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

Published online by Cambridge University Press:  31 January 2011

Li Peng Qian ,
Du Yuan ,
Guang Shun Yi  and
Gan Moog Chow
Guang Shun Yi
Affiliation:
Department of Materials Science and Engineering, National University of Singapore, Kent Ridge, Singapore 119260, Republic of Singapore
Gan Moog Chow*
Affiliation:
Department of Materials Science and Engineering, National University of Singapore, Kent Ridge, Singapore 119260, Republic of Singapore
*
b) Address all correspondence to this author. e-mail: msecgm@nus.edu.sg
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Abstract

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.

Keywords

Core/shellLuminescenceNanostructure
Type
Articles
Information
Journal of Materials Research , Volume 24 , Issue 12 , December 2009 , pp. 3559 - 3568
Copyright
Copyright © Materials Research Society 2009

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References

REFERENCES

1.Yu, M.X., Li, F.Y., Chen, Z.G., Hu, H., Zhan, C., Yang, H., and Huang, C.H.: Laser scanning up-conversion luminescence microscopy for imaging cells labeled with rare-earth nanophosphors. Anal. Chem. 81, 930 (2009).CrossRefGoogle ScholarPubMed
2.Kumar, R., Nyk, M., Ohulchanskyy, T.Y., Flask, C.A., and Prasad, P.N.: Combined optical and MR bioimaging using rare earth ion doped NaYF4 nanocrystals. Adv. Fund. Mater. 19, 853 (2009).CrossRefGoogle Scholar
3.Jiang, S., Zhang, Y., Lim, K.M., Sim, E.K.W., and Ye, L.: NIR-to-visible upconversion nanoparticles for fluorescent labeling and targeted delivery of siRNA. Nanotechnology 20, 155101 (2009).CrossRefGoogle ScholarPubMed
4.Feijo, J.A. and Moreno, N.: Imaging plant cells by two-photon excitation. Protoplasma 223, 1 (2004).CrossRefGoogle ScholarPubMed
5.Zijlmans, H., Bonnet, J., Burton, J., Kardos, K., Vail, T., Niedbala, R.S., and Tanke, H.J.: Detection of cell and tissue surface antigens using up-converting phosphors: A new reporter technology. Anal. Biochem. 267, 30 (1999).CrossRefGoogle ScholarPubMed
6.Sershen, S.R., Westcott, S.L., Halas, N.J., and West, J.L.: Temperaturesensitive polymer-nanoshell composites for photothermally modulated drug delivery. J. Biomed. Mater. Res. 51, 293 (2000).3.0.CO;2-T>CrossRefGoogle ScholarPubMed
7.Chan, W.C.W. and Nie, S.M.: Quantum dot bioconjugates for ultrasensitive nonisotopic detection. Science 281, 2016 (1998).CrossRefGoogle ScholarPubMed
8.Kim, S. and Bawendi, M.G.: Oligomeric ligands for luminescent and stable nanocrystal quantum dots. J. Am. Chem. Soc. 125, 14652 (2003).CrossRefGoogle ScholarPubMed
9.Dubertret, B., Skourides, P., Norris, D.J., Noireaux, V., Brivanlou, A.H., and Libchaber, A.: In vivo imaging of quantum dots encapsulated in phospholipid micelles. Science 298, 1759 (2002).CrossRefGoogle ScholarPubMed
10.Gerion, D., Pinaud, F., Williams, S.C., Parak, W.J., Zanchet, D., Weiss, S., and Alivisatos, A.P.: Synthesis and properties of biocompatible water-soluble silica-coated CdSe/ZnS semiconductor quantum dots. J. Phys. Chem. B 105, 8861 (2001).CrossRefGoogle Scholar
