Authors would like to thank the financial support from Swiss National Science Foundation (SNF) through the project no. 200021_160174.

注意:一双层的微流体装置的两个层是使用一个绘图软件设计， 例如 ，AutoCAD和印刷，以形成高分辨率膜掩模，用5微米的特征精度的限制。主模具由SU-8光刻在4"硅晶片中创建，允许生产结构50微米的高度。 1.主模具制造使用SU-8光刻<ol><li>放置在硅晶片上的热板上10分钟来脱水设定在200℃。 注:硅晶片脱水提供了更好的接触，并确保对SU-8光致抗蚀剂的旋涂步骤中的扩频。 </li><li>冷却该脱水晶片至室温历时3分钟。 </li><li>装载在晶片上旋转涂布机和存款4毫升的SU-8光致抗蚀剂中的晶片的中心（约1毫升的SU-8每衬底英寸）。 <ol><li>首先，传播沉积SU-8慢慢在500 revoluti每分钟（rpm）组件10秒。这样的旋转速度，确保的SU-8的覆盖在整个晶片表面增加。 </li><li>其次，通过以更高的速度旋转该衬底控制的SU-8的厚度。在目前的实验中，使用3000rpm的旋转速度为30秒，以产生的SU-8设有50微米高。 </li></ol></li><li>擦拭晶片同时以低转速（通常为100转）旋转小心用棉擦拭的边珠。 </li><li>在95℃下加热的热板上的旋涂的晶片15分钟，从SU-8（ 即 ，"软烘烤"）除去残留的溶剂。 注意:模式或"皱纹"，在抗蚀剂层的存在指示该不完全除去溶剂。 </li><li>冷却该焙烧晶片回落到室温，并在光掩模的乳剂打印面与前曝光晶片接触。 </li><li>打开紫外灯和曝光单元上，并让系统稳定一段10米英寸（根据时间=曝光能量/在365nm强度）测量灯强度在365nm用紫外视力计，并估计所需的曝光时间。 注意:在当前实验中的曝光能量计算为250毫焦/厘米2。 </li><li>露出旋涂的晶片于UV光在先前步骤中所估计的时间上的光掩模。在这里，揭露了79.6秒。 </li><li>曝光后立即烘烤的热板上曝光晶片在65℃下1分钟，随后在95℃下5分钟。在该步骤中，反应通过UV -light发起和烘烤后完成。 </li><li>离开后烘烤晶片历时3分钟冷却至室温。 </li><li>通过在8分钟在SU-8显影剂溶解它开发非交联SU-8在晶片上。为了确保能完全消除非交联SU-8的，分裂过程分为两个步骤。 <ol><li>在第一，沉浸在显影剂溶液中的晶片5分钟，再移动的大多数非交联SU-8。 </li><li>然后浸泡在显影剂的新鲜溶液晶片3分钟以溶解剩余的非交联SU-8（通常受困交联结构之间）。 </li></ol></li><li>冲洗显影晶片用异丙醇，并让具有图案化结构中的晶片（以下简称为"母模"）站干。漂洗后的母模乳白色的残留物的观察表明，发展是不完整的。 </li><li>加热的热板上干燥母模在200℃下2-5分钟，以"硬烘焙"中的抗蚀基板和退火潜在的裂纹。 </li><li>允许所制造的母模冷却至室温。 </li><li>放置在通风橱内，在干燥器的母模（连接到一个真空泵）。 </li><li>倾100μl的三甲基氯硅烷（TMCS）到玻璃烧杯中，并把这个干燥器内。 注意:TMCS是易燃，corrosive和毒性;因此，处理步骤应在通风橱内进行，与戴防护手套，护目镜和白大褂的用户。 </li><li>把干燥器真空并等待至少1小时，让TMCS蒸气沉积在母模的表面。 </li><li> 1小时后，慢慢地平衡干燥器内并到大气中的压力打开。 注意:不要直接开干燥器上述呼吸。 </li><li>取出硅烷化主机和关闭干燥器。 </li></ol> 2.双层微流体装置的研制注意:该协议是对时间和温度特别敏感。任何不遵循的时间帧和温度可能会导致非粘合的，因此，非功能器件的制造。 <ol><li>倾PDMS弹性体和固化剂的混合物，（5:1的重量比）到一次性称量皿，并用塑料刮铲充分混合。在目前的实验S，使用50克弹性体和10克固化剂，以形成一个PDMS层约5mm的高度19,26。 </li><li>放置均匀混合的PDMS在真空下干燥器中脱气和除去夹带的气泡为15分钟。 </li><li>混合的PDMS弹性体和固化剂（20:1的重量比）在一次性称量盘（ 例如 ，10g的弹性体和0.5克固化剂）19,26。 </li><li>修复一帧中的"控制层"母模（在当前的实验中，一个11毫米的圆形聚四氟乙烯（PTFE）环）。 </li><li> 15分钟后，放置20:在干燥器1的PDMS混合物在真空下脱气。 </li><li>从干燥器1 PDMS的混合物倒到这是位于圆框里面的"控制层"母模:在同一时间，前面的步骤，取出5。放置装有与PDMS和母模进入在真空下的干燥器以及该帧。保持顺差PDMS。 </li><li> 45分钟后（30分钟后推ING都PDMS混合物放入干燥器），取两者PDMS混合物出干燥器，并放置含5帧:1 PDMS和在80℃的"控制层"模具师傅在烤箱。 </li><li>与此同时，开始旋涂的"流体层"母模与20:1混合PDMS。用于旋涂的旋转速度根据所需的高度来确定，并且已在别处27日报道。瞄准60分钟以终止旋涂，并保持剩余的PDMS。 </li><li> 60分钟后，把涂覆有20"流体层"母模旋:1的PDMS入烘箱中在80℃。 </li><li>在75分钟，取这两个主模具出炉。 </li><li>剥离只有5:从"控制层"母模1 PDMS，骰子用刀片基体，并在设计中确定的入口位置1毫米的穿刺活检冲床冲床控制层的孔中。这里，控制层是在长度为24毫米和为24mm宽度。 </li><li> - [R从使用胶带切割好的芯片emove碎屑。 </li><li>手动组装切块并在20的顶部穿孔控制层芯片:涂覆在使用具有500X的放大倍数在立体显微镜（ 图1）中的"流体层"母模1的PDMS自旋。 </li><li>倒入周围画组装芯片的残余PDMS，使较厚的PDMS层，从而有利于在年底拆除保税流体和控制层。 </li><li>放置装有在烘箱两个层设备的"流体层的"主模在80℃和储存过夜。 </li><li>第二天，取该固化组件出炉并使其冷却至室温。 </li><li>剥离从"流体层"母模与PDMS组件，骰子用刀片的制造的双层器件（24毫米长和24毫米宽）和冲头的流体入口/出口用1.5毫米的活检穿孔。 </li><li>对待与OPE芯片表面n个信道和盖玻片（24毫米×40毫米），电晕放电，并立即粘结在一起。超过1分钟移动在PDMS板和玻璃盖玻片电晕放电处理。另外，使用台式等离子系统，以方便粘合。 </li><li>在70-80℃下储存在烘箱粘合双层芯片至少4小时。 </li></ol> 3.微流控系统组装<ol><li>微流体装置已被组装之后，用聚四氟乙烯（PTFE）管（1.3毫米内径）芯片的流体层的入口连接到流体储（注射器）。 </li><li>连接压力供给源，使用硅橡胶管和金属连接器具有1.6毫米的外径控制层入口。 </li><li>打开和使用由手动操作的压力源在3巴施加加压空气关闭阀门。使用一系列计算机控制的注射泵的供给流体通道。 </li><li>可视化的阀门驱动和设备操作与安装在倒置显微镜高分辨率摄像头。使用5X到63X的放大倍率。 </li></ol> 4.操作层流状​​态由气动执行机构凯奇注意:流体层包括两个入口会聚通道，其在宽度150微米，更广泛的主通道300微米的宽度。并且控制层具有一系列位于主流体通道的顶端相同的长方形阀（250微米×200微米）。 <ol><li>一旦设定了连接到注射器泵和气动控制器的系统，通过以20微升/分钟的流速在入口通道中的一个引入含水染料流。 </li><li>通过在3巴驱动它关闭阀门。 </li><li>请注意，流体仍然可以流阀周围。此功能是实现控制化学处理被困结构18,25的重要&lt;/ SUP&gt;。 </li><li>通过释放压力打开阀门。 </li><li>而将染料溶液流过第一通道，注入另一种水性流体送入第二进口通道20微升/分钟。两种水溶液流之间的界面是由于存在于微流体设备中的层流状态形成。 </li><li>通过在3巴驱动它关闭阀门。在这种情况下，阀的致动改变了两种水溶液流的接口;可用于在CP（ 参见下文 ）18,28的形成过程中修改合成途径的结果。 </li><li>改变流体流速至30微升/分钟，10微升/分钟，并观察向下或向上移引导两种流体之间产生界面。 </li></ol> 5.本地化的微粒<ol><li>连接所制造的双层芯片到注射器泵和气动控制器的系统。 </li><li>制备含有10％（重量）的聚苯乙烯的水溶液荧光体颗粒（分别为5微米的直径，激发和发射最大值在468纳米和508纳米）。 </li><li>使用在488纳米的波长下操作激光激发源。 </li><li>引入含颗粒的流体进入两个进入通道以20微升/分钟的总流速。 </li><li>等待2分钟，直到稳定的流被建立。 </li><li>将阀门在3巴将其关闭。几个颗粒将被夹在阀的下面，并同时将流保持在表面上的局部。 </li></ol> 6.生成和配位聚合物的可控的降低（CP） <ol><li>制备硝酸银的2.5 mM溶液（ 硝酸银）。 </li><li>准备半胱氨酸（半胱氨酸）为2.5 mm的水溶液。 </li><li>制备在乙醇18的饱和抗坏血酸溶液。 </li><li>使用相同的双层芯片和两种试剂注入到两个进入通道（每个入口一种试剂）的每个以流速50微升/分钟。 </li><li>观察两个共同流入水蒸气的界面银和半胱氨酸（银（Ⅰ）的Cys）CP的形成。 </li><li>将阀门在3巴套住形成的Ag（I）半胱氨酸的CP阀下方。 </li><li>冲洗蒸馏水成以50μl的流速的入口通道/分钟洗去在合成过程中使用的过剩的试剂。 </li><li>释放压力并打开阀门。所生成的CP的保持停流条件下的阀的下方。 </li><li>为了进行受控化学还原捕集的Ag（I）的半胱氨酸的CP时，释放阀压力在1巴，并以10微升/分钟的流速冲洗的乙醇饱和抗坏血酸溶液。 </li><li>观察到归因于（（0）的Ag）由抗坏血酸18还原银（Ⅰ）为金属银的清楚的颜色变化。 </li></ol>

