这项工作与海军研究办公室颁发的海军部奖励 N00014-20-1-2858 和 N00014-22-1-2654 有关。表征在一定程度上得到了美国国家科学基金会主要研究仪器计划2216240资助的支持。这项工作也得到了马萨诸塞大学洛厄尔分校和马萨诸塞联邦的部分支持。我们感谢马萨诸塞大学洛厄尔分校的核心研究设施。

研究中使用的设备和试剂列在 材料表中。
1. 枸橼酸盐封端金纳米颗粒种子的Turkevich合成方法
<ol><li>玻璃器皿的清洁<ol><li>使用王水（HNO3：HCl的1：3摩尔比）清洁玻璃器皿和搅拌棒。</li>
		<li>用超纯水冲洗至无异味，并使用前晾干。</li>
	</ol></li>
	<li>试剂溶液的制备<ol><li>使用分析天平测量 39.4 mg HAuCl4∙3H2O 到干净且标记的 20 mL 玻璃闪烁瓶中。要制备 10 mM 溶液，将 10 mL 超纯水微量移液器加入溶液中。</li>
		<li>使用分析天平测量 58.8 mg 柠檬酸三钠二水合物，放入干净且标记的 20 mL 玻璃闪烁瓶中。要制备 100 mM 溶液，请将 10 mL 超纯水微量移液器放入溶液中。</li>
		<li>在使用前对两种前体溶液进行超声处理 30 秒;目视确认已发生总试剂溶解。</li>
	</ol></li>
	<li>金种子的合成<ol><li>将干净的 25.4 mm 聚四氟乙烯 （PTFE） 搅拌棒放入干净的 250 mL 圆底烧瓶中。</li>
		<li>向烧瓶中加入 58.56 mL 超纯水。</li>
		<li>将该烧瓶移至120 V 250 mL加热罩上，置于搅拌板上。</li>
		<li>组装加热罩并将连接的加热控制器设置为 138 °C，以 640 rpm 的速度搅拌。</li>
		<li>将冷凝器连接到圆底烧瓶的顶部，将其固定在支架上，然后将水流过冷凝器。</li>
		<li>当水在100°C下沸腾并且反应处于回流状态时，通过短暂移除冷凝器，直接将1.2mL的10mM HAuCl4 移液到溶液中。</li>
		<li>让反应返回回流，然后分离冷凝器。</li>
		<li>在单次添加中一次快速注射 480 μL 100 mM 柠檬酸三钠溶液。 注：100 mM 柠檬酸三钠应通过单次进样快速加入，以确保一致的单分散颗粒形成。</li>
		<li>立即将冷凝器放回烧瓶上，让溶液回流 8 分钟。 注意：柠檬酸盐注射约2分钟后，应观察到可见的颜色变为深紫红色，最终颜色为勃艮第。</li>
		<li>8分钟后，从加热罩中取出圆底烧瓶，使其恢复到室温。</li>
	</ol></li>
</ol>2. Au-Sn双金属纳米粒子的合成
<ol><li>前驱体溶液的制备<ol><li>要制备 10 wt% 聚乙烯吡咯烷酮 （PVP） 溶液，请执行以下步骤：<ol><li>使用分析天平准确测量 0.1 g PVP，放入干净且标记的 20 mL 玻璃闪烁瓶中。</li>
			<li>微量移液器将 1 mL 超纯水放入小瓶中。超声处理 1 分钟以完全溶解。</li>
		</ol></li>
		<li>要制备 5 mM SnCl4 溶液，请按照以下步骤操作：<ol><li>使用微量移液管，将 7.5 mL 超纯水转移到干净的 20 mL 闪烁瓶中。</li>
			<li>使用微量移液管将 4.34 μL SnCl4 快速注入小瓶中，并旋转溶液直至完全溶解。 注意：SnCl4 溶液应在通风橱中处理，因为它具有腐蚀性、烟雾和在环境条件下的反应性，可能导致试剂分解。</li>
		</ol></li>
		<li>要制备 260 mM NaBH4 溶液，请按照以下步骤操作：<ol><li>使用分析天平准确测量 20 mg NaBH4 到干净且标记的 20 mL 玻璃闪烁瓶中。 注：NaBH4 溶液在注入样品之前立即制备。</li>
