Mesoporous silica-coated plasmonic nanostructures for surface-enhanced raman scattering detection and photothermal therapy

The design and fabrication of core–shell and yolk–shell nanostructures withsurface plasmon resonance (SPR)-active center protected by permeablemesoporous channels can raise the new vitality into the catalysis and biologicalapplications. Hybrid plasmonic-mesoporous silica nanocarriers consistingof Ag and Au–Ag alloy nanoparticles are fabricated through spatiallyconfi ned galvanic replacement approach. The plasmonic absorption peakscan be fi nely controlled to the near-infrared (NIR) region (500–790 nm) thatis benefi cial for tissue transmittance. The mesoporous silica shell facilitatesalso protection of Au–Ag cores and affords the channels between the exteriorand interior capsule environments, thereby endowing the multiple applications.In the present work, it is successfully demonstrated that mesoporoussilica-coated Au–Ag alloy core–shell and yolk–shell nanocarriers can serve asgood substrates for surface-enhanced Raman scattering (SERS) detection.The SERS signal intensities of nanocarriers are highly dependent on the SPRpeaks and the contents of gold. Simultaneously, the synthesized Au-Ag@mSiO 2 nanocarriers with SPR peak at ≈790 nm can be applied in NIR-sensitiveSERS detection and photothermal therapy.