Name: electrochemical preparation of poly(3,4-ethylenedioxythiophene) layers on gold microelectrodes for uric acid-sensing applications
Uploaded: 2021-07-28T15:00:00
Description: Watch this Scientific Journal Video about Electrochemical Preparation of Poly3,4-Ethylenedioxythiophene Layers on Gold Microelectrodes for Uric Acid-Sensing Applications at JoVE.com

感谢新西兰商业、创新和就业部（MBIE）在“高性能传感器”计划中提供的资金。

1. 准备分析溶液
<ol><li>在有机溶液中制备0.1 M EDOT<ol>
<li>称出0.213克LiClO4 并将其转移到20 mL容量瓶中。</li>
		<li>使用量筒从瓶子中取出20毫升PC。</li>
		<li>将PC加入含有LiClO4的20mL容量瓶中。通过将烧瓶置于超声波浴中30分钟来混合溶液。将溶液转移到20 mL玻璃瓶中。</li>
		<li>用铝箔覆盖小瓶，并将连接到氮气管的长针插入溶液中以脱气10分钟。然后，取下铝箔并紧紧盖住小瓶。 注?...

<ol>
	<li>Guimard, N. K., Gomez, N., Schmidt, C. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Conducting+polymers+in+biomedical+engineering.">Conducting polymers in biomedical engineering.</a> Progress in Polymer Science. 32 (8), 876-921 (2007).</li><li>Cui, X., Martin, D. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Electrochemical+deposition+and+characterization+of+poly(3,4-ethylenedioxythiophene)+on+neural+microelectrode+arrays.">Electrochemical deposition and characterization of poly(3,4-ethylenedioxythiophene) on neural microelectrode arrays.</a> Sensors and Actuators B: Chemical. 89 (1), 92-102 (2003).</li><li>Hong, S. Y., Marynick, D. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Understanding+the+conformational+stability+and+electronic+structures+of+modified+polymers+based+on+polythiophene.">Understanding the conformational stability and electronic structures of modified polymers based on polythiophene.</a> Macromolecules. 25 (18), 4652-4657 (1992).</li><li>Kundu, K., Giri, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Evolution+of+the+electronic+structure+of+cyclic+polythiophene+upon+bipolaron+doping.">Evolution of the electronic structure of cyclic polythiophene upon bipolaron doping.</a> Journal of Chemical Physics. 105 (24), 11075-11080 (1996).</li><li>Thomas, C. A., Zong, K., Schottland, P., Reynolds, J. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Poly(3,4-alkylenedioxypyrrole)s+as+highly+stable+aqueous-compatible+conducting+polymers+with+biomedical+implications.">Poly(3,4-alkylenedioxypyrrole)s as highly stable aqueous-compatible conducting polymers with biomedical implications.</a> Advanced Materials. 12 (3), 222-225 (2000).</li><li>Yamato, H., Ohwa, M., Wernet, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Stability+of+polypyrrole+and+poly(3,4-ethylenedioxythiophene)+for+biosensor+application.">Stability of polypyrrole and poly(3,4-ethylenedioxythiophene) for biosensor application.</a> Journal of Electroanalytical Chemistry. 397 (1-2), 163-170 (1995).</li><li>Latonen, R. -. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Poly(3,4-ethylenedioxythiophene)+based+enzyme-electrode+configuration+for+enhanced+direct+electron+transfer+type+biocatalysis+of+oxygen+reduction.">Poly(3,4-ethylenedioxythiophene) based enzyme-electrode configuration for enhanced direct electron transfer type biocatalysis of oxygen reduction.</a> Electrochimica Acta. 68, 25-31 (2012).</li><li>Liu, K., Xue, R., Hu, Z., Zhang, J., Zhu, J. