4. 液相中的单纳米颗粒催化剂利用纳米等离子体传感来研究单个纳米颗粒上的催化反应的想法大约在十年前首次实现。Mulvaney等人采用表面等离子体光谱法对单个金纳米颗粒表面抗坏血酸的氧化进行了检测。图5a显示了反应开始前和反应开始后一段时间内单个金纳米颗粒的典型散射光谱。在催化反应中，由于抗坏血酸盐离子的电子注入，观察到峰值发生了约20nm的显著的蓝移。因此，由于其对电子密度的敏感性，该方法能够实时监测单个纳米颗粒上的催化过程，并且能够检测到每秒65个分子的反应速率。[6] 图5. 抗坏血酸催化氧化过程中单个金纳米粒子的散射光谱(上图)和相应的光谱位移随反应时间的变化(下图) 5. 气相中的单纳米颗粒催化剂我们注意到，在以上所讨论的所有单粒子系统中，催化反应都发生在浸没在液体溶剂和反应物中的纳米粒子上，温度为或接近室温。这就使得气相催化反应这一非常重要的领域没有得到解决。气相催化反应通常发生在高温和大气压以上的环境中。因此，研究这样的过程对使用的仪器和应用的等离子体平台提出了更高的要求，以维持化学和热的苛刻的条件。但是，无论是直接的还是间接的检测，关于气相单粒子等离子体实验的报道仍然很少。唯一的例外是Mulvaney研究了单个金纳米棒和金属氧化物载体之间的氢溢出效应。（图6)[7] 图6. Au/TiO2−Pt结构LSPR测试 参考文献：[1] Svetlana A, et al., Single Particle Plasmonics for Materials Science and Single Particle Catalysis, ACS Photonics 2019, 6, 1319−1330.[2] Langhammer C, Larsson E. M. Nanoplasmonic In Situ Spectroscopy for Catalysis Applications. ACS Catal. 2012, 2, 2036−2045.[3] Langhammer C, et al., Hydrogen Storage in Pd Nanodisks Characterized with a Novel Nanoplasmonic Sensing Scheme. Nano Lett. 2007, 7, 3122−3127.[4] Syrenova S, et al., Hydride formation thermodynamics and hysteresis in individual Pd nanocrystals with different size and shape. Nat. Mater. 2015, 14, 1236−1244.[5] Gschneidtner T. A.,et al., Versatile SelfAssembly Strategy for the Synthesis of Shape-Selected Colloidal Noble Metal Nanoparticle Heterodimers. Langmuir 2014, 30, 3041−3050.[6] Li K.,;et al., DNA-Directed Assembly of Gold Nanohalo for Quantitative Plasmonic Imaging of Single-Particle Catalysis. J. Am. Chem. Soc. 2015, 137, 4292-4295.[7] Collins S. S. E,et al., Hydrogen Spillover between Single Gold Nanorods and Metal Oxide Supports: A Surface Plasmon Spectroscopy Study. ACS Nano 2015, 9, 7846−7856.相关推荐文献：[1]Lerch S, Reinhard B. M. Effect of interstitial palladium on plasmon-driven charge transfer in nanoparticle dimers. Nat. Commun. 2018, 9, 1608.[2]Wonner K, et al., Simultaneous Optoand Spectro-Electrochemistry: Reactions of Individual Nanoparticles Uncovered by Dark-Field Microscopy. J. Am. Chem. Soc. 2018, 140, 12658−12661.[3]Young, G, et al., Quantitative mass imaging of single biological macromolecules.Science 2018, 360, 423−427.[4] Acimovic S. S., et al., Antibody−Antigen Interaction Dynamics Revealed by Analysis of Single-Molecule Equilibrium Fluctuations on Individual Plasmonic Nanoparticle Biosensors. ACS Nano 2018, 12, 9958−9965.[5] Vadai M, et al., Insitu observation of plasmon-controlled photocatalytic dehydrogenation of individual palladium nanoparticles. Nat. Commun. 2018, 9,4658.[6]Hayee F, et al., In-situ visualization of solutedriven phase coexistence within individual nanorods. Nat. Commun. 2018, 9, 1775.[7] Nugroho, F. A. A, et al., Metal−Polymer Hybrid Nanomaterials for Plasmonic Ultrafast Hydrogen Detection. Nat. Mater. 2019, 18, 489−495.[8]Hanske C, et al., Silica-Coated Plasmonic Metal Nanoparticles in Action. Adv. Mater. 2018, 30, 1707003.[9] Hendriks, F. C., et al., Integrated Transmission Electron and SingleMolecule Fluorescence Microscopy Correlates Reactivity with Ultrastructure in a Single Catalyst Particle. Angew. Chem., Int. Ed. 2018, 57, 257−261.[10] Karim W, et al., Catalyst support effects on hydrogen spillover. Nature 2017, 541, 68−71.本文由Nano Optic供稿。