作者感谢Svilen Bobev他与XRD谱图和K Booksh与溅射镀膜机设备援助的帮助。

1.合成树状ZnO /纳米结构CdSSe <ol><li> 蓝宝石衬底的预处理和金涂层 注:金膜作为在ZnO纳米线的生长的催化剂。 <ol><li>清洁蓝宝石幻灯片（a面，10×10×1毫米）在99.5％乙醇，5分钟超声处理以制备金溅射基板上。 </li><li>沉积10纳米（±2纳米）的金厚的薄膜上用溅射镀膜机和黄金目标蓝宝石幻灯片。 </li></ol></li><li>氧化锌纳米线的合成 注:超声处理步骤1.2.2结果在均相ZnO和碳（氧化锌/ C）的混合物。混合后，混合物变为灰色。压实步骤1.2.3确保没有空气存在于混合物和氧化锌和碳紧密接触。 CVD法后，ZnO纳米线的白色膜在基片上进行沉积，朝下朝向船。 <ol><li>混合1克氧化锌纳米粉体和ACTIV的ated碳（50:50质量分数）在10毫升99.5％乙醇并用刮铲搅拌均匀。 </li><li>超声处理水浴中的混合物在20°C 30分钟，然后在80ºC烘干的烘箱中约5小时。 </li><li>放置在ZnO / C的混合物在氧化铝舟用刮刀紧凑很好。 </li><li>放在氧化铝舟的顶部的金涂层蓝宝石载玻片，用金涂覆的一面朝下。放置氧化铝舟中的石英管在水平管式炉的中心。 </li><li>吹扫1小时用Ar的石英管中，在在室温下（RT）40 SCCM的流量。增加从室温至900ºC温度在80ºC/ min的速率，并保持氩气流速率常数。 </li><li>保持在900ºC该温度2小时。通过去除橡胶塞气体入口打开两端的石英管，并让空气进入管，为反应提供氧。 </li><li>保持在900ºC反应温度3小时与るBBER塞子取出。冷却至RT在10℃/分钟的速率。 </li><li>乘船和滑动出炉外。 </li></ol></li><li> CdSSe分行对氧化锌纳米线的沉积 注:硫化镉的氧化铝舟/硒被显示在中心处的石英管中。所制备的氧化锌纳米线被向上并为下游10厘米从船上。该第二CVD法后，为橙色/黄色膜，其是在ZnO / CdSSe纳米结构，应在幻灯片沉积。 <ol><li>混合0.5克硫化镉和硒化镉（硫化镉/硒）粉末以及（50:50质量分数），并放置所述混合物中的氧化铝舟。紧凑型混合好。 </li><li>放置的CdS /硒的氧化铝舟中的石英管中预先制备的氧化锌纳米线样品。 </li><li>吹扫用Ar的管中在室温40SCCm的流速为1小时。提高反应温度到820ºC在80ºC/ min的速率。保持在820ºC该温度下30分钟。 </li><li>冷却到室温以的10℃/分钟的速率。乘船和滑动出炉外。 </li></ol></li><li> ZnO和纳米线CdSSe:对照样品的合成 <ol><li>合成氧化锌纳米线如在相同的实验条件下，第1.2节。 </li><li>合成CdSSe纳米线在第1.3节，在相同的实验条件下，用相同量的硫化镉和硒化镉组成的，但有一个干净的，镀金蓝宝石幻灯片作为基材代替ZnO系沉积滑动。 </li></ol></li></ol> 2.形态和晶体表征<ol><li>安装在SEM阶段的样品与一夹钳，并放置在SEM仪器的真空室中的样品。采取高分辨率模式的SEM图像与在3千伏的电压为12.0毫米的工作距离和3,000倍和1万倍11,12之间的放大率。 </li><li>使用X射线检测器在同一工作距离取EDS数据具有相同的样本12.0毫米。设置仪器来分析模式和调整电压20千伏，导致20至40微安13的电流。 </li><li>收集过滤用Cu靶射线（λ= 1.5418）11,12的X射线粉末衍射仪XRD谱图。 </li></ol> 3，PL发射光谱和时间分辨PL寿命的测量注:PL光谱和时间相关单光子计数（TCSPC）的测量在RT进行了利用放大的钛后二次谐波产生（SHG）蓝宝石振荡器，产生的在400纳米波长为中心50 FSEC脉冲的列车和随着1.76的输出功率14毫瓦。 <ol><li>固定样品进入该位置的样本面到激光器和检测器的试样保持器。对准激光聚焦在样品上。测量样品从500纳米到使用纤维光谱仪900纳米波长下的PL发射光谱。 </li><li>使用单光子探测器（AVA拦车光电二极管或光电管）来测量时间分辨PL寿命有彩色玻璃过滤器和一个500-或650纳米的干扰带通滤波器。 </li><li>插入物的ZnO，CdSSe，或ZnO / CdSSe滑入样品架。测量纯ZnO纳米线与500纳米的带通滤波器和CdSSe或ZnO / CdSSe样品用650纳米的带通滤波器。 </li><li>使用时间相关的单光子计数器或快速示波器测量时间分辨荧光衰减寿命。 </li></ol>

