TCL感谢英国皇家学会研究补助金2016 R1（RG150551）和UCL BEAMS未来领袖奖的支持，该奖项由EPSRC的机构赞助奖（EP/P511262/1）资助。WIKC，TCL和IPP感谢A * STAR-UCL研究实习计划通过EPSRC M3S CDT（EP / L015862 / 1）资助的学生奖学金。GD和TJ要感谢EPSRC M3S CDT（EP / L015862 / 1）赞助他们的学生奖学金。TJ和TCL感谢Camtech Innovations对TJ学生的贡献。所有作者都感谢伦敦大学学院开放获取基金。

1. 金核素的合成
<ol><li>通过传统的图尔克维奇方法合成金种子26<ol>
<li>通过溶解98.5mg HAuCl4 ， 制备10 mL 25 mM HAuCl4溶液3H2O前驱体与10mL去离子水在玻璃小瓶中。 注意：将少量HAuCl4 前驱体转移到称量船中，并使用塑料刮刀代替金属刮刀称量晶体，因为HAuCl4 前驱体会腐蚀金属实验室器具。称量步骤应尽可能快地进行，因为HAuCl4 具有吸湿性，因此会通过从大气中吸收水分来增加其重量。HAuCl4 具有高度腐蚀性，可引起严重的皮肤灼伤和眼睛损伤。处理时要格外小心。</li>
		<li>通过将64.5mg柠檬酸钠粉末与0.5mL去离子水溶解在玻璃瓶中来制备0.5mL 500mM柠檬酸钠溶液。</li>
		<li>在250 mL蓝封瓶中用99 mL水稀释1 mL 25 mM HAuCl4 溶液，得到100 mL 0.25 mM HAuCl4 溶液。</li>
		<li>将 99.5 mL 0.25 mM HAuCl4 溶液加入配备冷凝器的 250 mL 三颈圆底烧瓶中。在剧烈搅拌下将溶液加热至90°C并保持温度15分钟。</li>
		<li>将0.5mL的500mM柠檬酸钠溶液注入反应混合物中，并保持温度并搅拌，直到溶液的颜色变成红宝石红色。 注意：反应大约需要30分钟。</li>
	</ol></li>
	<li>通过动力学控制方法对Au NPs进行种子生长13
	<ol>
<li>将合成的Au种子溶液冷却至70°C。</li>
		<li>通过将154.8mg柠檬酸钠粉末与10mL去离子水溶解在玻璃瓶中来制备10mL 60mM柠檬酸钠溶液。</li>
		<li>向Au种子注入0.67mL的25mM HAuCl4 溶液和0.67mL的60mM柠檬酸钠溶液，时间间隔为2分钟。</li>
		<li>重复步骤1.2.3，逐渐将Au NPs的尺寸增加到40nm。 注意：大约需要10个生长步骤才能达到40nm。所需的实际步骤数可能取决于精确的设置。</li>
	</ol></li>
	<li>使用自动合成器对金NPs进行种子生长（图2）
	<ol>
<li>将第1节中制备的25mL Au种子溶液转移到50mL锥形离心管中，并在热混合器中冷却至70°C。 注：使用放置在装有25 mL水的50 mL离心管中的热电偶温度计监测热混合器内部的温度。</li>
		<li>在 3 mL 鲁尔锁一次性注射器中加入 2.5 mL 25 mM HAuCl4 溶液。用2.5 mL 60 mM柠檬酸钠溶液填充另一个3 mL鲁尔锁一次性注射器。</li>
		<li>将注射器放入注射泵中，并使用鲁尔到微密适配器将PEEK管（内径150μm）连接到注射器。将管子插入热混合器中含有Au种子溶液的离心管中。</li>
		<li>设置两个注射泵，在20分钟（每分钟8.357μL）内分配0.1675 mL溶液。</li>
		<li>将热混合器转速设置为700 rpm，然后在含有25 mM HAuCl4溶液的注射泵上按“启动”。</li>
		<li>2分钟后，在含有60mM柠檬酸钠溶液的注射泵上按 开始 。</li>
		<li>开始HAuCl4 溶液注射后30分钟，除去等分试样的Au NP溶液进行分析。</li>
		<li>重复步骤1.3.5 – 1.3.7，逐渐将Au NPs的直径增加到40nm。 注意：该设置可用于通过增加步骤1.3.4中添加的反应物的体积，一步将Au NPs生长到40nm。这是通过增加分配时间同时保持相同的注射速率来实现的。</li>
	</ol></li>
</ol>2. 金核素的表征
<ol><li>紫外-可见光谱<ol>
<li>将1 mL Au NP溶液加入半微量石英比色皿中。</li>
		<li>打开光谱仪。</li>
		<li>将波长范围设置为 400 - 800 nm。</li>
		<li>获取每个样品的紫外-可见光谱。</li>
	</ol>
</li>
	<li>动态光散射<ol>
<li>用0.22μm过滤器将样品溶液过滤到塑料半微比色皿中。</li>
		<li>打开 DLS 仪器。</li>
		<li>将温度设置为25°C并平衡60秒。</li>
		<li>测量每个样品的流体动力学尺寸。</li>
	</ol>
</li>
	<li>透射电子显微镜<ol>
<li>将 5 μL 样品溶液液滴滴浇注到 C 涂层的 300 目 Cu 网格上，并在空气中干燥。 注意：对于更浓缩的Au NP溶液样品，需要稀释才能在TEM网格上获得均匀分散的Au NPs。</li>
		<li>在200 kV加速电压下使用TEM为每个样品采集多个TEM图像。</li>
