Rare earth upconversion nano fluorescent probe and preparation and application thereof

Abstract

The invention relates to a rare earth upconversion nano fluorescent probe and preparation and an application thereof. Heterogeneous functional fluorescent nanoparticles are formed from upconversion fluorescent nanoparticles and Au nanoparticles; the molar ratio of the upconversion fluorescent nanoparticles NaYF4:Yb<3+> / Er<3+> to Au is 5:1, 10:1, 15:1 or 20:1, and stirring is carried out for 2.5 h at the temperature of 140 DEG C; compared with the upconversion fluorescent nanoparticles, the obtained particles have red fluorescence enhanced and green fluorescence decreased. The rare earth upconversion fluorescent nanoparticles are good in photochemical stability and low in toxicity; and moreover, a near-infrared laser is used as an excitation light source, the rare earth upconversion fluorescent nanoparticles have strong optical penetration ability, have no background fluorescence, and have potential application value in the fields of biological fluorescence imaging and CT developer.

Description

technical field [0001] The invention relates to rare earth up-conversion nano fluorescent probes, specifically NaYF 4 :Yb 3+ / Er 3+ - Preparation and application of Au heterostructured nanoparticles. Background technique [0002] Bioluminescent imaging technology is a molecular and gene expression analysis and detection technology developed in recent years. It has been widely used in clinical diagnosis, treatment, medical research, life science and other fields due to its advantages of fast, non-invasive, intuitive, and high sensitivity. Fluorescent probes have the function of labeling and tracking the detected substances in fluorescence imaging. An ideal bioluminescent imaging probe should meet the following conditions: 1. It has good photochemical stability and is not easy to be photolyzed or bleached; 2. It has good water solubility and biocompatibility, and low toxicity, which has almost no effect on biological functions. No effect; 3. Low energy excitation, outstan...

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Problems solved by technology

However, they have some limitations such as: narrow excitation spectrum and broad emission peak; poor photostability, easy photobleaching and photolysis, therefore, it is not conducive to real-time and dynamic detection in vivo for a long time

[0004] (2) Semiconductor quantum dots: With the development of nanomaterials in recent years, semiconductor quantum dots such as ZnS-CdSe (Document 3: Warren C.W. Chan and Shuming Nie, Science, 1998, 281, 2016-2018) have also begun to be widely used In fluorescence detection, it has the advantages of strong photostability, wide excitation spectrum and narrow emission spectrum, large Stokes shift, high quantum yield, etc., but due to its poor chemical stability and potential toxicity (heavy metals), and the need for ultraviolet excitation, light The penetrating ability is weak, and it will damage biological tissues, causing autofluorescence of biological tissues and other shortcomings, which limit their application in bioluminescence imaging

However, it has become a general consensus that the intensity of upconversion fluorescence is weak, and this single imaging mode cannot provide complete information on the structure and function of a substance, so it is necessary to combine nanomaterials with other functions on a nanomaterial to achieve multi-mode imaging

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