CN-118256239-B - Preparation method of core-shell structure self-assembled near-infrared nano particles with high quantum yield

Abstract

The invention provides a preparation method of a high quantum yield core-shell structure self-assembled near infrared nano particle, which is characterized by comprising the steps of respectively dissolving an amphiphilic polymer, near infrared quantum dots with oleic acid modified on the surfaces and AIE dye in chloroform, uniformly mixing the three, adding sodium dodecyl sulfate for emulsification, adding ultrapure water for rotary evaporation after the emulsification is completed to remove the chloroform, centrifuging and treating with alkaline water to obtain the self-assembled near infrared nano particle. The self-assembled near infrared nano particle with a core-shell three-layer structure is successfully constructed by using amphiphilic polymer to polymerize and simultaneously encapsulate near infrared quantum dots and AIE dye with the surface modified with oleic acid.

Inventors

• LI YUJIAN
• HUANG WEI
• CHEN RUI
• Ding shijia
• LI JUAN
• SHU JIA

Assignees

• 重庆医科大学

Dates

Publication Date

20260512

Application Date

20240328

Claims (7)

1. 1. A preparation method of a high quantum yield core-shell structured self-assembled near-infrared nanoparticle is characterized by comprising the steps of respectively dissolving an amphiphilic polymer, near-infrared quantum dots with oleic acid modified on the surfaces and AIE dye in chloroform, wherein the mass ratio of the near-infrared quantum dots with oleic acid modified on the surfaces to the AIE dye is 6-12:0.25-2, mixing the amphiphilic polymer and the near-infrared quantum dots with oleic acid modified on the surfaces uniformly in a mass ratio of 5:6-12, adding sodium dodecyl sulfate for emulsification, adding ultrapure water for rotary evaporation after emulsification is completed to remove chloroform, centrifuging and treating with alkaline water to obtain the self-assembled near-infrared nanoparticle, wherein the near-infrared nanoparticle is an AIE nanoparticle inner core, the near-infrared quantum dots are an inner shell, the amphiphilic polymer and an outer shell with uniform distribution of sodium dodecyl sulfate, and the near-infrared quantum dots with oleic acid modified on the surfaces have the same emission wavelength as the AIE dye.
2. 2. The method for preparing the self-assembled near-infrared nano-particles with high quantum yield core-shell structure according to claim 1, wherein the method comprises the following steps: the near infrared quantum dots are selected from PbS, pbSe, ag 2 S、Ag 2 Se, cdTe or CdS quantum dots.
3. 3. The method for preparing the self-assembled near-infrared nano particles with the high quantum yield, which is disclosed in claim 1, is characterized by comprising the steps of dissolving 5mg of amphiphilic polymer in chloroform, dissolving 6-12 mg of near-infrared quantum dots with oleic acid modified on the surfaces in chloroform, dissolving 0.25-2 mg of AIE dye in chloroform, fully mixing the three, adding 300 microliters of 0.5mg/mL of sodium dodecyl sulfate for emulsification, adding 3mL of ultrapure water after the emulsification is completed, steaming until no bubbles emerge, removing chloroform, centrifuging at 12000rpm for 15min, adding sodium hydroxide alkaline water with pH of 10 for 12 hours, centrifuging to remove alkaline water, adding pure water for preservation at 4 ℃.
4. 4. The method for preparing the self-assembled near-infrared nano particles with the high quantum yield and the core-shell structure, as claimed in claim 3, wherein the preparation method of the near-infrared quantum dots with the oleic acid modified on the surfaces comprises the steps of adding ODE and OA into a cationic compound, heating after vacuumizing, cooling under the protection of nitrogen after solid is dissolved into transparent liquid, adding an anion precursor solution for reaction, adding acetone for centrifugation, removing upper liquid, and washing with chloroform for later use.
5. 5. The method for preparing the self-assembled near infrared nano particles with high quantum yield core-shell structure according to claim 4, wherein the method comprises the following steps: the cationic compound is selected from PbO, pbAc, agAc, cdO or CdAc.
6. 6. The method of claim 4, wherein the anion precursor is selected from the group consisting of (TMS) 2 Se/ODE、(TMS) 2 S/ODE and TOP-Te.
7. 7. The method for preparing the self-assembled near-infrared nano-particles with high quantum yield core-shell structure according to claim 1, wherein the method comprises the following steps: the amphiphilic polymer is selected from PMAO or DSPE-PEG.