<ol>
	<li>. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Nicolet iS5 User Guide. , (2015).</li></ol>

The authors have nothing to disclose.

The reported approach can be easily modified to fabricate different valve shapes to afford other applications such as fluid confinement. Indeed, the flexibility of this protocol also allows for modification of the thickness of the bottom layer, and thereby of the PDMS membrane, from a couple of tens to a few hundreds of microns to fulfill any application of interest. Moreover, dimensions of structures in each layer of the device can be optimized for the desired application and various heights of structures on the master molds can be simply achieved by spinning the photoresist at different velocities. Spinning the photoresist at a higher speed results in thinner structures. 
To better implement the protocol, a clean room environment for the fabrication of the master molds is substantially essential; otherwise, the fabrication procedure will lead to defective master molds and thereby to unusable microfluidic devices. Two critical aspects should be emphasized in this protocol: i) the constant temperature of the oven that needs to be adjusted to 80 &#176;C and ii) the programmed time period between processes that has to be complied accurately. Any modification of temperature and time frame in the protocol might lead to non-bonded chips, and thus, to non-functional devices.
The "turbulent free" conditions typically encountered in microfluidic systems have recently been employed for the generation of microstructures or molecular materials inside30 and outside single layer microfluidic chips31. In double-layer microfluidic chips, the laminar flow regime, and hence, the interface generated between continuous co-flows can be manipulated using pneumatic cages18,28. These devices also provide for effective control over the synthetic pathway, which in turn leads to precise localization and trapping on surfaces18. 
As mentioned earlier, pneumatic actuation in double-layer microfluidic chips has been previously employed for various applications such as cell trapping20, enzymatic activity studies21 and protein crystallization24. However, the main objective of the reported approach is to propose a platform to be used for trapping and directing the coordination pathway of a crystalline molecular material and controlling chemical reactions onto on-chip trapped structures18,25. 
The described method does not only allow trapping of anisotropic structures but can be used to localize particles onto surfaces. Future studies can be effectively directed towards the design of new valve shapes for additional application in biology, materials science and sensor technologies. The combination of different valve shapes as well as altered channel heights and membrane thicknesses can be employed to fulfill specific applications, such as chemical studies based on diffusional mixing and the localization of material growth.
A further application of the described microfluidic platforms is in the controlled chemical doping of crystals, which can lead to a rationalized formation of interfaces in crystalline structures19. This approach also provides for a wide range of post-treatments of on-chip trapped structures; a methodology that will undoubtedly open new horizons in materials engineering.
It is important to underline that the number of technologies enabling controlled chemical reactions under dynamic conditions and onto crystalline matter are very limited at present, hence making this approach very attractive in materials-related fields. However, a major limitation of this technology is the use of PDMS. PDMS elastomer is incompatible with many organic solvents, which limits the number of reactions that can be conducted inside these microfluidic chips. In future, the development of other elastomers that can tolerate and be stable against a broader number of organic solvents will be highly required in order to expand this field of research to other materials and chemistries.

分子材料长期被研究在科学界，因为在诸如分子电子学，光学和传感器1-4他们的应用广泛的数目。在这些有机导体是一个特别令人兴奋的类，因为它们在柔性显示器和集成功能元件5,6的中心作用的分子的材料。然而，用于使能在基于分子的材料的电子电荷传输方法被限制的电荷输送配合物（的CTC）和电荷输送的盐（CTS消息）7-10的形成。频繁，的CTC和CTS消息是通过电化学方法或通过直接化学氧化还原反应产生的;妨碍供体或受体部分的受控转换到更复杂的结构，其中多功能可以设想流程。因此，为可控生成和分子基的操纵新系统的方法的澄清拆建物料仍保留在材料科学和分子工程领域的一个显著的挑战，如果成功，无疑将导致新的功能和新技术应用。 在这种情况下，微流体技术最近已用于合成基于分子的材料，由于其在合成过程11,12，以控制热与质量传递以及试剂的反应扩散体积的能力。简单地说，在连续的流动和在低雷诺数两个或更多个试剂流之间的稳定的接口，可以实现，其中，得到流路，其中，混合仅通过扩散13-16发生内部良好控制的反应区的形成。事实上，我们先前采用层流来本地化结晶分子材料，例如微流体通道17内的配位聚合物（CPS）的合成途径。虽然这种方法已经显示摹原位 18来实现在实现新颖的CP的纳米结构，所述直接集成这样的结构在表面上，以及控制化学处理它们的形成还没有经过REAT承诺。为了克服这一限制，最近我们表明，在两层微流体装置引入微流体气动笼（或阀门）的致动可以有利在这方面可以使用。由于地震的研究小组19的创举，微流控气动阀经常被用于单细胞捕获和隔离20，酶活性调查21，小的流体体积22俘获，在表面23和蛋白质结晶24功能材料的国产化。然而，我们已经表明，双层的微流体装置可用于捕获，本地化和原位整合形成的结构，以读出的组件和表面上的18。此外，我们还证明，这种技术可以用来在捕获结构进行控制的化学处理，使这两个"微流体辅助配体交换"18和控制的化学有机晶体18,25的掺杂。在这两种情况下，的CTC可以控制微流体的条件下进行合成，并在最近的研究中，多功能可以在相同的材料片进行说明。这里，我们证明采用染料载货流动这些双层的微流体装置的性能，产生和控制一个CP的协调通路以及其微流体通道的表面上的定位和最后评估控制的化学处理到芯片上被困结构。