		<li>使用ImageJ计算平均尺寸和标准偏差，测量每个样品的200 Au NP的直径。</li>
	</ol>
</li>
</ol>3. CB7-UA复合物的形成
<ol><li>0.4 mM CB7溶液的制备<ol>
<li>向15毫升玻璃瓶中加入4.65毫克CB7。 注：CB7的用量是根据CB7（= 1163 Da）的公式重量计算的，该公式重量已被文献中的大多数报告所采用。然而，CB7固体样品通常含有合成和纯化步骤中留下的水，HCl，甲醇和其他盐，有助于样品中的自重约为10-20%。滞留的溶剂和盐不能通过在真空炉或其他方式中加热来去除。它们的量因不同批次的样品而异，但可以使用元素分析进行量化。然而，所提出的方案对CB7样品中存在未定量的溶剂和盐不敏感。</li>
		<li>向小瓶中加入10 mL水并拧紧盖子。</li>
		<li>在室温下对样品进行超声处理，直到CB7固体完全溶解。 注：CB7是根据文献27 合成的，但它也是市售的。</li>
	</ol>
</li>
	<li>0.4 mM UA溶液的制备<ol>
<li>向50 mL离心管中加入2.69mg UA。</li>
		<li>向管中加入40 mL水并拧紧盖子。</li>
		<li>使用热混合器将温度设置为70°C，速度设置为800 rpm，时间设置为2小时，从而旋转样品溶液。让溶液冷却至室温。 注：UA在水中的溶解度较低（0.40 mM）5。如果UA粉末尚未完全溶解，则旋转更长时间。或者，超声处理可用于促进溶解。</li>
	</ol>
</li>
	<li>0.4 mM UA溶液的顺序稀释<ol>
<li>在15 mL玻璃瓶中用5 mL水稀释5 mL 0.4 mM UA溶液，得到10 mL 0.2 mM UA溶液。拧紧盖子并超声处理30秒。</li>
		<li>重复步骤3.3.1，使用适量的UA和水，如表1所述。</li>
	</ol>
</li>
	<li>CB7-UA复合物的制备<ol>
<li>将0.75 mL的0.4 mM CB7溶液和0.75 mL的0.4 mM UA溶液加入1.5 mL试管中。盖上盖子并超声处理30秒。</li>
		<li>等待30分钟，以确保形成东宾综合体。</li>
		<li>重复步骤3.4.1 – 3.4.2，使用不同浓度的UA溶液。</li>
	</ol>
</li>
</ol>4. 用户获取的 SERS 传感
<ol><li>拉曼系统的实验设置（图3）<ol>
<li>打开 633 nm 氦氖激光器 （22.5 mW）。</li>
		<li>打开模块化拉曼光谱仪。</li>
		<li>打开计算机并启动软件。</li>
		<li>单击“ 光谱学应用程序向导” 图标，然后选择“ 拉曼”。</li>
		<li>开始新的收购。将积分时间设置为 30 秒，将扫描设置为平均值 5，将 boxcar 设置为 0。</li>
		<li>存储背景光谱并输入激光波长（即633nm）。 注意：积分时间是每次扫描的时间，平均扫描是平均扫描次数，以创建每个光谱，boxcar是平均28的相邻像素数。</li>
	</ol>
</li>
	<li>SERS基板的形成<ol>
<li>将0.9 mL的40nm Au NP溶液和0.1mL的预成型CB7-UA复合溶液加入1.5mL管中。盖上盖子并超声处理，直到溶液从红宝石红色变为紫色。 注意：也可以使用商用柠檬酸盐稳定的40nm Au NP溶液样品。通常，通过从浓缩的储备溶液样品中稀释，将局部表面等离子体共振（LSPR）峰的光密度调节至1。样品中的柠檬酸盐浓度通常保持在2mM。</li>
		<li>将样品溶液转移到半微比色皿中。将比色皿放入拉曼样品架中，然后合上盖子。</li>
		<li>开始测量。</li>
		<li>设置自动保存以记录五个连续的SERS光谱。</li>
		<li>停止测量并更换样品。</li>
		<li>重复步骤4.2.1 – 4.2.5，使用不同浓度的CB7-UA溶液。 注意：发现聚集时间取决于纳米团聚体中UA的浓度，范围从0.1μM UA的30 s到20μM UA的30分钟，这是由于空CB7浓度的差异，这对介导Au NPs的聚集有重大贡献。对于CB7-UA复合物，一个门户被笨重的UA分子阻断，使其无法与Au NP表面结合，因此无法介导NP聚集体21。当溶液的颜色从红宝石红色变为紫色时，样品就可以进行测量了。</li>
	</ol>
</li>
</ol>5. 数据分析
<ol><li>数据处理<ol>
<li>将带有非对称最小二乘 （ALS） 插件的基线下载并安装到 Origin 中。 注意：ALS 插件需要 OriginPro。</li>
		<li>将原始数据插入到源中。</li>
		<li>根据每个样品的五个SERS光谱计算平均值。将该值除以激光器的功率（即22.5 mW）和积分时间（即30 s）。</li>
		<li>单击 ALS 图标以打开对话框。将非对称因子设置为 0.001，阈值设置为 0.03%，将平滑因子设置为 2，将迭代次数设置为 20，以校正每个平均频谱的基线。</li>
		<li>使用按 y 偏移的堆叠线绘制不同 UA 浓度的 SERS 光谱。输出应为强度（计数 s-1 mW-1）与拉曼位移 （cm-1）。</li>
	</ol>
</li>
</ol>

