作者感谢加拿大新前沿研究基金 （NFRF）、加拿大自然科学与工程研究委员会 （NSERC） 发现计划以及魁北克自然与技术研究基金会 （FRQNT） 硕士培训奖学金的资金支持。作者还要感谢McGill的Yaoyao Zhao教授团队对某些组件的3D打印提供的技术支持。

用于该方案的蚊子种类是未感染的成年雌性 埃及伊蚊 （A. aegypti），冷冻接收并储存在-20°C度的冰箱中。该物种由NIH/NIAID丝虫病研究试剂资源中心提供，通过BEI Resources，NIAID，NIH分发：未感染的 埃及伊蚊，菌株黑眼利物浦（冷冻），NR-48920。用于研究的试剂和设备列在 材料表中。
1. 从长鼻中解剖唇
<ol><li>使用镊子，将死蚊子放在显微镜下的载玻片上，并确保在长鼻的末端有一个锥形的尖端（图2A）。</li>
	<li>在将蚊子保持在载玻片上的同时，将手术刀刀片轻轻地放在蚊子头部附近的阴唇上（图2B）。</li>
	<li>继续在阴唇的整个上半部分（约 80 μm 的切口）做一个切口，在阴唇厚度上有一个较浅的穿透深度。确保对刀片施加轻微的压力，以便只切开阴唇，而不切开位于下方的束。</li>
	<li>用一把镊子牢牢握住蚊子的头部，然后用另一把精密镊子轻轻捏住锥形尖端和切口位置之间的任何位置的阴唇（图2B）。<ol><li>将夹住唇的镊子拉向锥形尖端的方向（图2C）。继续拉动镊子，直到阴唇脱离并完全从束中取出。</li>
	</ol></li>
	<li>将蚊子放在显微镜下，并确认盂唇的尖端是否存在。这可以通过束上存在锥形尖端来识别（图2D）。</li>
</ol>2. 将盂唇尖端与其他盂唇成员分开
<ol><li>夹住并闭合一组精密镊子的尖端，并将镊子的尖端放在靠近其尖端的盂唇旁边。</li>
	<li>使用镊子尖端在垂直于束长度的方向上对盂唇施加轻轻的力（图3A）。</li>
	<li>继续将盂唇推过载玻片，直到盂唇与其他束成员分离。</li>
	<li>在显微镜下检查样品，以验证盂唇和其他束成员之间已实现正确分离（图3，左）。如果分离不成功，请返回步骤 2.1。</li>
</ol>3. 切开盂唇尖端
<ol><li>当盂唇仍在载玻片上时，将手术刀刀片放在盂唇上，距离盂唇尖端约~200μm（图4A）。轻轻地施加足够的压力，将盂唇的尖端完全切开。虽然理想情况下，盂唇尖端应尽可能短，但 ~200 μm 是当前方法可以处理的最佳方法。</li>
	<li>使用任何数字测量软件测量切割盂唇的长度，以确保其长度不超过300μm（图4B）。在该协议中，使用ImageJ14。</li>
</ol>4.抓住盂唇的尖端
<ol><li>用一把精密镊子在载玻片上找到并隔离盂唇的尖端。丢弃载玻片上剩余的所有部分，但盂唇尖端除外。</li>
	<li>用同样精密的镊子，缓慢而轻微地捏住盂唇，使切割端自由且不受镊子的阻碍。此外，确保盂唇的方向平行于镊子长度的方向，并且盂唇的切割端远离镊子的身体。</li>
