Ag@Au core-shell nanoparticles synthesized by pulsed laser ablation in water: Effect of plasmon coupling and their SERS performance.
Ag@Au core-shell nanoparticles synthesized by pulsed laser ablation in water: Effect of plasmon coupling and their SERS performance.
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DOI：
10.1016/j.saa.2015.05.004
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发表时间：
2015-10
期刊：
影响因子：
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通讯作者：
M. Vinod;K. G. Gopchandran
中科院分区：
文献类型：
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作者：
M. Vinod;K. G. Gopchandran
利用低能量激光脉冲在水中进行脉冲激光烧蚀，合成了核壳纳米粒子Ag@Au。发现这些核壳纳米粒子的等离子体激元特性对金涂层的厚度高度敏感。在合成过程中，首先通过烧蚀Ag靶材制备银纳米胶体，然后对Au靶材进行不同时间的烧蚀，形成Ag@Au核壳纳米结构。通过减小纳米粒子之间的有效距离，研究了等离子体-等离子体耦合对吸收光谱的影响。这是通过简单地蒸发所用的溶剂水来减少胶体悬浮液的总体积来实现的。用结晶紫作为探针分子，测试了这些核壳纳米结构作为表面增强拉曼散射衬底的适用性。发现等离子体耦合对拉曼带增强的影响在不同的带上是不同的。
Ag@Au core–shell nanoparticles are synthesised by pulsed laser ablation in water using low energy laser pulses. The plasmon characteristics of these core–shell nanoparticles are found to be highly sensitive to the thickness of Au coating. In the synthesis, at first silver nanocolloid was prepared by ablating Ag target and then it is followed by ablation of Au target for different time durations to form Ag@Au core–shell nanostructures. The effect of plasmon–plasmon coupling on the absorption spectra is investigated by decreasing the effective distance between the nanoparticles. This is achieved by reducing the total volume of the colloidal suspension by simple evaporation of water, the solvent used. The suitability of these core–shell nanostructures for application as surface enhanced Raman scattering substrates are tested with crystal violet as probe molecules. Influence of plasmon coupling on the enhancement of Raman bands is found to be different for different bands.