Name: a closed-type wireless nanopore electrode for analyzing single nanoparticles
Uploaded: 2019-03-20T13:00:00
Description: Watch this Scientific Journal Video about A Closed-Type Wireless Nanopore Electrode for Analyzing Single Nanoparticles at JoVE.com

本研究得到了国家自然科学基金 (61871183, 21834001)、上海市教育委员会创新项目 (2017-01-07-07-02-e00023)、上海市教育 "陈光" 项目的支持。委员会和上海教育发展基金会 (17CG27)。

1. 解决方案的准备
注: 注意所有化学品的一般安全预防措施。在烟罩中处理化学物质, 戴上手套、护目镜和实验室外套。保持易燃液体远离火源或火花。所有水溶液均采用超纯水 (25°c 时 18.2 MΩ厘米) 制备。使用0.22μm 孔尺寸过滤器对制备的溶液进行过滤。
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KCl 溶液的制备
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<li>在100毫升去离子水中溶解0.074 克氯化钾。</li>
	</ol>
</li>
	<li>
Nbh4 溶液<...

<ol>
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制备定义明确的纳米孔是闭式 WNE 制造工艺的第一步。通过将 CO2激光聚焦在毛细管的中心, 一个毛细管分离成两个具有纳米圆锥形尖端的对称纳米粒子。通过调整激光拉拔器的参数, 可以轻松控制直径, 范围从30-200 纳米不等。需要注意的是, 不同的移液器的拉力参数可能会有所不同。环境温度和湿度也会影响纳米管的最终直径。
在制备纳米粒子后, 化学反应会在纳米管?...

纳米粒子由于其催化能力、特殊的光学特性、电活性和高地容比1、2、3 、4. 单纳米粒子的电化学分析是了解纳米水平的固有化学和电化学过程的直接方法。为了实现对单个纳米粒子的高度敏感测量, 以前已经采用了两种电化学方法从当前响应 5、6、7中读出纳米粒子信息。其中一种方法是在纳米电极界面上固定或捕获单个纳米粒子, 用于研究电催化8,9。另一种策略是由与电极表面的单纳米粒子碰撞驱动的, 这种碰撞会产生动态氧化还原过程的瞬态电流波动。
这两种方法都需要与单个纳米粒子直径相匹配的纳米超敏传感接口。然而, 传统的纳米电极制造主要采用了微机电系统 (MEMS) 或激光拉动技术, 这些技术繁琐且不规范10, 11,12, 13岁例如, 基于 mems 的纳米电极制造成本很高, 需要使用洁净室, 从而限制了纳米电极的大量生产和普及。另一方面, 纳米电极的激光拉力制造在很大程度上依赖于操作人员在毛细管内密封和拉拔金属丝过程中的经验。如果金属丝在毛细管中没有很好的密封, 纳米管内壁与金属丝之间的缝隙会极大地产生多余的背景电流噪声, 扩大电源传感区域。这些缺点在很大程度上降低了纳米电极的灵敏度。另一方面, 间隙的存在会扩大电极面积, 降低纳米电极的灵敏度。因此, 由于每个制造过程14、15 中的电极形态无法控制, 因此很难保证可重现的性能。因此, 迫切需要一种具有优良重现性的纳米电极的通用制备方法, 以促进对单个纳米粒子固有特性的电化学探索。
近年来, 纳米孔技术已发展成为一种优雅、无标签的单分子分析方法, 16、17、18、19、20。由于其可控的制造, 纳米管提供了一个纳米尺度的约束, 具有均匀的直径范围从30-200 纳米的激光毛细管拉拔器21,22, 23,24.此外, 这种简单和可重复的制造过程, 确保了纳米管的推广。最近, 我们提出了一个无线纳米粒子电极 (WNE), 它不需要密封在纳米粒子内的金属丝。通过简单、可重复的制造工艺, wne 在纳米粒子内具有纳米级金属沉积, 形成电活性界面 25、26、27、28。.由于 WNE 具有明确的结构和均匀的约束形态, 因此它实现了高电流分辨率和低电阻电容 (RC) 时间常数, 以实现较高的时间分辨率。我们以前报告了两种类型的 Wne, 开放型和闭式, 以实现单实体分析。开式 WNE 采用沉积在纳米粒子内壁上的纳米层, 它将单个实体的法格电流转换为离子电流响应26。通常, 开式 WNE 的直径约为100纳米。为了进一步减小 WNE 的直径, 我们提出了闭式 WNE, 其中固体金属纳米尖端通过化学电化学方法完全占据纳米颗粒尖端。这种方法可以在纳米孔约束内迅速产生30纳米金纳米尖。闭式 WNE 尖端区域定义明确的界面确保了单个纳米粒子电化学测量的高信噪比。由于带电金纳米粒子与闭式 WNE 发生碰撞, 在尖端界面上的超快充放电过程会在离子电流轨迹中引起电容反馈响应 (CFR)。与以往通过29内金属丝的纳米电极进行的单纳米粒子碰撞研究相比,闭式 wne 的电流分辨率较高, 为 0.6P±0.1 pa (rms), 时间分辨率较高, 为 0.01 ms。
在此, 我们描述了一种具有高度可控尺寸和出色重现性的闭式 WNE 的详细制造工艺。在这个协议中, 一个简单的反应之间的头名数-和bh4-是为了产生一个金纳米尖端, 完全阻止一个纳米孔。然后, 采用双极电化学连续生长的金纳米尖端, 达到几个微米的长度内的纳米。这个简单的程序使这种纳米电极制造的实施, 这可以在任何一般化学实验室进行, 没有一个干净的房间和昂贵的设备。为了确定闭式 WNE 的大小、形态和内部结构, 该协议提供了一个详细的表征程序, 使用扫描电子显微镜 (SEM) 和荧光光谱。最近的一个例子是, 它直接测量金纳米粒子 (AuNPs) 与闭合型 WNE 纳米界面碰撞的内在和动态相互作用。我们认为, 闭式 WNE 可能为未来在单实体层面上对活细胞、纳米材料和传感器进行电化学研究铺平道路。

