Mn2+ dopant-controlled synthesis of NaYF4:Yb/Er upconversion nanoparticles for in vivo imaging and drug delivery.

Pure dark red emission (650-670 nm) of NaYF(4):Yb/Er upconversion nanoparticles (UCNPs) is achieved by manganese ions (Mn(2+)) doping. In addition, the Mn(2+)-doping can also control the crystalline phase and size of the resulting UCNPs simultaneously. Drug delivery studies suggest the promise of these UCNPs as drug carriers for intracellular drug delivery and eventually as a multifunctional nanoplatform for simultaneous diagnosis and therapy.

Tian G ，Gu Z ，Zhou L ，Yin W ，Liu X ，Yan L ，Jin S ，Ren W ，Xing G ，Li S ，Zhao Y ... -  《-》

Facile synthesis of 5 nm NaYF₄:Yb/Er nanoparticles for targeted upconversion imaging of cancer cells.

5nm intense green emission NaYF4:Yb/Er upconversion nanoparticles (UCNPs) with pure β phase was synthesized with a simple "green" strategy for the first time. Traditional organic solvothermal method is often applied to prepare the high-quality and uniform UCNPs, but the preparation of lanthanide-oleate complexes is laborious as heating and multistep post-treatment for purification are often required. The water-alcohols solvothermal method is environmentally friendly, but the fabricated UCNPs have big size, poor biocompatibility and high cytotoxicity, which limited their application for cell imaging. Herein, NaYF4:Yb/Er UCNPs were prepared with rare-earth nitrates RE(NO3)3 (RE=Y0.80 Yb0.18 Er0.02) as precursors and diethylene glycol (DEG)/ethylene glycol (EG)/water as the solvent. A facile green solvothermal method with the temperature being controlled at 300°C was developed. The as-prepared NaYF4:Yb/Er UCNPs were characterized and were found to have enhanced UC emission and controllable particle size. The as-prepared UCNPs were further functionalized via folic acid coating for the targeted imaging and improved bio- compatibility. It was made the UCNPs potential for upconversion bioimaging of living cells by the strong upconversion luminescence, the excellent biocompatibility, and the super-small size. The good colloidal stability and low cell cytotoxicity of the as-prepared UCNPs and the developed synthesis protocol might advance both the fields of UCNPs and biomolecule-based nanotechnology for future studies.

Hu Y ，Wu B ，Jin Q ，Wang X ，Li Y ，Sun Y ，Huo J ，Zhao X ... -  《-》

Luminescence energy transfer detection of PSA in red region based on Mn2+-enhanced NaYF4:Yb, Er upconversion nanorods.

Zhang J ，Wang S ，Gao N ，Feng D ，Wang L ，Chen H ... -  《-》

Mn(2+)-doped NaYF4:Yb/Er upconversion nanoparticle-based electrochemiluminescent aptasensor for bisphenol A.

Guo X ，Wu S ，Duan N ，Wang Z ... -  《-》

Multifunctional NaYF4:Yb, Er@mSiO2@Fe3O4-PEG nanoparticles for UCL/MR bioimaging and magnetically targeted drug delivery.

Liu B ，Li C ，Ma P ，Chen Y ，Zhang Y ，Hou Z ，Huang S ，Lin J ... -  《-》