><li>逐滴加入500毫克N-羟基琥珀酰亚胺的溶液和30mg 4 - （二甲氨基）吡啶在10ml丙酮（PA）的1克11-巯基十一酸的40ml二氯甲烷（PA）在室温（RT）。 </li><li>将反应冷却至0℃，并逐滴加入1.1克N，N&#39; -二环己基碳在10毫升二氯甲烷中（氮气氛下）。保持在低温下进行1小时反应，然后在室温搅拌过夜。 </li><li>过滤出沉淀，干燥，减压。通过快速色谱纯化，用石油苯和乙酸乙酯（PA）以1:1的比率提纯产物。 </li></ol> 2。齐金层的制备<ol><li>干净的玻璃盖玻片精确湿巾含有乙酸乙酯（PA）和甲醇（PA）1:1混合物的溶液超声仪处理他们5分钟。 RINSË基板用甲醇和在氮气流中干枯脱落。 </li><li>将干净的基板中的溅射涂覆装置。疏散室。通过溅射60秒从铬靶中取出最上面的氧化铬层。将样品在金属梁和涂层它们与10纳米的铬层，接着用40nm金层覆盖的下面。 </li></ol> 3。 BMP-2的表面固定<ol><li>溶解的MU-NHS在N，N-dimethlyformamide酰胺（DMF），以约1mM的终浓度和孵育金衬底中的MU-NHS的溶液在室温氮气气氛下4小时。 </li><li>在DMF中的声处理的表面，持续2分钟，冲洗，用DMF和MeOH，并在氮气流干燥关闭。 </li><li>制备的rhBMP-2的储备溶液在无菌4mM的盐酸与100微克/毫升（店铺等份在-80℃下）的浓度。对于工作稀释液（3.5微克/毫升），稀原液在PBS /氯化钠（PBS含有1M NaCl的）和一个djust至pH 8.5在使用前立即。 </li><li>孵育功能化MU-NHS在4℃的的rhBMP-2工作液过夜表面。除去培养上清。在PBS / NaCl中2分钟声处理的表面和洗3次，用无菌PBS / NaCl洗涤。 </li></ol> 4。表面表征<ol><li>以阻止抗体的非特异性吸附，孵育用5％BSA的表面（重量/体积）中1小时，在室温下，接着温育用抗BMP-2抗体（1:100，以1％（w / v的PBS溶液）BSA / PBS溶液）处理1小时，在室温。用PBS超声，持续30秒洗两次面。 </li><li>孵育底物与HRP偶联的二抗（1:1,000以1％（重量/体积）BSA / PBS溶液）30分钟，在RT，然后用PBS洗两次。 </li><li>使用Ampliflu红测定法测量的HRP酶的活性在570nm处用酶标仪。 </li></ol> 5。生物活性分析<ol><li>种子1×10 5个鼠C2C12每孔在6孔PL成肌细胞阿泰在生长培养基中，由含有丙酮酸补充有10％FBS，1％青霉素/链霉素和37℃/ 5％CO 2孵育在他们24小时的高葡萄糖DMEM中。 </li><li>饥饿的细胞在无血清的DMEM培养前3-5小时至播种到装饰有固定的BMP-2的表面上。 </li><li>对于短期的信号感应的调查，以200μl的新鲜的无血清DMEM替换培养基，然后将固定化的BMP-2的表面上的细胞。表面应该用细尖镊子处理，以避免刮伤。 </li><li>轻轻地取出面和吸出培养基用移液管，用PBS洗细胞两次。进到细胞反应的分析。 </li><li>对于长期的生物活性，板单元的分析到六天表面并对其进行培养，在37℃/ 5％CO 2在低血清条件下（2％FBS）中。 </li></ol>

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作者什么都没有透露。

在这个协议中，我们描述了功能化与生物活性的rhBMP-2表面的准备。该方法包括两个步骤：在金表面的双官能连接体的自组装单层（SAM）的1）初步形成，2）共价的rhBMP-2蛋白的固定化。在以前的工作中，我们验证了双官能连接子和生长因子的有效结合，并表明表面固定化的rhBMP-2保持其生物活性19。在固定化的形式呈现的生长因子的生物活性也已显示在其他研究中，表明该蛋白的释放以及随?...