		</ol></li>
	</ol></li>
	<li>双金属纳米粒子的形成<ol><li>将 6 mL 金种子和相应量的超纯水移液到带有 12.7 mm PTFE 搅拌棒的干净 20 mL 玻璃闪烁瓶中。 注：超纯水、PVP、SnCl4 和 NaBH4 的量取决于所制备的 %Au-Sn 溶液，可在 表 1 中找到。</li>
		<li>将小瓶放在搅拌板上，以 1,500 rpm 的速度开始搅拌。</li>
		<li>吸取适量的 10 wt% PVP 到反应瓶中。</li>
		<li>将相应量的 5 mM SnCl4 溶液加入反应瓶中。</li>
		<li>取出并盖紧反应瓶，放入60°C热水浴中10分钟。 注意：在此步骤中，搅拌棒可能会留在小瓶中。</li>
		<li>10分钟后，从热水浴中取出小瓶，打开盖子，然后以1,500rpm的速度将其放回搅拌板上。</li>
		<li>将 2.03 mL 超纯水加入含有固体 NaBH4 的小瓶中，盖紧盖子，摇匀直至溶解。</li>
		<li>立即将 260 mM NaBH4 溶液移液到反应瓶中，一次快速注射，并使其搅拌 30 秒。 注意：溶液的颜色从勃艮第变为黄橙色，并形成气泡。</li>
		<li>从搅拌板中取出反应瓶，松开盖子，并将其放入60°C热水浴中20分钟。</li>
		<li>20分钟后，将小瓶从热水浴中取出。</li>
		<li>从反应瓶中取出搅拌棒。</li>
		<li>在表征之前，让溶液冷却至室温。</li>
	</ol></li>
</ol>3. 等离子体双金属纳米粒子的光学表征
<ol><li>使用石英比色皿中的超纯水作为空白将仪器归零，并运行背景校正。</li>
	<li>将样品转移到路径长度为 1 cm 的干净石英比色皿中，以获得范围为 200-700 nm 的紫外-可见光谱。</li>
</ol>4. 等离子体双金属纳米粒子的结构表征
<ol><li>使用微量移液管将适量样品转移到 2.0 mL 微量离心管中，并在室温下以 5,510 x g 离心 8 分钟。</li>
	<li>8分钟后，使用移液管从管中取出上清液，而不干扰沉淀。颗粒留在管子的底部。</li>
	<li>向含有沉淀的试管中加入 1.50 mL 超纯水，涡旋重悬。</li>
	<li>再次以5,510× g 离心样品8分钟。</li>
	<li>完成后，除去大部分上清液，在每个试管中留下浓缩样品。应保留约 200 μL 浓缩颗粒胶体。</li>
	<li>使用移液器，将浓缩的样品转移到零背景硅支架上。</li>
	<li>将未覆盖的支架放入干燥器中完全干燥。</li>
	<li>干燥后，将样品放入 X 射线衍射仪中以收集数据。以波长为1.54 Å的Cu Kα 作为X射线源，在10°-90°的2θ范围内，扫描速率为1° min-1 。</li>
</ol>5. 等离子体双金属纳米粒子的成像
<ol><li>使用微量移液管将适量样品转移到 2.0 mL 微量离心管中，并以 5,510 x g 离心 8 分钟（室温下）。</li>
	<li>8分钟后，使用移液管从管中取出上清液，而不干扰沉淀。颗粒留在管子的底部。</li>
	<li>向含有沉淀的试管中加入 1.5 mL 超纯水，涡旋重悬。</li>
	<li>再次以5,510× g 离心样品8分钟。</li>
	<li>完成后，除去大部分上清液，并通过摇动样品手动搅拌管，直到沉淀均匀分散到剩余的上清液中。在每个试管中留下浓缩的样品。</li>
	<li>使用微量移液器，将 10 μL 浓缩样品移液到铜碳 B 型透射电子显微镜 （TEM） 网格上。</li>
	<li>将未覆盖的网格放入干燥器中约2小时晾干。 注：样品成像是使用具有 100 kV 加速电压的 TEM 进行的;使用 ImageJ 软件进行了多分散性和尺寸分析的附加分析。</li>
</ol>

