Zhang Chengyun, Zhang Tingting, Zhang Zhenglong, Zheng Hairong
School of Physics and Information Technology, Shaanxi Normal University, Xi'an, China.
Front Chem. 2019 Sep 24;7:647. doi: 10.3389/fchem.2019.00647. eCollection 2019.
Silica-shell coated noble metal nanoparticles have shown a good performance in surface enhanced fluorescence and Raman scattering. However, silica-shell coated single noble nanoparticle cannot effectively enhance the optical signal due to the relative weak near-field enhancement. In this paper, [Au-Ag alloy NP cluster]@SiO core-shell nanostructure is employed to achieve the effective electric field enhancement. With the specific structure, simultaneous Raman scattering and fluorescence emission enhancement is obtained, and the enhancement comparison of fluorescence emission with Raman scattering in different type agglomeration of metal NPs is investigated . With different thickness of SiO shell, the optimized Raman and fluorescence enhancement systems are obtained, respectively, and corresponding study of power dependence are investigated in detail. The selectively enhanced Raman and fluorescence can be realized via controlling the shell thickness and laser power. Our work provides a non-polarization dependent [metal NP cluster]@SiO system, which may have a promising application in portable chemical and biochemistry detecting.
二氧化硅壳包覆的贵金属纳米颗粒在表面增强荧光和拉曼散射方面表现出良好的性能。然而，由于相对较弱的近场增强，二氧化硅壳包覆的单个贵金属纳米颗粒不能有效地增强光学信号。在本文中，采用[金-银合金纳米颗粒簇]@SiO核壳纳米结构来实现有效的电场增强。借助特定结构，实现了拉曼散射和荧光发射的同时增强，并研究了金属纳米颗粒不同类型团聚中荧光发射与拉曼散射的增强比较。通过不同厚度的SiO壳，分别获得了优化的拉曼和荧光增强系统，并详细研究了相应的功率依赖性。通过控制壳厚度和激光功率可以实现选择性增强的拉曼和荧光。我们的工作提供了一种非偏振依赖的[金属纳米颗粒簇]@SiO系统，其在便携式化学和生物化学检测中可能具有广阔的应用前景。
