Surface-Enhanced Raman Spectroscopy Based on a Silver-Film Semi-Coated Nanosphere Array

Wending Zhang; Tianyang Xue; Lu Zhang; Fanfan Lu; Min Liu; Chao Meng; Dong Mao; Ting Mei

doi:10.3390/s19183966

Surface-Enhanced Raman Spectroscopy Based on a Silver-Film Semi-Coated Nanosphere Array

Sensors (Basel). 2019 Sep 14;19(18):3966. doi: 10.3390/s19183966.

Authors

Wending Zhang¹, Tianyang Xue², Lu Zhang³, Fanfan Lu⁴, Min Liu⁵, Chao Meng⁶, Dong Mao⁷, Ting Mei⁸

Affiliations

¹ MOE Key Laboratory of Material Physics and Chemistry under Extraordinary Conditions and Shaanxi Key Laboratory of Optical Information Technology, School of Science, Northwestern Polytechnical University, Xi'an 710072, China. zhangwd@nwpu.edu.cn.
² MOE Key Laboratory of Material Physics and Chemistry under Extraordinary Conditions and Shaanxi Key Laboratory of Optical Information Technology, School of Science, Northwestern Polytechnical University, Xi'an 710072, China. xuetianyang0@mail.nwpu.edu.cn.
³ MOE Key Laboratory of Material Physics and Chemistry under Extraordinary Conditions and Shaanxi Key Laboratory of Optical Information Technology, School of Science, Northwestern Polytechnical University, Xi'an 710072, China. luzhangxgd@mail.nwpu.edu.cn.
⁴ MOE Key Laboratory of Material Physics and Chemistry under Extraordinary Conditions and Shaanxi Key Laboratory of Optical Information Technology, School of Science, Northwestern Polytechnical University, Xi'an 710072, China. lufanfan@mail.nwpu.edu.cn.
⁵ MOE Key Laboratory of Material Physics and Chemistry under Extraordinary Conditions and Shaanxi Key Laboratory of Optical Information Technology, School of Science, Northwestern Polytechnical University, Xi'an 710072, China. lmiuin@mail.nwpu.edu.cn.
⁶ MOE Key Laboratory of Material Physics and Chemistry under Extraordinary Conditions and Shaanxi Key Laboratory of Optical Information Technology, School of Science, Northwestern Polytechnical University, Xi'an 710072, China. mengc@mail.nwpu.edu.cn.
⁷ MOE Key Laboratory of Material Physics and Chemistry under Extraordinary Conditions and Shaanxi Key Laboratory of Optical Information Technology, School of Science, Northwestern Polytechnical University, Xi'an 710072, China. maodong@nwpu.edu.cn.
⁸ MOE Key Laboratory of Material Physics and Chemistry under Extraordinary Conditions and Shaanxi Key Laboratory of Optical Information Technology, School of Science, Northwestern Polytechnical University, Xi'an 710072, China. tmei@nwpu.edu.cn.

Abstract

In this paper, we present a convenient and economical method to fabricate a silver (Ag)-film semi-coated polystyrene (PS) nanosphere array substrate for surface-enhanced Raman spectroscopy (SERS). The SERS substrate was fabricated using the modified self-assembled method combined with the vacuum thermal evaporation method. By changing the thickness of the Ag film, the surface morphology of the Ag film coated on the PS nanospheres can be adjusted to obtain the optimized localized surface plasmonic resonance (LSPR) effect. The 3D-finite-difference time-domain simulation results show that the SERS substrate with an Ag film thickness of 10 nm has tens of times the electric field intensity enhancement. The Raman examination results show that the SERS substrate has excellent reliability and sensitivity using rhodamine-6G (R6G) and rhodamine-B (RB) as target analytes, and the Raman sensitivity can reach 10^-10 M. Meanwhile, the SERS substrate has excellent uniformity based on the Raman mapping result. The Raman enhancement factor of the SERS substrate was estimated to be 5.1 × 10⁶. This kind of fabrication method for the SERS substrate may be used in some applications of Raman examination.

Keywords: localized surface plasmonic resonance; self-assembled; surface-enhanced Raman spectroscopy.

Abstract

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