Vesicle-like polymer/silver composite microspheres with excellent toughness for surface-enhanced Raman scattering

• • Template removal via DMF dissolution yields intact hollow SPS@Ag microspheres with a diameter of ~1.5 μm, whereas conventional hollow silver spheres frequently collapse due to low surface coverage; this structural integrity directly enables reliable SERS substrate fabrication. • • Shell thickness is precisely tunable by the number of silver reduction cycles, allowing optimization of plasmonic properties; the vesicle-like architecture achieves a Raman enhancement factor significantly higher than that of core-shell SPS/Ag microspheres, as quantified by R6G detection. • • The incorporation of sulfonated polystyrene within the silver membrane provides excellent toughness, overcoming the inherent brittleness of hollow noble metal microspheres; this toughness is critical for withstanding capillary forces during solvent evaporation and for maintaining performance in repeated sensing cycles. • • The scalable dispersion polymerization and in situ reduction protocol avoids harsh reaction conditions and complex preparation steps associated with alternative methods such as calcite templating or gelatin-assisted reduction, offering a commercially viable route to robust SERS substrates.