Surface-enhanced Raman Scattering of Au-Ag bimetallic nanopillars fabricated using surface-plasmon lithography

Yimin Fan; Tao Zhang; Zubo Cai; Dongxian Li; Weisheng Yue; Tiancheng Gong; Yunfei Luo; Ping Gao

doi:10.1088/1361-6528/ac5df8

Surface-enhanced Raman Scattering of Au-Ag bimetallic nanopillars fabricated using surface-plasmon lithography

Nanotechnology. 2022 Apr 1;33(25). doi: 10.1088/1361-6528/ac5df8.

Authors

Yimin Fan^{1

2}, Tao Zhang¹, Zubo Cai¹, Dongxian Li¹, Weisheng Yue^{1

2}, Tiancheng Gong¹, Yunfei Luo^{1

2}, Ping Gao¹

Affiliations

¹ State Key Laboratory of Optical Technologies on Nano-Fabrication and Micro-Engineering, Institute of Optics and Electronics, Chinese Academy of Sciences, PO Box 350, Chengdu 610209, People's Republic of China.
² School of Optoelectronics, University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China.

PMID: 35290967
DOI: 10.1088/1361-6528/ac5df8

Abstract

Arrays of gold-silver (Au-Ag) bimetallic nanopillars were fabricated by a newly developed surface-plasmon lithography (SPL) and their enhancement properties as surface-enhanced Raman scattering (SERS) substrates have been studied. We demonstrated that the SPL is a low-cost and high efficiency method for the fabrication of SERS substrates with both high sensitivity and reproducibility. The nanopillars showed a good response in the detection of methylene blue molecules at a low concentration of 1.0 × 10^-11mol· l^-1. The SERS enhancement factors (EFs) are on the orders of 10⁷and the relative standard deviation of SERS intensity is <8% over an area of 50μm × 50μm. The EFs increase fast with the height increasing from 200 to 530 nm, then increase slowly when further increase the height of the nanopillars to 1100 nm. In addition, the Au-Ag bimetallic coating has shown much higher SERS enhancement than the coatings of either the pure Au or Ag. The excellent SERS enhancement and reproducibility of the Au-Ag coated nanopillars indicated that the fabricated SERS substrates can be used for the detection of biochemical molecules at trace level and the SPL is a promising method for fabrication of SERS substrates.

Keywords: Au–Ag bimetallic nanopillar; high enhancement; surface-enhanced Raman scattering (SERS); surface-plasmon lithography.