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Electrochemical+synthesis+of+acetonitrile-soluble+poly(3,4-ethylenedioxythiophene)+in+ionic+liquids+and+its+characterizations.">Electrochemical synthesis of acetonitrile-soluble poly(3,4-ethylenedioxythiophene) in ionic liquids and its characterizations.</a> Journal of Nanoscience and Nanotechnology. 9 (4), 2364-2367 (2009).</li><li>Cui, X., Martin, D. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fuzzy+gold+electrodes+for+lowering+impedance+and+improving+adhesion+with+electrodeposited+conducting+polymer+films.">Fuzzy gold electrodes for lowering impedance and improving adhesion with electrodeposited conducting polymer films.</a> Sensors and Actuators A: Physical. 103 (3), 384-394 (2003).</li><li>Wilks, S. J., Richardson-Burn, S. M., Hendricks, J. L., Martin, D., Otto, K. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Poly(3,4-ethylene+dioxythiophene)+(PEDOT)+as+a+micro-neural+interface+material+for+electrostimulation.">Poly(3,4-ethylene dioxythiophene) (PEDOT) as a micro-neural interface material for electrostimulation.</a> Frontiers in Neuroengineering. 2, 7 (2009).</li><li>Pranti, A. S., Schander, A., B&#246;decker, A., Lang, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Highly+stable+PEDOT:PSS+coating+on+gold+microelectrodes+with+improved+charge+injection+capacity+for+chronic+neural+stimulation.">Highly stable PEDOT:PSS coating on gold microelectrodes with improved charge injection capacity for chronic neural stimulation.</a> Proceedings. 1 (4), 492 (2017).</li><li>&#352;tul&#237;k, K., Amatore, C., Holub, K., Marecek, V., Kutner, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Microelectrodes:+Definitions,+characterization,+and+applications+(Technical+report).">Microelectrodes: Definitions, characterization, and applications (Technical report).</a> Pure and Applied Chemistry. 72 (8), 1483-1492 (2000).</li><li>&#352;tul&#237;k, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Activation+of+solid+electrodes.">Activation of solid electrodes.</a> Electroanalysis. 4 (9), 829-834 (1992).</li><li>Motshakeri, M., Travas-Sejdic, J., Phillips, A. R. J., Kilmartin, P. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Rapid+electroanalysis+of+uric+acid+and+ascorbic+acid+using+a+poly(3,4-ethylenedioxythiophene)-modified+sensor+with+application+to+milk.">Rapid electroanalysis of uric acid and ascorbic acid using a poly(3,4-ethylenedioxythiophene)-modified sensor with application to milk.</a> Electrochimica Acta. 265, 184-193 (2018).</li><li>Motshakeri, M., Phillips, A. R. J., Travas-Sejdic, J., Kilmartin, P. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Electrochemical+study+of+gold+microelectrodes+modified+with+PEDOT+to+quantify+uric+acid+in+milk+samples.">Electrochemical study of gold microelectrodes modified with PEDOT to quantify uric acid in milk samples.</a> Electroanalysis. 32 (9), 2101-2111 (2020).</li><li>Motshakeri, M., Phillips, A. R. J., Kilmartin, P. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Application+of+cyclic+voltammetry+to+analyse+uric+acid+and+reducing+agents+in+commercial+milks.">Application of cyclic voltammetry to analyse uric acid and reducing agents in commercial milks.</a> Food Chemistry. 293, 23-31 (2019).</li></ol>