<table>
	<tbody>
		<tr>
			<td>Acetone</td>
			<td>Sigma-Aldrich</td>
			<td>650501</td>
			<td>Highly flammable and volatile</td>
		</tr>
		<tr>
			<td>Analytical balance</td>
			<td>Mettler Toledo</td>
			<td>ME104E</td>
			<td></td>
		</tr>
		<tr>
			<td>Axopatch 200B amplifier</td>
			<td>Molecular Devices</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Blu-Tack reusable adhesive</td>
			<td>Bostik</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Centrifuge tube</td>
			<td>Corning Inc.</td>
			<td></td>
			<td>Centrifuge Tubes with CentriStar Cap, 15 ml</td>
		</tr>
		<tr>
			<td>Chloroauric acid</td>
			<td>Energy Chemical</td>
			<td>E0601760010</td>
			<td>HAuCl4</td>
		</tr>
		<tr>
			<td>Clampfit 10.4 software</td>
			<td>Molecular Devices</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Digidata 1550A digitizer</td>
			<td>Molecular Devices</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>DS Fi1c true-color CCD camera</td>
			<td>Nikon</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Ecoflex 5 Addtion cure silicone rubber</td>
			<td>Smooth-On</td>
			<td>17050377</td>
			<td></td>
		</tr>
		<tr>
			<td>Eppendorf Reference 2 pipettes</td>
			<td>Eppendorf</td>
			<td>492000904</td>
			<td>10, 100 and 1000 &#181;L</td>
		</tr>
		<tr>
			<td>Ethanol</td>
			<td>Sigma-Aldrich</td>
			<td>24102</td>
			<td>Highly flammable and volatile</td>
		</tr>
		<tr>
			<td>Faraday cage</td>
			<td></td>
			<td></td>
			<td>Copper</td>
		</tr>
		<tr>
			<td>iXon 888 EMCCD</td>
			<td>Andor</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Microcentrifuge tubes</td>
			<td>Axygen Scientific</td>
			<td></td>
			<td>0.6, 1.5 and 2.0 mL</td>
		</tr>
		<tr>
			<td>Microloader</td>
			<td>Eppendorf</td>
			<td>5242 956.003</td>
			<td>20 &#181;L</td>
		</tr>
		<tr>
			<td>Microscope Cover Glass</td>
			<td>Fisher Scientific</td>
			<td>LOT 16938</td>
			<td>20 mm*60 mm-1 mm thick</td>
		</tr>
		<tr>
			<td>Milli-Q water purifier</td>
			<td>Millipore</td>
			<td>SIMS00000</td>
			<td>Denton Electron Beam Evaporator</td>
		</tr>
		<tr>
			<td>P-2000 laser puller</td>
			<td>Sutter Instrument</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Pipette tips</td>
			<td>Axygen Scientific</td>
			<td></td>
			<td>10, 200 and 1,000 &#181;L</td>
		</tr>
		<tr>
			<td>Potassium chloride,+D25+A2:F2+A2:F25</td>
			<td>Sigma Aldrich</td>
			<td>P9333-500G</td>
			<td>KCl</td>
		</tr>
		<tr>
			<td>Quartz pipettes</td>
			<td>Sutter</td>
			<td>QF100-50-7.5</td>
			<td>O.D.:1.0 mm, I.D.:0.5 mm, 75 mm length</td>
		</tr>
		<tr>
			<td>Refrigerator</td>
			<td>Siemens</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Silicone thinner</td>
			<td>Smooth-On</td>
			<td>1506330</td>
			<td></td>
		</tr>
		<tr>
			<td>Silver wire</td>
			<td>Alfa Aesar</td>
			<td>11466</td>
			<td></td>
		</tr>
		<tr>
			<td>Sodium borohydride,</td>
			<td>Tianlian Chem. Tech.</td>
			<td>71320</td>
			<td>NaBH4</td>
		</tr>
		<tr>
			<td>Ti-U inverted dark-field microscope</td>
			<td>Nikon</td>
			<td></td>
			<td></td>
		</tr>
	</tbody>
</table>

