WO2022246725A1

WO2022246725A1 - Rare-earth core-shell nanomaterial and preparation method therefor

Info

Publication number: WO2022246725A1
Application number: PCT/CN2021/096293
Authority: WO
Inventors: 郑海荣; 盛宗海; 胡德红
Original assignee: 深圳先进技术研究院
Priority date: 2021-05-27
Filing date: 2021-05-27
Publication date: 2022-12-01

Abstract

A preparation method for a rare-earth core-shell nanomaterial, comprising: performing first mixing treatment on a terbium salt, a lutetium salt, an alkali, and a solvent to form a first solution; performing second mixing treatment on the first solution and ammonium fluoride to obtain a second solution; placing the second solution in a hydrothermal kettle for reaction to obtain a rare-earth core nanomaterial, the rare-earth core nanomaterial comprising nanoparticles having a molecular formula of NaLuf₄:Tb; performing third mixing treatment on a yttrium salt, the rare-earth core nanomaterial, the alkali, and the solvent to form a third solution; performing fourth mixing treatment on the third solution and ammonium fluoride to obtain a fourth solution; and placing the fourth solution in the hydrothermal kettle for reaction to obtain a rare-earth core-shell nanomaterial, the rare-earth core-shell nanomaterial comprising a shell layer having a molecular formula of NaYF₄. By means of the method, a rare-earth luminescent nanomaterial is prepared using a water-phase system, the process is simple, and the obtained rare-earth core-shell nanomaterial has regular morphology and can yield a strong luminescence effect under the excitation of X-rays, thereby facilitating application of the rare-earth core-shell nanomaterial in biological imaging.

Description

Rare earth core-shell nanomaterial and preparation method thereof

technical field

The present application relates to the field of nanomaterials, in particular to a rare earth core-shell nanomaterial and a preparation method thereof.

Background technique

Rare earth luminescent nanomaterials are a type of photoluminescent material that can store excitation energy in the material and release the stored energy in the form of radioluminescence after the excitation light stops irradiating. Rare earth luminescent nanomaterials have many advantages such as narrow emission, long lifetime, and resistance to photobleaching, and have important application values in biomarkers and bioimaging.

At present, the excitation light of rare earth luminescent nanomaterials used for biological imaging is in the infrared band, but infrared light has defects such as poor tissue penetration and poor three-dimensionality, which in turn leads to low luminous efficiency and poor imaging effect of rare earth luminescent nanomaterials. X-rays have good penetrability to the human body, which is conducive to the application in biological imaging. However, there are few kinds of rare earth luminescent nanomaterials that use X-rays as excitation light to realize biological imaging, and the preparation methods are complicated, and the production cost is high. If the time is long, the resulting rare earth luminescent nanomaterial has poor stability, which is unfavorable for popularization and use.

Contents of the invention

In view of this, the application provides a rare earth core-shell nanomaterial and a preparation method thereof. The method uses an aqueous phase system to prepare a rare earth luminescent nanomaterial, which improves the stability of the rare earth luminescent nanomaterial, and has a simple preparation process and low cost. It is conducive to large-scale production, and the obtained rare earth core-shell nanomaterials not only have regular shape and uniform particle size, but also can produce strong luminescent effect under X-ray excitation, which is conducive to its application in biological imaging. The present application also provides a rare earth core-shell nano material, which has good stability and high luminous efficiency, and can be applied in the fields of biomarkers, bioimaging and the like.

The first aspect of the present application provides a method for preparing rare earth core-shell nanomaterials, comprising the following steps:

The terbium salt, the lutetium salt, the alkali and the solvent are subjected to a first mixed treatment to form a first solution; the solvent includes water, n-butanol and oleic acid with a volume ratio of 1:(0.1-10):(0.1-10);

performing a second mixing treatment on the first solution and ammonium fluoride to obtain a second solution; placing the second solution in a hydrothermal kettle and reacting at 100°C-300°C for 1h-72h to obtain a rare earth core nanomaterial ; The rare earth core nanomaterial includes β-NaLuF ₄ : Tb;

performing a third mixing treatment on the yttrium salt, the rare earth core nanomaterial, the alkali, and the solvent to form a third solution;

The third solution is mixed with ammonium fluoride to obtain the fourth solution; the fourth solution is placed in a hydrothermal kettle and reacted at 100°C-300°C for 1h-72h to obtain the rare earth core-shell nano material, the shell layer of the rare earth core-shell nanomaterial includes NaYF ₄ .

This application adopts the aqueous phase synthesis method to prepare rare earth core-shell nanomaterials with molecular formula β-NaLuF ₄ :Tb@NaYF ₄ , wherein β-NaLuF ₄ :Tb is the core body of rare earth core-shell nanomaterials, and NaYF ₄ is rare earth core-shell Housings of nanomaterials. In the aqueous phase synthesis method of the present application, n-butanol and oleic acid in the solvent can form a microemulsion with water, thereby adsorbing metal ions in the solution, so that the reaction is carried out in the microbubbles of the microemulsion, and the structure of the rare earth nanomaterial is improved. Uniformity, so that the rare earth core-shell nanomaterial has a narrow particle size distribution and dispersion performance; and the obtained rare earth core-shell nanomaterial has high crystal phase purity and stable luminescence performance, which is beneficial for application in biological imaging.