CV方法可以快速简单地测量食品，葡萄酒和饮料，植物提取物甚至生物样品中的不同分析物。该技术产生各种各样的数据，包括氧化/还原峰值电位，目标分析物的峰值电流值（与浓度成正比），以及每次CV运行后的所有其他电流和电位值。虽然使用CV相对容易，但收集的数据有时需要从二进制文件转换为文本逗号格式，具体取决于所使用的恒电位仪系统。例如，在CH仪器的情况下，数据可以在每次?...

导电聚合物是广泛用于生物电子器件以改善界面的有机材料。与传统聚合物类似，导电聚合物易于合成，并且在加工过程中具有柔韧性1。导电聚合物可以使用化学和电化学方法合成;然而，电化学合成方法特别有利。这主要是由于它们能够形成薄膜，允许同时掺杂，捕获导电聚合物中的分子，最重要的是，合成过程1的简单性。此外，导电聚合物形成均匀、纤维状和凹凸不平的纳米结构，牢固地粘附在电极表面，这增加了电极2的活性表面积。
在20世纪80年代，开发了某些多杂核，如聚吡咯，聚苯胺，聚噻吩和PEDOT，显示出良好的导电性，易于合成和稳定性3，4。尽管聚吡咯比其他聚合物（例如，聚噻吩衍生物）更容易理解，但它容易发生不可逆氧化5。因此，PEDOT具有某些优于其他产品的优势，因为它具有更稳定的氧化状态，并且在类似条件下与聚吡咯相比保留了89%的电导率6。此外，PEDOT以高电导率（~500 S/cm）和中等带隙（即带隙或能隙是无电荷的区域，是指价带顶部和导带底部之间的能量差）7而闻名。
此外，PEDOT具有电化学性质，需要较低的电位才能被氧化，并且在合成后随着时间的推移比聚吡咯更稳定7。它还具有良好的光学透明度，这意味着其光学吸收系数，特别是以PEDOT-聚苯乙烯磺酸盐（PEDOT-PSS）的形式，在400-700nm处的电磁波谱的可见光区域为7。在电化学上形成PEDOT时，EDOT单体在工作电极处氧化形成自由基阳离子，其与其他自由基阳离子或单体反应形成沉积在电极表面的PEDOT链1。
PEDOT薄膜的电化学形成涉及不同的控制因素，如电解质，电解质类型，电极设置，沉积时间，掺杂剂类型和溶剂温度1 PEDOT可以通过使电流通过适当的电解质溶液以电化学方式产生。可以使用不同的电解质，例如水性（例如，PEDOT-PSS）、有机（例如，PC、乙腈）和离子液体（例如，1-丁基-3-甲基咪唑四氟硼酸盐（BMIMBF4））。
PEDOT涂层的优点之一是它可以将Au电极在1 kHz频率范围内的阻抗显着降低两到三个数量级，这使得它有助于提高直接电化学检测神经活性的灵敏度9。此外，当刺激电荷通过PEDOT10转移时，PEDOT修饰电极的电荷存储容量增加并导致更快和更低的电位响应。此外，当聚苯乙烯磺酸盐（PSS）用作在Au微电极阵列上形成PEDOT的掺杂剂时，它会产生具有高有源表面积，较低界面阻抗和较高电荷注入容量11的粗糙多孔表面。对于电聚合步骤，EDOT-PSS通常在水电解质中产生分散体。
然而，EDOT可溶于氯仿，丙酮，ACN和其他有机溶剂，如PC。因此，在这项研究中，在电聚合开始之前，以10：1的比例使用水与少量ACN的混合物来制造可溶性EDOT溶液。使用这种水性电解质的目的是省略PEDOT修饰微电极制备中的适应步骤，缩短步骤。用于与水/ACN电解质进行比较的其他有机电解质是PC。两种电解质都含有LiClO4 作为掺杂剂，有助于氧化EDOT单体并形成PEDOT聚合物。
微电极是伏安工作电极，直径小于宏观电极，尺寸约为数十微米或更小。与宏电极相比，它们的优势包括增强从溶液到电极表面的质量传递，产生稳态信号，更低的欧姆电位降，更低的双层电容和更高的信噪比12。与所有固体电极类似，微电极在分析前需要进行调节。适当的预处理或活化技术是机械抛光以获得光滑的表面，随后进行电化学或化学调节步骤，例如在合适的电解质13中在特定范围内进行电位循环。
CV非常常用于PEDOT的电化学聚合，方法是将电极插入涉及合适溶剂和掺杂剂电解质的单体溶液中。这种电化学技术有利于提供方向信息，例如导电聚合物掺杂过程的可逆性和转移电子的数量，分析物的扩散系数以及反应产物的形成。本文描述了用于PEDOT电聚合的两种不同的电解质如何产生具有电位传感应用的薄纳米结构薄膜，该应用取决于形态和其他固有特性。

