Study On Structure Control And Fluorescence Characteristics Of Upconversion Nanoparticles

Doxorubicin?Dox?is an important chemotherapeutic drug for cancer treatment,but it also has a very strong toxicity to cells.It is of great significance to study and prepare a unique and novel biological probe that is rapid,real-time,sensitive,and accurate for real-time detection of doxorubicin in blood.Core/shell upconversion fluorescent nanomaterials?UCNPs?have been widely studied and applied due to their strong penetrability,good biocompatibility,and unique optical properties.At present,high efficiency and multicolor core/shell nanocrystals have been synthesized by adjusting the proportion and proportion of rare earth elements,optimizing the reaction system parameters,and modifying the most essential physical and chemical properties of the modified nanoparticles.Therefore,it has potential application value in the field of biological cell fluorescence labeling,drug detection,biological therapy,biological materials and so on,and it is also a research hotspot at home and abroad.In this paper,we mainly discussed the physical and chemical properties of high efficiency core/shell structure upconversion luminescent nanocrystals,as well as the application of core/shell upconversion luminescent nanoparticles in quantitative chemical drug detection and biological functional qualitative analysis and testing.The following conclusions are drawn:?1?High quality and excellent NaGdF₄:18%Yb³⁺/2%Er³⁺upconversion luminescent nanoparticles were prepared.The upconversion nanocrystals of spherical structure with excellent hydrophilic properties,regular morphology and uniform size?about 20 2nm diameter?were prepared by solvothermal method.?2?The luminescence intensity of the nanoparticles is improved by modifying the outer layer of the nanoparticles.By the solvothermal method,through the epitaxial growth of NaGdF₄:18%Yb³⁺/2%Er³⁺nanocrystals in successfully coated multilayer NaYF₄shell,the nuclear nano crystal luminous intensity and luminous efficiency compared to the untreated surface modification improves greatly.The main reason is that epitaxial growth of the shell with different thickness reduces the influence of irregular surface on the luminescence center.Therefore,the upconversion efficiency of the luminescent nanoparticles is improved.?3?The experiment confirmed the best energy transfer distance between the fluorescent nanoparticles and the organic dyes.The core/shell structure upconversion fluorescent nanoparticles with different thickness were synthesized,and the luminescence spectra of upconversion nanocrystals were determined by adding rhodamine B?RhB?.The best energy transfer distance between fluorescent nanocrystals and organic dyes was confirmed by18.18nm.?4?the luminescence intensity is greatly enhanced by the upconversion luminescent nanoparticles in the nuclear shell structure.By adjusting the content of Yb³⁺/Er³⁺and the thickness of core shell,we can change the intensity of blue emission,green and red emission of the characteristic peaks of nanocrystals.So that the intensity of violet light is greatly improved,filled with colorful light,and colorful displays are more abundant.?5?The preparation of a new type of unique probes can achieve fast,real-time and accurate detection of synchronous drug doxorubicin concentration,biological detection technology the above conversion nanocrystal based adriamycin provides accurate and real-time detection method,which breaks the limitation of conventional UV laser detection.It is most noteworthy that this bioluminescent nano probe can be reused and harmless to the organism.This unique upconversion luminescent nano-probe has realized the quantitative monitoring of the doxorubicin.In this paper,the minimum limit for the detection of doxorubicin in the blood of a living mouse is 0.1 ug/ml.