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Nano Research

Article Title

Plasmon-tunable Au@Ag core-shell spiky nanoparticles for surface-enhanced Raman scattering

Authors

Zhulin Huang, Key Laboratory of Materials Physics and Anhui Key Laboratory of Nanomaterials and Technology, Institute of Solid State Physics, Chinese Academy of Sciences, P. O. Box 1129, Hefei 230031, China
Guowen Meng, Key Laboratory of Materials Physics and Anhui Key Laboratory of Nanomaterials and Technology, Institute of Solid State Physics, Chinese Academy of Sciences, P. O. Box 1129, Hefei 230031, China University of Science and Technology of China, Hefei 230026, China
Xiaoye Hu, Key Laboratory of Materials Physics and Anhui Key Laboratory of Nanomaterials and Technology, Institute of Solid State Physics, Chinese Academy of Sciences, P. O. Box 1129, Hefei 230031, China
Qijun Pan, Key Laboratory of Materials Physics and Anhui Key Laboratory of Nanomaterials and Technology, Institute of Solid State Physics, Chinese Academy of Sciences, P. O. Box 1129, Hefei 230031, China University of Science and Technology of China, Hefei 230026, China
Dexian Huo, Key Laboratory of Materials Physics and Anhui Key Laboratory of Nanomaterials and Technology, Institute of Solid State Physics, Chinese Academy of Sciences, P. O. Box 1129, Hefei 230031, China University of Science and Technology of China, Hefei 230026, China
Hongjian Zhou, Key Laboratory of Materials Physics and Anhui Key Laboratory of Nanomaterials and Technology, Institute of Solid State Physics, Chinese Academy of Sciences, P. O. Box 1129, Hefei 230031, China
Yan Ke, Key Laboratory of Materials Physics and Anhui Key Laboratory of Nanomaterials and Technology, Institute of Solid State Physics, Chinese Academy of Sciences, P. O. Box 1129, Hefei 230031, China
Nianqiang Wu, Department of Mechanical and Aerospace Engineering, West Virginia University, P.O. Box 6106, Morgantown, WV 26506, USA

Keywords

localized surface plasmon resonance, gold, silver, surface-enhanced Raman spectroscopy

Abstract

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.

Graphical Abstract

Publisher

Tsinghua University Press

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