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Upconversion

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Upconversion

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  1. Versatile Synthesis Strategy for Carboxylic Acid-functionalized Upconverting Nanophosphors as Biological Labels 演講者：洪柏楷 Zhigang Chen, Huili Chen, He Hu, Mengxiao Yu, Fuyou Li,* Qiang Zhang,Zhiguo Zhou, Tao Yi, and Chunhui Huang* J. AM. CHEM. SOC. 2008, 130, 3023-3029

  2. Outline • Phosphors • Synthesis of Oleic Acid-Capped UCNPs • Converting Hydrophobic UCNPs into Hydrophilic • Preparation of Streptavidin-Functionalized UCNPs • Detection of DNA

  3. Phosphors • Downconverting phosphors • Upconverting phosphors

  4. Downconversion fluorescent materials • 1. Organic dyes • 2. Semiconductor nanocrystal

  5. Up-converting rare-earth nanophosphors (UCNPs) • 1. sharp absorption and emission lines • 2. high quantum yields • 3. long lifetimes • 4. photostability

  6. oleic acid 2,6-diaminohexanoic acid (Lysine) 1-ethyl-3-(3-dimethylaminopropyl) carbodiimidehydrochloride (EDC)

  7. Hydroxy-2,5-dioxopyrrolidine-3- sulfonicacid sodium salt (Sulfo-NHS) 4-Morpholineethanesulfonic acid (MES) 2-Amino-2-hydroxymethyl-propane-1,3-diol (Tris)

  8. Synthesis of Oleic Acid-Capped UCNPs NaOH + water + ethanol + oleic acid rare-earth chloride (LnCl3) 1.0 M NaF transfer to autoclave 160 °C 8 h cyclohexane + ethanol oleic acid-capped UCNPs Ln: 78 mol% Y + 20 mol%Yb + 2 mol%Er

  9. NaYF4: 20 mol%Yb, 2 mol % Er

  10. Converting Hydrophobic UCNPs into Hydrophilic UCNP + cyclohexane + tert-butanol + water 5 wt % K2CO3 aqueous solution KMnO4 + NaIO4 (Lemieux-von Rudloff reagent) 40 °C 48 h. wash with deionized water acetone ethanol. HCl (50 mL) pH 4-5 30 min washed twice with deionized water hydrophilic UCNPs

  11. Oxidized NaYF4:Yb,Er

  12. TEM NaYF4:Yb,Er oxidized NaYF4:Yb,Er

  13. TEM NaYF4:Yb, Tm oxidized NaYF4:Yb, Tm

  14. TEM NaYF4:Yb, Ho oxidized NaYF4:Yb, Ho

  15. EDXA spectra oxidized NaYF4:Yb,Er NaYF4:Yb,Er

  16. XRD pattern * cubic phase ▼hexagonal phase oxidized NaYF4:Yb,Er NaYF4:Yb,Er

  17. 1H NMR Spectra oxidized NaYF4 undoped NaYF4

  18. FTIR spectra oxidized NaYF4:Yb,Er NaYF4:Yb,Er

  19. Thermogravimetric analysis (TGA) 7.55 % oxidized NaYF4:Yb,Er NaYF4:Yb,Er 11.32 %

  20. Oxidized NaYF4:Yb,Er water DMF DMSO

  21. Dynamic light scattering analysis

  22. Luminescence continuous-wave excitation at 980 nm red filter green filter

  23. Luminescence spectra 2H11/2 to 4I15/2 (A) NaYF4:Yb,Er (B) Oxidized NaYF4:Yb,Er 4S3/2 to 4I15/2 4F9/2 to 4I15/2 (I540 /I654 ) decrease

  24. Luminescence spectra

  25. Energy level diagram Leyu Wang ; Yadong Li Chem. Mater. 2007, 19, 727-734

  26. Luminescence spectra

  27. Preparation of Streptavidin-Functionalized UCNPs oxidized NaYF4:Yb,Er + EDC + sulfo-NHS + MES buffer 8 h water PBS buffer solution containing streptavidin 4 °C 48 h Lysine water Streptavidin-Functionalized UCNPs

  28. Streptavidin-Functionalized UCNPs

  29. Oligonucleotide 5'-(biotin)-GATGAGTATTGATGC-3 ' (as Capture-DNA) 5'-CGAATAGTTCCATTG-(TAMRA)-3 ' (as Report-DNA) 5 '-CAATGGAACTATTCG GCATCAATACTCATC-3 '(as Target-DNA)

  30. DNA nanosensors based on UCNPs

  31. TARMA-labeled reporter DNA absorption emission oxidized NaYF4: Yb, Er

  32. Detection of DNA streptavidin-functionalized UCNPs + Report-DNA + Capture-DNA + buffered solution. Target-DNA 37 °C for 20 min 980 nm luminescence spectrum

  33. Luminescence spectra

  34. DNA nanosensors based on UCNPs Fluorescence resonant energy transfer

  35. Conclusions • We have demonstrated a new, efficient and versatile procedure for converting hydrophobic UCNPs into water-soluble and carboxylic acid-functionalized derivatives by directly oxidizing oleic acid ligands to azelaic acid. • This procedure is not limited to hydrophobic UCNPs,and it can easily be applied to other hydrophobic nanoparticles (including rare earth, semiconductor and metal nanoparticles) where only surface ligands can be oxidized. • The presence of free carboxylic acid groups on the surface of azelaic acid-capped UCNPs allows further conjugation with various biomolecules, and streptavidin-functionalized UCNPs derived from azelaic acid-capped precursors provides a novel approach for detecting and/or binding to a broad range of biotinylated proteins or antibodies .

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