<table border="0" cellpadding="0" cellspacing="0" width="1065">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:264px;">High resolution film masks</td>
			<td style="width:267px;">Microlitho, UK</td>
			<td style="width:157px;">-</td>
			<td style="width:377px;">Features down to 5um</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:264px;">SU8 photoresist</td>
			<td style="width:267px;">MicroChem Corp., USA</td>
			<td style="width:157px;">SU8-3050</td>
			<td style="width:377px;">-</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:264px;">Silicon wafers</td>
			<td style="width:267px;">Silicon Materials Inc., Germany</td>
			<td style="width:157px;">4&#34; Silicon Wafers</td>
			<td style="width:377px;">Front surface: polished, Back surface: etched</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:264px;">Silicone Elastomer KIT (PDMS)</td>
			<td style="width:267px;">Dow Corning, USA</td>
			<td style="width:157px;">Sylgard&#174; 184</td>
			<td style="width:377px;">-</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:264px;">Spinner</td>
			<td style="width:267px;">Suiss MicroTech, Germany</td>
			<td style="width:157px;">Delta 80 spinner</td>
			<td style="width:377px;">-</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:264px;">UV-Optometer</td>
			<td style="width:267px;">Gigahertz-Optik Inc., USA</td>
			<td style="width:157px;">X1-1</td>
			<td style="width:377px;">-</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:264px;">Mask Aligner</td>
			<td style="width:267px;">Suiss MicroTech, Germany</td>
			<td style="width:157px;">Karl Suss MA/BA6&#160;</td>
			<td style="width:377px;">-</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:264px;">SU8 developer</td>
			<td style="width:267px;">Micro resist technology GmbH, Germany</td>
			<td style="width:157px;">mr-Dev 600</td>
			<td style="width:377px;">-</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:264px;">Trimethylsilyl chloride&#160;</td>
			<td style="width:267px;">Sigma-Aldrich, Switzerland</td>
			<td style="width:157px;">386529</td>
			<td style="width:377px;">&#8805;97%, CAUTION: Handle it only under fume hood.</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:264px;">Biopsy puncher</td>
			<td style="width:267px;">Miltex GmBH, Germany</td>
			<td style="width:157px;">33-31AA-P/25</td>
			<td style="width:377px;">1 mm</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:264px;">Biopsy puncher</td>
			<td style="width:267px;">Miltex GmBH, Germany</td>
			<td style="width:157px;">33-31A-P/25</td>
			<td style="width:377px;">1.5 mm</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:264px;">Glass coverslip</td>
			<td style="width:267px;">Menzel-Glaser, Germany</td>
			<td style="width:157px;">BB024040SC</td>
			<td style="width:377px;">24 mm &#215; 60 mm, #5</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:264px;">Laboratory Corona Treater</td>
			<td style="width:267px;">Electro-Technic Products, USA</td>
			<td style="width:157px;">BD-20ACV&#160;</td>
			<td style="width:377px;">-</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:264px;">PTFE tubing</td>
			<td style="width:267px;">PKM SA, Switzerland</td>
			<td style="width:157px;">AWG-TFS-XXX</td>
			<td style="width:377px;">AWG 20TFS, roll of 100 m</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:264px;">Silicone rubber tubing</td>
			<td style="width:267px;">Hi-Tek Products, UK</td>
			<td style="width:157px;">-</td>
			<td style="width:377px;">1 mm I.D.</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:264px;">neMESYS Syringe Pumps</td>
			<td style="width:267px;">Cetoni GmbH, Germany</td>
			<td style="width:157px;">Low Pressure (290N)</td>
			<td style="width:377px;">-</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:264px;">High resolution camera</td>
			<td style="width:267px;">Zeiss, Germany</td>
			<td style="width:157px;">Axiocam MRc 5</td>
			<td style="width:377px;">-</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:264px;">Fluorescent inverted microscope</td>
			<td style="width:267px;">Zeiss, Germany</td>
			<td style="width:157px;">Axio Observer A1</td>
			<td style="width:377px;">Operable at two wavelengths i.e. 350 nm and 488 nm</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:264px;">Green polystyrene fluorescent particles</td>
			<td style="width:267px;">Fisher Scientific, Switzerland</td>
			<td style="width:157px;">11523363</td>
			<td style="width:377px;">Size: 5.0 um, solid content: 1%</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:264px;">Silver nitrate (AgNO3)</td>
			<td style="width:267px;">Sigma-Aldrich, Switzerland</td>
			<td style="width:157px;">209139</td>
			<td style="width:377px;">&#8805;99.0%,&#160;</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:264px;">L-Cysteine (Cys)</td>
			<td style="width:267px;">Sigma-Aldrich, Switzerland</td>
			<td style="width:157px;">W326305</td>
			<td style="width:377px;">&#8805;97.0%,&#160;</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:264px;">Disposable weighing dish</td>
			<td style="width:267px;">Sigma-Aldrich, Switzerland</td>
			<td style="width:157px;">Z154881</td>
			<td>L &#215; W &#215; H : 86&#160;mm &#215; 86&#160;mm &#215; 25&#160;mm</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:264px;">Disposable weighing dish</td>
			<td style="width:267px;">Sigma-Aldrich, Switzerland</td>
			<td style="width:157px;">Z708593</td>
			<td>Hexagonal, Size XL</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:264px;">Plastic spatula</td>
			<td style="width:267px;">Semadeni, Switzerland</td>
			<td style="width:157px;">3340</td>
			<td>L &#215; W : 135 mm x 14 mm</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:264px;">Dye, Bemacron ROT E-G</td>
			<td style="width:267px;">Bezema, Switzerland</td>
			<td style="width:157px;">BZ 911.231</td>
			<td>Red</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:264px;">Stereomicroscope</td>
			<td style="width:267px;">Wild Heerbrugg, Switzerland</td>
			<td style="width:157px;">Wild M8</td>
			<td>500x magnification</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:264px;">Disposable scalpels</td>
			<td style="width:267px;">B. Braun, Switzerland</td>
			<td style="width:157px;">233-5320</td>
			<td>Nr. 20</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:264px;">L-Ascorbic acid</td>
			<td style="width:267px;">Sigma-Aldrich, Switzerland</td>
			<td style="width:157px;">A4403</td>
			<td>-</td>
		</tr>
	</tbody>
</table>