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本文数据和数字是从纳米技术文献Li 等17引用。

ZnO纳米线（茎）的垂直取向是基于在基板上外延生长。 ZnO纳米线沿着与蓝宝石12的一个平面的周期性匹配的&lt;0001&gt;方向优先生长。因此，类型和基片的质量是非常重要的。金涂层的衬底上，从5nm至20nm的厚度不同，已经过测试并表明在ZnO纳米线的生长没有显著差异。的ZnO纳米线的长度可以通过改变在ZnO / C的混合物被使用时，Ar流量率，和空气暴露时间的量来调节。对于具有一致长度合成ZnO纳米线，具有良好定义的比率或人造空气（氧/氮混合物）的氧/氩混合物，建议作为载气。到目前为止，已经在我们的实验室使用这种方法已生长最长ZnO纳米线分别为30微米，并在最短的分别为5微米。 <p class="jove_content"&gt;期间CdSSe沉积，在衬底位置上的温度是控制三元合金组合物中的关键参数。石英管内，从炉朝向端部的中心的温度梯度是由炉设置，管长度和直径，和载气的流率来控制。衬底的位置决定了生长温度，因此，该组合物。因为我们有强烈的迹象表明，CdSSe分支在ZnO茎的生长是外延，如下面所讨论的，发现在用正确的温度为50:50 S的生长在石英管中的位置是很重要的:硒摩尔比（约720℃）14。用于调谐S和Se的摩尔比，多次试验可能是必要的，以找到在管中的正确的设置和位置。所得的ZnO / CdSSe营养素的颜色是是否达到适当的比例的第一指示符;它应该是橙色。明亮的黄色表示高的硫含量，而暗红色表示在CdSSe太多硒。实际比率可以通过EDS或X射线衍射进行测量。 其原因CdSSe分支代替CdSSe /氧化锌核 - 壳结构的形成可通过在晶体结构的测定进行说明。 X射线衍射显示了在26.5°的肩部被识别为CdSSe的闪锌矿相的（111）面（ 图3）16。所述CdSSe枝条的生长可能是由点缺陷的六方晶系的ZnO干的（1010）表面上的启动。闪锌矿相的发生可以通过立方CdSSe的ZnO的（1010）面，通过整数在它们的晶格参数不同，并且能够产生外延生长的生长进行说明。作为枝生长时间越长，晶体结构合并成占在XRD强（101）的信号的更稳定的六方晶相。由于晶格参数是determi由摩尔比定义，和的摩尔比取决于该影响温度是非常关键的所有参数的生长温度，仔细调整。 这是不同的材料在树枝和树干组成树状纳米结构的一个示范。该方法应该在其他材料组合的原则工作。然而，需要以生长枝而非芯 - 壳结构的茎的晶格参数和分支之间的一些关系。此外，该分支材料的沉积温度必须低于该干材料制成，以防止杆的破坏中的最后制备步骤。用于纳米颗粒合成的另一种方法涉及溶剂热增长。已经有大约溶剂热合成方法类似树的复合营养素报告了一把。与溶剂热方法相比，无溶剂CVD是更加环保，使m的准备材料板具有较高的纯度。然而，CVD法也有一些限制。 CVD法通常是在高温度下操作蒸发前体，并制备的样品可具有在升高的温度不同的组合物。 总之，我们制备了一种新的ZnO / CdSSe垂直对准树状纳米结构。无论是氧化锌茎和CdSSe分支机构纤锌矿结构是主要。 TCSPC测量显示从CdSSe分支快速电荷转移到在ZnO茎。所述CdSSe分支的可调谐的BG，在透明的ZnO茎，和两者之间的有效的电荷转移使氧化锌/ CdSSe营养素用于光学，光电和光电应用的有前途的材料。