Optionally, the terbium salt includes one or more of terbium chloride, terbium acetate and terbium nitrate.

Optionally, the lutetium salt includes one or more of lutetium chloride, lutetium nitrate and lutetium acetate.

Optionally, in the first solution, the molar ratio of the terbium salt to the lutetium salt is 1:(4-99).

Optionally, in the first solution, the sum c ₁ of the molar concentrations of the terbium salt and the lutetium salt is 0.1 mol·L ^-1 -2 mol·L ^-1 .

Optionally, in the second solution, the ratio of the sum c ₁ of the molar concentrations of the terbium salt and the lutetium salt to the molar concentration c _F1 of the ammonium fluoride is 1:(1-50).

Optionally, the alkali includes one or more of sodium hydroxide and potassium hydroxide.

Optionally, the volume ratio of n-butanol and oleic acid is 1:(0.1-10).

Optionally, in the third solution, the molar concentration of the yttrium salt is 0.1 mol·L ^-1 -2 mol·L ^-1 .

Optionally, in the third solution, the molar ratio of the yttrium salt to the rare earth core nanomaterial is 1:(10-100).

Optionally, in the fourth solution, the molar concentration ratio of the yttrium salt to the ammonium fluoride is 1:(1-50).

Optionally, the pH of the first solution and the third solution is 10-12.

Optionally, the first mixing process, the second mixing process, the third mixing process and the fourth mixing process are mixed using probe ultrasound, and the power of the probe ultrasound is 50W-500W.

Optionally, the temperatures of the first mixing treatment, the second mixing treatment, the third mixing treatment and the fourth mixing treatment are 0°C-10°C.

The present application synthesized highly uniform and monodisperse β-NaLuF ₄ : Tb@NaYF ₄ rare earth core-shell nanomaterials through the aqueous phase synthesis method. The preparation method is simple, the reaction conditions are easy to control, and the production cost is low. The prepared rare earth core Shell nanomaterials have bright afterglow, long afterglow time, stable chemical properties, no radioactivity, and high safety to the human body.

The second aspect of the present application provides a rare earth core-shell nanomaterial, the rare earth core-shell nanomaterial includes a rare earth core nanomaterial and a shell layer coated on the surface of the rare earth core nanomaterial; the rare earth core nanomaterial includes β - NaLuF ₄ :Tb; the shell layer of the rare earth core-shell nanomaterial includes NaYF ₄ .

Description of drawings

Fig. 1 is the preparation method of the rare earth core-shell nanomaterial provided by an embodiment of the present application;

Figure 2 is a transmission electron microscope image of the rare earth core-shell nanomaterial provided in Example 1 of the present application;

3 is a transmission electron microscope image of the rare earth core-shell nanomaterial provided in Example 2 of the present application;

Figure 4 is a transmission electron microscope image of the rare earth core-shell nanomaterial provided in Example 3 of the present application;

Figure 5 is a transmission electron microscope image of the rare earth core-shell nanomaterial provided in Example 4 of the present application;

Figure 6 is a transmission electron microscope image of the rare earth core-shell nanomaterial provided in Example 5 of the present application;

Figure 7 is a transmission electron microscope image of the rare earth core-shell nanomaterial provided in Example 6 of the present application;

Figure 8 is a particle size distribution diagram of the rare earth core-shell nanomaterial provided in Example 1 of the present application;

Figure 9 is a diagram of the luminescence properties of the rare earth core-shell nanomaterial provided in Example 1 of the present application;

Figure 10 is the luminescent spectrum diagram of the rare earth core-shell nanomaterial provided in Example 1 of the present application;

Figure 11 is an in vivo imaging diagram of the rare earth core-shell nanomaterial provided in Example 1 of the present application;

Fig. 12 is a biotoxicity test chart of the rare earth core-shell nanomaterial provided in Example 1 of the present application.

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the application with reference to the drawings in the embodiments of the application. Apparently, the described embodiments are only some of the embodiments of the application, not all of them. Based on the embodiments in this application, all other embodiments obtained by persons of ordinary skill in the art without creative efforts fall within the protection scope of this application.

At present, the excitation light of rare earth luminescent nanomaterials used for biological imaging is in the infrared band. However, infrared light has defects such as poor tissue penetration and poor three-dimensionality, resulting in poor imaging effects. X-rays have good penetrability to the human body, and can penetrate the skin and muscles to directly see the bones in the body without directly contacting the human body. Therefore, the research and development of new rare earth luminescent nanomaterials based on X-ray excitation is of great significance for biomedical imaging, diagnosis and treatment. In order to promote the application of rare earth luminescent nanomaterials in biological imaging, this application provides a rare earth core-shell nanomaterial β-NaLuF ₄ :Tb@NaYF ₄ that uses X-rays as excitation light to achieve bioimaging, wherein the rare earth core-shell nanomaterial The core body includes β-NaLuF ₄ :Tb, and the shell of the rare earth core-shell nanomaterial includes NaYF ₄ .