等离子体金锡合金纳米颗粒的水合成

<ol>
	<li>Fonseca Guzman, M. V., 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=Plasmon+manipulation+by+post-transition+metal+alloying.">Plasmon manipulation by post-transition metal alloying.</a> Matter. 6 (3), 1-17 (2023).</li><li>Branco, A. 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=Synthesis+of+gold-tin+alloy+nanoparticles+with+tunable+plasmonic+properties.">Synthesis of gold-tin alloy nanoparticles with tunable plasmonic properties.</a> STAR Protoc. 4 (3), 102410 (2023).</li><li>Kelly, K. L., Coronado, E., Zhao, L. L., Schatz, G. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+optical+properties+of+metal+nanoparticles:+The+influence+of+size,+shape,+and+dielectric+environment.">The optical properties of metal nanoparticles: The influence of size, shape, and dielectric environment.</a> J Phys Chem B. 107 (3), 668-677 (2003).</li><li>Linic, S., Christopher, P., Xin, H., Marimuthu, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Catalytic+and+photocatalytic+transformations+on+metal+nanoparticles+with+targeted+geometric+and+plasmonic+properties.">Catalytic and photocatalytic transformations on metal nanoparticles with targeted geometric and plasmonic properties.</a> Acc Chem Res. 46 (8), 1890-1899 (2013).</li><li>Naldoni, A., Shalaev, V. M., Brongersma, M. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Applying+plasmonics+to+a+sustainable+future.">Applying plasmonics to a sustainable future.</a> Science. 356 (6341), 908-909 (2017).</li><li>King, M. E., Fonseca Guzman, M. V., Ross, M. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Material+strategies+for+function+enhancement+in+plasmonic+architectures.">Material strategies for function enhancement in plasmonic architectures.</a> Nanoscale. 14 (3), 602-611 (2022).</li><li>Zhou, M., Li, C., Fang, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Noble-metal+based+random+alloy+and+intermetallic+nanocrystals:+Syntheses+and+applications.">Noble-metal based random alloy and intermetallic nanocrystals: Syntheses and applications.</a> Chem Rev. 121 (2), 736-795 (2020).</li><li>Cortie, M. B., McDonagh, A. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Synthesis+and+optical+properties+of+hybrid+and+alloy+plasmonic+nanoparticles.">Synthesis and optical properties of hybrid and alloy plasmonic nanoparticles.</a> Chem Rev. 111 (6), 3713-3735 (2011).</li><li>Leitao, E. M., Jurca, T., Manners, I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Catalysis+in+service+of+main+group+chemistry+offers+a+versatile+approach+to+p-block+molecules+and+materials.">Catalysis in service of main group chemistry offers a versatile approach to p-block molecules and materials.</a> Nat Chem. 5 (10), 817-829 (2013).</li><li>Melen, R. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Frontiers+in+molecular+p-block+chemistry:+From+structure+to+reactivity.">Frontiers in molecular p-block chemistry: From structure to reactivity.</a> Science. 363 (6426), 479-484 (2019).</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> Farad Disc. 11, 55-75 (1951).</li></ol>

提交人声明没有竞争利益。

在这项研究中，使用Turkevich方法11制备了Au种子。关于该方法的程序局限性，有必要快速进行 480 μL 注射 100 mM 柠檬酸三钠。如果缓慢注入柠檬酸盐溶液，可能会形成具有大尺寸分布的多分散颗粒。此外，玻璃器皿的清洁度会显着影响金种子的质量和稠度。如果玻璃器皿在与王水一起使用之前没有很好地清洁，金种子就会聚集，如果紫色持续存在，可以目视观察到这一点。在表征?...

等离子体金属纳米粒子 1,2 在催化、光电子学、传感和可持续性方面具有应用，因为它们能够高效吸收光，将光集中到亚纳米体积中，并增强催化反应 3,4,5。只有少数金属表现出有效的局部表面等离子体共振（LSPRs）。其中，被广泛探索的金属之一是Au3。
金是一种被广泛研究的贵金属，以其与其他金属的稳定合金形成而闻名。然而，Au LSPR仅限于可见光和红外线，无法调谐到更高的能量6,7,8。同时，后过渡金属具有多种有趣的反应性和催化性，这与贵金属6,9,10不同。通过将金与后过渡金属合金化，LSPR可以向UV1的更高能量进行调整。该协议侧重于 Au-Sn 合金化。众所周知，Sn很容易与许多金属合金化，可以具有UV LSPRs，并且具有有趣的催化应用，例如通过二氧化碳还原形成甲酸6,7,8。Au 和 Sn 合金是通过化学还原和 Sn 扩散到晶种中来合成的。
该方法的主要目标是快速（即在几个小时内）合成水性金属纳米颗粒合金，并使用水化学在工作台上可重复地合成。最初，使用 Turkevich 方法11 制备 Au 晶种，然后进行基于晶种的扩散合成，这是形成无规合金纳米颗粒8 时的常用策略。值得注意的是，与其他需要更高温度、更高真空仪器或危险溶剂的方法 7,8 相比，Sn 的合金化在温和的环境中使用简单的设备需要相对较短的时间（~30 分钟）。该过程可以在温和的水性条件下进行，而无需繁重的环境控制。所得的Au-Sn合金具有一致的形貌、尺寸、形状和光学性能，可以通过控制Sn含量来控制。