氧化锌是一种II-VI族半导体，具有3.3电子伏特的带隙（BG），一个高电子迁移率，和一个大的激子结合能1,2。它是具有在光学装置现在和将来的应用，太阳能电池，和光催化登塔丰富半导体材料。然而，氧化锌都是透明的，这限制了它在可见光谱范围内的应用程序。因此，材料吸收可见光，如窄间隙半导体3，染料分子4和光敏聚合物5，经常被用于敏化的ZnO对可见光的吸收。 硫化镉（BG 2.43 EV）和硒化镉（BG 1.76电子伏特）是常见的II-VI族窄禁带半导体，并已深入研究。三元合金CdSSe的BG和晶格参数可以通过改变VI组件6,7的摩尔比进行调整。的ZnO / CdSSe纳米复合材料已被报告导致高效photovoltaic能量转换8,9。 朝着与CdSSe分支的改进的可见光吸收的基板结合垂直取向的ZnO纳米线的有效电子传递途径导致茎和树枝9,10之间有效的电子转移。因此，我们合成了一种新的树状的ZnO / CdSSe纳米结构，其中垂直排列的氧化锌纳米线都装饰有CdSSe分支机构。该复合材料可以作为构建块新颖太阳能转换装置。 这个协议描述如何氧化锌纳米线阵列由由ZnO和C粉末一步法化学气相沉积（CVD）在蓝宝石衬底上生长，之后以前已发表11的过程。以下ZnO纳米线的生长，采用CVD法的第二步骤，以在ZnO纳米线生长CdSSe分支。我们采用X射线粉末衍射（XRD），扫描电子显微镜（SEM），和能量色散X射线谱（EDS）测量晶体结构，形态和在ZnO / CdSSe nanotrees（NTS）的组合物。分支和杆之间的光学性质和电荷载体传输机制已经由光致发光（PL）光谱和时间分辨的PL寿命测量的影响。

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>ZnO</td>
			<td>Sigma Aldrich</td>
			<td>1314-13-2</td>
			<td></td>
		</tr>
		<tr>
			<td>Activated Carbon</td>
			<td>Alfa</td>
			<td>231-153-3</td>
			<td></td>
		</tr>
		<tr>
			<td>CdSe</td>
			<td>Sigma Aldrich</td>
			<td>1306-24-7</td>
			<td></td>
		</tr>
		<tr>
			<td>CdS</td>
			<td>Sigma Aldrich</td>
			<td>1306-23-6</td>
			<td></td>
		</tr>
		<tr>
			<td>Sapphire</td>
			<td>MTI</td>
			<td>2SP</td>
			<td>a-plane, 10 &#215; 10 &#215; 1 mm</td>
		</tr>
		<tr>
			<td>Furnace</td>
			<td>Lindberg Blue M</td>
			<td>SSP</td>
			<td></td>
		</tr>
		<tr>
			<td>Scanning electron microscope</td>
			<td>Hitachi</td>
			<td>S5700</td>
			<td>assembled with an Oxford Inca X-act detector</td>
		</tr>
		<tr>
			<td>X-ray powder diffractometer&#160;</td>
			<td>Rigaku&#160;</td>
			<td>MiniFlex</td>
			<td>filtered Cu K&#945; radiation (&#955;=1.5418 &#197;)</td>
		</tr>
		<tr>
			<td>Amplified Ti:sapphire oscillator&#160;</td>
			<td>Coherent Mantis</td>
			<td>Coherent Legend-Elite</td>
			<td></td>
		</tr>
		<tr>
			<td>Single photon detection module&#160;</td>
			<td>ID Quantique</td>
			<td>ID-100</td>
			<td></td>
		</tr>
		<tr>
			<td>Sputter coater</td>
			<td>Cressington</td>
			<td>308</td>
			<td>assembled with gold target</td>
		</tr>
		<tr>
			<td>Fiber probe spectrometer</td>
			<td>Photon Control</td>
			<td>SPM-002</td>
			<td></td>
		</tr>
		<tr>
			<td>Colored Glass Filter</td>
			<td>Thorlabs</td>
			<td>FGB37-A - &#216;25 mm BG40</td>
			<td>AR Coated: 350 - 700 nm&#160;</td>
		</tr>
		<tr>
			<td>Compressed argon gas</td>
			<td>Keen</td>
			<td>7440-37-1</td>
			<td></td>
		</tr>
	</tbody>
</table>

synthesis of hierarchical zno/cdsse heterostructure nanotrees

两步化学气相沉积过程是此处使用以制备树状分层的ZnO / CdSSe杂纳米结构。其结构是由CdSSe树枝上生长氧化锌纳米线被一个透明的蓝宝石衬底上垂直排列的。形态是通过扫描电子显微镜测定。晶体结构通过X射线粉末衍射分析来确定。两者的ZnO茎和CdSSe分支具有一个主要为纤维锌矿晶体结构。 S和Se中的CdSSe分支的摩尔比是由能量色散X射线光谱仪进行测定。该CdSSe树枝造成强烈的可见光吸收。光致发光（PL）光谱表明，茎和树枝形成II型异质结。相比于从单个氧化锌茎排放或CdSSe分支时并注明CdSSe和ZnO之间的快速电荷转移PL寿命测量显示，从树上排放的寿命减少。该VERTI卡利对齐的ZnO茎提供一个直接的电子传递途径到基板，并允许由可见光激发后有效的电荷分离。上述特性相结合，使氧化锌/ CdSSe nanotrees有希望的候选人在太阳能电池，光催化，和光电设备的应用程序。

