Synthesis And Performance Study Of Nanometer Rare Earth Oxides For Biological Probes

In this paper,Tb³⁺-doped Gd₂O₃ nanoparticles used as biological probes were synthesized by polyol method using DEG as solvent and the mixture of GdCl₃ and TbCl₃ as precursor;The polysioxane shell was encapsulated on the surface of the nanoparticle in a mixed solution of APTES and TEOS.The samples were dried at160°C for 12 h in air oven and later annealed at 800°C for 2 h in atmosphere furnace.Direct measurements of nanoparticles size distribution suspended in the polyol were performed by Zetasizer Nano.The samples were were titrated on carbon grid and charactered the morphological by Zeiss SUPRA40 field emission scanning electron microscopy?FESEM?.Transmission electron microscopy?TEM?images were obtained by Tecnai G2F20,operating at an accelerating voltage of 200 kV.The crystallographic data of sample were measured by an X-ray diffractometer?X?PertPowder?with Cu Ka radiation??=0.15405 nm?.The diffraction angle?2??was varied in the range of 20o–80o.Optical spectra were obtained by using a 150-W Xe lamp as the excitation source.For emission spectra,excitation was adjusted with a Jobin Yvon GEMINI double monochromator.?1?The change in the calcination temperature will result in a difference in the crystal phase of the Gd₂O₃:Tb³⁺.When the calcination temperature is 600°C,the precursor has not been completely converted into cubic phase Gd₂O₃;when the calcination temperature is 800°C,the sample is a fully transformed cubic phase Gd₂O₃:Tb³⁺;when the calcination temperature is 1000°C,the sample begins to consist of The cubic phase changes to the hexagonal phase.?2?The nanosphere and nanorod Gd₂O₃:Tb³⁺was prepared by adding different amount of NaOH in diethylene glycol?DEG?solvent by using polyol method.The X-ray diffractometers were used to characterize the analysis and found that the nanosphere and nanorod nanocrystals were cubic phase Gd₂O₃.The change of morphology did not affect the crystal phase of Gd₂O₃:Tb³⁺.However,due to the different aspect ratio of nanosphere and nanorod,nanosphere particles have a smaller aspect ratio and a lower surface energy,so that nanosphere particles Gd₂O₃:Tb³⁺has better luminescence properties than the nanorod Gd₂O₃:Tb³⁺.?3?The nanocrystalline Gd₂O₃:Tb³⁺/Zn²⁺was prepared by the polyol method.When the transition metal element Zn²⁺concentration was 0.05 mmol,the nanocrystals had the best luminescence properties.Gd₂O₃:Tb³⁺doped with different concentrations of Zn²⁺is a cubic phase Gd₂O₃,indicating that the doping of Zn²⁺ does not change the crystalline phase of the matrix and the appropriate concentration of Zn²⁺increases the crystallinity of the nano Gd₂O₃:Tb³⁺.?4?The nanocrystalline Gd₂O₃:Tb³⁺/Li⁺powders were prepared by the polyol method and the solid phase reaction method.The excitation and emission spectra of nanocrystalline samples with different Li⁺doping ratios were found to be 98:2.At the time,the luminous performance is best.From the X-ray diffraction pattern analysis,it can be seen that the Gd₂O₃:Tb³⁺doped with different ratios of Li⁺are cubic phases,the crystal structure of the matrix does not change,and the characteristic diffraction peaks of Li⁺do not appear in the figure,demonstrating that Li⁺has completely entered the Gd₂O₃ lattice.