title: Lanthanide-doped NaScF4 nanoprobes: crystal structure, optical spectroscopy and biodetection.
abstract: Trivalent lanthanide ions (Ln(3+))-doped inorganic nanoparticles (NPs) as potential luminescent bioprobes have been attracting tremendous interest because of their unique upconversion (UC) and downconversion (DC) luminescence properties. NaScF4, as an important host material, has been rarely reported and its crystal structure remains unclear. Herein, based on the single crystal X-ray diffraction, the space group of NaScF4 crystals was determined to be P31 containing multiple sites of Sc(3+) with crystallographic site symmetry of C1, which was verified by high-resolution photoluminescence spectroscopy of Eu(3+) at low temperature (10 K). Furthermore, monodisperse and size-controllable NaScF4:Ln(3+) NPs were synthesized via a facile thermal decomposition method. The biotinylated NaScF4:Er(3+)/Yb(3+) NPs were demonstrated for their applications as a heterogeneous UC luminescence bioprobe to detect avidin with a detection limit of 180 pM. After bioconjugation with amino-terminal fragment (ATF) of urokinase plasminogen activator (uPA), NaScF4:Ln(3+) NPs also exhibited specific recognition of cancer cells overexpressed with uPA receptor (uPAR, an important marker of tumor biology and metastasis), showing great potentials in tumor-targeted bioimaging.
authors.affiliation: Key Laboratory of Optoelectronic Materials Chemistry and Physics, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Ai
authors.forename: Datao
authors.initials: D
authors.lastname: Tu
authors.forename: Wei
authors.initials: W
authors.lastname: Zheng
authors.forename: Yongsheng
authors.initials: Y
authors.lastname: Liu
authors.forename: Jintao
authors.initials: J
authors.lastname: Kong
authors.forename: Ping
authors.initials: P
authors.lastname: Hu
authors.forename: Zhuo
authors.initials: Z
authors.lastname: Chen
authors.forename: Mingdong
authors.initials: M
authors.lastname: Huang
authors.forename: Xueyuan
authors.initials: X
authors.lastname: Chen
mesh_terms: D014408:Biomarkers, Tumor / Q000378:metabolism; D019921:Biotinylation; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D018360:Crystallography, X-Ray; D005456:Fluorescent Dyes / Q000737:chemistry / Q000633:toxicity; D005459:Fluorides / Q000737:chemistry*; D006801:Humans; D028581:Lanthanoid Series Elements / Q000737:chemistry*; D018613:Microscopy, Confocal; D008968:Molecular Conformation; D053758:Nanoparticles / Q000737:chemistry* / Q000633:toxicity; D055293:Receptors, Urokinase Plasminogen Activator / Q000378:metabolism; D012538:Scandium / Q000737:chemistry*; D017670:Sodium Compounds / Q000737:chemistry*
chemical_list: D014408:Biomarkers, Tumor; D005456:Fluorescent Dyes; D028581:Lanthanoid Series Elements; D055293:Receptors, Urokinase Plasminogen Activator; D017670:Sodium Compounds; D005459:Fluorides; D012538:Scandium