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>Acetonitrile</td>
			<td>Baker Analyzed HPLC Ultra Gradient Solvent</td>
			<td>75-05-8</td>
			<td>HPLC grade</td>
		</tr>
		<tr>
			<td>Alumina polishing pad</td>
			<td>BASi, USA</td>
			<td>MF-1040</td>
			<td>tan/velvet color</td>
		</tr>
		<tr>
			<td>Belgian chocolate milk</td>
			<td>Puhoi Valley dairy company, Auckland, NZ</td>
			<td>_</td>
			<td>Buy from local supermarket</td>
		</tr>
		<tr>
			<td>Caramel/white chocolate milk</td>
			<td>Puhoi Valley dairy company, Auckland, NZ</td>
			<td>_</td>
			<td>Buy from local supermarket</td>
		</tr>
		<tr>
			<td>CH instrument</td>
			<td>CH instruments, Inc. USA</td>
			<td>_</td>
			<td>Model CHI660E</td>
		</tr>
		<tr>
			<td>Counter electrode</td>
			<td>BASi, USA</td>
			<td>MW-1032</td>
			<td>7.5 cm long platinum wire (0.5 mm diameter) auxiliary/counter electrode, 99.95% purity</td>
		</tr>
		<tr>
			<td>Disodium hydrogen phosphate (Na2HPO4, 2H2O)</td>
			<td>Scharlau Chemie SA, Barcelona, Spain</td>
			<td>10028-24-7</td>
			<td>Weigh 17.8 g</td>
		</tr>
		<tr>
			<td>DURAN bottle</td>
			<td>University of Auckland</td>
			<td>_</td>
			<td>The glasswares were made locally at the University of Auckland</td>
		</tr>
		<tr>
			<td>Electrochemical cell</td>
			<td>BASi, USA</td>
			<td>MF-1208</td>
			<td>&#160;5-15 mL volume, glass</td>
		</tr>
		<tr>
			<td>Electrode Polishing Alumina Suspension</td>
			<td>BASi, USA</td>
			<td>CF-1050</td>
			<td>7 mL of 0.05 &#181;m particle size alumina polish</td>
		</tr>
		<tr>
			<td>Espresso milk</td>
			<td>Puhoi Valley dairy company, Auckland, NZ</td>
			<td>_</td>
			<td>Buy from local supermarket</td>
		</tr>
		<tr>
			<td>3,4-Ethylenedioxythiophene (EDOT), 97%</td>
			<td>Sigma-Aldrich</td>
			<td>126213-50-1</td>
			<td>Take 10.68 &#956;L from bottle</td>
		</tr>
		<tr>
			<td>FEI ESEM Quanta 200 FEG</td>
			<td>USA</td>
			<td>_</td>
			<td>SEM equipped with a Schottky field emission gun (FEG) for optimal spatial resolution. The instrument can be used in high vacuum mode (HV), low-vacuum mode (LV) and the so called ESEM (Environmental SEM) mode.&#160;</td>
		</tr>
		<tr>
			<td>Gold microelectrode</td>
			<td>BASi, USA</td>
			<td>MF-2006</td>
			<td>Working electrode (10 &#956;m diameter)</td>
		</tr>
		<tr>
			<td>Lithium perchlorate, ACS reagent, &#8805;95%</td>
			<td>Sigma-Aldrich</td>
			<td>7791-03-9</td>
			<td>Make 0.1 M solution</td>
		</tr>
		<tr>
			<td>Micropipettes</td>
			<td>Eppendorf</td>
			<td>_</td>
			<td>10-100 &#956;L and 100-1000 volumes</td>
		</tr>
		<tr>
			<td>MilliQ water</td>
			<td>Thermo Scientific, USA</td>
			<td>_</td>
			<td>18.2 M&#937;/cm at 25&#176;C, Barnstead Nanopure Diamond Water Purification System</td>
		</tr>
		<tr>
			<td>Propylene carbonate, Anhydrous, 99.7%</td>
			<td>Sigma-Aldrich</td>
			<td>108-32-7</td>
			<td>Take 20 mL from bottle</td>
		</tr>
		<tr>
			<td>Reference electrode</td>
			<td>BASi, USA</td>
			<td>MF-2052</td>
			<td>Silver/silver chloride (Ag/AgCl) electrode to be kept in 3 M sodium chloride</td>
		</tr>
		<tr>
			<td>Replacement glass polishing plate</td>
			<td>BASi, USA</td>
			<td>MF-2128</td>
			<td>Glass plate as a stand to attach the polishing pad on it</td>
		</tr>
		<tr>
			<td>Sodium dihydrogen phosphate&#160; (NaH2PO4, 1H2O)</td>
			<td>Sigma-Aldrich</td>
			<td>10049-21-5</td>
			<td>Weigh 13.8 g</td>
		</tr>
		<tr>
			<td>Sodium hydroxide pearls, AR</td>
			<td>ECP-Analytical Reagent</td>
			<td>1310-73-2</td>
			<td>Make 0.1 M solution</td>
		</tr>
		<tr>
			<td>Sodium perchlorate, ACS reagent, &#8805;98%</td>
			<td>Sigma-Aldrich</td>
			<td>7601-89-0</td>
			<td>Make 0.1 M solution</td>
		</tr>
		<tr>
			<td>Sulfuric acid (98%)</td>
			<td>Merck</td>
			<td>7664-93-9</td>
			<td>Make 0.5 M solution</td>
		</tr>
		<tr>
			<td>Uric acid</td>
			<td>Sigma-Aldrich</td>
			<td>69-93-2</td>
			<td>Make 1 mM solution</td>
		</tr>
		<tr>
			<td>Whole milk</td>
			<td>Anchor dairy company, Auckland, NZ</td>
			<td></td>
			<td>Blue cap milk, buy from local supermarket</td>
		</tr>
	</tbody>
</table>

