SERS From Transition Metals and Excited by Ultraviolet Light
SERS From Transition Metals and Excited by Ultraviolet Light
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DOI：
10.1007/3-540-33567-6_7
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发表时间：
2006
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影响因子：
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通讯作者：
Zhongbiao Tian;Zhilin Yang;B. Ren;De‐Yin Wu
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文献类型：
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作者：
Zhongbiao Tian;Zhilin Yang;B. Ren;De‐Yin Wu
4结论在本章中，我们采用3D-FDTD方法计算和评估了局部电磁场，研究了纳米粒子的表面几何形状、尺寸、形状和聚集形式对过渡金属体系Sers活性的影响。我们对菜花状结构纳米颗粒的计算表明，这种增强效应不仅与激发光的偏振态、金属的电子性质和表面形貌有关，而且还与Sers纳米结构的对称性有关。我们证明了纳米立方体系统中高增强的原因可能是由于相邻纳米立方体之间的强耦合所涉及的大有效体积。对于核-壳体系，我们发现，EM增强随壳层厚度的增加而迅速降低，当壳层厚度超过6 nm时，核不再影响壳层的Sers。在Pt、Rh、Ru和Co表面而不是Ag和Au表面上检测到相当好的UVSERS信号主要是由于过渡金属在UV区域中固有的合适的光学性质。总体而言，Sers基底的扩展到过渡金属体系和使用紫外激发提高了Sers技术的通用性，可能有助于全面理解Sers。
4 ConclusionIn this Chapter, we employed the 3D-FDTD method to calculate and evaluate the local electromagnetic field by investigating the effect of the surface geometry, the size, shape, and aggregation forms of nanoparticles on the SERS activity of transition metal systems. Our calculation on the cauliflowerstructured nanoparticles shows that the em enhancement is sensitive not only to the polarization of the exciting light, the electronic property of metal and the surface morphology, but also to the symmetric nature of the SERS nanostructures. We demonstrated that the reason for the high enhancement in the nanocube system could be due to the large effective volume involved in the strong coupling between neighboring nanocubes. For the core-shell system, we show that the em enhancement decreases rapidly with increasing shell thickness and when the shell thickness exceeds 6 nm, the core no longer influences the SERS of the shell. The detection of a reasonably good UVSERS signal on Pt, Rh, Ru and Co surfaces rather than Ag and Au is mainly due to the intrinsically suitable optical properties of transition metals in the UV region. Overall, the extension of SERS substrate to the transition-metal systems and use of UV excitation have improved the generality of the SERS technique and could be helpful for comprehensive understanding of SERS.