On-Fly Femtosecond-Laser Fabrication of Self-Organized Plasmonic Nanotextures for Chemo- and Biosensing Applications.

Surface-enhanced Raman scattering (SERS) and surface-enhanced photoluminescence (SEPL) are emerging as versatile widespread methods for biological, chemical, and physical characterization in close proximity of nanostructured surfaces of plasmonic materials. Meanwhile, single-step, facile, cheap, and green technologies for large-scale fabrication of efficient SERS or SEPL substrates, routinely demonstrating both broad plasmonic response and high enhancement characteristics, are still missing. In this research, single-pulse spallative micron-size craters in a thick Ag film with their internal nanotexture in the form of nanosized tips are for the first time shown to demonstrate strong polarization-dependent enhancement of SEPL and SERS responses from a nanometer-thick covering Rhodamine 6G layer with average enhancement factors of 40 and 2 × 10(6), respectively.