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K., 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=Selective+Detection+of+Nitroexplosives+Using+Molecular+Recognition+within+Self-Assembled+Plasmonic+Nanojunctions.">Selective Detection of Nitroexplosives Using Molecular Recognition within Self-Assembled Plasmonic Nanojunctions.</a> The Journal of Physical Chemistry C. 123 (25), 15769-15776 (2019).</li><li>Kasera, S., Biedermann, F., Baumberg, J. J., Scherman, O. A., Mahajan, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Quantitative+SERS+Using+the+Sequestration+of+Small+Molecules+Inside+Precise+Plasmonic+Nanoconstructs.">Quantitative SERS Using the Sequestration of Small Molecules Inside Precise Plasmonic Nanoconstructs.</a> Nano Letters. 12 (11), 5924-5928 (2012).</li><li>Taylor, R. W., 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=In+Situ+SERS+Monitoring+of+Photochemistry+within+a+Nanojunction+Reactor.">In Situ SERS Monitoring of Photochemistry within a Nanojunction Reactor.</a> Nano Letters. 13 (12), 5985-5990 (2013).</li><li>Kasera, S., Herrmann, L. O., Barrio, J. d., Baumberg, J. J., Scherman, O. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Quantitative+Multiplexing+with+Nano-Self-Assemblies+in+SERS.">Quantitative Multiplexing with Nano-Self-Assemblies in SERS.</a> Scientific Reports. 4, 6785 (2014).</li><li>Chio, W. I. K., 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=Dual-triggered+nanoaggregates+of+cucurbit[7]uril+and+gold+nanoparticles+for+multi-spectroscopic+quantification+of+creatinine+in+urinalysis.">Dual-triggered nanoaggregates of cucurbit[7]uril and gold nanoparticles for multi-spectroscopic quantification of creatinine in urinalysis.</a> Journal of Materials Chemistry C. 8, 7051-7058 (2020).</li><li>Turkevich, J., Stevenson, P. C., Hillier, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+study+of+the+nucleation+and+growth+processes+in+the+synthesis+of+colloidal+gold.">A study of the nucleation and growth processes in the synthesis of colloidal gold.</a> Discussions of the Faraday Society. 11, 55-75 (1951).</li><li>Lagona, J., Mukhopadhyay, P., Chakrabarti, S., Issacs, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+cucurbit[n]uril+family.">The cucurbit[n]uril family.</a> Angewandte Chemie International Edition. 44 (31), 4844-4870 (2005).</li><li>. OceanView Installation and Operation Manual Available from: <a target="_blank" href="https://www.oceaninsight.com/globalassets/catalog-blocks-and-images/manuals--instruction-old-logo/software/oceanviewio.pdf">https://www.oceaninsight.com/globalassets/catalog-blocks-and-images/manuals--instruction-old-logo/software/oceanviewio.pdf</a> (2013)</li><li>Mahajan, S., 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=Raman+and+SERS+spectroscopy+of+cucurbit[n]urils.">Raman and SERS spectroscopy of cucurbit[n]urils.</a> Physical Chemistry Chemical Physics. 12 (35), 10429-10433 (2010).</li><li>Langer, J., 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=Present+and+Future+of+Surface-Enhanced+Raman+Scattering.">Present and Future of Surface-Enhanced Raman Scattering.</a> ACS Nano. 14 (1), 28-117 (2020).</li><li>Pilot, R., 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=A+Review+on+Surface-Enhanced+Raman+Scattering.">A Review on Surface-Enhanced Raman Scattering.</a> Biosensors. 9 (2), 57 (2019).</li><li>Bantz, K. C., 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=Recent+progress+in+SERS+biosensing.">Recent progress in SERS biosensing.</a> Physical Chemistry Chemical Physics. 13 (24), 11551-11567 (2011).</li><li>Moore, T. J., 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=In+Vitro+and+In+Vivo+SERS+Biosensing+for+Disease+Diagnosis.">In Vitro and In Vivo SERS Biosensing for Disease Diagnosis.</a> Biosensors. 8 (2), 46 (2018).</li><li>Bonifacio, A., Cervo, S., Sergo, V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Label-free+surface-enhanced+Raman+spectroscopy+of+biofluids:+fundamental+aspects+and+diagnostic+applications.">Label-free surface-enhanced Raman spectroscopy of biofluids: fundamental aspects and diagnostic applications.</a> Analytical and Bioanalytical Chemistry. 407 (27), 8265-8277 (2015).</li><li>Jeong, H. H., Choi, E., Ellis, E., Lee, T. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Recent+advances+in+gold+nanoparticles+for+biomedical+applications:+from+hybrid+structures+to+multi-functionality.">Recent advances in gold nanoparticles for biomedical applications: from hybrid structures to multi-functionality.</a> Journal of Materials Chemistry B. 7 (22), 3480-3496 (2019).</li><li>Premasiri, W. R., Clarke, R. H., Womble, M. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Urine+Analysis+by+Laser+Raman+Spectroscopy.">Urine Analysis by Laser Raman Spectroscopy.</a> Lasers in Surgery and Medicine. 28 (4), 330-334 (2001).</li><li>Lu, Y., 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=Superhydrophobic+silver+film+as+a+SERS+substrate+for+the+detection+of+uric+acid+and+creatinine.">Superhydrophobic silver film as a SERS substrate for the detection of uric acid and creatinine.</a> Biomedical Optics Express. 9 (10), 4988-4997 (2018).</li><li>Feig, D. I., 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=Serum+Uric+Acid:+A+Risk+Factor+and+a+Target+for+Treatment.">Serum Uric Acid: A Risk Factor and a Target for Treatment.</a> Journal of the American Society of Nephrology. 17 (4), 69-73 (2006).</li><li>Maiuolo, J., Oppedisano, F., Gratteri, S., Muscoli, C., Mollace, V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Regulation+of+uric+acid+metabolism+and+excretion.">Regulation of uric acid metabolism and excretion.</a> International Journal of Cardiology. 213, 8-14 (2016).</li></ol>