electrochemical preparation of poly(3,4-ethylenedioxythiophene) layers on gold microelectrodes for uric acid-sensing applications

描述了在金电极上合成聚（3，4-乙二氧基噻吩）（PEDOT）的两种不同方法，即在水溶液和有机溶液中电聚3，4-乙二氧基噻吩（EDOT）单体。循环伏安法（CV）用于PEDOT薄层的合成。高氯酸锂（LiClO4）在水性（水性/乙腈（ACN））和有机（碳酸丙烯酯（PC））溶剂体系中均用作掺杂剂。在有机系统中产生PEDOT层后，电极表面通过在水溶液中连续循环进行适应，以用作水样样品的传感器。 
使用基于水基的电聚合方法具有去除适应性步骤以缩短传感器制备时间的潜在好处。虽然水法比有机溶剂法更经济、更环保，但在有机溶液中获得了优越的PEDOT形成。采用扫描电子显微镜（SEM）对所得PEDOT电极表面进行了表征， 结果表明，PEDOT在有机PC溶液的电聚合过程中生长恒定， 在金（Au）微电极上呈快速分形生长.

循环伏安法是一种在Au微电极表面上形成薄PEDOT层的简单技术，可在目标分析物的电化学检测过程中提高电极电导率和灵敏度。该协议演示了从有机溶液中电聚合0.1 M EDOT与从水电解质溶液中实现0.01 M EDOT相比的方法。在水溶液/ACN溶液中运行10个循环会导致PEDOT的适度增长，与在LiClO 4 / PC溶液中观察到的4个循环相当。图1显示了在水溶液/ ACN和有机溶液中电聚的EDOT之间的...

Watch this Scientific Journal Video about Electrochemical Preparation of Poly3,4-Ethylenedioxythiophene Layers on Gold Microelectrodes for Uric Acid-Sensing Applications at JoVE.com

Electrochemical Preparation of Poly3,4-Ethylenedioxythiophene Layers on Gold Microelectrodes for Uric Acid-Sensing Applications

我们描述了用于聚（3，4-乙烯二氧噻吩）电聚合的水性和有机溶剂体系，以在金微电极表面形成薄层，用于检测低分子量分析物。

在金微电极上电化学制备聚（3，4-乙烯二氧噻吩）层在尿酸传感应用中

Two different methods for the synthesis of poly(3,4-ethylenedioxythiophene) (PEDOT) on gold electrodes are described, using electropolymerization of ...

