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Versatile Synthesis Strategy for Carboxylic Acid-functionalized Upconverting Nanop

hosphors as Biological Labels

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

演講者：洪柏楷

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Outline Phosphors Synthesis of Oleic Acid-Capped UCNPs Converting Hydrophobic UCNPs into Hydrop

hilic Preparation of Streptavidin-Functionalized UC

NPs Detection of DNA

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Phosphors

Downconverting phosphors

Upconverting phosphors

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Downconversion fluorescent materials

1. Organic dyes

2. Semiconductor nanocrystal

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Up-converting rare-earth nanophosphors (UCNPs)

1. sharp absorption and emission lines2. high quantum yields 3. long lifetimes4. photostability

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oleic acid

2,6-diaminohexanoic acid (Lysine)

1-ethyl-3-(3-dimethylaminopropyl) carbodiimidehydrochloride (EDC)

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Hydroxy-2,5-dioxopyrrolidine-3-sulfonicacid sodium salt (Sulfo-NHS)

4-Morpholineethanesulfonic acid (MES)

2-Amino-2-hydroxymethyl-propane-1,3-diol (Tris)

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Synthesis of Oleic Acid-Capped UCNPs

Ln: 78 mol% Y + 20 mol%Yb + 2 mol%Er

NaOH + water + ethanol + oleic acid rare-earth chloride (LnCl3)

transfer to autoclave 160 °C 8 h

cyclohexane + ethanol

oleic acid-capped UCNPs

1.0 M NaF

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NaYF4: 20 mol%Yb, 2 mol % Er

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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 4-530 min

washed twice with deionized water

hydrophilic UCNPs

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Oxidized NaYF4:Yb,Er

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TEM

oxidized NaYF4:Yb,ErNaYF4:Yb,Er

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TEM

NaYF4:Yb, Tm oxidized NaYF4:Yb, Tm

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TEM

NaYF4:Yb, Ho oxidized NaYF4:Yb, Ho

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EDXA spectra

NaYF4:Yb,Er

oxidized NaYF4:Yb,Er

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XRD pattern

* cubic phase

▼ hexagonal phaseoxidized NaYF4:Yb,Er

NaYF4:Yb,Er

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1H NMR Spectra

undoped NaYF4

oxidized NaYF4

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FTIR spectra

NaYF4:Yb,Er

oxidized NaYF4:Yb,Er

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Thermogravimetric analysis (TGA)

oxidized NaYF4:Yb,Er

NaYF4:Yb,Er11.32 %

7.55 %

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Oxidized NaYF4:Yb,Er

water DMF DMSO

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Dynamic light scattering analysis

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Luminescence

continuous-wave excitation at 980 nm

red filter green filter

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Luminescence spectra

(A) NaYF4:Yb,Er

(B) Oxidized

NaYF4:Yb,Er

2H11/2 to 4I15/2

4S3/2 to 4I15/2 4F9/2 to 4I15/2

(I540 /I654 ) decrease

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Luminescence spectra

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Energy level diagram

Leyu Wang ; Yadong Li Chem. Mater. 2007, 19, 727-734

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Luminescence spectra

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Preparation of Streptavidin-Functionalized UCNPs

oxidized NaYF4:Yb,Er + EDC + sulfo-NHS + MES buffer 8 h

water

PBS buffer solutioncontaining streptavidin 4 °C 48 h

Lysine water

Streptavidin-Functionalized

UCNPs

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Streptavidin-Functionalized UCNPs

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Oligonucleotide

5' -(biotin)-GATGAGTATTGATGC-3 ' (as Capture-DNA)

5' -CGAATAGTTCCATTG-(TAMRA)-3 ' (as Report-DNA)

5 '-CAATGGAACTATTCG GCATCAATACTCATC-3 ' (as Target-DNA)

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DNA nanosensors based on UCNPs

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TARMA-labeled reporter DNA

absorptionemissionoxidized NaYF4: Yb, Er

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Detection of DNA

streptavidin-functionalized UCNPs + Report-DNA + Capture-DNA + buffered solution.

37 °C for 20 min

Target-DNA

980 nm

luminescencespectrum

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Luminescence spectra

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DNA nanosensors based on UCNPs

Fluorescence resonant energy transfer

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Conclusions We have demonstrated a new, efficient and versatile procedure for converti

ng 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 .