	<li>一旦试样被牢固地夹住，就移除将镊子尖端固定在一起的夹紧力。盂唇的尖端会粘在镊子的一个尖端上。</li>
	<li>在显微镜下，检查镊子的尖端，并确保盂唇的尖端位于镊子的一个尖端上（图5）。如果盂唇的尖端不在镊子上，请返回步骤 4.2，如果盂唇的尖端不在镊子上也不在载玻片上，请返回步骤 1。</li>
</ol>5. 在无尖悬臂梁上涂上环氧树脂
<ol><li>将一滴 （~0.05 mL） 环氧树脂滴在新载玻片的边缘，方法是直接从原来的瓶子/容器中滴铸粘合剂。将含环氧树脂的载玻片放在探针台下方并聚焦在其上。</li>
	<li>通过固定底座（即较大的端），将无尖 AFM 悬臂安装到夹具组件上，使悬臂端保持自由并悬挂在空间中。确保悬臂梁的底部朝下。</li>
	<li>将机械手安装到探针台上。</li>
	<li>将机械手的 Z 轴升高到无尖悬臂位于含环氧树脂玻璃载玻片上方几毫米的位置。</li>
	<li>手动移动机械手，使无尖端悬臂在探针台上的摄像机的视野视图中可见。</li>
	<li>使用机械手，沿 X 和 Y 方向移动悬臂梁，直到悬臂的尖端直接位于载玻片边缘的环氧树脂上方。</li>
	<li>再次使用机械手，将无尖悬臂沿 Z 方向缓慢降低到载玻片边缘上方。</li>
	<li>当悬臂降低并接近载玻片时，请继续非常缓慢地降低悬臂，直到它第一次接触环氧树脂。不要再降低悬臂。</li>
	<li>小心地接合机械手，在 X 或 Y 方向上缓慢移动悬臂，并通过沿选定方向连续移动悬臂，将悬臂从环氧树脂池中取出，直到悬臂与载玻片上的环氧树脂完全分离。无尖悬臂的尖端应有一个微型环氧树脂气泡，在探针台下方可见。</li>
	<li>使用机械手向 Z 方向升高悬臂。</li>
</ol>6. 将盂唇的尖端粘合到无尖端悬臂梁上
<ol><li>将机械手绕悬臂的长轴旋转 90 度，然后将机械手侧放在探针台上。在这种配置中，沿悬臂梁长度的厚度在垂直方向上。</li>
	<li>将包含盂唇尖端的精密镊子放在探针台摄像头下方，使盂唇尖端的整个长度在计算机显示器上可见。</li>
	<li>将握住夹具和无尖端悬臂的机械手组件放置在探针台摄像头下方，使无尖端悬臂的整个长度在计算机显示器上可见。</li>
	<li>将探针台显微镜聚焦在盂唇的尖端和无尖端悬臂上。</li>
	<li>通过小心和手动旋转操纵器，将悬臂垂直于盂唇的尖端（图6A）。</li>
	<li>利用机械手的自由度，沿XY方向缓慢移动无尖悬臂，使悬臂上的胶水接触盂唇尖端的切割端（图6B）。</li>
	<li>固化环氧树脂，固化悬臂和蚊子盂唇之间的交叉点。</li>
	<li>环氧树脂固化后，轻轻地在XY方向上接合机械手，并将悬臂从镊子上移开，确认盂唇的尖端现在位于无尖端悬臂梁上（图6C）。</li>
</ol>