图1显示了氧化锌/ CdSSe营养素的生长机理。该过程涉及催化气 - 液 - 固（VLS）的过程，随后通过非催化汽固体（VS）的增长。在第一VLS步骤，氧化锌和C在Ar气氛中反应，导致金属Zn和碳氧化物。锌随后溶解在蓝宝石基板上的金前体。氧化锌纳米线自溶锌和残留的氧气增长。在第二步骤中，暴露于长ZnO纳米线的通过VLS-VS在短的ZnO种子顶部生长空气的结果。在VLS-VS机制已经详细先前11,12进行了讨论。在最后的步骤中，CdSSe分支直接生长，没有催化剂，在ZnO纳米线。 在第一步骤后获得的ZnO纳米线（协议1.2）的SEM图像示于图2（a）。树状nanostruct的SEM图像（协议1.3）第二步骤之后获得的数目字示于图2（b）和（c）。我们采用EDS来确定营养素的成分。树枝包含S和SE，拥有约0.53摩尔百分比率:0.47。 EDS元素扫描，在与NT三个不同位置进行的，在如图2（c）表示。 图2（D），（e）和（f）示出杆的组合物，分支，和盖，分别。沿图2（G）的行的元素线扫描的映射如图2（H）。元件的扫描显示了端帽和杆可以在示出的杆的区域选自Zn和O的仅贡献扫描清楚区分。通过X射线衍射测定了营养素的晶体结构。他们相比，纯的ZnO和CdSSe纳米线， 图3中所示的晶体结构。纯ZnO和CdSSe纳米线的sh流的预期六方纤锌矿结构，具有的特征峰在（100），（002），（101），和（102）13,15。在（002）氧化锌一个非常强的和窄的峰可以通过垂直排列的ZnO纳米线的一个方向生长进行说明。该营养素的XRD测量结果显示ZnO和CdSSe纤锌矿结构的组合。根据Vegard定律，S的摩尔比:硒从X射线衍射数据确定为0.54:0.46，对应于EDS结果。该CdSSe在营养素表明被分配了闪锌矿相的（111）面和后面讨论的额外的峰。 PL光谱和采用TCSPC时间分辨PL测量分别示于图4（a）和（b）中 ，。在图4（a）中 ，氧化锌，CdSSe和ZnO / CdSSe的荧光发射分别在514纳米，646纳米，627纳米，有最大值。一个500纳米带通滤波器<html>选择用于氧化锌PL寿命测量，而用于测量从CdSSe和ZnO / CdSSe营养素的发射650纳米过滤器。时间分辨PL测量使用单或双指数函数拟合。在图2（b），氧化锌/ CdSSe营养素（0.11纳秒）的PL寿命比任一氧化锌（3.67纳秒）或CdSSe（1.06纳秒）在400纳米激发的寿命短。这可以通过从导带CdSSe的（CB）快速电子转移到ZnO的CB进行说明。在孤立的纳米线，激发电子辐射性重组在纳秒的时间尺度。如果CdSSe分支都与氧化锌的干接触，激发的电子可以从CdSSe传送非辐射的ZnO，以取决于所述接口上，并且可以比辐射寿命快得多时间尺度。因此，氧化锌/ CdSSe营养素的PL寿命被跨越接口的电子转移还原。 "SRC ="/文件/ ftp_upload / 54675 / 54675fig1.jpg"/&gt; 图1. 氧化锌/ CdSSe营养素的合成示意图，炉内的设立显示在左侧。下面的图像示出了三个步骤NT制备涉及:在氩的VLS过程中，空气中的VLS-VS过程，CdSSe分支的沉积。从参考转载。 17. <a href="https://ecsource-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/54675/54675fig1large.jpg" target="_blank">请点击此处查看该图的放大版本。</a> <img alt="图2" src="/files/ftp_upload/54675/54675fig2.jpg" /> 图2. SEM图像和EDS谱。一 ），通过化学气相沉积制备的ZnO纳米线的SEM图像; b）和c）通过化学气相沉积制备的ZnO / CdSSe营养素的SEM图像;氧化锌干，CdSSe帽，和ZnO / CdSSe营养素的CdSSe分公司的EDS光谱显示在D </强&gt;），e）和f）中 ，分别; H）沿以g所示的线），从参考再现的元素线扫描。 17. <a href="https://ecsource-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/54675/54675fig2large.jpg" target="_blank">请点击此处查看该图的放大版本。</a> <img alt="图3" src="/files/ftp_upload/54675/54675fig3.jpg" /> 图3 的ZnO，CdSSe，氧化锌/ CdSSe营养素的X射线衍射光谱。（100），（002），（101），和（102）峰，在ZnO和CdSSe纤锌矿结构的裸露纳米线的特性，被示出。从营养素的另外的峰可以在闪锌矿结构CdSSe的（111）面被识别，如文中讨论。从参考转载。 17. <a href="https://ecsource-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/54675/54675fig3large.jpg" target="_blank">请Ç</a>舔此处查看该图的放大版本。 <img alt="图4" src="/files/ftp_upload/54675/54675fig4.jpg" /> 氧化锌，CdSSe和ZnO / CdSSe营养素兴奋与400纳米波长激光的图4. PL光谱和TSCPC测量。PL光谱（a）和TSCPC测量装有单指数衰减（b）中 。氧化锌，CdSSe和ZnO / CdSSe的PL光谱显示荧光分别为514纳米，646纳米，和627纳米。氧化锌，CdSSe和ZnO / CdSSe的寿命分别为3.67纳秒，1.32纳秒，和0.72纳秒。从参考转载。 17. <a href="https://ecsource-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/54675/54675fig4large.jpg" target="_blank">请点击此处查看该图的放大版本。</a>

