Name: compact quantum dots for single-molecule imaging
Uploaded: 2012-10-09T12:00:00
Description: Watch this Scientific Journal Video about Compact Quantum Dots for Single-molecule Imaging at JoVE.com

作者想感谢香港易在埃默里大学综合显微镜核心的电子显微成像。这项工作是由美国国立卫生研究院拨款赞助（PN2EY018244，R01 CA108468，U54CA119338的，1K99CA154006-01）。

以下的合成程序涉及标准的无空气的技术和使用的真空/惰性气体歧管;参考文献10和11中可以找到详细的方法。所有潜在的有毒和易燃物质的MSDS应咨询在使用之前，所有的易燃和/或空气不稳定的化合物应分装到隔垫密封的小瓶，在手套箱中或手套袋。 1。合成的汞硒化镉量子点（汞X CD-X SE）核心<ol><li>准备辛基膦（TOP）为0.4的溶液中的硒。硒（0.316克，4毫摩尔）加入?...

<ol>
	<li>Toprak, E., Selvin, P. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=New+fluorescent+tools+for+watching+nanometer-scale+conformational+changes+of+single+molecules.">New fluorescent tools for watching nanometer-scale conformational changes of single molecules.</a> Annu. Rev. Biophys. Biomol. Struct. 36, 349-369 (2007).</li><li>Joo, C., Balci, H., Ishitsuka, Y., Buranachai, C., Ha, T. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Advances+in+single+molecule+fluorescence+methods+for+molecular+biology.">Advances in single molecule fluorescence methods for molecular biology.</a> Annu. Rev. Biochem. 77, 51-76 (2008).</li><li>Pinaud, F., Clarke, S., Sittner, A., Dahan, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Probing+cellular+events,+one+quantum+dot+at+a+time.">Probing cellular events, one quantum dot at a time.</a> Nat. Method. 7, 275-285 (2010).</li><li>Smith, A. M., Wen, M. M., Nie, S. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Imaging+dynamic+cellular+events+with+quantum+dots.">Imaging dynamic cellular events with quantum dots.</a> Biochemist. 32, 12-17 (2010).</li><li>Smith, A. M., Duan, H. W., Mohs, A. M., Nie, S. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Bioconjugated+quantum+dots+for+in+vivo+molecular+and+cellular+imaging.">Bioconjugated quantum dots for in vivo molecular and cellular imaging.</a> Adv. Drug Deliv. Rev. 60, 1226-1240 (2008).</li><li>Smith, A. M., Nie, S. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Next-generation+quantum+dots.">Next-generation quantum dots.</a> Nature Biotech. 27, 732-733 (2009).</li><li>Groc, L., Lafourcade, M., Heine, M., Renner, M., Racine, V., Sibarita, J. -. B., Lounis, B., Choquet, D., Cognet, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Single+trafficking+of+neurotransmitter+receptor:+comparison+between+single-molecule/quantum+dot+strategies.">Single trafficking of neurotransmitter receptor: comparison between single-molecule/quantum dot strategies.</a> J. Neurosci. 27, 12433-12437 (2007).</li><li>Smith, A. M., Nie, S. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Minimizing+the+hydrodynamic+size+of+quantum+dots+with+multifunctional+multidentate+polymer+ligands.">Minimizing the hydrodynamic size of quantum dots with multifunctional multidentate polymer ligands.</a> J. Am. Chem. Soc. 130, 11278-11279 (2008).</li><li>Smith, A. M., Nie, S. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Bright+and+compact+alloyed+quantum+dots+with+broadly+tunable+near-infrared+absorption+and+fluorescence+spectra+through+mercury+cation+exchange.">Bright and compact alloyed quantum dots with broadly tunable near-infrared absorption and fluorescence spectra through mercury cation exchange.</a> J. Am. Chem. Soc. 133, 24-26 (2011).</li><li>Shriver, D. F., Drezdzon, M. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> The Manipulation of Air-Sensitive Compounds. , (1986).</li><li>Errington, R. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Advanced Practical Inorganic and Metalorganic Chemistry. , (1997).