带有蚊唇的生物杂交 AFM 探针，用于研究叮咬行为

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作者无需声明任何利益冲突。

该协议的第 1 步旨在清洁不需要的阴唇的生物样本。为了实现这一点，在阴唇上做一个切口，但不在位于阴唇正下方的束上做一个切口（图1）。由于束和唇在其界面处没有连接在一起（即，唇可以沿着束自由滑动，并且仅通过其附着在蚊子头上保持到位），因此进行的切口旨在将唇的一部分与蚊子的头部分开，从而促进外罩的移除。当唇形物从样品中拉出时，技术人员应该...

世界卫生组织 （WHO） 报告说，病媒传播疾病 （VBD） 占所有传染病的 17% 以上，每年导致全球超过 7,00,000 人死亡。例如，作为世界上最致命的动物，蚊子通过吸血节肢动物传播登革热、疟疾和寨卡病毒等多种病原体，每年导致 7 亿例感染1。探索制定有效措施预防VBDs至关重要，包括模仿蚊子的侵入行为以研究其叮咬机制，以及研究潜在障碍以证明其预防侵入的有效性。一个关键的挑战是制定适当的方法来进行这种调查。在文献中已经做出了努力，包括开发类似于蚊子毒刺几何形状的微尺度针头;然而，许多用于制造这些微针的材料（即粘弹性材料2、硅 （Si）、玻璃、陶瓷3 等）与蚊子长鼻的生物材料具有不同的机械性能。工程材料可能很脆，容易断裂和屈曲 3,4，而蚊子的长鼻可以更好地承受断裂或屈曲4.使用蚊子的盂唇而不是工程材料的生物混合探针的好处是，它可以更准确地表示蚊子的穿刺机制。此外，必须将专用工具与微针集成以执行定量研究，例如力5 的准确测量，这对于使用工程微针的定制设置来说不容易实现。
基于原子力显微镜 （AFM） 的方法很有前途的，因为它通过使用带有超细尖端的悬臂来操作，该悬臂被小心地放置在靠近样品表面的位置。尖端既可以扫描表面，也可以被压向/压入表面，由于其与样品的相互作用，会受到不同的吸引力或排斥力6.这些相互作用导致悬臂的偏转，通过激光束从悬臂顶部反射到光电探测器6 上来跟踪偏转。AFM 对系统运动的超强灵敏度使 AFM 能够进行各种测量，包括但不限于皮米精度的形态映射、从皮牛顿到微牛顿的力测量以及全面的多物理场研究7。例如，可以执行 AFM 压痕以精确评估对样品施加力的响应，并通过与适当的分析模型耦合来测量样品的硬度、弹性和其他机械性能8。AFM 的探针通常由硅 （Si） 或氮化硅 （Si3N4）8 制成，长度为 20-300 μm9 ，尖端半径约为几到几十纳米10。纳米级针尖半径是高分辨率成像等应用的理想选择;然而，对于试图在刚度、半径、形状和纵横比方面模仿穿透行为的研究，它不具备生物毒刺的特征。例如，蚊子的微针结构是束，其纵横比为 ~6011 （长度 ~1.5 毫米至 2 毫米;直径 ~30 μm）12。虽然可以假设传统的AFM探针类似于盂唇等生物毒刺，但其独特的材料特性和尺寸并不能反映咬合过程中的真实情况。
为了能够对模仿昆虫或其他动物用毒刺的生物叮咬的穿透行为进行定量研究，这里开发了一种制造生物混合AFM悬臂的工艺，该工艺以生物毒刺为尖端。作为一个案例研究，成功地展示了一种带有蚊子盂唇尖端的AFM悬臂。利用文献中关于蚊子用来刺穿受害者皮肤的典型插入力的现有信息12,13，这种生物混合AFM悬臂有可能在常规AFM下实现蚊子叮咬的近乎真实的模拟。利用微生物毒刺制造生物混合 AFM 悬臂的方案也可应用于开发其他基于 Sharp Stinger 的生物混合 AFM 悬臂，用于对各种咬合机制进行定量研究。
术语 长鼻及其相关组件的示意图如图 1 所示，其定义是 （1） 长鼻：蚊子口中的身体部位，允许蚊子自我进食，其核壳结构由束（核心）和唇（壳）组成，（2） 唇：长鼻的深色和钝的外壳2，（3）束：一组细长的针头包含在唇内，包括两个上颌骨、两个下颌骨、一个下咽部和一个盂唇2、（4）下咽部：负责将唾液分泌到宿主的血液中2、（5）上颌骨：协助摄食机制的锯齿状构件2、（5）下颌骨：类似于上颌骨，它们帮助蚊子摄食机构，并有一个锋利的尖端2，（6）盂唇：穿透受害人皮肤的主要构件，比上颌骨、下颌骨和下咽部大得多。它还具有感觉结构，使其能够在皮肤下找到血管和内部通道2，（7） 操纵器：具有三个自由度和微米级定位精度的组件，允许在 XYZ 方向上移动，（8） 夹具组件：安装在机械手上的定制 2 部分夹具，用于在实验过程中夹紧无尖端 AFM 悬臂。

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>&#160;5-SA-SE Straight Tapered Ultra Fine-Pointed Tweezers</td>
			<td>Excelta</td>
			<td>N/A</td>
			<td>For manipulating/dissecting the proboscis.</td>
		</tr>
		<tr>
			<td>C-4D Probe station</td>
			<td>Everbeing Int&#8217;l Corp&#160;</td>
			<td>N/A</td>
			<td>Used for AFM assembly.</td>
		</tr>
		<tr>
			<td>Tipless Tapping Mode Cantilever</td>
			<td>NanoAndMore USA</td>
			<td>TL-NCH</td>
			<td>AFM cantilever used for mounting the labrum. 
			Specs are shown here: 
			 
