Zinc aluminate (ZnAl₂O₄) is found in nature as a mineral named gahnite. This spinel presents a close-packed face-centered cubic structure belonging to the Fd3m space group, having an optical band gap of 3.8 eV, which makes it suitable for photoelectronic devices, such as plasma display panels (PDPs), and field emission displays (FEDs). In recent years, several studies have been based on ZnAl₂O₄ doped rare earth ions (for example: Er³⁺, Yb³⁺, Dy³⁺, Tb³⁺, Eu³⁺, Tm³⁺).  

ZnAl₂O₄ co-doped Er³⁺and Yb³⁺  were prepared by a combustion aerosol process. The urea and nitrate compounds dissolved in distilled water and used for the production of aerosol were injected to a high– temperature reaction zone. As results we obtained spherical nanoparticles that up-converted infrared light (980nm) to visible light (540 nm and 650 nm). The synthesized nanopowders were characterized by: TEM, SEM, XRD, PL and confocal microscopy. TEM analysis showed a broad particle size distribution for (100 - 800 nm), for ZnAl_1,9Er_0,017Yb_0,083O₄ (Er:Yb = 1:5) for the oven calcined at 990^oC for 3h in the air and unheated nanoparticles . Spherical polycrystalline nanoparticles were presented on the SEM photographs (Figure 1).

In order to label cellular biological structures, the up-converting nanoparticles were transported into living HeLa cells and were detected by confocal microscopy.

Our results indicate that the spinels can be visualized in HeLa cells.

  Fig. 1. SEM photographs of ZnAl₂O₄ co-doped Er³⁺and Yb³⁺ nanoparticles (a) calcined at 990 ^oC for 3h in air (b) not heated.

The research was supported by the European Union within European Regional Development Fund, through grant Innovative Economy (POIG.01.01.02-00-008/08), and by the Ministry of Science and Higher Education (Poland) through Grant No. N518 424036 and Center of Excellance. The Polish National Centre for Research and Development NR13004704 and Center of Excellence

• Legal notice:
  

  Copyright (c) Pielaszek Research, all rights reserved.
  The above materials, including auxiliary resources, are subject to Publisher's copyright and the Author(s) intellectual rights. Without limiting Author(s) rights under respective Copyright Transfer Agreement, no part of the above documents may be reproduced without the express written permission of Pielaszek Research, the Publisher. Express permission from the Author(s) is required to use the above materials for academic purposes, such as lectures or scientific presentations.
  In every case, proper references including Author(s) name(s) and URL of this webpage: https://science24.com/paper/24933 must be provided.