</li><li>Jasieniak, J., Smith, L., van Embden, J., Mulvaney, P., Califano, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Re-examination+of+the+size-dependent+absorption+properties+of+CdSe+quantum+dots.">Re-examination of the size-dependent absorption properties of CdSe quantum dots.</a> J. Phys. Chem. C. 113, 19468-19474 (2009).</li><li>Leatherdale, C. A., Woo, W. K., Mikulec, F. V., Bawendi, M. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=On+the+absorption+cross+section+of+CdSe+nanocrystal+quantum+dots.">On the absorption cross section of CdSe nanocrystal quantum dots.</a> J. Phys. Chem. B. 106, 7619-7622 (2002).</li><li>Smith, A. M., Mohs, A. M., Nie, S. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tuning+the+optical+and+electronic+properties+of+colloidal+nanocrystals+by+lattice+strain.">Tuning the optical and electronic properties of colloidal nanocrystals by lattice strain.</a> Nature Nanotech. 4, 56-63 (2009).</li><li>Demas, J. N., Crosby, G. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+measurement+of+photoluminescence+quantum+yields.+A+review.">The measurement of photoluminescence quantum yields. A review.</a> J. Phys. Chem. 75, 991-1024 (1971).</li><li>Van Embden, J., Jasieniak, J., Mulvaney, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mapping+the+optical+properties+of+CdSe/CdS+heterostructure+nanocrystals:+the+effects+of+core+size+and+shell+thickness.">Mapping the optical properties of CdSe/CdS heterostructure nanocrystals: the effects of core size and shell thickness.</a> J. Am. Chem. Soc. 131, 14299-14309 (2009).</li><li>Smith, A. M., Duan, H. W., Rhyner, M. N., Ruan, G., Nie, S. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+systematic+examination+of+surface+coatings+on+the+optical+and+chemical+properties+of+semiconductor+quantum+dots.">A systematic examination of surface coatings on the optical and chemical properties of semiconductor quantum dots.</a> Phys. Chem. Chem. Phys. 8, 3895-3903 (2006).</li><li>Zhang, X., Mohandessi, S., Miller, L. W., Snee, P. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Efficient+functionalization+of+aqueous+CdSe/ZnS+nanocrystals+using+small-molecule+chemical+activators.">Efficient functionalization of aqueous CdSe/ZnS nanocrystals using small-molecule chemical activators.</a> Chem. Comm. 47, 3532-3534 (2011).</li><li>Bucio, L., Souza, V., Albores, A., Sierra, A., Chavez, E., Carabez, A., Guiterrez-Ruiz, 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=Cadmium+and+mercury+toxicity+in+a+human+fetal+hepatic+cell+line+(WRL-68+cells).">Cadmium and mercury toxicity in a human fetal hepatic cell line (WRL-68 cells).</a> Toxicol. 102, 285-299 (1995).</li><li>Han, S. G., Castranova, V., Vallyathan, V. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Comparative+cytotoxicity+of+cadmium+and+mercury+in+a+human+bronchial+epithelial+cell+line+(BEAS-2B)+and+its+role+in+oxidative+stress+and+induction+of+heat+shock+protein+70.">Comparative cytotoxicity of cadmium and mercury in a human bronchial epithelial cell line (BEAS-2B) and its role in oxidative stress and induction of heat shock protein 70.</a> J. Toxicol. Environ. Health Part A. 70, 852-860 (2007).</li><li>Strubelt, O., Kremer, J., Tilse, A., Keogh, J., Pentz, R. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Comparative+studies+on+the+toxicity+of+mercury,+cadmium,+and+copper+toward+the+isolated+perfused+rat+liver.">Comparative studies on the toxicity of mercury, cadmium, and copper toward the isolated perfused rat liver.</a> J. Toxicol. Environ. Health Part A. 47, 267-283 (1996).</li></ol>

相对于传统的CdSe量子点，三元合金汞X CD-X SE纳米晶体可调谐的大小和荧光波长独立。在合成过程中的CdSe纳米晶体核的大小是第一次选择，和荧光的波长选择在二次汞阳离子交换步骤中，基本上不改变纳米晶体尺寸9。重要的是要允许纯化汞X CD 1-X SE纳米晶体在室温下孵育，在至少24小时前封盖。这允许一些弱吸附汞阳离子扩散到的纳米晶体晶格。不使这个过程中发生，在近...