			Shape: Beam 
			Force Constant: 42 N/m (10 - 130 N/m) 
			Resonance Frequency: 330 kHz (204 - 497 kHz) 
			Length: 125 &#181;m (115 - 135 &#181;m) 
			Width: 30 &#181;m (22.5 - 37.5 &#181;m) 
			Thickness: 4 &#181;m ( 3 - 5 &#181;m)</td>
		</tr>
		<tr>
			<td>UV Expoxy</td>
			<td>Let&#39;s resin</td>
			<td>ALR00146</td>
			<td>For stinger attachment.</td>
		</tr>
	</tbody>
</table>

development of a bio-hybrid mosquito stinger-based atomic force microscopy probe

蚊子因其传播疾病的能力而臭名昭著，是对人类最致命的动物，对公共卫生构成持续挑战。目前使用的一级预防策略涉及化学驱虫剂，由于蚊子迅速产生抗药性，化学驱虫剂往往被证明是无效的。因此，发明新的预防方法至关重要。这种发展取决于对蚊子叮咬行为的透彻理解，因此需要一种实验装置，该实验装置能够通过可控的测试参数和定量测量准确复制实际叮咬场景。为了弥合这一差距，设计了一种生物混合原子力显微镜（AFM）探针，其尖端是生物毒刺 - 特别是蚊子盂唇。这种生物混合探针与标准AFM系统兼容，可以对蚊子的渗透行为进行近乎真实的模拟。这种方法标志着在叮咬机制的定量研究方面向前迈出了一步，有可能为对抗病媒传播疾病（VBDs）建立有效的屏障，并为对抗蚊媒传播疾病开辟新的途径。

制备的生物杂化AFM探针的扫描电子显微镜（SEM）图像如图 7所示。盂唇的末端成功地粘在无尖端悬臂梁上。由于蚊子毒刺的自然曲率和所提出协议的手动操作，因此获得具有完全垂直于悬臂的毒刺尖端的悬臂是极其困难的。毒刺与垂直于悬臂的假想中心线之间的偏心角通常为 ~10 度。虽然将探针安装到 AFM 悬臂15 上似乎是一个常见问题，但在执行力/应力分析...

Watch this Scientific Journal Video about Author Spotlight: Development of Bio-Hybrid AFM Cantilevers for Quantitative Analysis of Mosquito Biting Mechanisms at JoVE.com

作者聚焦：用于定量分析蚊子叮咬机制的生物混合 AFM 悬臂的开发

对昆虫叮咬行为进行定量和受控调查对于制定有效的策略来对抗病媒传播疾病至关重要。在此背景下，介绍了一种制备生物杂化原子力显微镜（AFM）探针的方法。

基于生物杂化蚊虫叮咬的原子力显微镜探针的研制

Mosquitoes, notorious as the deadliest animals to humans due to their capacity to transmit diseases, pose a persistent challenge to public health. The ...

我们正在开发一种AFM悬臂，以潜在地定量研究蚊子的叮咬机制。我们的协议提供了一种新方法，用于创建准确、可控和可靠的 AFM 探针，以研究动物咬伤或刺痛过程。我们的协议旨在准确模拟动物咬伤过程，导致当前的方法要么不可控，无法以可靠的方式重现，要么在某些情况下完全不准确。我们工作的影响是双重的。首先，我们创建了一个协议，使其他研究人员能够制造他们自己的定制生物混合AFM悬臂。其次，我们的工作为创建其他协议铺平了道路，这些协议将测试系统与生物材料相结合，以创建更真实的测试场景。

development-bio-hybrid-mosquito-stinger-based-atomic-force-microscopy

Research

JoVE Journal

Engineering

Development of a Bio-Hybrid Mosquito Stinger-Based Atomic Force Microscopy Probe

663 次观看.  McGill University. 我们正在开发一种AFM悬臂，以潜在地定量研究蚊子的叮咬机制。我们的协议提供了一种新方法，用于创建准确、可控和可靠的 AFM 探针，以研究动物咬伤或刺痛过程。我们的协议旨在准确模拟动物咬伤过程，导致当前的方法要么不可控，无法以可靠的方式重现，要么在某些情况下完全不准确。我们工作的影响是双重的。首先，我们创建了一个协议，使其他研究人员能够?...