作者没有什么可透露的。

协议中描述的自动合成方法允许可重复地合成尺寸增加的Au NPs。虽然有一些元素仍然需要手动进行，例如在种子合成过程中快速添加柠檬酸钠并定期检查以确保PEEK管是安全的，但这种方法允许大尺寸（高达40nm）的Au NPs，这通常需要多次手动注射HAuCl4 和柠檬酸钠， 通过长时间的连续加法合成。
可以进行进一步的表征以阐明CB配合物的基本性质。例如，宿主 - 客体复合...

尿酸是嘌呤核苷酸代谢的最终产物，是血清和尿液中诊断痛风，先兆子痫，肾脏疾病，高血压，心血管疾病和糖尿病等疾病的重要生物标志物1，2，3，4，5。目前用于尿酸检测的方法包括比色酶法、高效液相色谱法和毛细管电泳，这些方法既耗时又昂贵，并且需要复杂的样品制备6，7，8，9。
表面增强拉曼光谱是一种用于常规床旁诊断的有前途的技术，因为它允许通过其振动指纹选择性检测生物分子，并提供许多优点，如高灵敏度，快速响应，易用性以及无或最少的样品制备。基于贵金属纳米颗粒（例如，Au NPs）的SERS衬底可以通过表面等离子体共振引起的强电磁增强10将分析物分子的拉曼信号增强4至10个数量级10。与耗时的复杂金属纳米复合材料12相比，定制尺寸的Au NPs可以很容易地合成，因此由于其优越的性能13，14，15，16，因此被广泛用于生物医学应用。将大环分子，葫芦[n]尿素（CBn，其中n = 5-8，10）附着在Au NPs的表面上可以进一步增强分析物分子的SERS信号，因为高度对称和刚性的CB分子可以控制Au NPs之间的精确间距，并通过形成宿主 - 客体复合物将分析物分子定位在中心或靠近等离子体热点（图1）17，18，19，20.以前使用Au NP的SERS研究示例：CBn纳米聚集物包括硝基爆破剂，多环芳烃，二氨基二苯乙烯，神经递质和肌酐21，22，23，24，25，SERS测量在比色皿中进行或通过将小液滴加载到定制的样品架上。该检测方案对于快速定量具有高再现性的复杂基质中的生物标志物特别有用。
本文使用模块化光谱仪展示了一种简单的方法来形成CB7的宿主 - 客体复合物和重要的生物标志物UA，并通过CB7介导的Au NPs在水介质中的聚集物以0.2μM的检测限量化UA，这在诊断和临床应用中是有希望的。

