title: A strategy for simultaneously realizing the cubic-to-hexagonal phase transition and controlling the small size of NaYF4:Yb3+,Er3+ nanocrystals for in vitro cell imaging.
abstract: Hexagonal-phase NaYF(4):Yb(3+),Er(3+) up-conversion nanocrystals (UCNCs) are synthesized by a combination of refluxing and hydrothermal treatment. This strategy leads to only a slight increase in particle size, from 4.5 to ca. 10 nm, during the cubic-to-hexagonal phase transition. The hexagonal UCNCs can be internalized by HeLa cells and exhibit visible emission in the cells under near-infrared excitation.
authors.affiliation: Department of Applied Physics and Materials Research Centre, The Hong Kong Polytechnic University, Hung Hom, Hong Kong SAR.
authors.forename: Zhen-Ling
authors.initials: ZL
authors.lastname: Wang
authors.forename: Jianhua
authors.initials: J
authors.lastname: Hao
authors.forename: Helen L W
authors.initials: HL
authors.lastname: Chan
authors.forename: Wing-Tak
authors.initials: WT
authors.lastname: Wong
authors.forename: Ka-Leung
authors.initials: KL
authors.lastname: Wong
mesh_terms: D015374:Biosensing Techniques; D049109:Cell Proliferation; D002470:Cell Survival; D004871:Erbium / Q000737:chemistry*; D005456:Fluorescent Dyes / Q000737:chemistry / Q000494:pharmacology; D005459:Fluorides / Q000737:chemistry*; D006367:HeLa Cells; D006801:Humans; D066298:In Vitro Techniques; D028581:Lanthanoid Series Elements / Q000737:chemistry; D049449:Luminescence; D018613:Microscopy, Confocal / Q000379:methods; D046529:Microscopy, Electron, Transmission / Q000379:methods; D053758:Nanoparticles / Q000737:chemistry*; D036103:Nanotechnology / Q000379:methods*; D014961:X-Ray Diffraction; D015018:Ytterbium / Q000737:chemistry*; D015019:Yttrium / Q000737:chemistry*
chemical_list: D005456:Fluorescent Dyes; D028581:Lanthanoid Series Elements; C525362:sodium yttriumtetrafluoride; D015019:Yttrium; D004871:Erbium; D015018:Ytterbium; D005459:Fluorides