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Critical shell thickness and emission enhancement of NaYF4:Yb,Er/NaYF4/silica core/shell/shell nanoparticles

  • Li Peng Qian, Du Yuan, Guang Shun Yi (a1) and Gan Moog Chow (a1)
  • DOI:
  • Published online: 01 January 2011

Amorphous silica shells, used for functionalization of inorganic nanoparticles in bioapplications, were coated on chemically synthesized NaYF4:Yb,Er upconversion fluorescent nanoparticles via a reverse microemulsion method by using dual surfactants of polyoxyethylene (5) nonylphenylether and 1-hexanol, and tetraethyl orthosilicate as precursor. NaYF4:Yb,Er nanoparticles were equiaxed with a particle size of 11.1 ± 1.3 nm. The thickness of silica shell was ∼8 nm. NaYF4:Yb,Er/silica core/shell nanoparticles were well dispersed in solvents such as ethanol and deionized water. The emission intensities of NaYF4:Yb,Er/silica core/shell nanoparticles remained the same as that of uncoated nanoparticles after surface functionalization with an amine group using (3-aminopropyl)-trimethoxysilan. Silica, although providing a good barrier to the nonradiative relaxation between the upconversion nanoparticles and the environments, did not enhance the emission intensity of upconversion nanoparticles. To increase the emission intensity of NaYF4:Yb,Er/silica core/shell nanoparticles, an undoped NaYF4 shell (∼3-nm thick) was deposited on the upconversion nanoparticles before the silica coating. The total emission intensity of NaYF4:Yb,Er/NaYF4/silica core/shell/shell nanoparticles increased by 15 times compared to that without the intermediate NaYF4 shell. The critical shell thickness of NaYF4 was ∼3 nm, beyond which no further emission intensity enhancement was observed.

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1.M.X. Yu , F.Y. Li , Z.G. Chen , H. Hu , C. Zhan , H. Yang , and C.H. Huang : Laser scanning up-conversion luminescence microscopy for imaging cells labeled with rare-earth nanophosphors. Anal. Chem. 81, 930 (2009).

2.R. Kumar , M. Nyk , T.Y. Ohulchanskyy , C.A. Flask , and P.N. Prasad : Combined optical and MR bioimaging using rare earth ion doped NaYF4 nanocrystals. Adv. Fund. Mater. 19, 853 (2009).

3.S. Jiang , Y. Zhang , K.M. Lim , E.K.W. Sim , and L. Ye : NIR-to-visible upconversion nanoparticles for fluorescent labeling and targeted delivery of siRNA. Nanotechnology 20, 155101 (2009).

4.J.A. Feijo and N. Moreno : Imaging plant cells by two-photon excitation. Protoplasma 223, 1 (2004).

5.H. Zijlmans , J. Bonnet , J. Burton , K. Kardos , T. Vail , R.S. Niedbala , and H.J. Tanke : Detection of cell and tissue surface antigens using up-converting phosphors: A new reporter technology. Anal. Biochem. 267, 30 (1999).

6.S.R. Sershen , S.L. Westcott , N.J. Halas , and J.L. West : Temperaturesensitive polymer-nanoshell composites for photothermally modulated drug delivery. J. Biomed. Mater. Res. 51, 293 (2000).

7.W.C.W. Chan and S.M. Nie : Quantum dot bioconjugates for ultrasensitive nonisotopic detection. Science 281, 2016 (1998).

8.S. Kim and M.G. Bawendi : Oligomeric ligands for luminescent and stable nanocrystal quantum dots. J. Am. Chem. Soc. 125, 14652 (2003).

9.B. Dubertret , P. Skourides , D.J. Norris , V. Noireaux , A.H. Brivanlou , and A. Libchaber : In vivo imaging of quantum dots encapsulated in phospholipid micelles. Science 298, 1759 (2002).

10.D. Gerion , F. Pinaud , S.C. Williams , W.J. Parak , D. Zanchet , S. Weiss , and A.P. Alivisatos : Synthesis and properties of biocompatible water-soluble silica-coated CdSe/ZnS semiconductor quantum dots. J. Phys. Chem. B 105, 8861 (2001).

11.N. Menyuk , K. Dwight , and J.W. Pierce : NaYF4:Yb,Er—An efficient upconversion phosphor. Appl. Phys. Lett. 21, 159 (1972).

12.F. Wang and X. Liu : Recent advances in the chemistry of lanthanide-doped upconversion nanocrystals. Chem. Soc. Rev. 38, 976 (2009).

13.G.S. Yi and G.M. Chow : Synthesis of hexagonal-phase NaYF4: Yb,Er and NaYF4:Yb,Tm nanocrystals with efficient up-conversion fluorescence. Adv. Funct. Mater. 16, 2324 (2006).

14.J.N. Shan , J.B. Chen , J. Meng , J. Collins , W. Soboyejo , J.S. Friedberg , and Y.G. Ju : Biofunctionalization, cytotoxicity, and cell uptake of lanthanide doped hydrophobically ligated NaYF4 upconversion nanophosphors. J. Appl. Phys. 104, 094308 (2008).

