Fig. 2: All-flexible SERS Substrate: Ag nanoislands on ultrathin fluorocarbon.

a SEM images (left) and E-field distribution (right) of Ag nanoislands (Scale bar: 100 nm), (b) structural features including diameter and surface coverage (calculated from three SEM images taken at different regions of the same sample), and (c) absorption spectra for 10 nm Ag film on PDMS without fluorocarbon coating (green), single-dewetted 10 nm Ag film (red), and double-dewetted 10 nm Ag film (blue) on fluorocarbon coated PDMS. d SERS intensity of 10 µM R6G at 1365 cm⁻¹ and SNR (n = 12 technical replicates) depending on the fluorocarbon thickness (t_FC). e SERS intensity for 1 µM R6G depending on the Ag film thickness and dewetting repetition (blue: single dewetting, red: repeated dewetting). f Long-term stability of the CEP-SERS patch depending on storage duration measured by SERS peak intensity of 10 μM R6G solution at 1365 cm⁻¹ with (red) and without (blue) vacuum sealing (n = 6 technical replicates). SERS stability (g) under different pH measured by SERS peak intensity of 1 μM R6G solution at 1365 cm⁻¹ (n = 6 technical replicates). h Mechanical stability measured by SERS peak intensity variation of benzenethiol at 1070 cm⁻¹ after 200 cycles of twisting (red) and bending (blue) (Scale bar: 5 mm). i SERS performance stability under repeated peeling cycles of tape measured by SERS intensity of 1 μM R6G at 1365 cm⁻¹ (n = 6 technical replicates). The error bars represent one standard deviation from the mean (n = 6 technical replicates).