Fig. 3
High reproducibility and renewability. a Surface-enhanced Raman scattering (SERS) spectra in the line-scan across a randomly selected area on the surface of single Al-5 substrate, taken with a 20 nm step size (scale bar: 200 cps). b SERS spectra of 10−4 M rhodamine 6G (R6G) collected from 500 randomly selected positions on 50 batches of Al-5 substrates, with the overlapped signals forming a shaded area as outlined in red. Inset shows the batch-to-batch Raman intensity variation for the 612 cm−1 vibrational band measured for these 50 batches of Al-5 substrates. c Comparison between SERS intensity of the 612 cm−1 vibrational band of single substrates used for multiple cycles, renewed either through electrochromic or photocatalytic methods (scale bar: 400 cps). Error bars represent means ± SD of the SERS intensity