Description

Preparation method of core-shell structure self-assembled near-infrared nano particles with high quantum yield Technical Field The invention belongs to the technical field of near infrared nano fluorescent materials, and particularly relates to a preparation method of a high quantum yield core-shell structure self-assembled near infrared nano particle. Background Near infrared light (NIR) has found wide application in the scientific and industrial fields, particularly in biomedical imaging, therapy, and substance detection. In biomedical imaging, near infrared light is widely used in noninvasive imaging techniques, such as fluorescence imaging, to facilitate monitoring of functional states of cells and tissues, and early disease diagnosis, because it is relatively harmless due to its deep penetration into tissues. In therapeutic terms, near infrared light is commonly used in photodynamic therapy and photothermal therapy for the treatment of cancer and other diseases. In the field of substance detection, near infrared light technology is used for chemical component analysis, such as food safety detection and environmental monitoring. More and more near infrared fluorescent nanoparticles are developed, such as quantum dots, organic dyes, aggregation-induced emission dyes, up-conversion nano-luminescent materials, metal particles, high molecular polymers, and the like. However, these nanoparticles have limited their development in the medical field due to their limited quantum conversion efficiency, low biocompatibility, and weak chemical and photostability. To address the shortcomings of near infrared nanomaterials, various strategies have been currently adopted, mainly including surface modification and polymer encapsulation. Surface modification generally involves attaching biocompatible molecules, such as polyethylene glycol (PEG), silane compounds, or biomolecules, to the nanoparticle surface to improve its biocompatibility, reduce toxicity, enhance stability, and prevent non-specific adsorption. Polymer encapsulation, such as using PVP, PMAO, etc., also helps to improve the stability and biocompatibility of the nanomaterial, and can also be used to control drug release. While surface modification can improve the biocompatibility and stability of the nanomaterial, this process can adversely affect the intrinsic properties of the nanoparticle. First, surface modifications may alter the size, shape, and surface charge of the nanoparticle, which changes may affect its optical and electronic properties, thereby affecting its fluorescence properties and quantum yield. In addition, the choice and degree of modification of the surface modifying material needs to be carefully controlled to avoid performance degradation due to excessive modification. Polymer encapsulation, while it is an effective method for improving the biocompatibility and stability of nanoparticles, in some cases the encapsulation process may result in aggregation of the nanoparticles, which in turn may lead to fluorescence quenching. This is because, when the nanoparticles are excessively close in the polymer matrix, energy transfer or electron coupling may occur, resulting in a decrease in fluorescence intensity. Thus, the strategy of polymer encapsulation needs to be carefully designed to ensure that the nanoparticles remain properly dispersed in the encapsulating material, thereby maintaining their fluorescent properties. Aggregation-induced emission (AIE) dyes are unique in that they not only do not quench fluorescence when molecules aggregate, but rather enhance fluorescence efficiency due to aggregation. This is due to the limited movement of the AIE dye molecules in the aggregated state, reducing the chance of non-radiative energy dissipation, while the increased pi-pi stacking efficiency results in more efficient electron resonance transport, thus enhancing fluorescence emission. However, in the prior art, polymer encapsulation, template-based encapsulation, microemulsion technology, sol-gel method, electrostatic spinning and other encapsulation methods often lead to uneven distribution of AIE molecules, so that the aggregation effect is not ideal, and the fluorescence quantum efficiency is low. Disclosure of Invention In order to solve the problems that the prior art singly packages quantum dots with high quantum yield to increase stability and biocompatibility often encounters fluorescence quenching, and the singly packages aggregation-induced emission (AIE) dye are difficult to realize high aggregation effect, so that the quantum efficiency is not ideal, and the like, the invention provides a preparation method of self-assembled near-infrared nano particles with high quantum yield. The self-assembled near infrared nano particle with a core-shell three-layer structure is successfully constructed by using amphiphilic polymer to polymerize and simultaneously encapsulate near infrared quantum dots and AIE dye with the surface modified