Plasmon-tunable Au@Ag core-shell spiky nanoparticles for surface-enhanced Raman scattering
Plasmon-tunable Au@Ag core-shell spiky nanoparticles for surface-enhanced Raman scattering
复制标题
用于表面增强拉曼散射的等离激元可调Au@Ag核壳尖峰纳米颗粒
DOI：
10.1007/s12274-018-2238-y
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发表时间：
2019-02-01
期刊：
影响因子：
9.9
通讯作者：
Wu, Nianqiang
中科院分区：
文献类型：
--
作者：
Huang, Zhulin;Meng, Guowen;Wu, Nianqiang
发展了一种简便的合成方法来制备均匀且尺寸可调的尖峰Au@Ag核壳纳米颗粒(NPs)，以定制局域表面等离子体共振(LSPR)特性。细小的Au纳米晶体的逐渐组装使得尖峰状的Au纳米颗粒的尺寸可以通过调节初始Au种子和Au源的浓度从几十纳米调节到几百纳米；银壳的厚度可以通过逐步还原Ag(I)离子来调节。这种尖峰状的Au@Ag核壳纳米粒子的LSPR谱带在近红外区域与大小相近的纯Au纳米粒子的LSPR谱带相似，而增加Ag壳层厚度会导致近红外区域LSPR谱带的蓝移和展宽。此外，与裸露的尖状Au纳米颗粒和球形的Ag@Au纳米颗粒相比，尖状Au@Ag核壳纳米颗粒表现出更好的表面增强拉曼散射(SERS)活性。本工作提供了一种简便的合成等离子体金属纳米粒子的方法，该纳米粒子具有650~800 nm的LSPR谱带，具有很强的局域电磁场增强作用，为生物液和组织中的SERS成像和检测提供了有效的SERS衬底。
A facile synthetic approach has been developed to prepare uniform and size-tunable spiky Au@Ag core-shell nanoparticles (NPs) to tailor the localized surface plasmon resonance (LSPR) properties. The gradual assembly of small Au nanocrystals allows the size of spiky Au NPs to be modulated from tens to several hundreds of nanometers by tuning the concentration of initial Au seeds and Au source; and the thickness of the Ag shell can be adjusted with stepwise reduction of Ag(I) ions. The LSPR bands of such spiky Au@Ag core-shell NPs resemble those of pure spiky Au NP cores of similar sizes in near-infrared region, and increasing the Ag shell thickness results in a blue shift and broadening of the LSPR band in the near-infrared region. Additionally, the spiky Au@Ag core-shell NPs exhibit improved surface-enhanced Raman scattering (SERS) activity as compared to the bare spiky Au NPs and spherical Ag@Au NPs. This work has offered a facile route to synthesize plasmonic metal NPs with LSPR band in 650 to 800 nm that show strong enhancement of localized electromagnetic field, which provides an effective SERS substrate for SERS imaging and detection in biological fluids and tissues.