recyclable ag-tio₂ sers substrates fabricated via plasma jet printing

Recyclable surface-enhanced raman scattering (sers) substrates are important for real-world use because they can be used multiple times and are affordable. in this study, we developed a simple and low-cost method for fabricating recyclable sers substrates by depositing silver nanoparticles onto tio₂ nanostructures using an atmospheric pressure plasma jet without the need for chemical reducing or stabilizing agents. tio₂ nanoparticles were synthesized via a sol-gel process and drop-cast onto glass substrates, followed by silver nanoparticle deposition through plasma jet printing. structural analyses using xrd and fesem confirmed the formation of anatase-phase tio₂ and spherical ag nanoparticles with tunable density. the sers activity was optimized at a 60 s deposition time, and the substrates demonstrated strong plasmonic response and excellent reusability over five uv-assisted photocatalytic cleaning cycles using rhodamine b and methylene blue. the substrates maintained over 80% of their initial raman signal intensity, with no cross-contamination observed between analytes.  these results show that the ag-tio₂ substrates are very sensitive, stable, and can be reused, making them a practical option for real-world sers applications.