Fabrication of nanofiber-based SERS-active substrates by oxygen plasma removal of SU-8 photoresist

We present for the first time an approach to fabricate surface enhanced Raman scattering (SERS)-active substrates based on nanofibers simply by removing SU-8 photoresist in oxygen plasma bombardment. Compared with Raman spectral signals of Rhodamine B on smooth silicon substrates, the intensity of those on the nanofiber-based SERS-active substrates are much more distinctive and are at least 10³ folds greater. Moreover, the approach can be combined with conventional photolithography for fabricating photo-patternable SERS-active structures, together with the high hydrophilicity of the nanofibers, chemical reagents can be self-patterned in the SERS-active devices, which may have a variety of important applications in different fields.