视频: 作者聚焦：用于定量分析蚊子叮咬机制的生物混合 AFM 悬臂的开发

Scanning-probe Single-electron Capacitance Spectroscopy

The integration of low-temperature scanning-probe techniques and single-electron capacitance spectroscopy represents a powerful tool to study the electronic quantum structure of small systems - including individual atomic dopants in semiconductors. Here we present a capacitance-based method, known as Subsurface Charge Accumulation (SCA) imaging, which is capable of resolving single-electron charging while achieving sufficient spatial resolution to image individual atomic dopants. The use of a capacitance technique enables observation of subsurface features, such as dopants buried many nanometers beneath the surface of a semiconductor material1,2,3. In principle, this technique can be applied to any system to resolve electron motion below an insulating surface.
As in other electric-field-sensitive scanned-probe techniques4, the lateral spatial resolution of the measurement depends in part on the radius of curvature of the probe tip. Using tips with a small radius of curvature can enable spatial resolution of a few tens of nanometers. This fine spatial resolution allows investigations of small numbers (down to one) of subsurface dopants1,2. The charge resolution depends greatly on the sensitivity of the charge detection circuitry; using high electron mobility transistors (HEMT) in such circuits at cryogenic temperatures enables a sensitivity of approximately 0.01 electrons/Hz&frac12; at 0.3 K 5.

Scanning-probe single-electron capacitance spectroscopy facilitates the study of single-electron motion in localized subsurface regions. A sensitive charge-detection circuit is incorporated into a cryogenic scanning probe microscope to investigate small systems of dopant atoms beneath the surface of semiconductor samples.

扫描探针单电子电容谱

The integration of low-temperature scanning-probe techniques and single-electron capacitance spectroscopy represents a powerful tool to study the ...

科研

工程学

Development of a 3D Graphene Electrode Dielectrophoretic Device

The design and fabrication of a novel 3D electrode microdevice using 50 &#181;m thick graphene paper and 100 &#181;m double sided tape is described. The protocol details the procedures to construct a versatile, reusable, multiple layer, laminated dielectrophoresis chamber. Specifically, six layers of 50 &#181;m x&#160;0.7 cm x&#160;2 cm graphene paper and five layers of double sided tape were alternately stacked together, then clamped to a glass slide. Then a 700 &#956;m diameter micro-well was drilled through the laminated structure using a computer-controlled micro drilling machine. Insulating properties of the tape layer between adjacent graphene layers were assured by resistance tests. Silver conductive epoxy connected alternate layers of graphene paper and formed stable connections between the graphene paper and external copper wire electrodes. The finished device was then clamped and sealed to a glass slide. The electric field gradient was modeled within the multi-layer device. Dielectrophoretic behaviors of 6 &#956;m polystyrene beads were demonstrated in the 1 mm deep micro-well, with medium conductivities ranging from 0.0001 S/m to 1.3 S/m, and applied signal frequencies from 100 Hz to 10 MHz. Negative dielectrophoretic responses were observed in three dimensions over most of the conductivity-frequency space and cross-over frequency values are consistent with previously reported literature values. The device did not prevent AC electroosmosis and electrothermal flows, which occurred in the low and high frequency regions, respectively. The graphene paper utilized in this device is versatile and could subsequently function as a biosensor after dielectrophoretic characterizations are complete.

A microdevice with high throughput potential is used to demonstrate three-dimensional (3D) dielectrophoresis (DEP) with novel materials. Graphene nanoplatelet paper and double sided tape were alternately stacked; a 700 &#956;m micro-well was drilled transverse to the layers. DEP behavior of polystyrene beads was demonstrated in the micro-well.

三维石墨电极介电泳装置的研制

The design and fabrication of a novel 3D electrode microdevice using 50 &#181;m thick graphene paper and 100 &#181;m double sided tape is described. The ...