骨形态发生蛋白-2（BMP-2）是转化生长因子（TGF-β）家族，并作为新生骨形成的诱导剂，以及几种组织的胚胎发育和成年人中调节动态平衡1-3的成员。 具有生物活性的同型二聚体的BMP-2蛋白的每个单体包含一个“半胱氨酸结”的主题，它是高度保守的所有骨形成蛋白4。六七个半胱氨酸残基形成稳定的每个单体分子内二硫键，而第七个半胱氨酸参与二聚化，形成了两种单体5,6之间的分子键。这个高度保守的半胱氨酸结定义了BMP-2蛋白的三维结构，并确定其独特的性能，如对热，变性剂和酸性pH 7-9的阻力。 BMP-2的结合的丝氨酸/苏氨酸激酶的跨膜受体，从而诱导信号转导<sup&gt; 10-12。取决于受体寡聚化的模式下，不同的信号通路被激活：一个Smad蛋白非依赖性信号传导级联通过p38信号导致的碱性磷酸酶诱导，而Smad蛋白依赖性途径通过受体磷酸化的结果中的Smad复合物的核转位和活化的转录活化具体靶基因，例如分化的抑制剂（ID）12-14。 在骨，BMP-2诱导间充质干细胞分化为成骨细胞，从而刺激愈合和从头形成骨。目前，重组表达的BMP-2是临床应用，以提高骨折部位的愈合。在骨组织工程常见的策略是利用注射生长因子，相比本地投递系统，是创伤小。然而， 在体内研究和临床应用表明，短的生物半衰期，非特异性禄alization和BMP-2的快速局部间隙可能导致一些地方，异位和系统性问题15。因此，为了获得有效的演示，BMP-2的范围内或之上的材料的包封或固定是必要的，它的本地和持续递送于靶位点。持续释放可以通过非共价的保留的方法，如物理截留，吸附或离子络合16来实现。然而，它是已知的蛋白质的非特异性吸附到表面可导致分子17的变性。为共价的生长因子结合，已经开发了不同类型的支撑件，在过去十年。使用双官能连接基的分子靶向的蛋白质的氨基或羧基基团例如，是一种类型的，这并不一定需要的蛋白质修饰，以实现其固定的方法。事实上，当蛋白质修饰提供调控蛋白定向的优势，引入人工结构域，肽标记和特定于站点的链可改变生长的生物活性因子17。因此，为了规避变性由于与支撑材料的相互作用，表面可以事先官能化，例如，有自组装单分子层的连接分子（SAM），接着是所需的因子18的耦合。我们已经使用了基于SAM的方法，共价固定化的BMP-2在表面上通过靶向其游离胺残基且已经表明，固定化的蛋白保留其短期和长期的生物活性19。这个协议提供了一种简单而有效的方式提供的BMP-2的细胞的体外研究在其上发生在细胞膜和调节负责信令成骨细胞内信号传导的机制。

