RAFT Polymers-Capped Lanthanide-Doped Nanoparticles via "One-Pot" Aminolysis/Thiolate-Grafting

We here describe a synthetic strategy to efficiently prepare polymer-functionalized lanthanide-doped nanoparticles (LNPs) via "one-pot" ω-chain end aminolysis/thiolate-grafting of reversible addition-fragmentation chain-transfer (RAFT) polymers onto the surface of LNPs. Two representative polymers, poly(diethylene glycol methyl ether methacrylate) (PDEGMA) and poly[poly(ethylene glycol) methyl ether methacrylate] (PPEGMA), are prepared via RAFT, and their end-group functionalization onto the surface of NaYF₄:Yb, Tm-based LNPs is demonstrated via an in situ tandem process. The achieved nanohybrids exhibit enhanced water-dispersibility and cellular compatibility. Structural integrity and grafting confirmation of the constructed nanoconjugates are successfully made by combined studies of NMR, Fourier transform infrared (FTIR), fluorescence spectroscopy, and X-ray diffraction (XRD). The size and morphology of the hybrid nanomaterials in solution are determined by dynamic light scattering (DLS) spectroscopy and high-resolution transmission electron microscopy (HR-TEM), and the photothermal activity is probed for their potential theranostic applications.