Watch this Scientific Journal Video about Synthesis of Hierarchical ZnO/CdSSe Heterostructure Nanotrees at JoVE.com

Synthesis of Hierarchical ZnO/CdSSe Heterostructure Nanotrees

在这里，我们准备和特点新颖树形层次的ZnO /纳米结构CdSSe，其中CdSSe分支上垂直排列的ZnO纳米线生长。所得nanotrees是用于将太阳能转换和其他光电器件的潜在材料。

分层的ZnO / CdSSe异质Nanotrees的合成

A two-step chemical vapor deposition procedure is here employed to prepare tree-like hierarchical ZnO/CdSSe hetero-nanostructures. The structures are ...

synthesis-of-hierarchical-znocdsse-heterostructure-nanotrees

Nanyang Technological University

Research

JoVE Journal

Chemistry

9.9K 次观看.  University of Delaware. 在这里，我们准备和特点新颖树形层次的ZnO /纳米结构CdSSe，其中CdSSe分支上垂直排列的ZnO纳米线生长。所得nanotrees是用于将太阳能转换和其他光电器件的潜在材料。 

视频: Synthesis of Hierarchical ZnO/CdSSe Heterostructure Nanotrees

Synthesis of Immunotargeted Magneto-plasmonic Nanoclusters

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

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

Immunotargeted的合成磁等离子团簇

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

科研

化学

Synthesis and Characterization of Functionalized Metal-organic Frameworks

Metal-organic frameworks have attracted extraordinary amounts of research attention, as they are attractive candidates for numerous industrial and technological applications. Their signature property is their ultrahigh porosity, which however imparts a series of challenges when it comes to both constructing them and working with them. Securing desired MOF chemical and physical functionality by linker/node assembly into a highly porous framework of choice can pose difficulties, as less porous and more thermodynamically stable congeners (e.g., other crystalline polymorphs, catenated analogues) are often preferentially obtained by conventional synthesis methods. Once the desired product is obtained, its characterization often requires specialized techniques that address complications potentially arising from, for example, guest-molecule loss or preferential orientation of microcrystallites. Finally, accessing the large voids inside the MOFs for use in applications that involve gases can be problematic, as frameworks may be subject to collapse during removal of solvent molecules (remnants of solvothermal synthesis). In this paper, we describe synthesis and characterization methods routinely utilized in our lab either to solve or circumvent these issues. The methods include solvent-assisted linker exchange, powder X-ray diffraction in capillaries, and materials activation (cavity evacuation) by supercritical CO2 drying. Finally, we provide a protocol for determining a suitable pressure region for applying the Brunauer-Emmett-Teller analysis to nitrogen isotherms, so as to estimate surface area of MOFs with good accuracy.