Atomic Force Microscopy of Red-Light Photoreceptors Using PeakForce Quantitative Nanomechanical Property Mapping

Atomic force microscopy (AFM) uses a pyramidal tip attached to a cantilever to probe the force response of a surface. The deflections of the tip can be measured to ~10 pN by a laser and sectored detector, which can be converted to image topography. Amplitude modulation or &#8220;tapping mode&#8221; AFM involves the probe making intermittent contact with the surface while oscillating at its resonant frequency to produce an image. Used in conjunction with a fluid cell, tapping-mode AFM enables the imaging of biological macromolecules such as proteins in physiologically relevant conditions. Tapping-mode AFM requires manual tuning of the probe and frequent adjustments of a multitude of scanning parameters which can be challenging for inexperienced users. To obtain high-quality images, these adjustments are the most time consuming.
PeakForce Quantitative Nanomechanical Property Mapping (PF-QNM) produces an image by measuring a force response curve for every point of contact with the sample. With ScanAsyst software, PF-QNM can be automated. This software adjusts the set-point, drive frequency, scan rate, gains, and other important scanning parameters automatically for a given sample. Not only does this process protect both fragile probes and samples, it significantly reduces the time required to obtain high resolution images. PF-QNM is compatible for AFM imaging in fluid; therefore, it has extensive application for imaging biologically relevant materials.
The method presented in this paper describes the application of PF-QNM to obtain images of a bacterial red-light photoreceptor, RpBphP3 (P3), from photosynthetic R. palustris in its light-adapted state. Using this method, individual protein dimers of P3 and aggregates of dimers have been observed on a mica surface in the presence of an imaging buffer. With appropriate adjustments to surface and/or solution concentration, this method may be generally applied to other biologically relevant macromolecules and soft materials.

A method for investigating the structure of a protein photoreceptor using atomic force microscopy (AFM) is described in this paper. PeakForce Quantitative Nanomechanical Property Mapping (PF-QNM) reveals intact protein dimers on a mica surface.

冲红灯光感受器原子力显微镜使用PeakForce定量纳米机械性能映射

Atomic force microscopy (AFM) uses a pyramidal tip attached to a cantilever to probe the force response of a surface. The deflections of the tip can be ...

Preparation and Friction Force Microscopy Measurements of Immiscible, Opposing Polymer Brushes

Solvated polymer brushes are well known to lubricate high-pressure contacts, because they can sustain a positive normal load while maintaining low friction at the interface. Nevertheless, these systems can be sensitive to wear due to interdigitation of the opposing brushes. In a recent publication, we have shown via molecular dynamics simulations and atomic force microscopy experiments, that using an immiscible polymer brush system terminating the substrate and the slider surfaces, respectively, can eliminate such interdigitation. As a consequence, wear in the contacts is reduced. Moreover, the friction force is two orders of magnitude lower compared to traditional miscible polymer brush systems. This newly proposed system therefore holds great potential for application in industry. Here, the methodology to construct an immiscible polymer brush system of two different brushes each solvated by their own preferred solvent is presented. The procedure how to graft poly(N-isopropylacrylamide) (PNIPAM) from a flat surface and poly(methyl methacrylate) (PMMA) from an atomic force microscopy (AFM) colloidal probe is described. PNIPAM is solvated in water and PMMA in acetophenone. Via friction force AFM measurements, it is shown that the friction for this system is indeed reduced by two orders of magnitude compared to the miscible system of PMMA on PMMA solvated in acetophenone.

The methodology to perform friction force microscopy experiments for contacting brushes is presented: Two polymer brushes that are grafted from (a) substrates and (b) colloidal probes are slid to show that, by using two contacting immiscible brush systems, friction in sliding contacts is reduced compared to miscible brush systems.

互溶的测量准备和摩擦力显微镜，反对聚合物刷

Solvated polymer brushes are well known to lubricate high-pressure contacts, because they can sustain a positive normal load while maintaining low ...

Investigating Single Molecule Adhesion by Atomic Force Spectroscopy

Atomic force spectroscopy is an ideal tool to study molecules at surfaces and interfaces. An experimental protocol to couple a large variety of single molecules covalently onto an AFM tip is presented. At the same time the AFM tip is passivated to prevent unspecific interactions between the tip and the substrate, which is a prerequisite to study single molecules attached to the AFM tip. Analyses to determine the adhesion force, the adhesion length, and the free energy of these molecules on solid surfaces and bio-interfaces are shortly presented and external references for further reading are provided. Example molecules are the poly(amino acid) polytyrosine, the graft polymer PI-g-PS and the phospholipid POPE (1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoethanolamine). These molecules are desorbed from different surfaces like CH3-SAMs, hydrogen terminated diamond and supported lipid bilayers under various solvent conditions. Finally, the advantages of force spectroscopic single molecule experiments are discussed including means to decide if truly a single molecule has been studied in the experiment.