15.Z.Q. Li , Y. Zhang , and S. Jiang : Multicolor core/shell-structured upconversion fluorescent nanoparticles. Adv. Mater. 20, 4765 (2008).

16.X. Peng , M.C. Schlamp , A.V. Kadavanich , and A.P. Alivisatos : Epitaxial growth of highly luminescent CdSe/CdS Core/shell nanocrystals with photostability and electronic accessibility. J. Am. Chem. Soc. 119, 7019 (1997).

17.L. Spanhel , M. Haase , H. Weller , and A. Henglein : Photochemistry of colloidal semiconductors. 20. Surface modification and stability of strong luminescing CdS particles. J. Am. Chem. Soc. 109, 5649 (1987).

18.M.A. Hines and P. Guyot-Sionnest : Synthesis and characterization of strongly luminescing ZnS-Capped CdSe nanocrystals. J. Phys. Chem. 100, 468 (1996).

19.Z.G. Chen , H.L. Chen , H. Hu , M.X. Yu , F.Y. Li , Q. Zhang , Z.G. Zhou , T. Yi , and C.H. Huang : Versatile synthesis strategy for carboxylic acid-functionalized upconverting nanophosphors as biological labels. J. Am. Chem. Soc. 130, 3023 (2008).

20.G.S. Yi and G.M. Chow : Water-soluble NaYF4:Yb,Er(Tm)/NaYF4/polymer core/shell/shell nanoparticles with significant enhancement of upconversion fluorescence. Chem. Mater. 19, 341 (2007).

21.N.O. Nunez , H. Miguez , M. Quintanilla , E. Cantelar , F. Cusso , and M. Ocana : Synthesis of spherical down- and up-conversion NaYF4-based nanophosphors with tunable size in ethylene glycol without surfactants or capping additives. Eur. J. Inorg. Chem. 4517 (2008).

24.C.H. Dong and F. van Veggel : Cation exchange in lanthanide fluoride nanoparticles. ACS Nano. 3, 123 (2009).

25.S.T. Selvan , T.T. Tan , and J.Y. Ying : Robust, non-cytotoxic, silica-coated CdSe quantum dots with efficient photoluminescence. Adv. Mater. 17, 1620 (2005).

26.M. Darbandi , R. Thomann , and T. Nann : Single quantum dots in silica spheres by microemulsion synthesis. Chem. Mater. 17, 5720 (2005).

27.T. Uchino , A. Aboshi , S. Kohara , Y. Ohishi , M. Sakashita , and K. Aoki : Microscopic structure of nanometer-sized silica particles. Phys. Rev. B 69, 155409 (2004).

29.W. Stöer , A. Fink , and E. Bohn : Controlled growth of monodisperse silica spheres in the micron size range. J. Colloid Interface Sci. 26, 62 (1968).

30.F.J. Arriagada and K. Osseoasare : Phase and dispersion stability effects in the synthesis of silica nanoparticles in a nonionic reverse microemulsion. Colloids Surf. 69, 105 (1992).

31.O. Ehlert , R. Thomann , M. Darbandi , and T. Nann : A four-color colloidal multiplexing nanoparticle system. ACS Nano. 2, 120 (2008).

32.H. Hu , L.Q. Xiong , J. Zhou , F.Y. Li , T.Y. Cao , and C.H. Huang : Multimodal-luminescence core-shell nanocomposites for targeted imaging of tumor cells. Chem. Eur. J. 15, 3577 (2009).

33.Q. Lu , F.Y. Guo , L. Sun , A.H. Li , and L.C. Zhao : Silica-/titaniacoated Y2O3:Tm3+,Yb3+ nanoparticles with improvement in upconversion luminescence induced by different thickness shells. J. Appl. Phys. 103, 123533 (2008).

34.Z.Y. Liu , G.S. Yi , H.T. Zhang , J. Ding , Y.W. Zhang , and J.M. Xue : Monodisperse silica nanoparticles encapsulating upconversion fluorescent and superparamagnetic nanocrystals. Chem. Commun. (Camb.). 694 (2008).

35.R. Koole , M.M. van Schooneveld , J. Hilhorst , C.D. Donega , D.C. ‘t. Hart , A. van Blaaderen , D. Vanmaekelbergh , and A. Meijerink : On the incorporation mechanism of hydrophobic quantum dots in silica spheres by a reverse microemulsion method. Chem. Mater. 20, 2503 (2008).

36.J.F. Suyver , J. Grimm , M.K. van Veen , D. Biner , K.W. Kramer , and H.U. Gudel : Upconversion spectroscopy and properties of NaYF4 doped with Er3+, Tm3+ and/or Yb3+. J. Lumin. 117, 1 (2006).

37.G.P. Dong , X.F. Liu , X.D. Xiao , B. Qian , J. Ruan , H.C. Yang , S. Ye , D.P. Chen , and J.R. Qiu : Upconversion luminescence of Er3+-Yb3+ codoped NaYF4-PVP electrospun nanofibers. IEEE Photonics Technol. Lett. 21, 57 (2009).

38.R.C. Powell : Physics of Solid-State Laser Materials (Springer, New York, 1998).

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