<table border="1">
	<tbody>
		<tr>
			<td>Name of Material/ Equipment</td>
			<td>Company</td>
			<td>Catalog Number</td>
			<td>Comments/Description</td>
		</tr>
		<tr>
			<td>N-hydroxysuccinimide</td>
			<td>Sigma-Aldrich</td>
			<td>130672</td>
			<td></td>
		</tr>
		<tr>
			<td>4-(dimethylamino)pyridin</td>
			<td>Sigma-Aldrich</td>
			<td>522805</td>
			<td></td>
		</tr>
		<tr>
			<td>Acetone</td>
			<td>AppliChem</td>
			<td>A2282</td>
			<td></td>
		</tr>
		<tr>
			<td>11-mercaptoundecanoic acid</td>
			<td>Sigma-Aldrich</td>
			<td>674427</td>
			<td></td>
		</tr>
		<tr>
			<td>Dichlormethane</td>
			<td>Merck</td>
			<td>106050</td>
			<td></td>
		</tr>
		<tr>
			<td>N,N&#39;-dicyclohexylcarbodiimide</td>
			<td>Sigma-Aldrich</td>
			<td>D80002</td>
			<td></td>
		</tr>
		<tr>
			<td>Petroleum benzene</td>
			<td>Merck</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Glass coverslips</td>
			<td>Carl Roth</td>
			<td>M 875</td>
			<td></td>
		</tr>
		<tr>
			<td>Ethylacetate</td>
			<td>AppliChem</td>
			<td>A3550</td>
			<td></td>
		</tr>
		<tr>
			<td>Methanol</td>
			<td>Carl Roth</td>
			<td>4627</td>
			<td></td>
		</tr>
		<tr>
			<td>N,N-dimethylformamide</td>
			<td>Carl Roth</td>
			<td>T921</td>
			<td></td>
		</tr>
		<tr>
			<td>rhBMP-2</td>
			<td>R&#38;D Systems</td>
			<td>355-BM</td>
			<td>Carrier-free; expressed in E.coli</td>
		</tr>
		<tr>
			<td>PBS</td>
			<td>PAA</td>
			<td>H15-002</td>
			<td></td>
		</tr>
		<tr>
			<td>NaCl</td>
			<td>Carl Roth</td>
			<td>HN00.2</td>
			<td></td>
		</tr>
		<tr>
			<td>Poly(dimethyl siloxane) (PDMS)</td>
			<td>Dow Corning</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Sylgard 184 silicone elastomer kit</td>
			<td>Dow Corning</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Anti-rhBMP-2</td>
			<td>Sigma</td>
			<td>B9553</td>
			<td></td>
		</tr>
		<tr>
			<td>Goat anti-mouse IgG-HRP</td>
			<td>Santa Cruz</td>
			<td>sc-2005</td>
			<td>Secondary antibody</td>
		</tr>
		<tr>
			<td>Ampliflu Red assay</td>
			<td>Sigma</td>
			<td>90101</td>
			<td></td>
		</tr>
		<tr>
			<td>Dulbecco&#39;s Modified Eagle Medium (DMEM) (1x), liquid</td>
			<td>Gibco</td>
			<td>41966</td>
			<td>High glucose</td>
		</tr>
		<tr>
			<td>Fetal Bovine Serum (FBS)</td>
			<td>Sigma</td>
			<td>F7524</td>
			<td>Sterile filtered, cell culture tested</td>
		</tr>
		<tr>
			<td>Pen/Strep</td>
			<td>Gibco</td>
			<td>15140</td>
			<td></td>
		</tr>
		<tr>
			<td>Trypsin 0.05% (1x) with EDTA 4Na</td>
			<td>Gibco</td>
			<td>25300</td>
			<td></td>
		</tr>
		<tr>
			<td>Glycine (0.1 M)</td>
			<td>Riedel-de Ha&#235;n</td>
			<td>33226</td>
			<td></td>
		</tr>
		<tr>
			<td>IGEPAL CA-630 (1%)</td>
			<td>Sigma</td>
			<td>I8896</td>
			<td>Lysis buffer (ALP assay)19</td>
		</tr>
		<tr>
			<td>Magnesium chloride (MgCl2)(1 mM)</td>
			<td>Carl Roth</td>
			<td>HNO3.2</td>
			<td></td>
		</tr>
		<tr>
			<td>Zinc chloride (ZnCl2) (1 mM)</td>
			<td>Carl Roth</td>
			<td>3533.1</td>
			<td></td>
		</tr>
		<tr>
			<td>p-nitrophenylphosphate (pNPP)</td>
			<td>Sigma</td>
			<td>S0942</td>
			<td>Phosphatase substrate</td>
		</tr>
		<tr>
			<td>Anti-mysin heavy chain (MHC)</td>
			<td>Developmental Studies Hybridoma Bank, University of Iowa</td>
			<td>MF20</td>
			<td>Monoclonal antibody</td>
		</tr>
		<tr>
			<td>Alexa Fluor 488 Goat anti-mouse IgG</td>
			<td>Invitrogen</td>
			<td>A11001</td>
			<td></td>
		</tr>
		<tr>
			<td>DAPI</td>
			<td>Sigma</td>
			<td>D9542</td>
			<td></td>
		</tr>
		<tr>
			<td></td>
			<td></td>
			<td></td>
			<td>Equipment</td>
		</tr>
		<tr>
			<td>Ultrsonic bath (Sonorex Super RK 102H), Frequency 35 kHz</td>
			<td>BANDELIN electronic GmbH &#38; Co. KG</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>MED 020 Sputtercoating system</td>
			<td>BAL-TEC AG</td>
			<td></td>
			<td>Coating conditions 
			Cr: 120 mA, 1.3 x 10-2 mbar, 30 sec 
			Au: 60 mA, 5.0 x 10-2 mbar, 45 sec</td>
		</tr>
		<tr>
			<td>Tecan Infinite M200 Plate reader</td>
			<td>Tecan</td>
			<td></td>
			<td></td>
		</tr>
	</tbody>
</table>

