Sensitive SERS detection of antibiotics using Ag-coated nanostructures fabricated by femtosecond laser cross-scanning.
TL;DR
A scalable surface-enhanced Raman scattering (SERS) platform based on silver-coated cross-scanned laser-induced periodic surface structures (CS-LIPSS) fabricated via femtosecond laser processing, offering a cost-effective route to reproducible, high-performance SERS substrates.
Abstract
The excessive use of antibiotics in medicine, agriculture, and aquaculture has led to widespread environmental contamination and public health concerns, underscoring the urgent need for rapid, sensitive, and cost-effective detection methods. Here, we report a scalable surface-enhanced Raman scattering (SERS) platform based on silver-coated cross-scanned laser-induced periodic surface structures (CS-LIPSS) fabricated via femtosecond laser processing. By employing cylindrical lens-assisted beam shaping followed by orthogonal double-pass scanning, we generated periodic nanostructures enriched with dense nanoparticles. Subsequent Ag deposition produce a dense distribution of plasmonic hotspots, enabling strong electromagnetic enhancement. Compared with conventional mesh and single-scanned LIPSS substrates, the CS-LIPSS demonstrate superior SERS activity, with an enhancement factor of 6.4×107 and a detection limit down to 10-11 M for crystal violet. More importantly, the platform enable reliable identification of representative antibiotics including amoxicillin, tetracycline, and neomycin sulfate at concentrations as low as 1 ppm, highlighting its sensitivity and molecular specificity. The fabrication process is chemical-free, template-free, and compatible with wafer-scale production, offering a cost-effective route to reproducible, high-performance SERS substrates.