The colleagues from Department of Gaseous Electronics at Jožef Stefan Institute developed a fast-processing micro-plasma method for producing a plasmonic metasurface densely packed with electromagnetic hotspots, based on vertically aligned Cu₂O/CuO nanosheets decorated with silver nanoparticles. This lithography-free scaffold enables surface-enhanced Raman scattering with detection limits in the low nanomolar range for fast-tracing of different explosives such as tetryl and HMX, outperforming many commercial sensors while ensuring reproducibility. The approach also uncovers laser-dependent shifts in vibrational modes that define the nanostructure, providing valuable input for machine-learning-based data processing. Because the plasma treatment requires only short processing and is scalable simultaneously, the technique paves the way for compact lab-on-chip devices. Such devices could identify trace explosives and hazardous chemicals on-site, offering robust, portable, data-driven tools for border security, forensic applications, and environmental monitoring. The research was published in the journal Small.