covalent binding of bmp-2 on surfaces using a self-assembled monolayer approach

骨形态发生蛋白-2（BMP-2）是嵌入在骨组织中的细胞外基质的生长因子。 BMP-2作为间充质细胞分化为成骨细胞的触发器，从而刺激愈合和新生骨形成。与支架结合临床使用的重组人BMP-2（的rhBMP-2）提出了一些争议，根据演示文稿的方式和交付量。这里介绍的协议提供了一种简单而有效的方式提供的BMP-2的体外研究细胞。我们描述了如何形成自组装单分子层组成的异双功能连接物，并显示在下面的结合步骤中获得的rhBMP-2的共价固定。用这种方法，可以实现BMP-2的持续文稿，同时保持了蛋白质的生物活性。事实上，BMP-2的表面固定允许有针对性的调查，防止非特异性的广告orption，同时减少的生长因子的量和，最值得注意的是，阻碍了从表面不受控制的释放。由BMP-2引起的短期和长期的信号传导事件正在发生时，细胞暴露于表面呈共价固定的rhBMP-2，使得该方法适于在体外研究细胞对BMP-2刺激。

在我们的设置中，黄金被选为赋形剂，因为它提供了一种生物，但非特异性化学可调系统。另外，自组装单分子膜的应用嗣继承很多益处：通过自组装膜对金属和形式的单层缺陷少其“头部基团”自发地吸附，而其末端官能基团可以被进一步修饰。因此，他们提供一个平台，在受控而高度适应性的方式20定制界面的属性。 对于BMP-2对金涂覆的表面上的固定化，我们使?...

Watch this Scientific Journal Video about Covalent Binding of BMP-2 on Surfaces Using a Self-assembled Monolayer Approach at JoVE.com

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

我们描述了用于实现BMP-2的有效固定化在表面上的方法。我们的方法是基于一个自组装单层实现共价通过其游离胺残基的BMP-2的结合的形成。这个方法是研究信令在细胞膜的有用工具。

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 ...

covalent-binding-bmp-2-on-surfaces-using-self-assembled-monolayer

Research

Education

JoVE Journal

JoVE Core

Organic Chemistry

Chemistry

Unit 1

Covalent Bonding and Structure

SCIENTISTS IN ACTION

13.8K 次观看.  University of Heidelberg. 我们描述了用于实现BMP-2的有效固定化在表面上的方法。我们的方法是基于一个自组装单层实现共价通过其游离胺残基的BMP-2的结合的形成。这个方法是研究信令在细胞膜的有用工具。 

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

Stabilizing Hepatocellular Phenotype Using Optimized Synthetic Surfaces

Currently, one of the major limitations in cell biology is maintaining differentiated cell phenotype. Biological matrices are commonly used for culturing and maintaining primary and pluripotent stem cell derived hepatocytes. While biological matrices are useful, they permit short term culture of hepatocytes, limiting their widespread application. We have attempted to overcome the limitations using a synthetic polymer coating. Polymers represent one of the broadest classes of biomaterials and possess a wide range of mechanical, physical and chemical properties, which can be fine-tuned for purpose. Importantly, such materials can be scaled to quality assured standards and display batch-to-batch consistency. This is essential if cells are to be expanded for high through-put screening in the pharmaceutical testing industry or for cellular based therapy. Polyurethanes (PUs) are one group of materials that have shown promise in cell culture. Our recent progress in optimizing a polyurethane coated surface, for long-term culture of human hepatocytes displaying stable phenotype, is presented and discussed.