Synthesis, activation, and characterization of intentionally designed metal-organic framework materials is challenging, especially when building blocks are incompatible or unwanted polymorphs are thermodynamically favored over desired forms. We describe how applications of solvent-assisted linker exchange, powder X-ray diffraction in capillaries and activation via supercritical CO2 drying, can address some of these challenges.

功能化的合成与表征金属 - 有机骨架

Metal-organic frameworks have attracted extraordinary amounts of research attention, as they are attractive candidates for numerous industrial and ...

Synthesis of Indoxyl-glycosides for Detection of Glycosidase Activities

Indoxyl glycosides proved to be valuable and versatile tools for monitoring glycosidase activities. Indoxyls are released by enzymatic hydrolysis and are rapidly oxidized, for example by atmospheric oxygen, to indigo type dyes. This reaction enables fast and easy screening in vivo without isolation or purification of enzymes, as well as rapid tests on agar plates or in solution (e.g., blue-white screening, micro-wells) and is used in biochemistry, histochemistry, bacteriology and molecular biology. Unfortunately the synthesis of such substrates proved to be difficult, due to various side reactions and the low reactivity of the indoxyl hydroxyl function. Especially for glucose type structures low yields were observed. Our novel approach employs indoxylic acid ester as key intermediates. Indoxylic acid esters with varied substitution patterns were prepared on scalable pathways. Phase transfer glycosylations with those acceptors and peracetylated glycosyl halides can be performed under common conditions in high yields. Ester cleavage and subsequent mild silver mediated glycosylation yields the peracetylated indoxyl glycosides in high yields. Finally deprotection is performed according to Zempl&#233;n.

Indoxyl glycosides are well-established and widely used tools for enzyme screening and enzyme activity monitoring. Especially for glucose type structures previous syntheses proved to be challenging and low yielding. Our novel approach employs indoxylic acid esters as precious intermediates to yield a considerable number of indoxyl glycosides in good yields.

的吲哚酚苷的检测糖苷酶活动的合成

Indoxyl glycosides proved to be valuable and versatile tools for monitoring glycosidase activities. Indoxyls are released by enzymatic hydrolysis and are ...

Synthesis and Characterization of Supramolecular Colloids

Control over colloidal assembly is of utmost importance for the development of functional colloidal materials with tailored structural and mechanical properties for applications in photonics, drug delivery and coating technology. Here we present a new family of colloidal building blocks, coined supramolecular colloids, whose self-assembly is controlled through surface-functionalization with a benzene-1,3,5-tricarboxamide (BTA) derived supramolecular moiety. Such BTAs interact via directional, strong, yet reversible hydrogen-bonds with other identical BTAs. Herein, a protocol is presented that describes how to couple these BTAs to colloids and how to quantify the number of coupling sites, which determines the multivalency of the supramolecular colloids. Light scattering measurements show that the refractive index of the colloids is almost matched with that of the solvent, which strongly reduces the van der Waals forces between the colloids. Before photo-activation, the colloids remain well dispersed, as the BTAs are equipped with a photo-labile group that blocks the formation of hydrogen-bonds. Controlled deprotection with UV-light activates the short-range hydrogen-bonds between the BTAs, which triggers the colloidal self-assembly. The evolution from the dispersed state to the clustered state is monitored by confocal microscopy. These results are further quantified by image analysis with simple routines using ImageJ and Matlab. This merger of supramolecular chemistry and colloidal science offers a direct route towards light- and thermo-responsive colloidal assembly encoded in the surface-grafted monolayer.

A protocol for the synthesis and characterization of colloids coated with supramolecular moieties is described. These supramolecular colloids undergo self-assembly upon the activation of the hydrogen-bonds between the surface-anchored molecules by UV-light.

超分子胶体的合成与表征

Control over colloidal assembly is of utmost importance for the development of functional colloidal materials with tailored structural and mechanical ...

Hydroquinone Based Synthesis of Gold Nanorods

Gold nanorods are an important kind of nanoparticles characterized by peculiar plasmonic properties. Despite their widespread use in nanotechnology, the synthetic methods for the preparation of gold nanorods are still not fully optimized. In this paper we describe a new, highly efficient, two-step protocol based on the use of hydroquinone as a mild reducing agent. Our approach allows the preparation of nanorods with a good control of size and aspect ratio (AR) simply by varying the amount of hexadecyl trimethylammonium bromide (CTAB) and silver ions (Ag+) present in the "growth solution". By using this method, it is possible to markedly reduce the amount of CTAB, an expensive and cytotoxic reagent, necessary to obtain the elongated shape. Gold nanorods with an aspect ratio of about 3 can be obtained in the presence of just 50 mM of CTAB (versus 100 mM used in the standard protocol based on the use of ascorbic acid), while shorter gold nanorods are obtained using a concentration as low as 10 mM.