In this application, the core body β-NaLuF ₄ :Tb of the rare earth core-shell nanomaterial can be excited by X-rays and generate strong fluorescence. The crystal phase of NaLuF ₄ : Tb is a body-centered cubic structure (β-), and NaLuF ₄ : Tb with a body-centered cubic structure has a higher degree of crystallization and fewer surface defects, so it has high luminous brightness and stable luminescent performance. The shell NaYF ₄ of rare earth core-shell nanomaterials can improve the surface lattice of rare earth core-shell nanomaterials, reduce surface scattering, and suppress the phenomenon of fluorescence quenching, thereby improving the energy transfer efficiency between surface ions and making rare earth core-shell nanomaterials The material has high luminous efficiency.

In this application, β-NaLuF ₄ :Tb means terbium-doped sodium lutetium fluoride, wherein the molar ratio of Tb to Lu is 1:(4-99). In some embodiments of the present application, the molar ratio of Tb and Lu is 1:(4-10). Doping terbium in lutetium sodium fluoride can adjust the luminescent properties of rare earth core-shell nanomaterials, so that the rare earth core-shell nanomaterials have a suitable afterglow emission time.

In the embodiment of the present application, the afterglow emission duration of the rare earth core-shell nanomaterial is 5 days to 30 days, and the afterglow emission duration of the rare earth core-shell nanomaterial can be, but not limited to, 5 days, 10 days, 15 days, 20 days, 25 days. days or 30 days. If the afterglow emission time of rare earth core-shell nanomaterials is too short, the biological imaging process will be shorter and the imaging effect will be poor; if the afterglow emission time is too long, it will be unfavorable for subsequent imaging detection and repetition of in vitro diagnostic test strips Therefore, the afterglow emission time of rare earth core-shell nanomaterials should be controlled to ensure better imaging effect and not affect the repeated use of multiple injections in vivo and in vitro diagnostic test strips.

In the embodiment of the present application, the particle size of the core body of the rare earth core-shell nanomaterial is 1-300 nm. The particle size of the core body of the rare earth core-shell nanomaterial can be, but not limited to, 1 nm, 10 nm, 50 nm, 100 nm, 200 nm or 300 nm. In the embodiment of the present application, the thickness of the shell of the rare earth core-shell nanomaterial is 1-40 nm. Specifically, the thickness of the shell of the rare earth core-shell nanomaterial can be, but not limited to, 1 nm, 10 nm, 30 nm, 40 nm or 50 nm. In the embodiment of the present application, in the rare earth core-shell nanomaterial, the ratio of the particle size of the core to the thickness of the shell is 1:(1-10). The ratio of the particle size of the core to the thickness of the shell may be, but not limited to, 1:1, 1:3, 1:5 or 1:10. Controlling the particle size of the core body and the thickness of the shell can ensure that the rare earth core-shell nanomaterial has stable luminescence performance and high luminescence efficiency.

In the embodiment of the present application, the rare earth core-shell nanomaterial is a spherical particle, and the spherical particle has a small specific surface area, the quenching effect of the particle surface on the luminescent ion is small, and the luminous efficiency of the particle is high. In the embodiment of the present application, the average particle size of the rare earth core-shell nanomaterial is 50nm-200nm. The average particle size of the rare earth core-shell nanomaterial β-NaLuF ₄ :Tb@NaYF ₄ can be, but not limited to, 50nm, 70nm, 90nm, 95nm, 100nm, 105nm, 110nm, 130nm, 150nm or 200nm.

The rare earth core-shell nanomaterial β-NaLuF ₄ :Tb@NaYF ₄ provided by this application can realize fluorescence emission under X-ray excitation, has high luminous efficiency and stable luminescent performance, and is beneficial for application in biological imaging.

The present application also provides a preparation method of the above-mentioned rare earth core-shell nanomaterial β-NaLuF ₄ :Tb@NaYF ₄ , please refer to FIG. 1 . FIG. 1 is a preparation method of the rare earth core-shell nanomaterial provided in an embodiment of the present application, including:

Step 100: performing a first mixing treatment on terbium salt, lutetium salt, alkali and solvent to form a first solution;

Step 200: performing a second mixing treatment on the first solution and ammonium fluoride to obtain a second solution; placing the second solution in a hydrothermal kettle and reacting at 100°C-300°C for 1h-72h to obtain a rare earth core nanomaterial;

Step 300: performing a third mixing treatment on the yttrium salt, the rare earth core nanomaterial, the alkali and the solvent to form a third solution;

Step 400: Perform fourth mixing treatment on the third solution and ammonium fluoride to obtain the fourth solution; place the fourth solution in a hydrothermal kettle and react at 100°C-300°C for 1h-72h to obtain rare earth core-shell nanomaterials .