This article will focus on developing polymer coated surfaces for long-term, stable culture of stem cell derived human hepatocytes.

稳定肝细胞表型采用优化合成表面

Currently, one of the major limitations in cell biology is maintaining differentiated cell phenotype. Biological matrices are commonly used for culturing ...

科研

化学

An Inverse Analysis Approach to the Characterization of Chemical Transport in Paints

The ability to directly characterize chemical transport and interactions that occur within a material (i.e., subsurface dynamics) is a vital component in understanding contaminant mass transport and the ability to decontaminate materials. If a material is contaminated, over time, the transport of highly toxic chemicals (such as chemical warfare agent species) out of the material can result in vapor exposure or transfer to the skin, which can result in percutaneous exposure to personnel who interact with the material. Due to the high toxicity of chemical warfare agents, the release of trace chemical quantities is of significant concern. Mapping subsurface concentration distribution and transport characteristics of absorbed agents enables exposure hazards to be assessed in untested conditions. Furthermore, these tools can be used to characterize subsurface reaction dynamics to ultimately design improved decontaminants or decontamination procedures. To achieve this goal, an inverse analysis mass transport modeling approach was developed that utilizes time-resolved mass spectroscopy measurements of vapor emission from contaminated paint coatings as the input parameter for calculation of subsurface concentration profiles. Details are provided on sample preparation, including contaminant and material handling, the application of mass spectrometry for the measurement of emitted contaminant vapor, and the implementation of inverse analysis using a physics-based diffusion model to determine transport properties of live chemical warfare agents including distilled mustard (HD) and the nerve agent VX.

In this paper, a procedure for quantifying the mass transport parameters of chemicals in various materials is presented. This process involves employing an inverse-analysis based diffusion model to vapor emission profiles recorded by real-time, mass spectrometry in high vacuum.

一个反分析方法化工运输的油漆表征

The ability to directly characterize chemical transport and interactions that occur within a material (i.e., subsurface dynamics) is a vital component in ...

Facile Preparation of Internally Self-assembled Lipid Particles Stabilized by Carbon Nanotubes

We present a facile method to prepare nanostructured lipid particles stabilized by carbon nanotubes (CNTs). Single-walled (pristine) and multi-walled (functionalized) CNTs are used as stabilizers to produce Pickering type oil-in-water (O/W) emulsions. Lipids namely, Dimodan U and Phytantriol are used as emulsifiers, which in excess water self-assemble into the bicontinuous cubic Pn3m phase. This highly viscous phase is fragmented into smaller particles using a probe ultrasonicator in presence of conventional surfactant stabilizers or CNTs as done here. Initially, the CNTs (powder form) are dispersed in water followed by further ultrasonication with the molten lipid to form the final emulsion. During this process the CNTs get coated with lipid molecules, which in turn are presumed to surround the lipid droplets to form a particulate emulsion that is stable for months. The average size of CNT-stabilized nanostructured lipid particles is in the submicron range, which compares well with the particles stabilized using conventional surfactants. Small angle X-ray scattering data confirms the retention of the original Pn3m cubic phase in the CNT-stabilized lipid dispersions as compared to the pure lipid phase (bulk state). Blue shift and lowering of the intensities in characteristic G and G&#39; bands of CNTs observed in Raman spectroscopy characterize the interaction between CNT surface and lipid molecules. These results suggest that the interactions between the CNTs and lipids are responsible for their mutual stabilization in aqueous solutions. As the concentrations of CNTs employed for stabilization are very low and lipid molecules are able to functionalize the CNTs, the toxicity of CNTs is expected to be insignificant while their biocompatibility is greatly enhanced. Hence the present approach finds a great potential in various biomedical applications, for instance, for developing hybrid nanocarrier systems for the delivery of multiple functional molecules as in combination therapy or polytherapy.

We report on a smart application of carbon nanotubes for kinetic stabilization of lipid particles that contain self-assembled nanostructures in their cores. The preparation of lipid particles requires rather low concentrations of carbon nanotubes permitting their use in biomedical applications such as drug delivery.