11.Menyuk, N., Dwight, K., and Pierce, J.W.: NaYF4:Yb,Er—An efficient upconversion phosphor. Appl. Phys. Lett. 21, 159 (1972).CrossRefGoogle Scholar
12.Wang, F. and Liu, X.: Recent advances in the chemistry of lanthanide-doped upconversion nanocrystals. Chem. Soc. Rev. 38, 976 (2009).CrossRefGoogle ScholarPubMed
13.Yi, G.S. and Chow, G.M.: Synthesis of hexagonal-phase NaYF4: Yb,Er and NaYF4:Yb,Tm nanocrystals with efficient up-conversion fluorescence. Adv. Funct. Mater. 16, 2324 (2006).CrossRefGoogle Scholar
14.Shan, J.N., Chen, J.B., Meng, J., Collins, J., Soboyejo, W., Friedberg, J.S., and Ju, Y.G.: Biofunctionalization, cytotoxicity, and cell uptake of lanthanide doped hydrophobically ligated NaYF4 upconversion nanophosphors. J. Appl. Phys. 104, 094308 (2008).CrossRefGoogle Scholar
15.Li, Z.Q., Zhang, Y., and Jiang, S.: Multicolor core/shell-structured upconversion fluorescent nanoparticles. Adv. Mater. 20, 4765 (2008).CrossRefGoogle Scholar
16.Peng, X., Schlamp, M.C., Kadavanich, A.V., and Alivisatos, A.P.: Epitaxial growth of highly luminescent CdSe/CdS Core/shell nanocrystals with photostability and electronic accessibility. J. Am. Chem. Soc. 119, 7019 (1997).CrossRefGoogle Scholar
17.Spanhel, L., Haase, M., Weller, H., and Henglein, A.: Photochemistry of colloidal semiconductors. 20. Surface modification and stability of strong luminescing CdS particles. J. Am. Chem. Soc. 109, 5649 (1987).CrossRefGoogle Scholar
18.Hines, M.A. and Guyot-Sionnest, P.: Synthesis and characterization of strongly luminescing ZnS-Capped CdSe nanocrystals. J. Phys. Chem. 100, 468 (1996).CrossRefGoogle Scholar
19.Chen, Z.G., Chen, H.L., Hu, H., Yu, M.X., Li, F.Y., Zhang, Q., Zhou, Z.G., Yi, T., and Huang, C.H.: Versatile synthesis strategy for carboxylic acid-functionalized upconverting nanophosphors as biological labels. J. Am. Chem. Soc. 130, 3023 (2008).CrossRefGoogle ScholarPubMed
20.Yi, G.S. and Chow, G.M.: Water-soluble NaYF4:Yb,Er(Tm)/NaYF4/polymer core/shell/shell nanoparticles with significant enhancement of upconversion fluorescence. Chem. Mater. 19, 341 (2007).CrossRefGoogle Scholar
21.Nunez, N.O., Miguez, H., Quintanilla, M., Cantelar, E., Cusso, F., and Ocana, M.: 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).CrossRefGoogle Scholar
22.Ghosh, P. and Patra, A.: Tuning of crystal phase and luminescence properties of Eu3+ doped sodium yttrium fluoride nanocrystals. J. Phys. Chem. C 112, 3223 (2008).Google Scholar
23.Wang, Y., Tu, L.P., Zhao, J.W., Sun, Y.J., Kong, X.G., and Zhang, H.: Upconversion luminescence of beta-NaYF4:Yb3+,Er3+@beta-NaYF4 core/shell nanoparticles: Excitation power, density and surface dependence. J. Phys. Chem. C 113, 7164 (2009).Google Scholar
24.Dong, C.H. and van Veggel, F.: Cation exchange in lanthanide fluoride nanoparticles. ACS Nano. 3, 123 (2009).CrossRefGoogle ScholarPubMed