<table>
	<tbody>
		<tr>
			<td>40 nm gold nanoparticles</td>
			<td>NanoComposix</td>
			<td>AUCN40-100M</td>
			<td>NanoXact, 0.05 mg/ mL, bare (citrate)</td>
		</tr>
		<tr>
			<td>Centrifuge tube</td>
			<td>Corning Falcon</td>
			<td>14-432-22</td>
			<td>50 mL volume</td>
		</tr>
		<tr>
			<td>Cucurbit[7]uril</td>
			<td>Lab-made</td>
			<td></td>
			<td>see ref. 19</td>
		</tr>
		<tr>
			<td>Gold(III) chloride trihydrate</td>
			<td>Sigma aldrich</td>
			<td>520918</td>
			<td>&#8805;99.9% trace metals basis</td>
		</tr>
		<tr>
			<td>Luer lock disposable syringe</td>
			<td>Cole-Parmer</td>
			<td>WZ-07945-15</td>
			<td>3 mL volume</td>
		</tr>
		<tr>
			<td>Luer-to-MicroTight adapter</td>
			<td>LuerTight</td>
			<td>P-662</td>
			<td>360 &#956;m outer diameter Tubing to Luer Syringe</td>
		</tr>
		<tr>
			<td>PEEK tubing</td>
			<td>IDEX</td>
			<td>1572</td>
			<td>360 &#956;m outer diameter, 150 &#956;m inner diameter</td>
		</tr>
		<tr>
			<td>PEEK tubing cutter</td>
			<td>IDEX</td>
			<td>WZ-02013-30</td>
			<td>Capillary Polymer Chromatography Tubing Cutter For 360 &#181;m to 1/32&#34; OD tubing</td>
		</tr>
		<tr>
			<td>Raman spectrometer</td>
			<td>Ocean Optics</td>
			<td>QE pro</td>
			<td></td>
		</tr>
		<tr>
			<td>Sodium citrate tribasic dihydrate</td>
			<td>Sigma aldrich</td>
			<td>S4641</td>
			<td>ACS reagent, &#8805;99.0%</td>
		</tr>
		<tr>
			<td>Sonicator</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Standard Probe</td>
			<td>Digi-Sense</td>
			<td>WZ-08516-55</td>
			<td>Type-K</td>
		</tr>
		<tr>
			<td>Syringe pump</td>
			<td>Aladdin</td>
			<td>ALADDIN2-220</td>
			<td>2 syringes, maximum syringe volume 60 mL</td>
		</tr>
		<tr>
			<td>Thermocouple thermometer</td>
			<td>Digi-Sense</td>
			<td>WZ-20250-91</td>
			<td>Single-Input Thermocouple Thermometer with NIST-Traceable Calibration</td>
		</tr>
		<tr>
			<td>ThermoMixer</td>
			<td>Eppendorf</td>
			<td>5382000031</td>
			<td>With an Eppendorf SmartBlock for 50 mL tubes</td>
		</tr>
		<tr>
			<td>Uric acid</td>
			<td>Sigma aldrich</td>
			<td>U2625</td>
			<td>&#8805;99%, crystalline</td>
		</tr>
	</tbody>
</table>

quantitative sers detection of uric acid via formation of precise plasmonic nanojunctions within aggregates of gold nanoparticles and cucurbit[n]uril

这项工作描述了一种快速且高度灵敏的方法，用于通过表面增强拉曼光谱（SERS）定量检测重要的生物标志物尿酸（UA），使用模块化光谱仪对指纹区域中的多个特征峰具有约0.2μM的低检测限。这种生物传感方案由大环，葫芦[7]uril（CB7）和UA之间的宿主 - 客体络合以及随后在自组装的Au NP：CB7纳米聚集体内形成精确的等离子体纳米结介导。基于经典的柠檬酸盐还原方法，还进行了SERS底物所需尺寸的简单Au NP合成，并可以选择使用实验室制造的自动合成器来促进。该方案可以很容易地扩展到体液中生物标志物的多重检测，用于临床应用。

在所提出的Au NP合成中，紫外 - 可见光谱显示LSPR峰在10个生长步骤后从521 nm移动到529 nm（图4A，B），而DLS数据显示随着Au NPs的尺寸从25.9 nm增加到42.8 nm而窄尺寸分布（图4C，D）。从TEM图像（图4E）测量的G0，G5和G10的平均尺寸分别为20.1±2.1nm，32.5±2.3nm和40.0±2.2nm，每种情况下计数200个颗粒。这些结果表明，?...

Watch this Scientific Journal Video about Quantitative SERS Detection of Uric Acid via Formation of Precise Plasmonic Nanojunctions within Aggregates of Gold Nanoparticles and Cucurbit[n]uril at JoVE.

Quantitative SERS Detection of Uric Acid via Formation of Precise Plasmonic Nanojunctions within Aggregates of Gold Nanoparticles and Cucurbit[n]uril

在水溶液中形成葫芦[7]尿酸和尿酸的宿主 - 客体复合物，然后向Au NP溶液中加入少量，以使用模块化光谱仪进行定量表面增强拉曼光谱（SERS）传感。

通过在金纳米颗粒和葫芦的聚集体中形成精确的等离子体纳米结来定量检测尿酸

This work describes a rapid and highly sensitive method for the quantitative detection of an important biomarker, uric acid (UA), via surface-enhanced ...

quantitative-sers-detection-uric-acid-via-formation-precise-plasmonic

Research

JoVE Journal

Chemistry

Quantitative SERS Detection of Uric Acid via Formation of Precise Plasmonic Nanojunctions within Aggregates of Gold Nanoparticles and Cucurbit[n]uril