A protocol to couple a large variety of single molecules covalently onto an AFM tip is presented. Procedures and examples to determine the adhesion force and free energy of these molecules on solid supports and bio-interfaces are provided.

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 ...

Probing C84-embedded Si Substrate Using Scanning Probe Microscopy and Molecular Dynamics

This paper reports an array-designed C84-embedded Si substrate fabricated using a controlled self-assembly method in an ultra-high vacuum chamber. The characteristics of the C84-embedded Si surface, such as atomic resolution topography, local electronic density of states, band gap energy, field emission properties, nanomechanical stiffness, and surface magnetism, were examined using a variety of surface analysis techniques under ultra, high vacuum (UHV) conditions as well as in an atmospheric system. Experimental results demonstrate the high uniformity of the C84-embedded Si surface fabricated using a controlled self-assembly nanotechnology mechanism, represents an important development in the application of field emission display (FED), optoelectronic device fabrication, MEMS cutting tools, and in efforts to find a suitable replacement for carbide semiconductors. Molecular dynamics (MD) method with semi-empirical potential can be used to study the nanoindentation of C84-embedded Si substrate. A detailed description for performing MD simulation is presented here. Details for a comprehensive study on mechanical analysis of MD simulation such as indentation force, Young&#39;s modulus, surface stiffness, atomic stress, and atomic strain are included. The atomic stress and von-Mises strain distributions of the indentation model can be calculated to monitor deformation mechanism with time evaluation in atomistic level.

Probing C84-embedded Si Substrate Using Scanning Probe Microscopy and Molecular Dynamics

This paper reports the nanomaterial fabrication of a fullerene Si substrate inspected and verified by nanomeasurements and molecular dynamic simulation.

探测ç<sub&gt; 84</sub&gt; - 嵌入式硅衬底利用扫描探针显微镜和分子动力学

This paper reports an array-designed C84-embedded Si substrate fabricated using a controlled self-assembly method in an ultra-high vacuum chamber. The ...

Sub-nanometer Resolution Imaging with Amplitude-modulation Atomic Force Microscopy in Liquid

Atomic force microscopy (AFM) has become a well-established technique for nanoscale imaging of samples in air and in liquid. Recent studies have shown that when operated in amplitude-modulation (tapping) mode, atomic or molecular-level resolution images can be achieved over a wide range of soft and hard samples in liquid. In these situations, small oscillation amplitudes (SAM-AFM) enhance the resolution by exploiting the solvated liquid at the surface of the sample. Although the technique has been successfully applied across fields as diverse as materials science, biology and biophysics and surface chemistry, obtaining high-resolution images in liquid can still remain challenging for novice users. This is partly due to the large number of variables to control and optimize such as the choice of cantilever, the sample preparation, and the correct manipulation of the imaging parameters. Here, we present a protocol for achieving high-resolution images of hard and soft samples in fluid using SAM-AFM on a commercial instrument. Our goal is to provide a step-by-step practical guide to achieving high-resolution images, including the cleaning and preparation of the apparatus and the sample, the choice of cantilever and optimization of the imaging parameters. For each step, we explain the scientific rationale behind our choices to facilitate the adaptation of the methodology to every user's specific system.

We present a method for achieving sub-nanometer resolution images with amplitude-modulation (tapping mode) atomic force microscopy in liquid. The method is demonstrated on commercial atomic force microscopes. We explain the rationale behind our choices of parameters and suggest strategies for resolution optimization.

亚纳米级分辨率成像与调幅原子力显微镜在液体

Atomic force microscopy (AFM) has become a well-established technique for nanoscale imaging of samples in air and in liquid. Recent studies have shown ...