In step 100 of the present application, the solvent includes water, n-butanol and oleic acid. N-butanol can be used as a co-surfactant to promote the formation of microemulsion system between oleic acid and water. The microemulsion system has a large reaction interface, which can increase the reaction rate and facilitate the formation of uniform and monodisperse nanoparticles. In the embodiment of the present application, the volume ratio of water, n-butanol and oleic acid is 1:(0.1-10):(0.1-10). In some embodiments of the present application, the volume ratio of water, n-butanol and oleic acid is 1:(0.1-1):(0.1-1), and when the volume of water is relatively high, it is beneficial to improve the dispersion of the product rare earth core nanomaterial in water performance. Under the above volume ratio range, an isotropic thermodynamically stable microemulsion system can be formed, thereby ensuring the formation of highly uniform, monodisperse rare earth core nanomaterials.

In this application, the pH value of the reaction system can be adjusted by adding alkali, thereby changing the solubility of terbium salt and lutetium salt in the reaction system, thereby controlling the reaction rate. In addition, the pH value will also affect the relative growth rate of each crystal plane. Thus forming crystals with different structures. In the embodiment of the present application, the pH of the first solution is 10-12. Under the above pH conditions, it is beneficial for the reaction to proceed rapidly and stably, and can promote the formation of β-NaLuF ₄ :Tb rare earth core-shell nanomaterials. In some embodiments of the present application, the alkali includes one or more of sodium hydroxide and potassium hydroxide.

In the embodiment of the present application, the terbium salt includes one or more of terbium chloride, terbium acetate and terbium nitrate. In the embodiment of the present application, the lutetium salt includes one or more of lutetium chloride, lutetium nitrate and lutetium acetate. In the embodiment of the present application, the molar ratio of the terbium salt and the lutetium salt is 1:(4-99). In some embodiments of the present application, the molar ratio of the terbium salt and the lutetium salt is 1:(4-10). The molar ratio of the terbium salt to the lutetium salt may be, but not limited to, 1:4, 1:6, 1:10, 1:15, 1:20, 1:40, 1:60 or 1:99. In the embodiment of the present application, the sum c _{1 of} the molar concentrations of the terbium salt and the lutetium salt is 0.1 mol·L ^-1 -2 mol·L ^-1 .

In the embodiment of the present application, the first mixing process is to use probe ultrasound for mixing, the power of the probe ultrasound is 50W-500W, and the time of the probe ultrasound is 10min-30min. In some embodiments of the present application, the power of the probe ultrasound is 50W-200W, and the time of the probe ultrasound is 15min-25min. Ultrasonication during the first mixing process can promote the uniform dispersion of the reactants in the microemulsion system and ensure the stable progress of the reaction.

In some embodiments of the present application, step 100 specifically includes: mixing 0.1g-4g of sodium hydroxide with 0.1mL-100mL of deionized water to form a lye; adding 0.1mL-100mL to the lye with a volume ratio of 1: (0.1-10) oleic acid and n-butanol mixed solution to form a microemulsion system; weigh terbium salt and lutetium salt according to the molar ratio of 1:(4-99), and prepare the total molar concentration of 0.1mol L ^-1 -2mol·L ^-1 rare earth solution, adding the rare earth solution into the microemulsion system, and performing ultrasonic treatment at 0°C-10°C for 10min-30min to obtain the first solution.

In step 200 of the present application, in the second solution, the ratio of the sum c ₁ of the molar concentration of terbium salt and lutetium salt to the molar concentration c _F1 of ammonium fluoride is 1:(1-50). In the embodiment of the present application, the second mixing process is to use probe ultrasound for mixing, the power of the probe ultrasound is 50W-500W, and the time of the probe ultrasound is 30min-100min. The ultrasonic power of the probe during the second mixing process may specifically be, but not limited to, 50W, 100W, 200W, 300W, 400W or 500W. In the second mixing process, on the one hand, ultrasonic treatment can cause the microemulsion system to produce sharp movements, including the appearance of gas nuclei, the growth of microbubbles, and the bursting of microbubbles, thereby expanding the reaction interface of the microemulsion and promoting the nano-particles of rare earth nuclei. The generation and development of materials, and shorten the reaction time. On the other hand, ultrasonic treatment can use ultrasonic energy to disperse and control the particle size through the shear crushing mechanism, thereby forming rare earth core nanomaterials with uniform structure and monodisperse.

In the present application, the second solution is placed in a hydrothermal kettle for hydrothermal reaction, and the temperature of the hydrothermal reaction is 100°C-300°C. In some embodiments of the present application, the reaction temperature of the hydrothermal reaction is 170°C-250°C, and a higher reaction temperature is conducive to the formation of rare earth core nanomaterials with good crystallinity. In the embodiment of the present application, the reaction time of the hydrothermal reaction is 1h-72h. In some embodiments of the present application, the reaction time of the hydrothermal reaction is 2h-55h. In the embodiment of the present application, after the hydrothermal reaction is completed, the reaction kettle is cooled to room temperature, and the reaction solution is centrifuged at a speed of (1000-100000) r min- ¹ for 1min-30min, and the supernatant is removed to obtain a white precipitate, the white precipitate That is β-NaLuF ₄ :Tb. In the embodiment of the present application, the yield of β-NaLuF ₄ :Tb is 40%-60%, and the yield of β-NaLuF ₄ :Tb can be, but not limited to, 40%, 50%, 55% or 60%. In some embodiments of the present application, the white precipitate is washed with ethanol, dispersed in 1 mL-50 mL of water, and stored at 0°C-10°C.

