Patterned superhydrophobic/superhydrophilic SERS sensors fabricated by femtosecond laser for precise positioning and ultra-sensitive detection

Superhydrophobic surface-enhanced Raman scattering (S-SERS) sensors enhance detection performance by concentrating analyte molecules into small areas, which have been widely used in biochemical analysis. However, the uncertainty of droplet position on the superhydrophobic surface limits the application. In this paper, patterned superhydrophobic/superhydrophilic SERS (PS-SERS) sensor is fabricated by femtosecond laser, and the R6G solution is distributed homogeneously in the superhydrophilic zone after evaporation enrichment. On the PS-SERS sensor with the diameter of 400 mu m circular superhydrophilic pattern, the detection sensitivity of R6G molecules is as low as 10-13 M. The results provide an efficient way for ultratrace molecular detection.