A facile ＂ship-in-a-bottle＂ approach to construct nanorattles based on upconverting lanthanide-doped fluorides

Rattle structure is a topic of great interest in design and application of nano- materials due to the unique core@void@shell architecture and the integration of functions. Herein, we developed a novel ＂ship-in-a-bottle＂ method to fabricate upconverting （UC） luminescent nanorattles by incorporating lanthanide-doped fluorides into hollow mesoporous silica. The size of nanorattles and the filling amount of fluorides can be well controlled. In addition, the modification of silica shell （with phenylene and amine groups） and the variation of efficient UC fluorides （NaYF4：Yb, Er, NaLuF4：Yb, Er, NaGdF4：Yb, Er and LiYF4：Yb, Er） were readily achieved. The resulting nanorattles exhibited a high capacity and pH-dependent release of the anti-cancer drug doxorubicin （DOX）. Furthermore, we employed these nanorattles in proof-of-concept UC-monitoring drug release by utilizing the energy transfer process from UC fluorides to DOX, thus revealing the great potential of the nanorattles as efficient cancer theranostic agent.

A new strategy to achieve enhanced upconverted circularly polarized luminescence in chiral perovskite nanocrystals

Achieving large luminescence dissymmetry factors(pium)is challenging in the research field of circularly polarized luminescence(CPL).While various approaches have been developed to construct organic systems with CPL activity,there is still a lack of effective methods for fabricating CPL active inorganic materials.Herein,we propose an approach for endowing upconversion nanoparticles(UCNPs)and perovskite nanocrystal(PKNC)hybrid nanomaterials with upconverted circularly polarized luminescence(UC-CPL)activity.Chiral cesium lead bromides(CsPbBr_(3))PKNCs were synthesized by a chiral-ligand-assistant method.Meanwhile,UCNP could be embedded into the chiral PKNC,enabling a photon upconvesion feature to the PKNC.The embedded UCNPs in PKNCs were confirmed by electron tomography.Consequently,various CPL activities,including prompt CPL,UC-CPL,and energy transfer enhanced circularly polarized luminescence(ET-CPL),were realized.The chiral perovskite nanocrystals could reabsorb the chiral energy generated from UCNPs,showing energy transfer enhanced CPL activity with four times magnification of the circular polarization.These findings provide a meaningful strategy for designing chiral photon upconversion inorganic nanomaterials with highly efficient UC-CPL activity.