In step 300 of the present application, the solvent includes water, n-butanol and oleic acid, and the volume ratio of water, n-butanol and oleic acid is 1:(0.1-10):(0.1-10). Under the microemulsion system, it is beneficial to form a stable shell on the surface of rare earth core nanomaterials, thereby effectively inhibiting the surface quenching of rare earth nanomaterials, passivating lattice defects on the surface of rare earth core nanomaterials, and isolating the interference of external unfavorable factors. In turn, the fluorescence efficiency of the material is greatly improved. In the embodiment of the present application, the yttrium salt includes one or more of yttrium chloride, yttrium nitrate and yttrium acetate, and the base includes one or more of sodium hydroxide and potassium hydroxide. In the embodiment of the present application, the pH of the third solution is 10-12.

In the embodiment of the present application, the molar ratio of the yttrium salt to the rare earth core nanomaterial in the third solution is 1:(10-100). The molar ratio of the yttrium salt to the rare earth core nanomaterial may be, but not limited to, 1:10, 1:30, 1:50, 1:70 or 1:100. In the above molar ratio range, the obtained rare earth core-shell nanomaterial can have high luminous efficiency and good stability. In the embodiments of the present application, the molar concentration of the yttrium salt is 0.1 mol·L ^-1 -2 mol·L ^-1 . The molar concentration of the yttrium salt may be, but not limited to, 0.1 mol·L ^-1 , 0.5 mol·L ^-1 , 1 mol·L ^-1 or 2 mol·L ^-1 .

In the embodiment of the present application, the third mixing process is to use probe ultrasound for mixing, the power of the probe ultrasound is 50W-500W, and the time of the probe ultrasound is 10min-30min. Ultrasound in the third mixing process can promote the uniform dispersion of the reactants in the microemulsion system and ensure the stable progress of the reaction.

In some embodiments of the present application, step 300 specifically includes: mixing 0.1g-4g of sodium hydroxide with 0.1mL-100mL of deionized water to form a lye; adding 0.1mL-100mL to the lye with a volume ratio of 1: (0.1-10) oleic acid and n-butanol mixture form a microemulsion system; dissolve 0.1mmol-2mmol yttrium salt in 1mL-10mL water and add the yttrium salt solution to the microemulsion system, according to the yttrium salt and rare earth core nanomaterials The molar ratio is 1:(10-100), the rare earth core nanomaterial β-NaLuF ₄ :Tb is added into the microemulsion system, and ultrasonic treatment is performed at 0°C-10°C for 1min-30min to obtain the third solution.

In step 400 of the present application, in the fourth solution, the molar concentration ratio of yttrium salt to ammonium fluoride is 1:(1-50). The molar concentration ratio of the yttrium salt to the ammonium fluoride may be, but not limited to, 1:1, 1:5, 1:10, 1:20 or 1:50. In the embodiment of the present application, the fourth mixing process is to use probe ultrasound for mixing, the power of the probe ultrasound is 50W-500W, and the time of the probe ultrasound is 1min-100min. In some embodiments of the present application, the power of the probe ultrasound is 100W-200W, and the time of the probe ultrasound is 50min-70min. In the fourth mixing process, the ultrasonic treatment expands the reaction interface of the microemulsion, and promotes NaYF ₄ to evenly coat the surface of the rare earth core nanomaterial, thereby forming a uniform and monodisperse rare earth core-shell nanomaterial.

In the present application, the fourth solution is placed in a hydrothermal kettle for hydrothermal reaction, and the temperature of the hydrothermal reaction is 100°C-300°C. In some embodiments of the present application, the reaction temperature of the hydrothermal reaction is 170°C-250°C. In the embodiment of the present application, the reaction time of the hydrothermal reaction is 1h-72h. In some embodiments of the present application, the reaction time of the hydrothermal reaction is 2h-55h. In the embodiment of the present application, after the hydrothermal reaction is completed, the reaction kettle is cooled to room temperature, and the reaction solution is centrifuged at a speed of (1000-100000) r min- ¹ for 1min-30min, and the supernatant is removed to obtain a white precipitate, the white precipitate That is NaLuF ₄ :Tb@NaYF ₄ , the white precipitate was washed with ethanol and then dried and stored. In the embodiment of the present application, in step 400, the yield of NaLuF ₄ :Tb@NaYF ₄ is 40%-60%, and the yield of NaLuF ₄ :Tb@NaYF ₄ can be, but not limited to, 40%, 50%, 55% or 60%.