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>Basix Microcentrifuge Tubes</td>
			<td>Fisher Scientific</td>
			<td>Cat#02-682-004</td>
			<td></td>
		</tr>
		<tr>
			<td>Cary 100 UV-visible Spectrophotometer</td>
			<td>Agilent Technologies</td>
			<td>Cat#G9821A; RRID:SCR_019481</td>
			<td></td>
		</tr>
		<tr>
			<td>Cary WinUV</td>
			<td>Agilent Technologies</td>
			<td></td>
			<td>https://www.agilent.com/en/product/molecular-spectroscopy/uv-vis-uv-visnir-spectroscopy/uv-vis-uv-vis-nirsoftware/cary-winuv-softwar</td>
		</tr>
		<tr>
			<td>Crystallography Open Database</td>
			<td>CrystalEye</td>
			<td>RRID: SCR_005874</td>
			<td>http://www.crystallography.net/</td>
		</tr>
		<tr>
			<td>Cu Carbon Type-B Grids 
			(200 mesh, 97 &#181;m grid holes)</td>
			<td>Ted Pella</td>
			<td>Cat#01811</td>
			<td></td>
		</tr>
		<tr>
			<td>Direct-Q 3 UV-R Water Purification System</td>
			<td>MilliporeSigma</td>
			<td>Cat#ZRQSVR300</td>
			<td></td>
		</tr>
		<tr>
			<td>Entris Analytical Balance</td>
			<td>Sartorius</td>
			<td>Cat#ENTRIS64I-1SUS</td>
			<td></td>
		</tr>
		<tr>
			<td>Glass round-bottom flask (250 mL)</td>
			<td>Fisher Scientific</td>
			<td>Cat#FB201250</td>
			<td></td>
		</tr>
		<tr>
			<td>Glass scintillation vials</td>
			<td>Wheaton</td>
			<td>Cat#986548</td>
			<td></td>
		</tr>
		<tr>
			<td>Hydrochloric acid 
			(HCl, NF/FCC)</td>
			<td>Fisher Scientific</td>
			<td>CAS: 7647-01-0, 7732-18-5</td>
			<td></td>
		</tr>
		<tr>
			<td>Hydrogen tetrachloroaurate (III) trihydrate 
			(HAuCl4&#183;3H2O, 99.99%)</td>
			<td>Alfa Aesar</td>
			<td>CAS: 16961-25-4</td>
			<td>kept in a desiccator for consistency of purity and stability</td>
		</tr>
		<tr>
			<td>ImageJ</td>
			<td>National Institute of Health</td>
			<td>RRID: SCR_003070</td>
			<td>https://imagej.nih.gov/ij/download.html</td>
		</tr>
		<tr>
			<td>Isotemp GPD 10 Hot Water Bath</td>
			<td>Fisher Scientific</td>
			<td>Cat#FSGPD10</td>
			<td></td>
		</tr>
		<tr>
			<td>Isotemp Hot Plate Stirrer</td>
			<td>Fisher Scientific</td>
			<td>Cat#SP88857200</td>
			<td></td>
		</tr>
		<tr>
			<td>Mili-Q Ultrapure Water 
			(18.2 M&#937;-cm)</td>
			<td>Water purification system</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Miniflex X-Ray Diffractometer</td>
			<td>Rigaku</td>
			<td>RRID:SCR_020451</td>
			<td>https://www.rigaku.com/products/xrd/miniflex</td>
		</tr>
		<tr>
			<td>Model 5418 Microcentrifuge</td>
			<td>Eppendorf</td>
			<td>Cat#022620304</td>
			<td></td>
		</tr>
		<tr>
			<td>Nitric acid 
			(HNO3, Certified ACS Plus)</td>
			<td>Fisher Scientific</td>
			<td>CAS: 7697-37-2, 7732-18-5</td>
			<td></td>
		</tr>
		<tr>
			<td>On/Off Temperature Controller for Heating Mantle</td>
			<td>Fisher Scientific</td>
			<td>Cat#11476289</td>
			<td></td>
		</tr>
		<tr>
			<td>Optifit Racked Pipette Tips (0.5-200 &#181;L)</td>
			<td>Sartorius</td>
			<td>Cat#790200</td>
			<td></td>