a closed-type wireless nanopore electrode for analyzing single nanoparticles

用纳米电化学技术测量单纳米粒子的内在特性具有深刻的基础意义, 对纳米科学具有潜在的影响。然而, 电化学分析单个纳米粒子是具有挑战性的, 因为传感纳米界面是不可控制的。为了应对这一挑战, 我们在这里描述了一种闭式无线纳米粒子电极 (WNE) 的制造和表征, 该电极具有高度可控的形态和出色的重现性。WNE 的简单制造使其能够在一般化学实验室中制备出定义明确的纳米电极, 而无需使用洁净室和昂贵的设备。还重点介绍了30纳米闭式 WNE 在混合物中单个金纳米颗粒分析中的一个应用, 该应用显示了 0.6 pA 的高电流分辨率和 0.01 ms 的高时间分辨率。闭式 Wne 的更有潜力的应用可以从纳米粒子表征扩展到单分子检测和单细胞探测。

我们展示了一种简单的方法, 可以在石英锥形纳米粒子的基础上制备出定义良好的30nm 无线纳米粒子电极。图 1显示了纳米粒子的制备, 其中包括三个主要步骤。在拉拔器中固定一个内径为 0.5 mm、外径为 1.0 mm 的微毛细管, 然后激光聚焦在毛细管的中心, 以熔化石英。通过对毛细管端子施加力, 最终用纳米圆锥形尖端分离并形成两个部分。拉拔参数见<stro...

Watch this Scientific Journal Video about A Closed-Type Wireless Nanopore Electrode for Analyzing Single Nanoparticles at JoVE.com

A Closed-Type Wireless Nanopore Electrode for Analyzing Single Nanoparticles

在这里, 我们提出了一种用于制造闭式无线纳米粒子电极和随后对单个纳米粒子碰撞进行电化学测量的协议。

一种用于分析单纳米粒子的闭式无线纳米粒子电极

Measuring the intrinsic features of single nanoparticles by nanoelectrochemistry holds deep fundamental importance and has potential impacts in ...