This application synthesized highly uniform and monodisperse NaLuF ₄ :Tb@NaYF ₄ rare earth core-shell nanomaterials by ultrasonic microemulsion method. The method adopts aqueous phase synthesis of rare earth core-shell nanomaterials, the preparation process is simple, and the production cost is low. The obtained rare earth core-shell nanomaterials are not only stable in properties, non-radioactive, and will not cause harm to humans and the environment, but also can be activated under X-ray excitation. It produces a strong luminescent effect and can be used for biological imaging, thus providing more choices for biological imaging materials.

The technical solution of the present application will be further described in the following by a plurality of embodiments.

Example 1

A preparation method of rare earth core-shell nanomaterials, comprising the following steps:

(1) Synthesis of rare earth core nanomaterials:

a. Add 0.5g NaOH to a 50mL Erlenmeyer flask filled with 10mL deionized water; then add 15mL n-butanol and 5mL oleic acid into the Erlenmeyer flask, immerse the ultrasonic probe of the cell disruptor in the solution, and place in an ice bath (0°C) the probe was sonicated for 2 min to form a yellow transparent microemulsion; 0.4 mmol of LuCl ₃ ·6H ₂ O and 0.1 mmol of Tb(NO ₃ ) ₃ were prepared into an aqueous solution with a concentration of 0.5 mol·L ^-1 The aqueous solution was added to the microemulsion, _and the probe was sonicated for 3 minutes under an ice bath to obtain the first solution. The pH of the first solution was 12; solution, the second solution is a white emulsion.

b. Put the second solution into a 50mL polytetrafluoroethylene reactor, heat at 200°C for 6h, cool to room temperature after the reaction, centrifuge the reaction solution at a rate of 15000r·min ^-1 for 5min, and remove the supernatant A white precipitate was obtained; after washing the white precipitate with ethanol three times in sequence, the β-NaLuF ₄ :Tb rare earth core nanomaterial was obtained, and the reaction yield was 45%. β-NaLuF ₄ :Tb was dispersed in 4 mL of water to obtain a β-NaLuF ₄ :Tb dispersion, which was stored at 4°C.

(2) Synthesis of rare earth core-shell nanomaterials:

c. Add 0.5g NaOH to a 50mL Erlenmeyer flask filled with 10mL deionized water; then add 15mL n-butanol and 5mL oleic acid to the Erlenmeyer flask, immerse the ultrasonic probe of the cell disruptor in the solution, and place in an ice bath (0°C) ultrasonically treat the probe for 2 min to form a yellow transparent microemulsion; dissolve 0.5 mmol of YCl ₃ 6H ₂ O in 4 mL of water to obtain an aqueous solution, and add the aqueous solution to the microemulsion, and then add the β in step (1) -NaLuF ₄ : Tb dispersion was added to the microemulsion, and the probe was sonicated for 3 minutes under an ice bath to obtain a third solution, wherein the pH of the third solution was 12; 10 mmol of NH ₄ F was added to the third solution and probed under an ice bath After ultrasonic treatment for 1 min, the fourth solution was obtained, and the fourth solution was a white emulsion.

d. Put the fourth solution into a 50mL polytetrafluoroethylene reactor, heat at 200°C for 6h, cool to room temperature after the reaction, centrifuge the reaction solution at a rate of 15000r·min ^-1 for 5min, and remove the supernatant A precipitate was obtained; the precipitate was washed with ethanol three times in sequence, and then dried to obtain a β-NaLuF ₄ :Tb@NaYF ₄ rare earth core-shell nanomaterial with a reaction yield of 50%.

Example 2

(1) Synthesis of rare earth core nanomaterials:

a. Add 0.5g NaOH to a 50mL Erlenmeyer flask containing 10mL deionized water; then add 15mL n-butanol and 5mL oleic acid into the Erlenmeyer flask, stir for 20min to obtain a yellow transparent microemulsion; add 0.4mmol of LuCl ₃ ·6H ₂ O and 0.1mmol of Tb(NO ₃ ) ₃ were formulated into an aqueous solution with a concentration of 0.5mol·L ^-1 , then the aqueous solution was added to the microemulsion, and stirred for 30 minutes to obtain the first solution; 10mmol of NH ₄ F was added to the first The solution was then stirred for 1 h to obtain a second solution, which was a white emulsion.

b. Put the second solution into a 50mL polytetrafluoroethylene reactor, heat at 200°C for 48h, cool to room temperature after the reaction, centrifuge the reaction solution at a rate of 15000r·min ^-1 for 5min, and remove the supernatant A white precipitate was obtained; after washing the white precipitate with ethanol three times in sequence, the β-NaLuF ₄ :Tb rare earth core nanomaterial was obtained, and the yield of the reaction was 50%. β-NaLuF ₄ :Tb was dispersed in 4 mL of water to obtain a β-NaLuF ₄ :Tb dispersion, which was stored at 4°C.