3.7K 次观看.  University College London (UCL). 在水溶液中形成葫芦[7]尿酸和尿酸的宿主 - 客体复合物，然后向Au NP溶液中加入少量，以使用模块化光谱仪进行定量表面增强拉曼光谱（SERS）传感。

视频: Quantitative SERS Detection of Uric Acid via Formation of Precise Plasmonic Nanojunctions within Aggregates of Gold Nanoparticles and Cucurbit[n]uril

Template Directed Synthesis of Plasmonic Gold Nanotubes with Tunable IR Absorbance

A nearly parallel array of pores can be produced by anodizing aluminum foils in acidic environments1, 2. Applications of anodic aluminum oxide (AAO) membranes have been under development since the 1990's and have become a common method to template the synthesis of high aspect ratio nanostructures, mostly by electrochemical growth or pore-wetting. Recently, these membranes have become commercially available in a wide range of pore sizes and densities, leading to an extensive library of functional nanostructures being synthesized from AAO membranes. These include composite nanorods, nanowires and nanotubes made of metals, inorganic materials or polymers 3-10. Nanoporous membranes have been used to synthesize nanoparticle and nanotube arrays that perform well as refractive index sensors, plasmonic biosensors, or surface enhanced Raman spectroscopy (SERS) substrates 11-16, as well as a wide range of other fields such as photo-thermal heating 17, permselective transport 18, 19, catalysis 20, microfluidics 21, and electrochemical sensing 22, 23. Here, we report a novel procedure to prepare gold nanotubes in AAO membranes. Hollow nanostructures have potential application in plasmonic and SERS sensing, and we anticipate these gold nanotubes will allow for high sensitivity and strong plasmon signals, arising from decreased material dampening 15.

Solution-suspendable gold nanotubes with controlled dimensions can be synthesized by electrochemical deposition in porous anodic aluminum oxide (AAO) membranes using a hydrophobic polymer core. Gold nanotubes and nanotube arrays hold promise for applications in plasmonic biosensing, surface-enhanced Raman spectroscopy, photo-thermal heating, ionic and molecular transport, microfluidics, catalysis and electrochemical sensing.

的模板导演电浆黄金纳米管的合成与可调谐红外吸收

A nearly parallel array of pores can be produced by anodizing aluminum foils in acidic environments1, 2. Applications of anodic aluminum oxide (AAO) ...

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 diameters ranging from 30-250 nm by varying the reaction conditions. Through the selection of a microwave compatible solvent, silicic acid precursor, catalyst, and microwave irradiation time, these microwave-assisted methods were capable of overcoming the previously reported shortcomings associated with synthesis of silica nanoparticles using microwave reactors. The siloxane precursor was hydrolyzed using the acid catalyst, HCl. Acetone, a low-tan &#948; solvent, mediates the condensation reactions and has minimal interaction with the electromagnetic field. Condensation reactions begin when the silicic acid precursor couples with the microwave radiation, leading to silica nanoparticle sol formation. The silica nanoparticles were characterized by dynamic light scattering data and scanning electron microscopy, which show the materials&#39; morphology and size to be dependent on the reaction conditions. Microwave-assisted reactions produce silica nanoparticles with roughened textured surfaces that are atypical for silica sols produced by St&#246;ber&#39;s methods, which have smooth surfaces.

Silica nanoparticles were prepared using acid-catalysis of a siloxane precursor and microwave-assisted synthetic techniques resulting in the controlled growth of nanomaterials ranging from 30-250 nm in diameter. The growth dynamics can be controlled by varying the initial silicic acid concentration, time of the reaction, and temperature of reaction.

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

Reducing dilute aqueous HAuCl4 with sodium thiocyanate (NaSCN) under alkaline conditions produces 2 to 3 nm diameter nanoparticles. Stable grape-like oligomeric clusters of these yellow nanoparticles of narrow size distribution are synthesized under ambient conditions via two methods. The delay-time method controls the number of subunits in the oligoclusters by varying the time between the addition of HAuCl4 to alkaline solution and the subsequent addition of reducing agent, NaSCN. The yellow oligoclusters produced range in size from ~3 to ~25 nm. This size range can be further extended by an add-on method utilizing hydroxylated gold chloride (Na+[Au(OH4-x)Clx]-) to auto-catalytically increase the number of subunits in the as-synthesized oligocluster nanoparticles, providing a total range of 3 nm to 70 nm. The crude oligocluster preparations display narrow size distributions and do not require further fractionation for most purposes. The oligoclusters formed can be concentrated &#62;300 fold without aggregation and the crude reaction mixtures remain stable for weeks without further processing. Because these oligomeric clusters can be concentrated before derivatization they allow expensive derivatizing agents to be used economically. In addition, we present two models by which predictions of particle size can be made with great accuracy.

We describe a simple method for producing highly stable oligomeric clusters of gold nanoparticles via the reduction of chloroauric acid (HAuCl4) with sodium thiocyanate (NaSCN). The oligoclusters have a narrow size distribution and can be produced with a wide range of sizes and surface coats.