电化学测量单纳米粒子的内在特征在纳米科学中具有十分重要的意义。该方法演示了一种简单但高度可重复的方法，用于快速单纳米粒子分析的无线纳米孔电极。通过这种简单的制造方法，纳米电子的尺寸可以达到30纳米。分析期间的当前分辨率和时间分辨率分别是 0.6 皮安和 0.01 毫秒。由于纳米电极尖端的纳米级尺寸，预计该无线纳米孔电极将用于体内和非侵入性世俗分析。金纳米尖端的局部表面质共振特性和交叉纳米吹风器的完美光学视觉可实现纳米级电光学检测。对无线纳米孔电极制造感兴趣的研究人员应掌握纳米管浇注过程。因为这是过程中的关键步骤。浇注移液器时应注意环境温度和湿度。首先加入4.8毫升氯酸，质量为1%至40毫升的去维水，并大力搅拌。然后加热溶液煮沸。快速添加 10 毫升的三钠柠檬酸盐溶液，质量分数为 1%。将溶液加热 15 分钟，直到最终溶液为红色。将石英毛细管放在充满丙酮的 15 毫升离心管中，并在超声波清洁剂中清洁 10 分钟。完成后，取出丙酮并加入乙醇。然后将离心管放在超声波清洗器中，再清洁十分钟。接下来，将石英毛细管放入另一个15毫升离心管中，用去电化水去除乙醇，并进行超声波清洗10分钟。使用氮气流干燥石英毛细管，并将其存放在干净的离心管中。之后，打开二氧化碳激光拉拔器并预热 15-20 分钟，以确保稳定的激光功率。在预热二氧化碳激光拉拔器中安装清洁的石英毛细管。将特定直径的二氧化碳激光拉拔器面板上的热量、灯丝、速度、延迟和拉力的拉力参数设置为一定。用可重复使用的粘合剂将准备好的纳米烟碟固定在培养皿上，以进一步定性。用微装载机将10微升的预装氯尿酸溶液注入纳米管。将纳米烟尘在约1，878倍G下离心5分钟，以去除纳米管中的气泡。离心后，用先前准备的硅橡胶将纳米移子固定在盖滑上，并定义纳米套内部的区域为 cis 侧，外部定义为横面。等待橡胶固化五分钟后，将集成合奏放在倒置显微镜的客观桌子上。打开并调整暗场照明，将纳米管尖端聚焦在 10 倍显微镜目标下。更改为 40 倍目标，实现更高的空间分辨率。接下来在纳米管内放置一个氯化银银电极。然后将第二个接地的氯化银电极放在横面上。将氯化银电极连接到前置放大器。打开当前测量系统和相应的离子电流记录软件。然后将应用电位设置为 300 毫伏。现在慢慢加入150微升的波罗氢钠溶液到横面，以触发氯尿酸和波罗氢钠之间的反应。同时，使用电流测量和暗场检测系统，以电气和光学方法记录电流轨迹和暗场图像散射光谱。在离子电流跟踪返回零皮安后关闭应用电位。用从底部到尖端的流动去化水清洗准备好的封闭式 WNE 型。在制造封闭型 WNE 后，将转面和 cis 面的溶液更改为氯化钾溶液。将 30 纳米摩尔金纳米部分溶液的 50 微升转移到横面。然后记录单个纳米粒子碰撞事件的电流信号，其电位为300毫伏。最后，更改施加的电压以监控当前信号的频率、振幅和形状变化。纳米管的制造包括三个主要步骤。内径为0.5毫米，外径为1毫米的微胶囊固定在拉拔器中，然后用激光聚焦在毛细管的中心以熔化石英。通过将力施加到毛细管的端子上，它最终用纳米级锥形尖端分离并形成两个部分。拉拔过程后在纳米管尖端内生成金纳米尖的过程如下。通过同时记录电流响应和暗场图像，使用原位特征系统来监控封闭型WNE的制造过程。在对焦离子束分割侧视图 SEM 图像提供闭合型 WNE 内金纳米尖的形态后，此处显示了裸纳米移子和闭合型 WNE 的顶视图 SEM 图像。在单个纳米粒子碰撞实验中，将金纳米粒子添加到WNE的横面。此 CNE 出色的噪声性能以高信号频率揭开隐藏信号。生成金纳米尖端时，应使用低应用电位生成电化学界面。高应用潜力可以加速黄金的产生，并导致纳米尖端结构的缺陷。该方法的高对比度分辨率和高特殊分辨率可以帮助研究人员进一步了解纳米尺度的电子转移过程。波罗氢钠是危险的，会与水发生剧烈反应。在准备氢化钠溶液时，请小心。