(2) Synthesis of rare earth core-shell nanomaterials:

c. 0.5gNaOH is joined in the 50mL Erlenmeyer flask that 10mL deionized water is housed; Then 15mL n-butanol and 5mL oleic acid are added into the Erlenmeyer flask and stirred for 20min to obtain a yellow transparent microemulsion; 0.5mmol of YCl ₃ . 6H ₂ O was dissolved in 4 mL of water to obtain an aqueous solution, and the aqueous solution was added to the microemulsion, and then the β-NaLuF ₄ :Tb dispersion in step (1) was added to the microemulsion; 10 mmol of NH ₄ F was added to the third solution and stirred After 1 h, the fourth solution was obtained, which was a white emulsion.

d. Put the fourth solution into a 50mL polytetrafluoroethylene reactor, heat at 200°C for 48h, cool to room temperature after the reaction, centrifuge the reaction solution at a rate of 15000r·min ^-1 for 5min, and remove the supernatant A precipitate was obtained; the precipitate was washed with ethanol three times in sequence, and then dried to obtain a β-NaLuF ₄ :Tb@NaYF ₄ rare earth core-shell nanomaterial with a reaction yield of 60%.

Example 3

The difference between embodiment 3 and embodiment 1 is that in step a and step b, the volume ratio of water, oleic acid and n-butanol is 1:1:1.

Example 4

The difference between embodiment 4 and embodiment 1 is that in step a and step b, the volume ratio of water, oleic acid and n-butanol is 1:1:2.

Example 5

The difference between Example 5 and Example 1 is that the sonication of the probe in Example 5 is carried out at room temperature (25° C.).

Example 6

The difference between Example 6 and Example 1 is that the pH of the first solution and the third solution in Example 6 is 10.

Effect Example

In order to verify the structure and performance of the rare earth core-shell nanomaterials prepared in this application, this application also provides effect examples.

1) The morphology of the rare earth core-shell nanomaterials in Examples 1-6 was characterized by transmission electron microscopy.

Please refer to Fig. 2-Fig. 7, wherein Fig. 2 is a transmission electron micrograph of the rare earth core-shell nanomaterial provided in Example 1 of the present application; Fig. 3 is a transmission electron micrograph of the rare earth core-shell nanomaterial provided in Example 2 of the present application; Figure 4 is a transmission electron micrograph of the rare earth core-shell nanomaterial provided in Example 3 of the present application; Figure 5 is a transmission electron micrograph of the rare earth core-shell nanomaterial provided in Example 4 of the present application; Figure 6 is a transmission electron micrograph of the rare earth core-shell nanomaterial provided in Example 5 of the present application Transmission electron micrograph of the rare earth core-shell nanomaterial; FIG. 7 is a transmission electron micrograph of the rare earth core-shell nanomaterial provided in Example 6 of the present application. It can be seen from Figures 2 to 7 that in Examples 1-6, rare earth core-shell nanomaterials with uniform structure and monodisperse were successfully synthesized. Please refer to Figure 8, Figure 8 is the particle size distribution diagram of the rare earth core-shell nanomaterial provided in Example 1 of the present application, as can be seen from Figure 8, the particle size distribution of the rare earth core-shell nanomaterial in Example 1 is concentrated at 80nm-150nm , the average particle size of rare earth core-shell nanomaterials is 110nm. Use the same method to characterize the rare earth core-shell nanomaterials of Examples 2-6, and obtain the structural parameters of the rare earth core-shell nanomaterials of Examples 2-6. Please refer to Table 1 for the characterization results, and Table 1 is Examples 1-6. Structural parameter table of rare earth core-shell nanomaterials.

Table 1 The structure parameter table of the rare earth core-shell nanomaterial of embodiment 1-6

test group

Average particle size (nm)

Shell thickness (nm)

实施例1Example 1	110110	2020
实施例2Example 2	200200	3030
实施例3Example 3	150150	2525
实施例4Example 4	200200	3030
实施例5Example 5	120120	2020
实施例6Example 6	150150	2727

2) Test the luminescent performance of the rare earth core-shell nanomaterial of Example 1. The test process is specifically: dispersing the β-NaLuF ₄ : Tb@NaYF ₄ rare earth core-shell nanomaterial of Example 1 in water, the quality of the dispersion is With a concentration of 10 mg/mL, 100 μL of the dispersion was taken and irradiated under X-rays with a radiation dose of 10 Gy, and the luminescence was recorded after irradiation. Please refer to Fig. 9, Fig. 9 is the luminescent performance diagram of the rare earth core-shell nanomaterial provided in Example 1 of the present application. It can be seen from Fig. 9 that after the X-ray source is turned off, β-NaLuF ₄ :Tb@NaYF ₄ The material has obvious afterglow luminescence within 0-14 days. As the afterglow becomes weaker, the afterglow is basically invisible at 28 days. Appropriate afterglow emission time is conducive to subsequent imaging detection and repeated use of in vitro diagnostic test strips.