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

Aliphatic ligands are typically used during the synthesis of nanoparticles to help mediate their growth in addition to operating as high-temperature solvents. These coordinating ligands help solubilize and stabilize the nanoparticles while in solution, and can influence the resulting size and reactivity of the nanoparticles during their formation. Despite the ubiquity of using ligands during synthesis, the presence of aliphatic ligands on the nanoparticle surface can result in a number of problems during the end use of the nanoparticles, necessitating further ligand stripping or ligand exchange procedures. We have developed a way to synthesize cadmium sulfide (CdS) nanoparticles using a unique sulfur copolymer. This sulfur copolymer is primarily composed of elemental sulfur, which is a cheap and abundant material. The sulfur copolymer has the advantages of operating both as a high temperature solvent and as a sulfur source, which can react with a cadmium precursor during nanoparticle synthesis, resulting in the generation of ligand free CdS. During the reaction, only some of the copolymer is consumed to produce CdS, while the rest remains in the polymeric state, thereby producing a nanocomposite material. Once the reaction is finished, the copolymer stabilizes the nanoparticles within a solid polymeric matrix. The copolymer can then be removed before the nanoparticles are used, which produces nanoparticles that do not have organic coordinating ligands. This nascent synthesis technique presents a method to produce metal-sulfide nanoparticles for a wide variety of applications where the presence of organic ligands is not desired.

Herein we present a method to synthesize ligand-free cadmium sulfide (CdS) nanoparticles based on a unique sulfur copolymer. The sulfur copolymer operates as a high temperature solvent and a sulfur source during the nanoparticle synthesis and stabilizes the nanoparticles after the reaction.

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 ...

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

Here, we demonstrate a detailed protocol for the radiosynthesis of a 125I-labeled azide prosthetic group and its application to the efficient radiolabeling of DBCO-group-functionalized gold nanoparticles using a copper-free click reaction. Radioiodination of the stannylated precursor (2) was carried out by using [125I]NaI and chloramine T as an oxidant at room temperature for 15 min. After HPLC purification of the crude product, the purified 125I-labeled azide (1) was obtained with high radiochemical yield (75 &plusmn; 10%, n = 8) and excellent radiochemical purity (&gt;99%). For the synthesis of radiolabeled 13-nm-sized gold nanoparticles, the DBCO-functionalized gold nanoparticles (3) were prepared by using a thiolated polyethylene glycol polymer. A copper-free click reaction between 1 and 3 gave the 125I-labeled gold nanoparticles (4) with more than 95% of radiochemical yield as determined by radio-thin-layer chromatography (radio-TLC). These results clearly indicate that the present radiolabeling method using a strain-promoted copper-free click reaction will be useful for the efficient and convenient radiolabeling of DBCO-group-containing nanomaterials.

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

A detailed procedure for the synthesis of a 125I-labeled azide and the radiolabeling of dibenzocyclooctyne (DBCO)-group-conjugated, 13-nm-sized gold nanoparticles using a copper-free click reaction is described.

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 ...

Luminophore Formation in Various Conformations of Bovine Serum Albumin by Binding of Gold(III)

The purpose of the presented protocols is to study the process of Au(III) binding to BSA, yielding conformation change-induced red fluorescence (&#955;em = 640 nm) of BSA-Au(III) complexes. The method adjusts the pH to show that the emergence of the red fluorescence is correlated with the pH-induced equilibrium transitions of the BSA conformations. Red fluorescent BSA-Au(III) complexes can only be formed with an adjustment of pH at or above 9.7, which corresponds to the &#34;A-form&#34; conformation of BSA. The protocol to adjust the BSA to Au molar ratio and to monitor the time-course of the process of Au(III) binding is described. The minimum number of Au(III) per BSA, to produce the red fluorescence, is less than seven. We describe the protocol in steps to illustrate the presence of multiple Au(III) binding sites in BSA. First, by adding copper (Cu(II)) or nickel (Ni(II)) cations followed by Au(III), this method reveals a binding site for Au(III) that is not the red fluorophore. Second, by modifying BSA by thiol capping agents, another nonfluorophore-forming Au(III) binding site is revealed. Third, changing the BSA conformation by cleaving and capping of the disulfide bonds, the possible Au(III) binding site(s) are illustrated. The protocol described, to control the BSA conformations and Au(III) binding, can be generally applied to study the interactions of other proteins and metal cations.

Luminophore Formation in Various Conformations of Bovine Serum Albumin by Binding of GoldIII

The protocols for studying the binding of gold cations (Au(III)) to various conformations of bovine serum albumin (BSA) as well as for characterizing the conformational dependent unique BSA-Au fluorescence are presented.

结合金 (III.) 对牛血清白蛋白不同构象的 Luminophore 形成

The purpose of the presented protocols is to study the process of Au(III) binding to BSA, yielding conformation change-induced red fluorescence (&#955;em ...