This paper describes a protocol for the synthesis of gold nanorods, based on the use of hydroquinone as reducing agent, plus the different mechanisms for controlling their size and aspect ratio.

金纳米棒基于对苯二酚合成

Gold nanorods are an important kind of nanoparticles characterized by peculiar plasmonic properties. Despite their widespread use in nanotechnology, the ...

Synthesis and Mass Spectrometry Analysis of Oligo-peptoids

Peptoids are sequence-controlled peptide-mimicking oligomers consisting of N-alkylated glycine units. Among many potential applications, peptoids have been thought of as a type of molecular information storage. Mass spectrometry analysis has been considered the method of choice for sequencing peptoids. Peptoids can be synthesized via solid phase chemistry using a repeating two-step reaction cycle. Here we present a method to manually synthesize oligo-peptoids and to analyze the sequence of the peptoids using tandem mass spectrometry (MS/MS) techniques. The sample peptoid is a nonamer consisting of alternating N-(2-methyloxyethyl)glycine (Nme) and N-(2-phenylethyl)glycine (Npe), as well as an N-(2-aminoethyl)glycine (Nae) at the N-terminus. The sequence formula of the peptoid is Ac-Nae-(Npe-Nme)4-NH2, where Ac is the acetyl group. The synthesis takes place in a commercially available solid-phase reaction vessel. The rink amide resin is used as the solid support to yield the peptoid with an amide group at the C-terminus. The resulting peptoid product is subjected to sequence analysis using a triple-quadrupole mass spectrometer coupled to an electrospray ionization source. The MS/MS measurement produces a spectrum of fragment ions resulting from the dissociation of charged peptoid. The fragment ions are sorted out based on the values of their mass-to-charge ratio (m/z). The m/z values of the fragment ions are compared against the nominal masses of theoretically predicted fragment ions, according to the scheme of peptoid fragmentation. The analysis generates a fragmentation pattern of the charged peptoid. The fragmentation pattern is correlated to the monomer sequence of the neutral peptoid. In this regard, MS analysis reads out the sequence information of the peptoids.

A protocol is described for the manual synthesis of oligo-peptoids followed by sequence analysis by mass spectrometry.

寡 peptoids 的合成及质谱分析

Peptoids are sequence-controlled peptide-mimicking oligomers consisting of N-alkylated glycine units. Among many potential applications, peptoids have ...

Synthesis of Substrate-Bound Au Nanowires Via an Active Surface Growth Mechanism

Advancing synthetic capabilities is important for the development of nanoscience and nanotechnology. The synthesis of nanowires has always been a challenge, as it requires asymmetric growth of symmetric crystals. Here, we report a distinctive synthesis of substrate-bound Au nanowires. This template-free synthesis employs thiolated ligands and substrate adsorption to achieve the continuous asymmetric deposition of Au in solution at ambient conditions. The thiolated ligand prevented the Au deposition on the exposed surface of the seeds, so the Au deposition only occurs at the interface between the Au seeds and the substrate. The side of the newly deposited Au nanowires is immediately covered with the thiolated ligand, while the bottom facing the substrate remains ligand-free and active for the next round of Au deposition. We further demonstrate that this Au nanowire growth can be induced on various substrates, and different thiolated ligands can be used to regulate the surface chemistry of the nanowires. The diameter of the nanowires can also be controlled with mixed ligands, in which another &#34;bad&#34; ligand could turn on the lateral growth. With the understanding of the mechanism, Au nanowire-based nanostructures can be designed and synthesized.

We report a solution-based method to synthesize substrate-bound Au nanowires. By tuning the molecular ligands used during the synthesis, the Au nanowires can be grown from various substrates with different surface properties. Au nanowire-based nanostructures can also be synthesized by adjusting the reaction parameters.

通过活性表面生长机制合成基片束缚金纳米线

Advancing synthetic capabilities is important for the development of nanoscience and nanotechnology. The synthesis of nanowires has always been a ...