内部自组装脂质颗粒的简易制备碳纳米管稳定

We present a facile method to prepare nanostructured lipid particles stabilized by carbon nanotubes (CNTs). Single-walled (pristine) and multi-walled ...

Highly Stable, Functional Hairy Nanoparticles and Biopolymers from Wood Fibers: Towards Sustainable Nanotechnology

Nanoparticles, as one of the key materials in nanotechnology and nanomedicine, have gained significant importance during the past decade. While metal-based nanoparticles are associated with synthetic and environmental hassles, cellulose introduces a green, sustainable alternative for nanoparticle synthesis. Here, we present the chemical synthesis and separation procedures to produce new classes of hairy nanoparticles (bearing both amorphous and crystalline regions) and biopolymers based on wood fibers. Through periodate oxidation of soft wood pulp, the glucose ring of cellulose is opened at the C2-C3 bond to form 2,3-dialdehyde groups. Further heating of the partially oxidized fibers (e.g., T = 80 &#176;C) results in three products, namely fibrous oxidized cellulose, sterically stabilized nanocrystalline cellulose (SNCC), and dissolved dialdehyde modified cellulose (DAMC), which are well separated by intermittent centrifugation and co-solvent addition. The partially oxidized fibers (without heating) were used as a highly reactive intermediate to react with chlorite for converting almost all aldehyde to carboxyl groups. Co-solvent precipitation and centrifugation resulted in electrosterically stabilized nanocrystalline cellulose (ENCC) and dicarboxylated cellulose (DCC). The aldehyde content of SNCC and consequently surface charge of ENCC (carboxyl content) were precisely controlled by controlling the periodate oxidation reaction time, resulting in highly stable nanoparticles bearing more than 7 mmol functional groups per gram of nanoparticles (e.g., as compared to conventional NCC bearing &#60;&#60; 1 mmol functional group/g). Atomic force microscopy (AFM), transmission electron microscopy (TEM), and scanning electron microscopy (SEM) attested to the rod-like morphology. Conductometric titration, Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR), dynamic light scattering (DLS), electrokinetic-sonic-amplitude (ESA) and acoustic attenuation spectroscopy shed light on the superior properties of these nanomaterials.

Synthesis schemes to prepare highly stable wood fiber-based hairy nanoparticles and functional cellulose-based biopolymers have been detailed.

高稳定性，功能性毛纳米粒子和木纤维生物聚合物：迈向可持续纳米技术

Nanoparticles, as one of the key materials in nanotechnology and nanomedicine, have gained significant importance during the past decade. While ...

Microfluidic-based Synthesis of Covalent Organic Frameworks (COFs): A Tool for Continuous Production of COF Fibers and Direct Printing on a Surface

Covalent Organic Frameworks (COFs) are a class of porous covalent materials which are frequently synthesized as unprocessable crystalline powders. The first COF was reported in 2005 with much effort centered on the establishment of new synthetic routes for its preparation. To date, most available synthetic methods for COF synthesis are based on bulk mixing under solvothermal conditions. Therefore, there is increasing interest in developing systematic protocols for COF synthesis that provide for fine control over reaction conditions and improve COF processability on surfaces, which is essential for their use in practical applications. Herein, we present a novel microfluidic-based method for COF synthesis where the reaction between two constituent building blocks, 1,3,5-benzenetricarbaldehyde (BTCA) and 1,3,5-tris(4-aminophenyl)benzene (TAPB), takes place under controlled diffusion conditions and at room temperature. Using such an approach yields sponge-like, crystalline fibers of a COF material, hereafter called MF-COF. The mechanical properties of MF-COF and the dynamic nature of the approach allow the continuous production of MF-COF fibers and their direct printing onto surfaces. The general method opens new potential applications requiring advanced printing of 2D or 3D COF structures on flexible or rigid surfaces.

Microfluidic-based Synthesis of Covalent Organic Frameworks COFs: A Tool for Continuous Production of COF Fibers and Direct Printing on a Surface

We present a novel microfluidic-based method for synthesis of covalent organic frameworks (COFs). We demonstrate how this approach can be used to produce continuous COF fibers, and also 2D or 3D COF structures on surfaces.