Synthesis and Characterization of Amphiphilic Gold Nanoparticles

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

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

两栖金纳米粒子的合成与表征

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

Assembly of Gold Nanorods into Chiral Plasmonic Metamolecules Using DNA Origami Templates

The inherent addressability of DNA origami structures makes them ideal templates for the arrangement of metal nanoparticles into complex plasmonic nanostructures. The high spatial precision of a DNA origami-templated assembly allows controlling the coupling between plasmonic resonances of individual particles and enables tailoring optical properties of the constructed nanostructures. Recently, chiral plasmonic systems attracted a lot of attention due to the strong correlation between the spatial configuration of plasmonic assemblies and their optical responses (e.g., circular dichroism [CD]). In this protocol, we describe the whole workflow for the generation of DNA origami-based chiral assemblies of gold nanorods (AuNRs). The protocol includes a detailed description of the design principles and experimental procedures for the fabrication of DNA origami templates, the synthesis of AuNRs, and the assembly of origami-AuNR structures. In addition, the characterization of structures using transmission electron microscopy (TEM) and CD spectroscopy is included. The described protocol is not limited to chiral configurations and can be adapted for the construction of various plasmonic architectures.

We describe the detailed protocol for the DNA origami-based assembly of gold nanorods into chiral plasmonic metamolecules with strong chiroptical responses. The protocol is not limited to chiral configurations and can be easily adapted for the fabrication of various plasmonic architectures.

利用 dna 折纸模板将金纳米产物组装成手性质浆细胞分裂体

The inherent addressability of DNA origami structures makes them ideal templates for the arrangement of metal nanoparticles into complex plasmonic ...

Performing Spectroscopy on Plasmonic Nanoparticles with Transmission-Based Nomarski-Type Differential Interference Contrast Microscopy

Differential interference contrast (DIC) microscopy is a powerful imaging tool that is most commonly employed for imaging microscale objects using visible-range light. The purpose of this protocol is to detail a proven method for preparing plasmonic nanoparticle samples and performing single particle spectroscopy on them with DIC microscopy. Several important steps must be followed carefully in order to perform repeatable spectroscopy experiments. First, landmarks can be etched into the sample substrate, which aids in locating the sample surface and in tracking the region of interest during experiments. Next, the substrate must be properly cleaned of debris and contaminants that can otherwise hinder or obscure examination of the sample. Once a sample is properly prepared, the optical path of the microscope must be aligned, using Kohler Illumination. With a standard Nomarski style DIC microscope, rotation of the sample may be necessary, particularly when the plasmonic nanoparticles exhibit orientation-dependent optical properties. Because DIC microscopy has two inherent orthogonal polarization fields, the wavelength-dependent DIC contrast pattern reveals the orientation of rod-shaped plasmonic nanoparticles. Finally, data acquisition and data analyses must be carefully performed. It is common to represent DIC-based spectroscopy data as a contrast value, but it is also possible to present it as intensity data. In this demonstration of DIC for single particle spectroscopy, the focus is on spherical and rod-shaped gold nanoparticles.

The goal of this protocol is to detail a proven approach for the preparation of plasmonic nanoparticle samples and for performing single particle spectroscopy on them with differential interference contrast (DIC) microscopy.

基于传输的野武学型差分干涉对比显微镜对等离子体纳米粒子的光谱处理

Differential interference contrast (DIC) microscopy is a powerful imaging tool that is most commonly employed for imaging microscale objects using ...

Synthesis of Aptamer-PEI-g-PEG Modified Gold Nanoparticles Loaded with Doxorubicin for Targeted Drug Delivery

Due to drug resistance and toxicity in healthy cells, use of doxorubicin (DOX) has been limited in clinical cancer therapy. This protocol describes the designing of poly(ethylenimine) grafted with polyethylene glycol (PEI-g-PEG) copolymer functionalized gold nanoparticles (AuNPs) with loaded aptamer (AS1411) and DOX through amide reactions. AS1411 is specifically bonded with targeted nucleolin receptors on cancer cells so that DOX targets cancer cells instead of healthy cells. First, PEG is carboxylated, then grafted to branched PEI to obtain a PEI-g-PEG copolymer, which is confirmed by 1H NMR analysis. Next, PEI-g-PEG copolymer coated gold nanoparticles (PEI-g-PEG@AuNPs) are synthesized, and DOX and AS1411 are covalently bonded to AuNPs gradually via amide reactions. The diameter of the prepared AS1411-g-DOX-g-PEI-g-PEG@AuNPs is ~39.9 nm, with a zeta potential of -29.3 mV, indicating that the nanoparticles are stable in water and cell medium. Cell cytotoxicity assays show that the newly designed DOX loaded AuNPs are able to kill cancer cells (A549). This synthesis demonstrates the delicate arrangement of PEI-g-PEG copolymers, aptamers, and DOX on AuNPs that are achieved by sequential amide reactions. Such aptamer-PEI-g-PEG functionalized AuNPs provide a promising platform for targeted drug delivery in cancer therapy.

In this protocol, doxorubicin-loaded AS1411-g-PEI-g-PEG modified gold nanoparticles are synthesized via three-step amide reactions. Then, doxorubicin is loaded and delivered to target cancer cells for cancer therapy.

合成阿普塔默-PEI-g-PEG改性金纳米粒子装载多索鲁比辛用于靶向药物输送

Due to drug resistance and toxicity in healthy cells, use of doxorubicin (DOX) has been limited in clinical cancer therapy. This protocol describes the ...