Highly sensitive and stable SERS probes of alternately deposited Ag and Au layers on 3D SiO2 nanogrids for detection of trace mercury ions*

Project supported by the National Key Research and Development Program of China (Grant No. 2017YFA0207104), the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No. XDA09040101), the National Natural Science Foundation of China (Grant No. Y6061111JJ), the Youth Innovation Promotion Association of Chinese Academy of Sciences (Grant No. 2015030), and the Key Technology Talent Program of Chinese Academy of Sciences (Grant Nos. Y8482911ZX and Y7602921ZX).
Tian Yi1, 2, Wang Han-Fu1, Yan Lan-Qin1, Zhang Xian-Feng1, Falak Attia1, 2, Chen Pei-Pei1, 2, †, Dong Feng-Liang1, ‡, Sun Lian-Feng1, 2, §, Chu Wei-Guo1, 2, ¶
       

Tilt SEM images of annealed Au, Ag–Au and Ag/198 nm SiO2 nanogrids. (a)–(f) 36 nm Au, (3 nm Ag–1 nm Au)-9c, (5 nm Ag–1 nm Au)-6c, (11 nm Ag–1 nm Au)-3c, (17 nm Ag–1 nm Au)-2c, and 36 nm Ag/198 nm SiO2_h188, respectively. (g)–(i) (2 nm Ag–2 nm Au)-9c, (7 nm Ag–2 nm Au)-4c, and (16 nm Ag–2 nm Au)-2c/198 nm SiO2_h157, respectively. Scale bars: 200 nm.