microfluidic pneumatic cages: a novel approach for in-chip crystal trapping, manipulation and controlled chemical treatment

The precise localization and controlled chemical treatment of structures on a surface are significant challenges for common laboratory technologies. Herein, we introduce a microfluidic-based technology, employing a double-layer microfluidic device, which can trap and localize in situ and ex situ synthesized structures on microfluidic channel surfaces. Crucially, we show how such a device can be used to conduct controlled chemical reactions onto on-chip trapped structures and we demonstrate how the synthetic pathway of a crystalline molecular material and its positioning inside a microfluidic channel can be precisely modified with this technology. This approach provides new opportunities for the controlled assembly of structures on surface and for their subsequent treatment.

双层微流体装置包括在PDMS结构粘结的微流控芯片， 如图1。第一层，它是在键合到表面的同时，被用于流动流体（液体层），而第二层，这是直接键合到第一PDMS层，用于流气体（控制层）。 <img alt="图1" src="/files/ftp_upload/54193/54193fig1.jpg" /> 图1.双层微流体装置。（A）示意图，并在我们的调查中使用的双层微流体装置（ 二 ）显微照片。 <a href="https://www.jove.com/files/ftp_upload/54193/54193fig1large.jpg" target="_blank">请点击此处查看该图的放大版本。</a> 通过在通道的气体的注射控制层挤压朝向表面（ 图2A和图2B）中的流体层，允许结构的捕集和本地化微流体通道表面上。 PDMS膜致动可以用来产生气动笼和/或由一个气动控制器控制微阀。作为膜致动的范例模型中，我们表明，流体层的完整偏转如何避免了染料的载货流分发其致动（ 图2C）和微通道表面上的荧光微粒的捕集后的阀下方（ 图2D和2E） 。 <img alt="图2" src="/files/ftp_upload/54193/54193fig2.jpg" /> 图2.膜驱动和诱捕结构。（A）侧和（B）顶视图插图显示双层微流体装置是前（上）和后气动阀的（底部）致动。双层的微流体装置（C）的显微照片之前（上图）和流体层（底部）的挤压后。在底部面板，流体层填充有若丹明染料的膜致动的一个更好的感知的水溶液。 （D）的前（顶）双层的微流体装置的明视场显微照片和后（底）用流动的水溶液含有溶液的聚苯乙烯荧光发色粒子在阀的致动（10重量％）。在D所示的光学显微镜图像（E）荧光图像<a href="https://www.jove.com/files/ftp_upload/54193/54193fig2large.jpg" target="_blank">请点击此处查看该图的放大版本。</a> 图3A示出的原位捕获生成的CP的双层微流体装置内部通过actuat气动笼离子。请注意，一个新的协调通路的第一阀的致动之后产生。阀致动确保了银（Ⅰ）的Cys在两个试剂流的界面产生CP的俘获并促进新的协调通路（ 图3A）的形成。银（I）半胱氨酸的两个试剂流的界面产生CP的详细化学特性可以在以往的研究17,18找到。此外，与后除去多余的试剂溶液用纯水（ 图3B）的流动，在乙醇中的饱和抗坏血酸溶液可以添加到用于受控化学还原芯片上捕获结构（ 图3C）的微流体通道。减少3个酒吧，以1杆阀门压力有利于被困银（I）半胱氨酸CP夹紧区18下方的控制化学处理。被困银（I）半胱氨酸CP的颜色变化至黑褐色是ttributed到一价银的还原到金属，在符合以前的观察18,29。 <img alt="图3" src="/files/ftp_upload/54193/54193fig3.jpg" /> 图3.陷印银（I）半胱氨酸CP和控制化学还原法。（A）光学显微镜图像显示的原位原料合成一个新的协调途径的银（I）半胱氨酸CP和产生诱捕。钳位区域下面困的CP（二）显微照片水流去除多余的试剂的解决方案后，并在（C），还原反应过程后，同样的微阀的显微照片。 <a href="https://www.jove.com/files/ftp_upload/54193/54193fig3large.jpg" target="_blank">请点击此处查看大图这个数字。</a>