Using a fluorescence spectrometer to test the luminescent properties of rare earth core-shell nanomaterials, the test process is as follows: disperse the β-NaLuF ₄ : Tb@NaYF ₄ rare earth core-shell nanomaterials of Example 1 in water, and the mass concentration of the dispersion is 10mg/mL , Take 100 μL of the dispersion and place it under X-ray irradiation with a radiation dose of 10Gy. After half an hour of irradiation, use a fluorescence spectrometer to measure the luminescence spectrum of the rare earth core-shell nanomaterial. Please refer to Fig. 10, Fig. 10 is the luminescence spectrum diagram of the rare earth core-shell nanomaterial provided in Example 1 of the present application. It can be seen from Fig. 10 that the emission peak wavelengths of the rare earth core-shell nanomaterial are 490nm, 540nm, 580nm, and 620nm.

Take 100 μL of the dispersion of rare earth core-shell nanomaterials and irradiate it with X-rays at a radiation dose of 10 Gy, then inject the dispersion subcutaneously into mice, and perform luminescence detection by live imaging of small animals (detection of emission light without excitation light ), please refer to FIG. 11, which is an in vivo imaging diagram of the rare earth core-shell nanomaterial provided in Example 1 of the present application. It can be seen from Figure 11 that rare earth core-shell nanomaterials have strong luminescence properties, and can clearly observe the state of the body, thereby achieving effective treatment.

3) The biotoxicity of the rare earth core-shell nanomaterial in Example 1 was tested. The test process was as follows: the rare earth core-shell nanomaterial in Example 1 was formulated into a dispersion, and the dispersion was injected through the tail vein according to the amount of 10 mg/kg. Injected into the mice as the experimental group, the control group was injected with phosphate buffered saline (PBS), and after a week, the organs of the mice were taken for HE staining, please refer to Figure 12, Figure 12 is the rare earth core-shell provided in Example 1 of the present application The biotoxicity test chart of the nanomaterials, from Figure 12, it can be seen that the organs and tissues of the mice are normal after injection of the dispersion solution, that is, the rare earth core-shell nanomaterials are not toxic to organisms.

The above descriptions are preferred implementations of the present application, but should not be construed as limiting the scope of the present application. It should be pointed out that those skilled in the art can make some improvements and modifications without departing from the principle of the present application, and these improvements and modifications are also regarded as the protection scope of the present application.

Claims

A method for preparing rare earth core-shell nanomaterials, comprising the following steps:

The terbium salt, the lutetium salt, the alkali and the solvent are subjected to a first mixed treatment to form a first solution; the solvent includes water, n-butanol and oleic acid with a volume ratio of 1:(0.1-10):(0.1-10);

performing a second mixing treatment on the first solution and ammonium fluoride to obtain a second solution; placing the second solution in a hydrothermal kettle and reacting at 100°C-300°C for 1h-72h to obtain a rare earth core nanomaterial ; The rare earth core nanomaterial includes β-NaLuF 4 : Tb;

performing a third mixing treatment on the yttrium salt, the rare earth core nanomaterial, the alkali, and the solvent to form a third solution;

The third solution is mixed with ammonium fluoride to obtain the fourth solution; the fourth solution is placed in a hydrothermal kettle and reacted at 100°C-300°C for 1h-72h to obtain the rare earth core-shell nano material, the shell layer of the rare earth core-shell nanomaterial includes NaYF 4 .
The preparation method according to claim 1, characterized in that, the first mixing treatment, the second mixing treatment, the third mixing treatment and the fourth mixing treatment use probe ultrasound for mixing, and the probe The power of ultrasound is 50W-500W.
The preparation method according to claim 1 or 2, characterized in that, the temperature of the first mixing treatment, the second mixing treatment, the third mixing treatment and the fourth mixing treatment is 0°C-10 ℃.
The preparation method according to any one of claims 1-3, characterized in that the pH of the first solution and the third solution is 10-12.
The preparation method according to any one of claims 1-4, wherein the volume ratio of said n-butanol and oleic acid is 1:(0.1-10).
The preparation method according to any one of claims 1-5, characterized in that, in the first solution, the molar ratio of the terbium salt to the lutetium salt is 1:(4-99).
The preparation method according to any one of claims 1-6, characterized in that, in the first solution, the sum c 1 of the molar concentrations of the terbium salt and the lutetium salt is 0.1mol·L -1 - 2mol L −1 ; in the second solution, the ratio of the sum c of the molar concentrations of the terbium salt and the lutetium salt to the molar concentration c F of the ammonium fluoride is 1:(1-50) .
The preparation method according to any one of claims 1-7, characterized in that, in the third solution, the molar concentration of the yttrium salt is 0.1mol·L -1 -2mol·L -1 ; the yttrium The molar ratio of the salt to the rare earth core nanomaterial is 1:(10-100).
The preparation method according to any one of claims 1-8, in the fourth solution, the ratio of the molar concentration of the yttrium salt to the ammonium fluoride is 1:(1-50).
A rare earth core-shell nanomaterial, characterized in that it is prepared by the preparation method according to any one of claims 1-9, and the rare earth core-shell nanomaterial comprises a rare earth core nanomaterial and a rare earth core nanomaterial coated on the rare earth core nanomaterial. The shell layer on the surface of the material; the rare earth core nanomaterial includes β-NaLuF 4 :Tb; the shell layer of the rare earth core shell nanomaterial includes NaYF 4 .