基于微流体的共价有机骨架（COFs）的合成：用于连续生产COF纤维和直接印刷在表面上的工具

Covalent Organic Frameworks (COFs) are a class of porous covalent materials which are frequently synthesized as unprocessable crystalline powders. The ...

Light-driven Molecular Motors on Surfaces for Single Molecular Imaging

The design and synthesis of a synthetic system that aims for the direct visualization of a synthetic rotary motor at the single molecule level on surfaces are demonstrated. This work requires careful design, considerable synthetic effort, and proper analysis. The rotary motion of the molecular motor in solution is shown by 1H NMR and UV-vis absorption spectroscopy techniques. In addition, the method to graft the motor onto an amine-coated quartz is described. This method helps to gain more insight into molecular machines.

The manuscript describes how to synthesize and graft a molecular motor on surfaces for single molecular imaging.

表面光驱动分子电机的单分子成像

The design and synthesis of a synthetic system that aims for the direct visualization of a synthetic rotary motor at the single molecule level on surfaces ...

Analysis of Complex Molecules and Their Reactions on Surfaces by Means of Cluster-Induced Desorption/Ionization Mass Spectrometry

Desorption/Ionization Induced by Neutral SO2 Clusters (DINeC) is employed as a very soft and efficient desorption/ionization technique for mass spectrometry (MS) of complex molecules and their reactions on surfaces. DINeC is based on a beam of SO2 clusters impacting on the sample surface at low cluster energy. During cluster-surface impact, some of the surface molecules are desorbed and ionized via dissolvation in the impacting cluster; as a result of this dissolvation-mediated desorption mechanism, low cluster energy is sufficient and the desorption process is extremely soft. Both surface adsorbates and molecules of which the surface is composed of can be analyzed. Clear and fragmentation-free spectra from complex molecules such as peptides and proteins are obtained. DINeC does not require any special sample preparation, in particular no matrix has to be applied. The method yields quantitative information on the composition of the samples; molecules at a surface coverage as low as 0.1 % of a monolayer can be detected. Surface reactions such as H/D exchange or thermal decomposition can be observed in real-time and the kinetics of the reactions can be deduced. Using a pulsed nozzle for cluster beam generation, DINeC can be efficiently combined with ion trap mass spectrometry. The matrix-free and soft nature of the DINeC process in combination with the MSn capabilities of the ion trap allows for very detailed and unambiguous analysis of the chemical composition of complex organic samples and organic adsorbates on surfaces.

Neutral SO2 clusters of low kinetic energy (&#60; 0.8 eV/constituent) are used to desorb complex surface molecules such as peptides or lipids for further analysis by means of mass spectrometry using an ion trap mass spectrometer. No special sample preparation is required, and real-time observation of reactions is possible.

聚类诱导解吸/电电质谱法对复杂分子及其在表面的反应分析

Desorption/Ionization Induced by Neutral SO2 Clusters (DINeC) is employed as a very soft and efficient desorption/ionization technique for mass ...

Covalent Attachment of Single Molecules for AFM-based Force Spectroscopy

Atomic force microscopy (AFM)-based single molecule force spectroscopy is an ideal tool for investigating the interactions between a single polymer and surfaces. For a true single molecule experiment, covalent attachment of the probe molecule is essential because only then can hundreds of force-extension traces with one and the same single molecule be obtained. Many traces are in turn necessary to prove that a single molecule alone is probed. Additionally, passivation is crucial for preventing unwanted interactions between the single probe molecule and the AFM cantilever tip as well as between the AFM cantilever tip and the underlying surface. The functionalization protocol presented here is reliable and can easily be applied to a variety of polymers. Characteristic single molecule events (i.e., stretches and plateaus) are detected in the force-extension traces. From these events, physical parameters such as stretching force, desorption force and desorption length can be obtained. This is particularly important for the precise investigation of stimuli-responsive systems at the single molecule level. As exemplary systems poly(ethylene glycol) (PEG), poly(N-isopropylacrylamide) (PNiPAM) and polystyrene (PS) are stretched and desorbed from SiOx (for PEG and PNiPAM) and from hydrophobic self-assembled monolayer surfaces (for PS) in aqueous environment.