Solid-phase Synthesis of [4.4] Spirocyclic Oximes

A convenient synthetic route for spirocyclic heterocycles is well sought after due to the molecule&#39;s potential use in biological systems. By means of solid-phase synthesis, regenerating Michael (REM) linker strategies, and 1,3-dipolar cycloaddition, a library of structurally similar heterocycles, both with and without a spirocyclic center, can be constructed. The main advantages of the solid-support synthesis are as follows: first, each reaction step can be driven to completion using a large excess of reagents resulting in high yields; next, the use of commercially available starting materials and reagents keep the costs low; finally, the reaction steps are easy to purify via simple filtration. The REM linker strategy is attractive because of its recyclability and traceless nature. Once a reaction scheme is completed, the linker can be reused multiple times. In a typical solid-phase synthesis, the product contains either a part of or the whole linker, which can prove undesirable. The REM linker is &#34;traceless&#34; and the point of attachment between the product and the polymer is indistinguishable. The high diastereoselectivity of the intramolecular 1,3-dipolar cycloaddition is well documented. Limited by the insolubility of the solid support, the reaction progression can only be monitored by a change in the functional groups (if any) via infrared (IR) spectroscopy. Thus, the structural identification of intermediates cannot be characterized by conventional nuclear magnetic resonance (NMR) spectroscopy. Other limitations to this method stem from the compatibilities of the polymer/linker to the desired chemical reaction scheme. Herein we report a protocol that allows for the convenient production of spirocyclic heterocycles that, with simple modifications, can be automated with high-throughput techniques.

Here we present a protocol to demonstrate an efficient method for the synthesis of spirocyclic heterocycles. The five-step process utilizes solid-phase synthesis and regenerating Michael linker strategies. Generally difficult to synthesize, we present a customizable method for the synthesis of spirocyclic molecules otherwise inaccessible to other modern approaches.

[4.4] 刺环氧基的固相合成

A convenient synthetic route for spirocyclic heterocycles is well sought after due to the molecule&#39;s potential use in biological systems. By means of ...

Synthesis and Characterization of Amphiphilic Gold Nanoparticles

Gold nanoparticles covered with a mixture of 1-octanethiol (OT) and 11-mercapto-1-undecane sulfonic acid (MUS) have been extensively studied because of their interactions with cell membranes, lipid bilayers, and viruses. The hydrophilic ligands make these particles colloidally stable in aqueous solutions and the combination with hydrophobic ligands creates an amphiphilic particle that can be loaded with hydrophobic drugs, fuse with the lipid membranes, and resist nonspecific protein adsorption. Many of these properties depend on nanoparticle size and the composition of the ligand shell. It is, therefore, crucial to have a reproducible synthetic method and reliable characterization techniques that allow the determination of nanoparticle properties and the ligand shell composition. Here, a one-phase chemical reduction, followed by a thorough purification to synthesize these nanoparticles with diameters below 5 nm, is presented. The ratio between the two ligands on the surface of the nanoparticle can be tuned through their stoichiometric ratio used during synthesis. We demonstrate how various routine techniques, such as transmission electron microscopy (TEM), nuclear magnetic resonance (NMR), thermogravimetric analysis (TGA), and ultraviolet-visible (UV-Vis) spectrometry, are combined to comprehensively characterize the physicochemical parameters of the nanoparticles.

Amphiphilic gold nanoparticles can be used in many biological applications. A protocol to synthesize gold nanoparticles coated by a binary mixture of ligands and a detailed characterization of these particles is presented.

两栖金纳米粒子的合成与表征

Gold nanoparticles covered with a mixture of 1-octanethiol (OT) and 11-mercapto-1-undecane sulfonic acid (MUS) have been extensively studied because of ...

Hierarchical and Programmable One-Pot Oligosaccharide Synthesis

This article presents a general experimental protocol for programmable one-pot oligosaccharide synthesis and demonstrates how to use Auto-CHO software for generating potential synthetic solutions. The programmable one-pot oligosaccharide synthesis approach is designed to empower fast oligosaccharide synthesis of large amounts using thioglycoside building blocks (BBLs) with the appropriate sequential order of relative reactivity values (RRVs). Auto-CHO is a cross-platform software with a graphical user interface that provides possible synthetic solutions for programmable one-pot oligosaccharide synthesis by searching a BBL library (containing about 150 validated and &#62;50,000 virtual BBLs) with accurately predicted RRVs by support vector regression. The algorithm for hierarchical one-pot synthesis has been implemented in Auto-CHO and uses fragments generated by one-pot reactions as new BBLs. In addition, Auto-CHO allows users to give feedback for virtual BBLs to keep valuable ones for further use. One-pot synthesis of stage-specific embryonic antigen 4 (SSEA-4), which is a pluripotent human embryonic stem cell marker, is demonstrated in this work.

This protocol demonstrates how to use the Auto-CHO software for hierarchical and programmable one-pot synthesis of oligosaccharides. It also describes the general procedure for RRV determination&#160;experiments and one-pot glycosylation of SSEA-4.

分层和可编程单罐寡糖合成

This article presents a general experimental protocol for programmable one-pot oligosaccharide synthesis and demonstrates how to use Auto-CHO software for ...