Measurement of Quantum Interference in a Silicon Ring Resonator Photon Source

Silicon photonic chips have the potential to realize complex integrated quantum information processing circuits, including photon sources, qubit manipulation, and integrated single-photon detectors. Here, we present the key aspects of preparing and testing a silicon photonic quantum chip with an integrated photon source and two-photon interferometer. The most important aspect of an integrated quantum circuit is minimizing loss so that all of the generated photons are detected with the highest possible fidelity. Here, we describe how to perform low-loss edge coupling by using an ultra-high numerical aperture fiber to closely match the mode of the silicon waveguides. By using an optimized fusion splicing recipe, the UHNA fiber is seamlessly interfaced with a standard single-mode fiber. This low-loss coupling allows the measurement of high-fidelity photon production in an integrated silicon ring resonator and the subsequent two-photon interference of the produced photons in a closely integrated Mach-Zehnder interferometer. This paper describes the essential procedures for the preparation and characterization of high-performance and scalable silicon quantum photonic circuits.

Silicon photonic chips have the potential to realize complex integrated quantum systems. Presented here is a method for preparing and testing a silicon photonic chip for quantum measurements.

量子干涉效应在硅谐振环光子源测量

Silicon photonic chips have the potential to realize complex integrated quantum information processing circuits, including photon sources, qubit ...

Atomic Layer Deposition of Vanadium Dioxide and a Temperature-dependent Optical Model

Vanadium dioxide is a material that has a reversible metal-insulator phase change near 68 &#176;C. To grow VO2 on a wide variety of substrates, with wafer-scale uniformity and angstrom level control of thickness, the method of atomic-layer deposition was chosen. This ALD process enables high-quality, low-temperature (&#8804;150 &#176;C) growth of ultrathin films (100-1000 &#197;) of VO2. For this demonstration, the VO2 films were grown on sapphire substrates. This low temperature growth technique produces mostly amorphous VO2 films. A subsequent anneal in an ultra-high vacuum chamber with a pressure of 7x10-4 Pa of ultra-high purity (99.999%) oxygen produced oriented, polycrystalline VO2 films. The crystallinity, phase, and strain of the VO2 were determined by Raman spectroscopy and X-ray diffraction, while the stoichiometry and impurity levels were determined by X-ray photoelectron spectroscopy, and finally the morphology was determined by atomic force microscopy. These data demonstrate the high-quality of the films grown by this technique. A model was created to fit to the data for VO2 in its metallic and insulating phases in the near infrared spectral region. The permittivity and refractive index of the ALD VO2 agreed well with the other fabrication methods in its insulating phase, but showed a difference in its metallic state. Finally, the analysis of the films&#39; optical properties enabled the creation of a wavelength- and temperature-dependent model of the complex optical refractive index for developing VO2 as a tunable refractive index material.

Thin films (100-1000 &#197;) of vanadium dioxide (VO2) were created by atomic-layer deposition (ALD) on sapphire substrates. Following this, the optical properties were characterized through the metal-insulator transition of VO2. From the measured optical properties, a model was created to describe the tunable refractive index of VO2.

二氧化钒原子层沉积与温度依赖性光学模型

Vanadium dioxide is a material that has a reversible metal-insulator phase change near 68 &#176;C. To grow VO2 on a wide variety of substrates, with ...

An Efficient Method for Selective Desalination of Radioactive Iodine Anions by Using Gold Nanoparticles-Embedded Membrane Filter

Here, we demonstrate a detail protocol for the preparation of nanomaterials-embedded composite membranes and its application to the efficient and ion-selective removal of radioactive iodines. By using citrate-stabilized gold nanoparticles (mean diameter: 13 nm) and cellulose acetate membranes, gold nanoparticle-embedded cellulose acetate membranes (Au-CAM) have easily been fabricated. The nano-adsorbents on Au-CAM were highly stable in the presence of high concentration of inorganic salts and organic molecules. The iodide ions in aqueous solutions could rapidly be captured by this engineered membrane. Through a filtration process using an Au-CAM containing filter unit, excellent removal efficiency (&gt;99%) as well as ion-selective desalination result was achieved in a short time. Moreover, Au-CAM provided good reusability without significant decrease of its performances. These results suggested that the present technology using the engineered hybrid membrane will be a promising process for the large-scale decontamination of radioactive iodine from liquid wastes.

An efficient method for the rapid and ion-selective desalination of radioactive iodine in several aqueous solutions is described by using gold nanoparticles-immobilized cellulose acetate membrane filters.