		</tr>
		<tr>
			<td>Optifit Racked Pipette Tips (10-1000 &#181;L)</td>
			<td>Sartorius</td>
			<td>Cat#791000</td>
			<td></td>
		</tr>
		<tr>
			<td>Philips CM12 120 kV Transmission Electron Microscope</td>
			<td>Philips</td>
			<td>RRID:SCR_020411</td>
			<td></td>
		</tr>
		<tr>
			<td>Pipette Tups (1-10 mL)</td>
			<td>USA Scientific</td>
			<td>Cat#1051-0000</td>
			<td></td>
		</tr>
		<tr>
			<td>Poly(vinylpyrrolidone) 
			(PVP; molecular weight [MW] = 40,000)</td>
			<td>Alfa Aesar</td>
			<td>CAS: 9003-39-8</td>
			<td>kept in a desiccator for consistency of purity and stability</td>
		</tr>
		<tr>
			<td>Practum Precision Balance</td>
			<td>Sartorius</td>
			<td>Cat# PRACTUM1102-1S</td>
			<td></td>
		</tr>
		<tr>
			<td>PTFE Magnetic Stir Bar (12.7 mm)</td>
			<td>Fisher Scientific</td>
			<td>Cat#14-513-93</td>
			<td></td>
		</tr>
		<tr>
			<td>PTFE Magnetic Stir Bar (25.4 mm)</td>
			<td>Fisher Scientific</td>
			<td>Cat#14-513-94</td>
			<td></td>
		</tr>
		<tr>
			<td>Quartz Cuvette 
			(length &#215; width &#215; height: 10 mm &#215; 12.5 mm &#215; 45 mm)</td>
			<td>Fisher Scientific</td>
			<td>Cat#14-958-126</td>
			<td></td>
		</tr>
		<tr>
			<td>Round Bottom Heating Mantle 120 V 250 mL</td>
			<td>Fisher Scientific</td>
			<td>Cat#11-476-004</td>
			<td></td>
		</tr>
		<tr>
			<td>SmartLab Studio II</td>
			<td>Rigaku</td>
			<td></td>
			<td>https://www.rigaku.com/products/xrd/studio</td>
		</tr>
		<tr>
			<td>Sodium borohydride 
			(NaBH4, 97+%)</td>
			<td>Alfa Aesar</td>
			<td>CAS: 16940-66-2</td>
			<td>kept in a desiccator for consistency of purity and stability</td>
		</tr>
		<tr>
			<td>SureOne Pipette Tips (0.1-10 &#181;L)</td>
			<td>Fisher Scientific</td>
			<td>Cat#02-707-437</td>
			<td></td>
		</tr>
		<tr>
			<td>Tacta Mechanical Pipette (P10)</td>
			<td>Sartorius</td>
			<td>Cat#LH-729020</td>
			<td></td>
		</tr>
		<tr>
			<td>Tacta Mechanical Pipette (P1000)</td>
			<td>Sartorius</td>
			<td>Cat#LH-729070</td>
			<td></td>
		</tr>
		<tr>
			<td>Tacta Mechanical Pipette (P10000)</td>
			<td>Sartorius</td>
			<td>Cat#LH-729090</td>
			<td></td>
		</tr>
		<tr>
			<td>Tacta Mechanical Pipette (P20)</td>
			<td>Sartorius</td>
			<td>Cat#LH-729030</td>
			<td></td>
		</tr>
		<tr>
			<td>Tacta Mechanical Pipette (P200)</td>
			<td>Sartorius</td>
			<td>Cat#LH-729060</td>
			<td></td>
		</tr>
		<tr>
			<td>Tin (IV) chloride 
			(SnCl4, 99.99%)</td>
			<td>Alfa Aesar</td>
			<td>CAS: 7646-78-8</td>
			<td>kept in the fume hood and sealed with Parafilm between uses to avoid exposure to ambient conditions</td>
		</tr>
		<tr>
			<td>Trisodium citrate dihydrate 
			(C6H5Na3O7&#183;2H2O, 99%)</td>
			<td>Alfa Aesar</td>
			<td>CAS: 6132-04-3</td>
			<td>kept in a desiccator for consistency of purity and stability</td>
		</tr>
		<tr>
			<td>Zero-Background Si Sample Holder</td>
			<td>Rigaku</td>
			<td></td>
			<td></td>
		</tr>
	</tbody>
</table>