<table border="1"><tbody><tr><td> 的试剂的名称 </td><td> 公司 </td><td> 目录编号 </td><td> 评论（可选） </td></tr><tr><td>硒</td><td> Sigma-Aldrich公司</td><td> 229865 </td><td></td></tr><tr><td>三-n-辛基</td><td> STREM </td><td> 15-6655 </td><td>纯度为97％，在空气中不稳定</td></tr><tr><td>氧化镉</td><td> Sigma-Aldrich公司</td><td> 202894 </td><td>剧毒：谨慎使用</td></tr><tr><td> Tetradecylphosphonic酸</td><td> PCI合成</td><td> 4671-75-4 </td><td></td></tr><tr><td>十八</td><td>阿法埃莎</td><td> L11004 </td><td>工业级</td></tr><tr><td>十六胺</td><td> Sigma-Aldrich公司</td><td> H7408 </td><td></td></tr><tr><td>二苯基</td><td> Sigma-Aldrich公司</td><td> 252964 </td&gt; <td>发火的</td></tr><tr><td>醋酸汞</td><td> Sigma-Aldrich公司</td><td> 456012 </td><td>剧毒：谨慎使用</td></tr><tr><td> 1 - 辛硫醇</td><td> Sigma-Aldrich公司</td><td> 471836 </td><td>强烈的气味</td></tr><tr><td>油酸</td><td> Sigma-Aldrich公司</td><td> W281506 </td><td></td></tr><tr><td>醋酸锌</td><td>阿法埃莎</td><td> 35792 </td><td></td></tr><tr><td>醋酸镉水合物</td><td> Sigma-Aldrich公司</td><td> 229490 </td><td>剧毒：谨慎使用</td></tr><tr><td>油胺</td><td> Fisher Scientific则</td><td> AC12954 </td><td>在空气中不稳定</td></tr><tr><td>硫</td><td> Sigma-Aldrich公司</td><td> 344621 </td><td></td></tr><tr><td>三正辛基氧</td><td> STREM </td><td> 15-6661 </td><td> 99％ </td></tr><tr><td>吡啶</td><td> VWR </td><td> EM-PX2012-6 </td><td>无水</td></tr><tr><td>甘油</td><td> Sigma-Aldrich公司</td><td> M1753 </td><td>强烈的气味</td></tr><tr><td>三乙胺</td><td> Sigma-Aldrich公司</td><td> 471283 </td><td>无水</td></tr><tr><td>透析管</td><td>光谱实验室</td><td> 131342 </td><td> 20 kDa的截止</td></tr><tr><td>离心式过滤器</td><td>密理博</td><td> UFC801024 </td><td> 10 kDa的截止</td></tr><tr><td>单氨基-PEG </td><td>拉普Polymere </td><td> 12 750-2 </td><td> 750大</td></tr><tr><td> DMTMM，4 - （4,6 - 二甲氧基-1,3,5 - 三嗪-2 - 基） - 4 - 甲基吗啉鎓水合物</td><td>阿法埃莎</td><td> H26333 </td><td></td></tr><tr><td> AKTAprime加色谱系统</td><td> GE医疗集团</td><td></td><td></td></tr><tr><td> SUPEROSE 6 10/300 GL层析柱</td><td> GE医疗集团</td><td> 17-5172-01 </td><td></td></tr><tr><td>琼脂糖，OmniPur </td><td> VWR </td><td> EM-2120 </td><td></td></tr><tr><td></td><td></td><td></td><td>附录 合成硫醇的汞 ：慢慢加入乙酸汞的甲醇溶液（1当量）1 -辛硫醇（3当量）和氢氧化钾（3当量），在室温下在甲醇中的搅拌溶液。汞（II）硫醇的沉淀通过过滤分离，用甲醇和一次，用乙醚洗两次，然后在真空下干燥。 多齿聚合物的合成 ：将聚丙烯酸（1克，1773沓）溶解在25毫升二甲基甲酰胺（DMF）中，在一个150毫升的三颈烧瓶中，并用氩气泡30分钟。添加无水半胱胺（374毫克，4.87毫摩尔）在10毫升DMF中的溶液。在室温下，在剧烈搅拌下，慢慢加入无水二异丙基（DIC，736毫克，5.83毫摩尔）超过30分钟，然后加入三乙胺（170微升，1.22毫摩尔），使反应继续进行72小时，在60℃下加入巯​​基乙醇（501毫克，6.41毫摩尔），以便淬灭反应，并在室温下搅拌2小时。通过旋转蒸发除去DMF，和隔离的聚合物为2:1的混合物加入冰冷的丙酮：氯仿，随后离心。 〜5毫升无水DMF中，过滤器中的聚合物溶解，沉淀再次用二乙醚，并重复。干燥产物在氩气下在真空下和存储。 CdSe核直径的测定 ：从UV-Vis吸收光谱确定的波长，所述第一激子峰（λ，以nm为单位），这是最长的波长峰值（ 例如，在图2a中的大约498纳米的CdSe），并使用上浆曲线马瓦尼和他的同事12： <img src="/files/ftp_upload/4236/4236eq1.jpg" alt=“式（1）”/&gt; 硒化镉纳米晶体浓度的测定 ：从背景中减去的紫外-可见光谱的CdSe纳米晶体的光学透明的解决方案，确定在350 nm波长的吸收。系列稀释液，可以使用，以确定是否是光吸收Beer定律的线性范围内。的纳米晶体的浓度（QD，M）可以通过以下来确定插入的纳米晶体的直径（D，单位为nm）的光吸收值（A 3SA），和比色皿的路径长度（l，单位：cm）变成下面的等式从的经验关系的Bawendi和他的同事13： <img src="/files/ftp_upload/4236/4236eq2.jpg" alt="公式2" /></td></tr></tbody></table>