1. Synthesis of multiwalled carbon nanotube-polymer nanohybrids and their internalization to biological systems
2. Studies the size of palladium nanoparticles in Pd-C films annealing at different temperatures.
3. Growth and properties of inclined GaN nanowires on Si(001) substrates by PAMBE
4. Defect distribution along needle-shaped PrVO₄ single crystals grown by the slow-cooling method
5. Spin texture of topological crystalline insulator surface states in Pb_1-xSn_xSe 
6. Measurements of strain in AlGaN/GaN HEMT structures grown by plasma assisted molecular beam epitaxy
7. Optical Characterisation of Bulk ZnO Crystals Grown by CVT
8. Physical properties of unique ZnO single crystals from Oława Foundry
9. The influence of growth atmosphere on the self-selection of the grains during ZnO crystal growth
10. New Ca₁₀Li(VO₄)₇ laser host: growth and properties
11. MBE growth of GaN nanowires on Si(111) substrates for gas sensor applications 
12. Electronic and optical properties – As and As+Sb doped ZnO grown by PA-MBE
13. Grown ZnMgO/ZnO/ZnMgO heterostructures on p-type Si(111) by MBE method
14. Dual-acceptor doped p-ZnO:(As+Sb)/n-GaN heterojunctions grown by PA-MBE as a highly selective UV detector
15. Up-conversion and down-conversion processes observed in Er³⁺, Yb³⁺ and Mn²⁺ doped ZnAl₂O₄ nanoparticles
16. Synthesis and properties of up-converted NaYF₄: Er, Yb nanoparticles for biomedical applications
17. Transmission Electron Microscopy characterization of gold nanoparticles
18. Synthesis and properties of NaYF₄: Er, Yb, Gd nanoparticles with and without SiO₂ coating for biomedical applications.
19. Designing biosensors based on semiconductor nanoparticles for an early detection of neurodegenerative diseases.
20. High-pressure diffraction study of structural and elastic properties of zircon-type and scheelite-type RVO₄ (R = Nd, Eu)
21. Elastic properties of dysprosium orthovanadate: An in-situ powder-diffraction study
22. Thermal expansion of Si₃N₄ and Ge₃N₄
23. Resonant photoemission study of Sm atoms on ZnO surface
24. Location of metals in ZnO electrospined nanofibers
25. X-ray photoemission from CdTe/PbTe/CdTe nanostructure in normal and grazing-incidence modes
26. ZnO and core/shell ZnO/ZnS nanofibers: Characterization and applications
27. Inhomogeneities of InGaN/GaN MOVPE multi quantum wells grown with two temperatures process studied by transmission electron microscopy.
28. Synthesis of gallium nitride nanowires by Sublimation Sandwich Method
29. Zinc oxide grown by Atomic Layer Deposition - a material for novel 3D electronics
30. Thin films of ZnS and ZnSe by Atomic Layer Deposition for light sensor applications
31. Effects related to deposition temperature of ZnCoO films grown by Atomic Layer Deposition – uniformity of Co distribution, structural, electric and magnetic properties
32. Pressure dependence of lattice parameter of Gadolinium Gallium Garnet crystals
33. Lattice parameters of hard materials in the low-temperature range
34. Lattice parameters of a wurtzite-type (Zn,Mg)Se crystal as a function of temperature
35. Rietveld refinement for Li₂Si₂O₅ doped with vanadium
36. High-pressure diffraction study of α and β Ge₃N₄
37. Effect of annealing on the structure and microstructure of Pr doped ZrO₂-Y₂O₃ nanocrystals
38. ZnO thin films for organic/inorganic heterojunctions
39. Optimisation of parameters of a dynamic penalty function for a test example of powder pattern indexing
40. Wide band-gap II-VI semiconductors for optoelectronic applications
41. Low temperature ZnMnO by ALD
42. Immunolocalization of Ca²⁺ -activated potassium channel beta4 subunit in neuronal mitochondria
43. Substrate effect on the ground state of the magnetic order in NSMO/YBCO superlattices
44. Method of Manganese co-doping of LT ZnO films
45. Ferromagnetism in ZnO:Mn thin films deposited by PEMOCVD
46. Structure properties of bulk ZnO crystals
47. Magnetic anisotropy and structural properties of ferromagnet/MgO/ferromagnet system
48. Rietveld refinement for polycrystalline indium nitride
49. LATTICE PARAMETERS OF INDIUM NITRIDE IN THE 22-310 K TEMPERATURE RANGE
50. Promising high quality short period Fe/Fe-N multilayers deposited by the sputtering
51. Magnetic stripe domains in Fe/Fe-N multilayers
52. Structural and Magnetic Properties of Cr/Gd Multilayers Deposited on Sapphire and MgO Substrates
53. X-ray diffraction studies of thermal-expansion with the use of 1D detectors installed at synchrotron beamlines
54. Sensitivity of a genetic algorithm to the mutation rate parameter value: results for a crystallographic test
55. Rietveld refinement of powder diffraction data collected with a laboratory diffractometer equipped with a linear X-ray detector
56. Phase relationships in annealed Cu-Al-O layers
57. Fabrication and characterization of II-VI diluted magnetic p-n junctions
58. Growth and characterization of thin films of ZnO by Atomic Layer Epitaxy
59. Area detector as a tool to study properties of the magnetic multilayers by the neutron scattering
60. Influence of hydrogen adsorption on magnetic properties of Fe films and multilayers
61. Transmission electron microscopy and X-ray diffraction study of α'-Al₂ CO crystals
62. Diamond as X-ray Wavelength Standard for Thermal-Expansion Studies Using Synchrotron Sources
63. X-Ray Study of Lattice Parameters of GaN in a Broad Temperature Range
64. Differential Reflectivity and Photoemission study of ZnTe and CdTe(110) surface