通过用有机溶剂制成的一层薄薄的PEDOT修饰金微电极表面，我们可以获得更高的表面积并提高传感器灵敏度。微电极程序是对各种介质中抗氧化剂的快速分析。这可以应用于不同的环境，从监测饮料到对住院患者状态的即时评估。使用合适的恒电位仪运行循环伏安法作为感兴趣的电化学技术。打开恒电位仪和连接到它的计算机。要测试计算机和仪器之间的通信，请启动软件，然后在设置菜单下，选择硬件测试命令。在听到恒电位仪发出的一些声音后，硬件测试结果将显示在单独的窗口中。单击“确定”并继续运行实验。有时，通过单击硬件测试命令，会出现链接失败错误。检查连接和端口设置。测试连接后，单击设置菜单，选择技术，然后从打开的窗口中选择循环伏安法方法。然后返回设置菜单，单击参数以输入相应的实验参数。例如，要在裸金微电极上的有机电解质中运行0.1摩尔EDOT电聚合，将初始电位设置为负0.3伏，将最终电位设置为负0.3伏，将高电位设置为1.2伏，将段数设置为8，扫描速率设置为每秒100毫伏，并将方向设置为正。输入适当的循环伏安法参数后，在玻璃电化学电池中准备三个电极设置，包括工作电极，参比电极和铂丝对电极。将这些清洁和干燥的电极通过连接到支架上的电极支架的孔，然后将支架放在电化学池上方，将电极插入目标溶液或样品中。确保电极表面没有气泡。如果有气泡，请取出电极，再次用去离子水冲洗，然后用纸巾拍干。然后将电极放回支架和溶液中。如果参比电极周围有气泡，请轻轻敲击尖端。如果开始扫描后对电极周围有气泡，请清洁对电极。如果循环伏安法扫描变得嘈杂，请清洁电极表面并检查系统连接、电线和夹子。确保参考电极、工作电极和对电极的所有三根导线连接均正确连接后，单击“运行”开始实验。要预处理金微电极，用氧化铝浆在放置在玻璃抛光板上的氧化铝抛光垫上抛光30秒，进行圆形和八形的手部运动，然后用去离子水冲洗微电极。将其插入含有15毫升无水乙醇和超声波酸盐的玻璃汁中两分钟。接下来，用乙醇和水冲洗微电极，并在去离子水中再次超声处理四分钟，以从电极表面除去多余的氧化铝。最后，通过在0.5摩尔硫酸中循环20段以每秒50毫伏的扫描速率在负0.4和正1.6伏电位之间去除额外的杂质。确保每次在硫酸中清洁电极时，由于在一致的阳极和阴极电位下形成和还原氧化金，因此有两个清晰的峰。为了在有机溶液中制备0.1摩尔EDOT，首先将一毫升制备的0.1摩尔高氯酸锂溶液转移到电化学电池中。然后使用微量移液管，向电化学池中加入10.68微升EDOT单体。要在裸金微电极表面上电聚合EDOT，请将所有电极设置插入溶液中并进行循环伏安法。然后使用扫描电子显微镜，表征这种修饰电极的表面。用去离子水冲洗电极并用纸巾擦干。然后，为了将这种PEDOT修饰的金微电极用于传感目的，通过将电极浸入0.1摩尔高氯酸钠溶液中并进行循环伏安法扫描，使其表面适应水溶液。然后用去离子水冲洗后，将这种有机PEDOT修饰和适应的微电极浸入磷酸盐缓冲溶液中，并进行循环伏安法以产生背景扫描。最后，将电极从缓冲溶液中取出，无需冲洗，立即将其插入尿酸或牛奶溶液中，以进行循环伏安法扫描。接下来，在乙腈水溶液中制备0.01摩尔EDOT，使用微量移液管并在玻璃小瓶中加入10.68微升乙氧乙腈到一毫升乙腈中，然后在小瓶中加入9毫升去离子水，制备10毫升0.01摩尔EDOT溶液。向制备的EDOT溶液中加入110毫克高氯酸锂粉末，得到0.1摩尔高氯酸锂溶液，轻轻混合。将制备的溶液转移到电化学池中。将电极插入乙腈水溶液中，通过循环伏安法在电极表面电聚合0.01摩尔EDOT，然后通过扫描电镜表征该修饰电极的表面。使用在有机溶液中合成的PEDOT传感器分析普通鲜奶中的尿酸含量，在0.35伏特下产生28.4纳安培的阳极峰电流，相当于82.7微摩尔的浓度。在0.65伏特的普通牛奶的循环伏安扫描中，第二个大氧化峰与可氧化化合物有关，包括半胱氨酸，色氨酸和酪氨酸等电活性氨基酸。对焦糖和白巧克力牛奶样品进行的循环伏安法扫描显示，尿酸在0.36伏特处有一个清晰的峰值，在0.5伏特处还有一个额外的峰值，可能与香草酸的存在有关，香草酸是风味牛奶的成分之一。比利时巧克力牛奶样品的循环伏安法显示儿茶素氧化峰在0.26伏特时和儿茶素还原峰在0.22伏特。0.3伏峰值电流在儿茶素峰的尾部出现为尖锐的峰值，这是由于尿酸氧化。哥伦比亚浓缩咖啡牛奶样品的循环伏安法在0.35伏特和0.23伏特处分别表现出宽的阳极和阴极峰电流，这是由于咖啡中的主要酚类抗氧化剂，即绿原和咖啡酸。清洁和扰动电极是本实验中最重要的部分，可能会影响获得的电流信号。需要对抗氧化剂化合物进行更详细的分析，然后我们可以转向LCMS等色谱方法。但是，这很耗时，并且并非每个样品都需要。

