Revealing the Interplay between Adsorbed Molecular Layers and Gold Nanoparticles by Linear and Nonlinear Optical Properties
Revealing the Interplay between Adsorbed Molecular Layers and Gold Nanoparticles by Linear and Nonlinear Optical Properties
复制标题
DOI：
10.1021/acs.jpcc.5b03601
复制
发表时间：
2015-07-30
影响因子：
3.7
通讯作者：
Busson, Bertrand
中科院分区：
文献类型：
--
作者：
Dalstein, Laetitia;Ben Haddada, Maroua;Busson, Bertrand
化学接枝在基底上的金纳米颗粒（AuNPs）由于其等离子体特性而被广泛用作传感器。这种传感器的效率和鲁棒性强烈地依赖于微电子子层结构，其影响AuNP的分布，并因此影响层的等离子体性质。很少有光谱分析工具能够在纳米粒子沉积之前和之后检测接枝层.在这里，我们使用和频产生（SFG）光谱，深入研究接枝层和固定的金纳米粒子。我们将联合收割机、SFG、反射紫外-可见光谱和扫描电子显微镜（SE-M）相结合，对分散在改性硅表面上的14 nm直径的金纳米粒子进行了研究，这些纳米粒子具有胺或混合胺/硫醇封端层。SEG光谱通过亚甲基和甲基振动模式的振幅显示了每个支撑层的特定振动指纹，并证明了来自（3-氨基丙基）三乙氧基硅烷的未反应乙氧基的存在：我们建立了吸光度振幅与AuNP表面覆盖度的线性演变，i_关系有效高达10（11）的聚集极限。AuNPs.cm同样，SFG振幅与紫外-维斯吸收振幅之间也遵循二次函数关系，表明非线性光学性质与线性光学性质之间存在密切的相关性。此外，AuNP层的光学性质在几个月内是稳定的（等离子体位置和阻尼），尽管它们储存在环境空气中并长时间暴露于可见激光。
Gold nanoparticles (AuNPs) chemically grafted on substrates are widely used as sensors due to their plasmonic properties. The efficiency and robustness of such sensors,strongly depend on the rrioleeillar Sublayer structure, which influences the distribution of AuNPs, and therefore the plasmonic properties,of the layer. Few,spectrosebpic tools are able to sense the grafting layer both before and after - particle deposition. Here, we use sum-frequency generation (SFG) spectroscopy to deeply investigate both the grafting layer and the immobilized AuNPs. We combine, SFG with reflectance UV-visible spectroscopy and scanning electron microscopy (SE-M) for 14 nm diameter AuNPs, dispersedon modified Silicon surfaces With either amine or mixed amine/thiol terminated layers. SEG spectra show the specific vibrational fingerprint of each supporting layer through the amplitudes of methylene ancI methyl vibration modes and prove the presence of unreacted ethoxy groups from (3-aminopropy0 triethoxysilane: We establish a linear evolution of the absorbance amplitudes with AuNP surface coverage, i_relationship valid up to the aggregation limit of 10(11) AuNPs.cm(-2). In the same way, SFG amplitudes follow a quadratic dependence with the UV vis absorbance amplitudes, Showing the close correlation between nonlinear And linear optical properties. In addition, the optical properties of the AuNP layers are stable for several months (plasinon position and damping) despite their storage in Ambient air and long exposure to visible laser light.