25.Selvan, S.T., Tan, T.T., and Ying, J.Y.: Robust, non-cytotoxic, silica-coated CdSe quantum dots with efficient photoluminescence. Adv. Mater. 17, 1620 (2005).CrossRefGoogle Scholar
26.Darbandi, M., Thomann, R., and Nann, T.: Single quantum dots in silica spheres by microemulsion synthesis. Chem. Mater. 17, 5720 (2005).CrossRefGoogle Scholar
27.Uchino, T., Aboshi, A., Kohara, S., Ohishi, Y., Sakashita, M., and Aoki, K.: Microscopic structure of nanometer-sized silica particles. Phys. Rev. B 69, 155409 (2004).CrossRefGoogle Scholar
28.Lue, Q., Guo, F., Sun, L., Li, A., and Zhao, L.: Surface modification of ZrO2:Er3+ nanoparticles to attenuate aggregation and enhance upconversion fluorescence. J. Phys. Chem. C 112, 2836 (2008).Google Scholar
29.Stöer, W., Fink, A., and Bohn, E.: Controlled growth of monodisperse silica spheres in the micron size range. J. Colloid Interface Sci. 26, 62 (1968).CrossRefGoogle Scholar
30.Arriagada, F.J. and Osseoasare, K.: Phase and dispersion stability effects in the synthesis of silica nanoparticles in a nonionic reverse microemulsion. Colloids Surf. 69, 105 (1992).CrossRefGoogle Scholar
31.Ehlert, O., Thomann, R., Darbandi, M., and Nann, T.: A four-color colloidal multiplexing nanoparticle system. ACS Nano. 2, 120 (2008).CrossRefGoogle ScholarPubMed
32.Hu, H., Xiong, L.Q., Zhou, J., Li, F.Y., Cao, T.Y., and Huang, C.H.: Multimodal-luminescence core-shell nanocomposites for targeted imaging of tumor cells. Chem. Eur. J. 15, 3577 (2009).CrossRefGoogle ScholarPubMed
33.Lu, Q., Guo, F.Y., Sun, L., Li, A.H., and Zhao, L.C.: Silica-/titaniacoated Y2O3:Tm3+,Yb3+ nanoparticles with improvement in upconversion luminescence induced by different thickness shells. J. Appl. Phys. 103, 123533 (2008).CrossRefGoogle Scholar
34.Liu, Z.Y., Yi, G.S., Zhang, H.T., Ding, J., Zhang, Y.W., and Xue, J.M.: Monodisperse silica nanoparticles encapsulating upconversion fluorescent and superparamagnetic nanocrystals. Chem. Commun. (Camb.). 694 (2008).CrossRefGoogle ScholarPubMed
35.Koole, R., van Schooneveld, M.M., Hilhorst, J., Donega, C.D., ‘t. Hart, D.C., van Blaaderen, A., Vanmaekelbergh, D., and Meijerink, A.: On the incorporation mechanism of hydrophobic quantum dots in silica spheres by a reverse microemulsion method. Chem. Mater. 20, 2503 (2008).CrossRefGoogle Scholar
36.Suyver, J.F., Grimm, J., van Veen, M.K., Biner, D., Kramer, K.W., and Gudel, H.U.: Upconversion spectroscopy and properties of NaYF4 doped with Er3+, Tm3+ and/or Yb3+. J. Lumin. 117, 1 (2006).CrossRefGoogle Scholar
37.Dong, G.P., Liu, X.F., Xiao, X.D., Qian, B., Ruan, J., Yang, H.C., Ye, S., Chen, D.P., and Qiu, J.R.: Upconversion luminescence of Er3+-Yb3+ codoped NaYF4-PVP electrospun nanofibers. IEEE Photonics Technol. Lett. 21, 57 (2009).CrossRefGoogle Scholar
38.Powell, R.C.: Physics of Solid-State Laser Materials (Springer, New York, 1998).CrossRefGoogle Scholar
39.Yuan, D., Yi, G.S., and Chow, G.M.: Effects of size and surface on luminescence properties of submicron upconversion NaYF4:Yb, Er particles. J. Mater. Res. 24, 2042 (2009).CrossRefGoogle Scholar