Covalent attachment of probe molecules to atomic force microscopy (AFM) cantilever tips is an essential technique for the investigation of their physical properties. This allows us to determine the stretching force, desorption force and length of polymers via AFM-based single molecule force spectroscopy with high reproducibility.

基于AFM的力光谱单分子共价附价

Atomic force microscopy (AFM)-based single molecule force spectroscopy is an ideal tool for investigating the interactions between a single polymer and ...

Synthesis of pH Dependent Pyrazole, Imidazole, and Isoindolone Dipyrrinone Fluorophores using a Claisen-Schmidt Condensation Approach

Methine-bridged conjugated bicyclic aromatic compounds are common constituents of a range of biologically relevant molecules such as porphyrins, dipyrrinones, and pharmaceuticals. Additionally, restricted rotation of these systems often results in highly to moderately fluorescent systems as observed in 3H,5H-dipyrrolo[1,2-c:2',1'-f]pyrimidin-3-ones, xanthoglows, pyrroloindolizinedione analogs, BODIPY analogs, and the phenolic and imidazolinone ring systems of Green Fluorescent Protein (GFP). This manuscript describes an inexpensive and operationally simple method of performing a Claisen-Schmidt condensation to generate a series of fluorescent pH dependent pyrazole/imidazole/isoindolone dipyrrinone analogs. While the methodology illustrates the synthesis of dipyrrinone analogs, it can be translated to produce a wide range of conjugated bicyclic aromatic compounds. The Claisen-Schmidt condensation reaction utilized in this method is limited in scope to nucleophiles and electrophiles that are enolizable under basic conditions (nucleophile component) and non-enolizable aldehydes (electrophile component). Additionally, both the nucleophilic and electrophilic reactants must contain functional groups that will not inadvertently react with hydroxide. Despite these limitations, this methodology offers access to completely novel systems that can be employed as biological or molecular probes.

The Claisen-Schmidt condensation reaction is an important methodology for the generation of methine-bridged conjugated bicyclic aromatic compounds. Through utilizing a base-mediated variant of the aldol reaction, a range of fluorescent and/or biologically relevant molecules can be accessed through a generally inexpensive and operationally simple synthetic approach.

使用克莱森-施密特凝结方法合成pH依赖皮拉佐尔、伊米达佐尔和伊森多龙二苯酮氟磷

Methine-bridged conjugated bicyclic aromatic compounds are common constituents of a range of biologically relevant molecules such as porphyrins, ...

Analysis of Organochlorine Pesticides in a Soil Sample by a Modified QuEChERS Approach Using Ammonium Formate

Currently, the QuEChERS method represents the most widely used sample preparation protocol worldwide for analyzing pesticide residues in a broad variety of matrices both in official and non-official laboratories. The QuEChERS method using ammonium formate has previously proven to be advantageous compared to the original and the two official versions. On the one hand, the simple addition of 0.5 g of ammonium formate per gram of sample is sufficient to induce phase separation and achieve good analytical performance. On the other hand, ammonium formate reduces the need for maintenance in routine analyses. Here, a modified QuEChERS method using ammonium formate was applied for the simultaneous analysis of organochlorine pesticide (OCP) residues in agricultural soil. Specifically, 10 g of the sample was hydrated with 10 mL of water and then extracted with 10 mL of acetonitrile. Next, phase separation was carried out using 5 g of ammonium formate. After centrifugation, the supernatant was subjected to a dispersive solid-phase extraction clean-up step with anhydrous magnesium sulfate, primary-secondary amine, and octadecylsilane. Gas chromatography-mass spectrometry was used as the analytical technique. The QuEChERS method using ammonium formate is demonstrated as a successful alternative for extracting OCP residues from a soil sample.

The present protocol describes the utilization of ammonium formate for phase partitioning in QuEChERS, together with gas chromatography-mass spectrometry, to successfully determine organochlorine pesticide residues in a soil sample.

使用甲酸铵的改进QuEChERS方法分析土壤样品中的有机氯农药

Currently, the QuEChERS method represents the most widely used sample preparation protocol worldwide for analyzing pesticide residues in a broad variety ...