Research

JoVE Journal

Chemistry

Steady-state, Pre-steady-state, and Single-turnover Kinetic Measurement for DNA Glycosylase Activity

稳态，稳定前的状态，单营业额动力学测量DNA糖基化酶活性

Human 8-oxoguanine DNA glycosylase (OGG1) excises the mutagenic oxidative DNA lesion 8-oxo-7,8-dihydroguanine (8-oxoG) from DNA. Kinetic characterization ...

科研

化学

Preparation of Silica Nanoparticles Through Microwave-assisted Acid-catalysis

Microwave-assisted synthetic techniques were used to quickly and reproducibly produce silica nanoparticle sols using an acid catalyst with nanoparticle ...

A Simple Method for the Size Controlled Synthesis of Stable Oligomeric Clusters of Gold Nanoparticles under Ambient Conditions

根据环境条件的金纳米粒子的稳定低聚簇的大小控制合成的一种简便方法

Reducing dilute aqueous HAuCl4 with sodium thiocyanate (NaSCN) under alkaline conditions produces 2 to 3 nm diameter nanoparticles. Stable grape-like ...

Synthesis of Ligand-free CdS Nanoparticles within a Sulfur Copolymer Matrix

a硫磺共聚物基质内的免费配体硫化镉纳米粒子的合成

Aliphatic ligands are typically used during the synthesis of nanoparticles to help mediate their growth in addition to operating as high-temperature ...

A Protocol for the Production of Gliadin-cyanoacrylate Nanoparticles for Hydrophilic Coating

一种醇溶蛋白氰基丙烯酸酯纳米粒子为亲水涂料生产协议

This article presents a protocol for the production of protein-based nanoparticles that changes the hydrophobic surface to hydrophilic by a simple spray ...

An Optimized Protocol for the Efficient Radiolabeling of Gold Nanoparticles by Using a 125I-labeled Azide Prosthetic Group

An Optimized Protocol for the Efficient Radiolabeling of Gold Nanoparticles by Using a 125I-labeled Azide Prosthetic Group

一个优化的协议通过使用金纳米粒子的放射性标记效率<sup&gt; 125</sup&gt;我标记的叠氮辅基

Here, we demonstrate a detailed protocol for the radiosynthesis of a 125I-labeled azide prosthetic group and its application to the efficient ...

In Situ Detection and Single Cell Quantification of Metal Oxide Nanoparticles Using Nuclear Microprobe Analysis

In Situ Detection and Single Cell Quantification of Metal Oxide Nanoparticles Using Nuclear Microprobe Analysis

原位金属氧化物纳米粒子的核探针检测与单细胞定量研究

Micro-analytical techniques based on chemical element imaging enable the localization and quantification of chemical composition at the cellular level. ...

Liquid-cell Transmission Electron Microscopy for Tracking Self-assembly of Nanoparticles

用于跟踪纳米粒子自组装的液体细胞透射电子显微镜

Drying a nanoparticle dispersion is a versatile way to create self-assembled structures of nanoparticles, but the mechanism of this process is not fully ...

In Situ Lithiated Reference Electrode: Four Electrode Design for In-operando Impedance Spectroscopy

原位锂化参考电极: 四原位阻抗谱的电极设计

Extending operating voltage of Li-ion batteries results in higher energy output from these devices. High voltages, however, may trigger or accelerate ...

Ligand-Mediated Nucleation and Growth of Palladium Metal Nanoparticles

配体介导成核与钯金属纳米粒子的生长

The size, size distribution and stability of colloidal nanoparticles are greatly affected by the presence of capping ligands. Despite the key contribution ...