Search for content and authors
 

Up-conversion and down-conversion processes observed in Er3+, Yb3+ and Mn2+ doped ZnAl2O4 nanoparticles

Izabela Kamińska 1Krzysztof Fronc 1Bożena Sikora 1Anna Baranowska-Korczyc 1Kamil Sobczak 1Tomasz Wojciechowski 1Wojciech Paszkowicz 1Roman Minikayev 1Mateusz Chwastyk Kamil Koper 2,3Piotr Stępień 2,3Bohdan Paterczyk 4Grzegorz M. Wilczyński 5Jakub Włodarczyk 5Maciej Gawlak 5Danek Elbaum 1

1. Polish Academy of Sciences, Institute of Physics, al. Lotników 32/46, Warszawa 02-668, Poland
2. Institute of Biochemistry and Biophysics PAS, Pawińskiego 5a, Warszawa 02-106, Poland
3. Institute of Genetics and Biotechnology, University of Warsaw, Pawińskiego 5a, Warszawa 02-106, Poland
4. Faculty of Biology,University of Warsaw, Ilji Miecznikowa 1, Warszawa 02-096, Poland
5. Nencki Institute of Experimental Biology, Pasteura 3, Warszawa 02-093, Poland

Abstract

Our objective was to synthesize hydrophilic zinc-aluminum spinel nanostructures doped with rare earth ions such as Er3+ and Yb3+ (fig. 1a) and ions from transition metal group such as Mn2+. Spinels are isomorphic metal oxides AB2O4, where A and B are divalent and trivalent ions, respectively. The material shows a close-packed face centered cubic structure with Fd3m space group symmetry. They are applicable as useful luminescent bio-marker due to a significant improvement in the signal to background ratio and high resilience to photo-bleaching.

12_1_2.jpg

Fig. 1. (a) Spinel ZnAl2O4: Er3+, Yb3+ unit cell geometry (upconversion process) [2], (b) Chemical distribution maps of elements: Zn, O, Er, Yb.

A wide variety of emission spectra could be obtained by changing the concentrations and proportions of the rare earth ions in the crystal host. Although upconversion can be expected, in principle, from most lanthanide-doped crystalline host materials, efficient UC occurs only by using a limited number of well selected host-dopant combinations [1].

The nanoparticles were synthesized in  aerosol solutions consisting of droplets (4μm in diameter) by injecting a solution  containing the reductors and oxidants to a furnace at the temperature of 1000oC. The structures of the materials were characterized by transmission electron microscopy and X-ray diffraction.

We obtained regular spherical polycrystalline nanoparticles with a broad size distribution from 20 to 800 nm. To evaluate morphological changes of nanoparticles surface and to visualize the surface topography we used scanning electron microscope.  In addition, we performed the EDX material analysis  in order to determine distribution of elements in the samples. The results confirmed the presence of Zn, Al, O and Er and Yb (fig. 1b). To check the toxicity of the ZnAl2O4: Er3+, Yb3+ nanoparticles, we introduced them to the body of the living nematode (Caenorhabditiselegans). C. elegans is a frequently used model organism in biological research, such as process development, embryogenesis, morphogenesis and aging. Confocal microscope images confirm the presence of the nanoparticles inside the gastrointestinal tract of C. elegans.

References

[1] Wang F., Liu X., Chem. Soc. Rev. 2009, 38, 976-989.

[2] Humphrey W., Dalke A., Schulten K.,VMD -Visual Molecular Dynamics, J. Molecular   Graphics, 1996, 14, 33-38.

 

The research was supported by the European Union within European Regional Development Fund, through grant Innovative Economy (POIG.01.01.02-00-008/08). The Polish National Centre for Research and Development NR13004704 and Center of Excellence. This work was (partially) performed in the NanoFun laboratories co-financed by the European Regional Development Fund within the Innovation Economy Operational Programme, the Project No. POIG.02.02.00-00-025/09/.

 

 

Legal notice
  • Legal notice:
 

Related papers

Presentation: Poster at Nano-Biotechnologia PL, by Izabela Kamińska
See On-line Journal of Nano-Biotechnologia PL

Submitted: 2012-06-28 11:25
Revised:   2012-09-13 07:54