Silver microplasma-engineered nanoassemblies on periodic nanostructures for SERS applications

This research aimed to enhance the performance of surface-enhanced Raman scattering (SERS) substrates through the implementation of periodic nanostructures, effectively increasing surface area and uniformity. The approach involved a two-step process: initially, magnetron sputtering was employed to minimize the Raman background signal from the polymer substrate, and subsequently, the microplasma nanoparticle coating method was utilized to augment the presence of silver nanoparticles (AgNPs) for enhancing SERS efficacy. The outcome revealed several key findings: a coefficient of variation (CV) of approximately 8% for individual substrates (3 x 3 cm2), a CV of 6% between different fabrication batches, and a sustained signal strength of 85% over a storage period exceeding two months in a moisture-proof enclosure, thus meeting commercial product standards. Moreover, the substrate demonstrated a limit of detection of 8.4 x 10-7 M (306.5 ppb) for malachite green under non-resonance Raman excitation conditions along with an impressive enhancement factor of 2.69 x 106, establishing it as a high-performance and stable SERS substrate. Ag-MEN enhances SERS by decorating silver nanoparticles on a periodic nanostructured template, improving both the enhancement factor, uniformity, and reproducibility.