compact quantum dots for single-molecule imaging

单分子成像是一个重要的工具，对于理解生物分子功能的机制和可视化的空间和时间异质性的分子行为的基础细胞生物学1-4。要图像的个别分子的利益，它是典型的共轭到一个荧光标记（染料，蛋白质，小珠，或量子点），并与落射荧光或总内部反射荧光显微镜（TIRF）观察。它们的荧光染料和荧光蛋白质已被几十年来的荧光成像的主体，是不稳定的必要观察单个分子的高光子通量下，得到信号完全丧失之前只需要几秒钟的观察。乳胶珠和染料标记的珠提供改进的信号的稳定性，但在急剧放大的流体动力学尺寸，它可以有害地改变所研究的分子的扩散和行为的牺牲。 ntent“量子点（量子点）之间的平衡这两个问题的制度。这些纳米粒子组成的半导体材料，可以设计一个水动力紧凑的尺寸，优异的抗光降解5。因此，近年来，量子点已经在使长期观察单分子水平上的复杂大分子的行为。然而，这些粒子仍然表现出受损的扩散分子在拥挤的环境中，如细 ​​胞的细胞质和神经元突触间隙，它们的尺寸仍然过大，4,6 ，7。 最近，我们已设计的流体动力学尺寸最小化的量子点的芯和表面涂层，而平衡的偏移量的胶体稳定性，耐光性，亮度，和在过去8,9阻碍紧凑量子点的实用程序的非特异性结合。这篇文章的目的是展示这些优化的纳米晶的合成，修饰和表征，由汞的合金X CD-X SE核心涂有绝缘CDŸ锌1-Y的外壳，再涂上一多与短聚乙二醇修饰的高分子配体（ PEG）链（ 图1）。与传统的CdSe纳米晶体相比，汞X CD 1-X SE合金提供了更大的荧光量子产率，在增强的信号噪声在细胞中，和在非细胞毒性的可见光波长的激发的红光和近红外波长的荧光。多齿聚合物涂层的纳米晶体的表面，在一个封闭的和平面的构象结合的流体动力学尺寸最小化，并，PEG中和表面电荷，以尽量减少非特异性结合的细胞和生物分子。最终的结果是一个明亮的荧光纳米晶与排放之间550-800 nm和总的水动力大小近12处。这是在sAME许多可溶性的球形细胞中的蛋白质，远小于传统的聚乙二醇化量子点（25-35纳米）的尺寸范围。