Watch this Scientific Journal Video about Microfluidic Pneumatic Cages: A Novel Approach for In-chip Crystal Trapping, Manipulation and Controlled Chemical Treatment at JoVE.com

Microfluidic Pneumatic Cages: A Novel Approach for In-chip Crystal Trapping, Manipulation and Controlled Chemical Treatment

Herein, we describe the fabrication and operation of a double-layer microfluidic system made of polydimethylsiloxane (PDMS). We demonstrate the potential of this device for trapping, directing the coordination pathway of a crystalline molecular material and controlling chemical reactions onto on-chip trapped structures.

微流控气动笼:在芯片水晶捕获，处理的新方法和控制化学处理

The precise localization and controlled chemical treatment of structures on a surface are significant challenges for common laboratory technologies. ...

microfluidic-pneumatic-cages-novel-approach-for-chip-crystal-trapping

Research

JoVE Journal

Chemistry

9.4K 次观看.  Empa - Swiss Federal Laboratories for Materials Science and Technology. Herein, we describe the fabrication and operation of a double-layer microfluidic system made of polydimethylsiloxane (PDMS). We demonstrate the potential of this device for trapping, directing the coordination pathway of a crystalline molecular material and controlling chemical reactions onto on-chip trapped structures. 

视频: Microfluidic Pneumatic Cages: A Novel Approach for In-chip Crystal Trapping, Manipulation and Controlled Chemical Treatment

Free Radicals in Chemical Biology: from Chemical Behavior to Biomarker Development

The involvement of free radicals in life sciences has constantly increased with time and has been connected to several physiological and pathological processes. This subject embraces diverse scientific areas, spanning from physical, biological and bioorganic chemistry to biology and medicine, with applications to the amelioration of quality of life, health and aging. Multidisciplinary skills are required for the full investigation of the many facets of radical processes in the biological environment and chemical knowledge plays a crucial role in unveiling basic processes and mechanisms. We developed a chemical biology approach able to connect free radical chemical reactivity with biological processes, providing information on the mechanistic pathways and products. The core of this approach is the design of biomimetic models to study biomolecule behavior (lipids, nucleic acids and proteins) in aqueous systems, obtaining insights of the reaction pathways as well as building up molecular libraries of the free radical reaction products. This context can be successfully used for biomarker discovery and examples are provided with two classes of compounds: mono-trans isomers of cholesteryl esters, which are synthesized and used as references for detection in human plasma, and purine 5',8-cyclo-2'-deoxyribonucleosides, prepared and used as reference in the protocol for detection of such lesions in DNA samples, after ionizing radiations or obtained from different health conditions.

Radical-based biomimetic chemistry has been applied to building-up libraries necessary for biomarker development.

自由基化学生物学的化学行为，生物标记开发

The involvement of free radicals in life sciences has constantly increased with time and has been connected to several physiological and pathological ...

科研

化学

A Guided Materials Screening Approach for Developing Quantitative Sol-gel Derived Protein Microarrays

Microarrays have found use in the development of high-throughput assays for new materials and discovery of small-molecule drug leads. Herein we describe a guided material screening approach to identify sol-gel based materials that are suitable for producing three-dimensional protein microarrays. The approach first identifies materials that can be printed as microarrays, narrows down the number of materials by identifying those that are compatible with a given enzyme assay, and then hones in on optimal materials based on retention of maximum enzyme activity. This approach is applied to develop microarrays suitable for two different enzyme assays, one using acetylcholinesterase and the other using a set of four key kinases involved in cancer. In each case, it was possible to produce microarrays that could be used for quantitative small-molecule screening assays and production of dose-dependent inhibitor response curves. Importantly, the ability to screen many materials produced information on the types of materials that best suited both microarray production and retention of enzyme activity. The materials data provide insight into basic material requirements necessary for tailoring optimal, high-density sol-gel derived microarrays.