aqueous synthesis of plasmonic gold-tin alloy nanoparticles

该协议描述了Au纳米颗粒种子的合成以及随后形成的Au-Sn双金属纳米颗粒。这些纳米颗粒在催化、光电子学、成像和药物输送方面具有潜在的应用。以前，生产合金纳米颗粒的方法非常耗时，需要复杂的反应条件，并且可能产生不一致的结果。概述的协议首先描述了使用Turkevich方法合成约13nm Au纳米颗粒种子。该协议接下来描述了Sn的还原及其掺入Au种子中以生成Au-Sn合金纳米颗粒。描述了这些纳米颗粒的光学和结构表征。从光学角度来看，使用紫外-可见光谱法可以明显地看到突出的局部表面等离子体共振（LSPRs）。在结构上，粉末 X 射线衍射 （XRD） 反射所有小于 20 nm 的颗粒，并显示 Au、Sn 和多个 Au-Sn 金属间相的图案。通过透射电子显微镜（TEM）成像获得球形貌和尺寸分布。透射电镜显示，在Sn掺入后，纳米颗粒的直径增长到约15 nm。

图1 显示了Au种子和Au-Sn合金纳米颗粒的代表性结果。按照金种子合成方案，在517 nm附近观察到一个明显的不对称吸收峰，消光最大值约为0.7，对应于LSPR。峰值蓝色随着 Sn 的加入而移动，与样品中明显的光学颜色变化相关，从勃艮第色到橙色再到棕褐色。随着 Sn 添加百分比的增加，观察到峰的进一步蓝移和加宽。如果添加 10%、20%、30% 和 40% Sn，预期的 LSPR 最大值约为 514 nm、...

Read this Scientific Article Protocol about Author Spotlight: Designing Sustainable Nanomaterials for Advancing Synthesis and Element Mixing at JoVE.com

作者聚焦：设计可持续的纳米材料以促进合成和元素混合

在这里，使用 Turkevich 方法描述了金 （Au） 种子的合成。然后，这些种子用于合成具有可调等离子体特性的金锡合金（Au-Sn）纳米颗粒。

This protocol describes the synthesis of Au nanoparticle seeds and the subsequent formation of Au-Sn bimetallic nanoparticles. These nanoparticles have ...

我们的研究重点是设计和创造新型纳米材料，这些纳米材料结合了影响可持续性和能源方面重大挑战的各种元素。这项工作的一个主要重点是了解如何在元素周期表中混合具有不同属性的元素。大多数合金金属纳米颗粒的合成都需要高温、有机溶剂，并且我们需要去除氧气。我们的合成产品在温和的条件下，在水中，并在温和的加热下在工作台上工作。我们未来的研究将侧重于探索这种策略的普遍性，将多种元素整合到合金纳米颗粒中，同时控制它们的大小和形状。这些对于解锁新属性至关重要。

aqueous-synthesis-of-plasmonic-gold-tin-alloy-nanoparticles

Research

JoVE Journal

Chemistry

Aqueous Synthesis of Plasmonic Gold-Tin Alloy Nanoparticles

685 次观看.  University of Massachusetts Lowell. 我们的研究重点是设计和创造新型纳米材料，这些纳米材料结合了影响可持续性和能源方面重大挑战的各种元素。这项工作的一个主要重点是了解如何在元素周期表中混合具有不同属性的元素。大多数合金金属纳米颗粒的合成都需要高温、有机溶剂，并且我们需要去除氧气。我们的合成产品在温和的条件下，在水中，并在温和的加热下在工作台上工作。我们未来的研究?...

视频: 作者聚焦：设计可持续的纳米材料以促进合成和元素混合

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

Synthesis of Immunotargeted Magneto-plasmonic Nanoclusters

Magnetic and plasmonic properties combined in a single nanoparticle provide a synergy that is advantageous in a number of biomedical applications including contrast enhancement in novel magnetomotive imaging modalities, simultaneous capture&#160;and detection of circulating tumor cells (CTCs),&#160;and multimodal molecular imaging combined with photothermal therapy of cancer cells. These applications have stimulated significant interest in development of protocols for synthesis of magneto-plasmonic nanoparticles with optical absorbance in the near-infrared (NIR) region and a strong magnetic moment. Here, we present a novel protocol for synthesis of such hybrid nanoparticles that is based on an oil-in-water microemulsion method. The unique feature of the protocol described herein is synthesis of magneto-plasmonic nanoparticles of various sizes from primary blocks which also have magneto-plasmonic characteristics. This approach yields nanoparticles with a high density of magnetic and plasmonic functionalities which are uniformly distributed throughout the nanoparticle volume. The hybrid nanoparticles can be easily functionalized by attaching antibodies through the Fc moiety leaving the Fab portion that is responsible for antigen binding available for targeting.