图2描述了有代表性的吸收光谱和荧光光谱CdSe纳米晶，汞X CD-X SE阳离子交换后，汞纳米晶X CD 1-X SE / CDŸ锌1-Y S纳米晶后壳的增长。核心CdSe纳米晶有一个荧光量子产率接近15％（包括深阱长波长发射），但这样的效率下降到不到1％，汞交换，可能是由于引入通过表面原子扰乱9充电载流子陷阱。然而，增长的薄壳CDŸ锌1-Y S提高了?...

Watch this Scientific Journal Video about Compact Quantum Dots for Single-molecule Imaging at JoVE.com

Compact Quantum Dots for Single-molecule Imaging

我们描述了准备的胶体量子点与最小化的流体力学尺寸为单分子荧光成像。相比传统的量子点，这些纳米颗粒的尺寸类似于球状蛋白质单分子反对光降解，亮度，稳定性和耐非特异性结合的蛋白质和细胞进行了优化。

紧凑型量子点的单分子成像

Single-molecule imaging is an important tool for  understanding the mechanisms of biomolecular function and for visualizing the  spatial and temporal ...

Research

JoVE Journal

Engineering

Gradient Echo Quantum Memory in Warm Atomic Vapor

梯度回波量子存储在温暖的原子蒸气

Gradient  echo memory (GEM) is a protocol for storing optical quantum states of light in  atomic ensembles. The primary motivation for such a technology ...

科研

工程学

Nanofabrication of Gate-defined GaAs/AlGaAs Lateral Quantum Dots

纳米加工门定义的GaAs / AlGaAs多量子点横向

A quantum computer is a computer composed of quantum bits (qubits) that takes advantage of quantum effects, such as superposition of states and ...

Analysis of Contact Interfaces for Single GaN Nanowire Devices

单氮化镓纳米线设备分析接触界面

Single GaN nanowire (NW) devices fabricated on SiO2 can exhibit  a strong degradation after annealing due to the  occurrence of void formation at the ...

Construction and Characterization of External Cavity Diode Lasers for Atomic Physics

外腔半导体激光器的原子物理的构建与鉴定

Since their development in the late 1980s, cheap, reliable external cavity diode lasers (ECDLs) have replaced complex and expensive traditional dye and ...

Quantum State Engineering of Light with Continuous-wave Optical Parametric Oscillators

光与连续波光学参量振荡器的量子态工程

Engineering non-classical states of the electromagnetic field is a central quest for quantum optics1,2. Beyond their fundamental significance, such states ...

Investigating Single Molecule Adhesion by Atomic Force Spectroscopy

调查单分子粘附的原子力谱

Atomic force spectroscopy is an ideal tool to study molecules at surfaces and interfaces. An experimental protocol to couple a large variety of single ...

Selective Area Modification of Silicon Surface Wettability by Pulsed UV Laser Irradiation in Liquid Environment

硅表面润湿性的选择区域改性脉冲紫外激光照射在液体环境

The wettability of silicon (Si) is one of the important parameters in the technology of surface functionalization of this material and fabrication of ...

Silicon Metal-oxide-semiconductor Quantum Dots for Single-electron Pumping

硅金属 - 氧化物 - 半导体量子点单电子泵

As mass-produced silicon transistors have reached the nano-scale, their behavior and performances are increasingly affected, and often deteriorated, by ...

Use of a Multi-compartment Dynamic Single Enzyme Phantom for Studies of Hyperpolarized Magnetic Resonance Agents

一个多腔动态单一酶幻影超极化磁共振剂研究的用途

Imaging of hyperpolarized substrates by magnetic resonance shows great clinical promise for assessment of critical biochemical processes in real time. Due ...

Compact Lens-less Digital Holographic Microscope for MEMS Inspection and Characterization

紧凑的镜头少数字全息显微镜的MEMS检测与表征

A micro-electro-mechanical-system (MEMS) is a widely used component in many industries, including energy, biotechnology, medical, communications, and ...