Luminescent-plasmonic core-shell microspheres, doped with Nd3+ and modified with Au nanoparticles, exhibiting whispering gallery modes and SERS activity

Abstract Multifunctional core/shell type, luminescent-plasmonic material composed of lanthanide doped microspheres (≈50 μm) and gold nanoparticles (Au NPs; ≈10–20 nm) deposited onto their surface, were successfully prepared (Nd 3+ :YAS@Au). The material was synthesized to combine the luminescence properties of the Nd 3+ -doped microspheres, i.e. whispering resonance with plasmonic activity of the surface Au NPs, i.e. surface enhanced Raman scattering (SERS) effect, within a single, micro-sized material. The luminescent-plasmonic microspheres were used as the active SERS substrate for detection of the organic probe, and for generation of Whispering Gallery Modes (WGM), which red-shift together with increasing laser power (temperature elevation). The products obtained were analysed with optical, scanning and transmission electron microscopy (SEM and TEM), as well as by Raman, absorption and photoluminescence spectroscopies.