Here, we describe a protocol for synthesis of magneto-plasmonic nanoparticles with a strong magnetic moment and a strong near-infrared (NIR) absorbance. The protocol also includes antibody conjugation to the nanoparticles through the Fc moiety for various biomedical applications which require molecular specific targeting.

Immunotargeted的合成磁等离子团簇

Magnetic and plasmonic properties combined in a single nanoparticle provide a synergy that is advantageous in a number of biomedical applications ...

Reverse Microemulsion-mediated Synthesis of Monometallic and Bimetallic Early Transition Metal Carbide and Nitride Nanoparticles

A reverse microemulsion is used to encapsulate monometallic or bimetallic early transition metal oxide nanoparticles in microporous silica shells. The silica-encapsulated metal oxide nanoparticles are then carburized in a methane/hydrogen atmosphere at temperatures over 800 &#176;C to form silica-encapsulated early transition metal carbide nanoparticles. During the carburization process, the silica shells prevent the sintering of adjacent carbide nanoparticles while also preventing the deposition of excess surface carbon. Alternatively, the silica-encapsulated metal oxide nanoparticles can be nitridized in an ammonia atmosphere at temperatures over 800 &#176;C to form silica-encapsulated early transition metal nitride nanoparticles. By adjusting the reverse microemulsion parameters, the thickness of the silica shells, and the carburization/nitridation conditions, the transition metal carbide or nitride nanoparticles can be tuned to various sizes, compositions, and crystal phases. After carburization or nitridation, the silica shells are then removed using either a room-temperature aqueous ammonium bifluoride solution or a 0.1 to 0.5 M NaOH solution at 40-60 &#176;C. While the silica shells are dissolving, a high surface area support, such as carbon black, can be added to these solutions to obtain supported early transition metal carbide or nitride nanoparticles. If no high surface area support is added, then the nanoparticles can be stored as a nanodispersion or centrifuged to obtain a nanopowder.

A &#8220;removable ceramic coating method&#8221; is presented in visual format for the synthesis of non-sintered and metal-terminated monometallic and bimetallic early transition metal carbide and nitride nanoparticles with tunable sizes and crystal structures.

单金属和双金属前过渡金属碳化物和氮化物纳米粒子的反相微乳液介导的合成

A reverse microemulsion is used to encapsulate monometallic or bimetallic early transition metal oxide nanoparticles in microporous silica shells. The ...

Synthesis, Characterization, and Functionalization of Hybrid Au/CdS and Au/ZnS Core/Shell Nanoparticles

Plasmonic nanoparticles are an attractive material for light harvesting applications due to their easily modified surface, high surface area and large extinction coefficients which can be tuned across the visible spectrum. Research into the plasmonic enhancement of optical transitions has become popular, due to the possibility of altering and in some cases improving photo-absorption or emission properties of nearby chromophores such as molecular dyes or quantum dots. The electric field of the plasmon can couple with the excitation dipole of a chromophore, perturbing the electronic states involved in the transition and leading to increased absorption and emission rates. These enhancements can also be negated at close distances by energy transfer mechanism, making the spatial arrangement of the two species critical. Ultimately, enhancement of light harvesting efficiency in plasmonic solar cells could lead to thinner and, therefore, lower cost devices. The development of hybrid core/shell particles could offer a solution to this issue. The addition of a dielectric spacer between a gold nanoparticles and a chromophore is the proposed method to control the exciton plasmon coupling strength and thereby balance losses with the plasmonic gains. A detailed procedure for the coating of gold nanoparticles with CdS and ZnS semiconductor shells is presented. The nanoparticles show high uniformity with size control in both the core gold particles and shell species allowing for a more accurate investigation into the plasmonic enhancement of external chromophores.

The synthesis of uniform gold nanoparticles coated with semiconductor shells of CdS or ZnS is performed. The semiconductor coating is conducted by first depositing a silver sulfide shell and exchanging the silver cations for zinc or cadmium cations.

合成，表征和混合金/硫化镉和Au / ZnS核/壳纳米颗粒功能化

Plasmonic nanoparticles are an attractive material for light harvesting applications due to their easily modified surface, high surface area and large ...

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 ...