A guided material screening approach to develop sol-gel derived protein doped microarrays using an emerging pin-printing method of fabrication is described. This methodology is demonstrated through the development of acetylcholinesterase and multikinase microarrays, which are used for cost-effective small-molecule screening.

在导游的带领下材料的筛选方法定量溶胶 - 凝胶蛋白芯片开发

Microarrays have found use in the development of high-throughput assays for new materials and discovery of small-molecule drug leads. Herein we describe a ...

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 ...

Preparing Adherent Cells for X-ray Fluorescence Imaging by Chemical Fixation

X-ray fluorescence imaging allows us to non-destructively measure the spatial distribution and concentration of multiple elements simultaneously over large or small sample areas. It has been applied in many areas of science, including materials science, geoscience, studying works of cultural heritage, and in chemical biology. In the case of chemical biology, for example, visualizing the metal distributions within cells allows us to study both naturally-occurring metal ions in the cells, as well as exogenously-introduced metals such as drugs and nanoparticles. Due to the fully hydrated nature of nearly all biological samples, cryo-fixation followed by imaging under cryogenic temperature represents the ideal imaging modality currently available. However, under the circumstances that such a combination is not easily accessible or practical, aldehyde based chemical fixation remains useful and sometimes inevitable. This article describes in as much detail as possible in the preparation of adherent mammalian cells by chemical fixation for X-ray fluorescent imaging.

Here, we present a protocol on how to determine the quantity and distribution of metals in a sample using synchrotron X-ray fluorescence. We focus on adherent cells, and describe the chemical fixation method to prepare this sample. We then describe how to mount and image the sample using synchrotron X-rays.

化学固定准备贴壁细胞的X射线荧光成像

X-ray fluorescence imaging allows us to non-destructively measure the spatial distribution and concentration of multiple elements simultaneously over ...

High Pressure Single Crystal Diffraction at PX^2

In this report we describe detailed procedures for carrying out single crystal X-ray diffraction experiments with a diamond anvil cell (DAC) at the GSECARS 13-BM-C beamline at the Advanced Photon Source. The DAC program at 13-BM-C is part of the Partnership for Extreme Xtallography (PX^2) project. BX-90 type DACs with conical-type diamond anvils and backing plates are recommended for these experiments. The sample chamber should be loaded with noble gas to maintain a hydrostatic pressure environment. The sample is aligned to the rotation center of the diffraction goniometer. The MARCCD area detector is calibrated with a powder diffraction pattern from LaB6. The sample diffraction peaks are analyzed with the ATREX software program, and are then indexed with the RSV software program. RSV is used to refine the UB matrix of the single crystal, and with this information and the peak prediction function, more diffraction peaks can be located. Representative single crystal diffraction data from an omphacite (Ca0.51Na0.48)(Mg0.44Al0.44Fe2+0.14Fe3+0.02)Si2O6 sample were collected. Analysis of the data gave a monoclinic lattice with P2/n space group at 0.35 GPa, and the lattice parameters were found to be: a = 9.496 &#177;0.006 &#197;, b = 8.761 &#177;0.004 &#197;, c = 5.248 &#177;0.001 &#197;, &#946; = 105.06 &#177;0.03&#186;, &#945; = &#947; = 90&#186;.

In this report, we describe detailed procedures for carrying out single crystal X-ray diffraction experiments with a diamond anvil cell at the GSECARS 13-BM-C beamline at the Advanced Photon Source. ATREX and RSV programs are used to analyze the data.

高压单晶衍射PX ^ 2

In this report we describe detailed procedures for carrying out single crystal X-ray diffraction experiments with a diamond anvil cell (DAC) at the ...

Preparation and Evaluation of 99mTc-labeled Tridentate Chelates for Pre-targeting Using Bioorthogonal Chemistry

Pre-targeting combined with bioorthogonal chemistry is emerging as an effective way to create new radiopharmaceuticals. Of the methods available, the inverse electron demand Diels-Alder (IEDDA) cycloaddition between a radiolabeled tetrazines and trans-cyclooctene (TCO) linked to a biomolecule has proven to be a highly effective bioorthogonal approach to imaging specific biological targets. Despite the fact that technetium-99m remains the most widely used isotope in diagnostic nuclear medicine, there is a scarcity of methods for preparing 99mTc-labeled tetrazines. Herein we report the preparation of a family of tridentate-chelate-tetrazine derivatives and their Tc(I) complexes. These hitherto unknown compounds were radiolabeled with 99mTc using a microwave-assisted method in 31% to 83% radiochemical yield. The products are stable in saline and PBS and react rapidly with TCO derivatives in vitro. Their in vivo pre-targeting abilities were demonstrated using a TCO-bisphosphonate (TCO-BP) derivative that localizes to regions of active bone metabolism or injury. In murine studies, the 99mTc-tetrazines showed high activity concentrations in knees and shoulder joints, which was not observed when experiments were performed in the absence of TCO-BP. The overall uptake in non-target organs and pharmacokinetics varied greatly depending on the nature of the linker and polarity of the chelate.