Research

JoVE Journal

Chemistry

Electrochemical Preparation of Poly(3,4-Ethylenedioxythiophene) Layers on Gold Microelectrodes for Uric Acid-Sensing Applications

Microfluidic On-chip Capture-cycloaddition Reaction to Reversibly Immobilize Small Molecules or Multi-component Structures for Biosensor Applications

微流控芯片上捕获环加成反应可逆地固定小分子或多组分结构的生物传感器应用

Methods  for rapid surface immobilization of bioactive small molecules with control over  orientation and immobilization density are highly desirable for ...

科研

化学

Preparation of Hydrophobic Metal-Organic Frameworks via Plasma Enhanced Chemical Vapor Deposition of Perfluoroalkanes for the Removal of Ammonia

增强型氟烷烃的化学气相沉积等离子通过疏水金属 - 有机骨架的制备氨的去除

Plasma enhanced chemical vapor deposition (PECVD) of perfluoroalkanes has long been studied for tuning the wetting properties of surfaces. For high ...

Dynamic Electrochemical Measurement of Chloride Ions

氯离子的动态电化学测试

This protocol describes the dynamic measurement of chloride ions using the transition time of a silver silver chloride (Ag/AgCl) electrode. Silver silver ...

Hydroquinone Based Synthesis of Gold Nanorods

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 ...

Simple Methods for the Preparation of Non-noble Metal Bulk-electrodes for Electrocatalytic Applications

用于制备用于电催化应用的非贵金属体电极的简单方法

The rock material pentlandite with the composition Fe4.5Ni4.5S8 was synthesized via high temperature synthesis from the elements. The structure and ...

Electrochemical Impedance Spectroscopy as a Tool for Electrochemical Rate Constant Estimation

电化学阻抗谱作为电化学速率常数估计的一种工具

Electrochemical impedance spectroscopy (EIS) was used for advanced characterization of organic electroactive compounds along with cyclic voltammetry (CV). ...

Gold Nanoparticle Modified Carbon Fiber Microelectrodes for Enhanced Neurochemical Detection

用于增强神经化学检测的金纳米粒子改性碳纤维微电极

For over 30 years, carbon-fiber microelectrodes (CFMEs) have been the standard for neurotransmitter detection. Generally, carbon fibers are aspirated into ...

Electrochemical Roughening of Thin-Film Platinum Macro and Microelectrodes

薄膜铂金宏观和微电极的电化学粗加工

This protocol demonstrates a method for electrochemical roughening of thin-film platinum electrodes without preferential dissolution at grain boundaries ...

Growth of Gold Dendritic Nanoforests on Titanium Nitride-coated Silicon Substrates

氮化钛涂层硅基板上金石榴石的生长

In this study, a high-power impulse magnetron sputtering system is used to coat a flat and firm titanium nitride (TiN) film on silicon (Si) wafers, and a ...

Asymmetric Thermoelectrochemical Cell for Harvesting Low-grade Heat under Isothermal Operation

用于在等温操作下收集低档热量的不对称热电化学电池

Low-grade heat is abundantly available in the environment as waste heat. The efficient conversion of low-grade heat into electricity is very difficult. We ...