Synthesis of Bimetallic Pt/Sn-based Nanoparticles in Ionic Liquids

We demonstrate a method for the synthesis of bimetallic nanoparticles consisting of Pt and Sn. A synthesis strategy is used in which the particular physico-chemical properties of ionic liquids (ILs) are exploited to control both nucleation and growth processes. The nanoparticles form colloidal sols of very high colloidal stability in the IL, which is particularly interesting in view of their use as quasi-homogeneous catalysts. Procedures for both nanoparticle extraction in conventional solvents and for nanoparticle precipitation are presented. The size, structure and composition of the synthesized nanocrystals are confirmed using inductively coupled plasma atomic emission spectroscopy (ICP-AES), X-ray diffraction analysis (XRD) and transmission electron microscopy (TEM) with energy-dispersive X-ray spectroscopy (EDX). By this, we show that the nanocrystals are random-type alloy and of small (2-3 nm) size. The catalytic activity and selectivity in the hydrogenation of &#945;,&#946;-unsaturated aldehydes is tested in a semi-continuous batch-type reactor. In this context, the bimetallic Pt/Sn-based nanoparticles reveal a high selectivity towards the unsaturated alcohol.

A protocol for the synthesis of bimetallic nanoparticles in ionic liquids and the procedure of their catalytic testing in the selective hydrogenation of unsaturated aldehydes are described.

离子液体中双金属 Pt/锡基纳米粒子的合成

We demonstrate a method for the synthesis of bimetallic nanoparticles consisting of Pt and Sn. A synthesis strategy is used in which the particular ...

Molten-Salt Synthesis of Complex Metal Oxide Nanoparticles

The development of feasible synthesis methods is critical for the successful exploration of novel properties and potential applications of nanomaterials. Here, we introduce the molten-salt synthesis (MSS) method for making metal oxide nanomaterials. Advantages over other methods include its simplicity, greenness, reliability, scalability, and generalizability. Using pyrochlore lanthanum hafnium oxide (La2Hf2O7) as a representative, we describe the MSS protocol for the successful synthesis of complex metal oxide nanoparticles (NPs). Furthermore, this method has the unique ability to produce NPs with different material features by changing various synthesis parameters such as pH, temperature, duration, and post-annealing. By fine-tuning these parameters, we are able to synthesize highly uniform, non-agglomerated, and highly crystalline NPs. As a specific example, we vary the particle size of the La2Hf2O7&#160;NPs by changing the concentration of the ammonium hydroxide solution used in the MSS process, which allows us to further explore the effect of particle size on various properties. It is expected that the MSS method will become a more popular synthesis method for nanomaterials and more widely employed in the nanoscience and nanotechnology community in the upcoming years.

Here, we demonstrate a unique, relatively low-temperature, molten-salt synthesis method for preparing uniform complex metal oxide lanthanum hafnate nanoparticles.

复合金属氧化物纳米粒子的熔融盐合成

The development of feasible synthesis methods is critical for the successful exploration of novel properties and potential applications of nanomaterials. ...

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 ...

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 Monodisperse Cylindrical Nanoparticles via Crystallization-driven Self-assembly of Biodegradable Block Copolymers

The production of monodisperse cylindrical micelles is a significant challenge in polymer chemistry. Most cylindrical constructs formed from diblock copolymers are produced by one of three techniques: thin film rehydration, solvent switching or polymerization-induced self-assembly, and produce only flexible, polydisperse cylinders. Crystallization-driven self-assembly (CDSA) is a method which can produce cylinders with these properties, by stabilizing structures of a lower curvature due to the formation of a crystalline core. However, the living polymerization techniques by which most core-forming blocks are formed are not trivial processes and the CDSA process may yield unsatisfactory results if carried out incorrectly. Here, the synthesis of cylindrical nanoparticles from simple reagents is shown. The drying and purification of reagents prior to a ring-opening polymerization of &#949;-caprolactone catalyzed by diphenyl phosphate is described. This polymer is then chain extended by methyl methacrylate (MMA) followed by N,N-dimethyl acrylamide (DMA) using reversible addition&#8722;fragmentation chain-transfer (RAFT) polymerization, affording a triblock copolymer that can undergo CDSA in ethanol. The living CDSA process is outlined, the results of which yield cylindrical nanoparticles up to 500 nm in length and a length dispersity as low as 1.05. It is anticipated that these protocols will allow others to produce cylindrical nanostructures and elevate the field of CDSA in the future.

Crystallization-driven self-assembly (CDSA) displays the unique ability to fabricate cylindrical nanostructures of narrow length distributions. The organocatalyzed ring-opening polymerization of &#949;-caprolactone and subsequent chain extensions of methyl methacrylate and N,N-dimethyl acrylamide are demonstrated. A living CDSA protocol that produces monodisperse cylinders up to 500 nm in length is outlined.

通过结晶驱动生物降解块共聚物的自组装合成单分散圆柱状纳米粒子

The production of monodisperse cylindrical micelles is a significant challenge in polymer chemistry. Most cylindrical constructs formed from diblock ...