Preparation and Evaluation of 99mTc-labeled Tridentate Chelates for Pre-targeting Using Bioorthogonal Chemistry

Here, we describe a protocol for radiolabeling and in vivo testing of tridentate 99mTc(I) chelate-tetrazine derivatives for pre-targeting and bioorthogonal chemistry.

制备和评价<sup&gt;99米</sup&gt;锝标记的三齿螯合物预靶向使用生物正交化学

Pre-targeting combined with bioorthogonal chemistry is emerging as an effective way to create new radiopharmaceuticals. Of the methods available, the ...

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 ...

Microfluidic Dry-spinning and Characterization of Regenerated Silk Fibroin Fibers

The protocol demonstrates a method for mimicking the spinning process of silkworm. In the native spinning process, the contracting spinning duct enables the silk proteins to be compact and ordered by shearing and elongation forces. Here, a biomimetic microfluidic channel was designed to mimic the specific geometry of the spinning duct of the silkworm. Regenerated silk fibroin (RSF) spinning doped with high concentration, was extruded through the microchannel to dry-spin fibers at ambient temperature and pressure. In the post-treated process, the as-spun fibers were drawn and stored in ethanol aqueous solution. Synchrotron radiation wide-angle X-ray diffraction (SR-WAXD) technology was used to investigate the microstructure of single RSF fibers, which were fixed to a sample holder with the RSF fiber axis normal to the microbeam of the X-ray. The crystallinity, crystallite size, and crystalline orientation of the fiber were calculated from the WAXD data. The diffraction arcs near the equator of the two-dimensional WAXD pattern indicate that the post-treated RSF fiber has a high orientation degree.

A protocol for the microfluidic spinning and microstructure characterization of regenerated silk fibroin monofilament is presented.

微流控干纺及再生丝素纤维的表征

The protocol demonstrates a method for mimicking the spinning process of silkworm. In the native spinning process, the contracting spinning duct enables ...

Controlled Photoredox Ring-Opening Polymerization of O-Carboxyanhydrides Mediated by Ni/Zn Complexes

Here, we describe an effective protocol that combines photoredox Ni/Ir catalysis with the use of a Zn-alkoxide for efficient ring-opening polymerization, allowing for the synthesis of isotactic poly(&#945;-hydroxy acids) with expected molecular weights (&#62;140 kDa) and narrow molecular weight distributions (Mw/Mn &#60; 1.1). This ring-opening polymerization is mediated by Ni and Zn complexes in the presence of an alcohol initiator and a photoredox Ir catalyst, irradiated by a blue LED (400 - 500 nm). The polymerization is performed at a low temperature (-15 &#176;C) to avoid undesired side reactions. The complete monomer consumption can be achieved within 4 - 8 hours, providing a polymer close to the expected molecular weight with narrow molecular weight distribution. The resulted number-average molecular weight shows a linear correlation with the degree of polymerization up to 1000. The homodecoupling 1H NMR study confirms that the obtained polymer is isotactic without epimerization. This polymerization reported herein offers a strategy for achieving rapid, controlled O-carboxyanhydrides polymerization to prepare stereoregular poly(&#945;-hydroxy acids) and its copolymers bearing various functional side-chain groups.

Controlled Photoredox Ring-Opening Polymerization of O-Carboxyanhydrides Mediated by Ni/Zn Complexes

A protocol for the controlled photoredox ring-opening polymerization of O-carboxyanhydrides mediated by Ni/Zn complexes is presented.

镍/锌配合物介导的O-Carboxyanhydrides 的控制 Photoredox 环开聚合

Here, we describe an effective protocol that combines photoredox Ni/Ir catalysis with the use of a Zn-alkoxide for efficient ring-opening polymerization, ...

An Engineered Split-TET2 Enzyme for Chemical-inducible DNA Hydroxymethylation and Epigenetic Remodeling

DNA methylation is a stable and heritable epigenetic modification in the mammalian genome and is involved in regulating gene expression to control cellular functions. The reversal of DNA methylation, or DNA demethylation, is mediated by the ten-eleven translocation (TET) protein family of dioxygenases. Although it has been widely reported that aberrant DNA methylation and demethylation are associated with developmental defects and cancer, how these epigenetic changes directly contribute to the subsequent alteration in gene expression or disease progression remains unclear, largely owing to the lack of reliable tools to accurately add or remove DNA modifications in the genome at defined temporal and spatial resolution. To overcome this hurdle, we designed a split-TET2 enzyme to enable temporal control of 5-methylcytosine (5mC) oxidation and subsequent remodeling of epigenetic states in mammalian cells by simply adding chemicals. Here, we describe methods for introducing a chemical-inducible epigenome remodeling tool (CiDER), based on an engineered split-TET2 enzyme, into mammalian cells and quantifying the chemical inducible production of 5-hydroxymethylcytosine (5hmC) with immunostaining, flow cytometry or a dot-blot assay. This chemical-inducible epigenome remodeling tool will find broad use in interrogating cellular systems without altering the genetic code, as well as in probing the epigenotype&#8722;phenotype relations in various biological systems.

Detailed protocols for introducing an engineered split-TET2 enzyme (CiDER) into mammalian cells for chemical inducible DNA hydroxymethylation and epigenetic remodeling are presented.