Fig. 7. (a) 3D bionic silicon nanograss arrays treated in different AgNO3 concentration and their corresponding SERS spectra of R6G: curve (b) 10−1 M, curve (c) 10−5 M, curve (d) 10−4 M, curve (e) 10−2 M, curve (f) 10−3 M, and curve (a) 0 M; (b) SERS spectra of R6G (incident power was 3.4 mW, data acquisition time was 10 s) at different concentration: curve (a) 10−13 M, curve (b) 10−11 M, curve (c) 10−10 M, and curve (d) 10−9 M.
