Tuning Localized Surface Plasmon Resonance of Nanoporous Gold with a Silica Shell for Surface Enhanced Raman Scattering

Wei Li; Chao Ma; Ling Zhang; Bin Chen; Luyang Chen; Heping Zeng

doi:10.3390/nano9020251

Tuning Localized Surface Plasmon Resonance of Nanoporous Gold with a Silica Shell for Surface Enhanced Raman Scattering

Nanomaterials (Basel). 2019 Feb 12;9(2):251. doi: 10.3390/nano9020251.

Authors

Wei Li¹, Chao Ma², Ling Zhang³, Bin Chen⁴, Luyang Chen⁵, Heping Zeng⁶

Affiliations

¹ Shanghai Key Laboratory of Modern Optical System, Engineering Research Center of Optical Instrument and System (Ministry of Education), School of Optical-Electrical and Computer Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China. liwei_usst_329@163.com.
² Shanghai Key Laboratory of Modern Optical System, Engineering Research Center of Optical Instrument and System (Ministry of Education), School of Optical-Electrical and Computer Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China. machao_usst@163.com.
³ Shanghai Key Laboratory of Modern Optical System, Engineering Research Center of Optical Instrument and System (Ministry of Education), School of Optical-Electrical and Computer Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China. lzhang@usst.edu.cn.
⁴ State Key Laboratory of Metal Matrix Composites, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200030, China. steelboy@sjtu.edu.cn.
⁵ Key Laboratory for Ultrafine Materials of Ministry of Education, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237, China. chenly@ecust.edu.cn.
⁶ Shanghai Key Laboratory of Modern Optical System, Engineering Research Center of Optical Instrument and System (Ministry of Education), School of Optical-Electrical and Computer Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China. hpzeng@phy.ecnu.edu.cn.

Abstract

We report the tuning of localized surface plasmon resonance (LSPR) of nanoporous gold (NPG) by silica coating, which also affects the surface enhanced Raman scattering (SERS) of NPG. In this study, controllable silica shell is assembled on the NPG surface, and a fully silica thin layer causes more than 50 nm red-shift of LSPR band due to dielectric medium dependence. Additionally, ~1 nm silica coated NPG film shows excellent SERS enhancement, which is due to electromagnetic coupling between ligaments and local surface plasmon field enhancement within pores, and theoretical analysis indicates that silica coating further improves the coupling effect, which demonstrates the electromagnetic origin of the tuning of SERS effect.

Keywords: localized surface plasmon resonance (LSPR); nanoporous gold (NPG); surface-enhanced Raman scattering (SERS).

Abstract

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