Method for synthesizing rare earth borate nanoparticles
By rapidly injecting a mixed solution of rare earth metal precursors and boron precursors into an organic phase and rapidly heating to form rare earth borate nanoparticles, the problems of time-consuming synthesis and uncontrollable morphology and size of rare earth borate nanoparticles in the prior art are solved. This method achieves the preparation of nanoparticles with regular morphology and uniform size, which is suitable for boron neutron capture therapy in biomedicine.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- SUZHOU UNIV
- Filing Date
- 2024-06-27
- Publication Date
- 2026-06-26
AI Technical Summary
Existing technologies make it difficult to synthesize rare earth borate nanoparticles with uniform size and regular morphology in the biomedical field, especially rare earth borate nanoparticles used in boron neutron capture therapy. The synthesis methods are time-consuming and require strict conditions, making it difficult to control the morphology and size.
By rapidly injecting a mixed solution of rare earth metal precursor and boron precursor into an organic phase, the temperature is rapidly raised to a high temperature and maintained for a certain period of time to form uniform rare earth borate nanoparticles. Excess ligands are removed by ethanol precipitation, centrifugation and resuspension washing process to prepare rare earth borate nanoparticles with regular morphology and uniform size.
We have achieved rapid synthesis of rare earth borate nanoparticles with controllable morphology and tunable size under laboratory conditions. These nanoparticles have the potential for near-infrared II imaging guidance and are suitable for boron neutron capture therapy in the biomedical field.
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Figure CN118894535B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to nanomaterial preparation technology, specifically to a method for synthesizing rare earth borate nanoparticles. Background Technology
[0002] Rare earth elements have wide applications in the biomedical field due to their rich optical and magnetic properties, such as imaging, therapy, and drug delivery. To maximize their effectiveness in various biological applications, it is necessary to synthesize rare earth nanoparticles of appropriate sizes and morphologies. Currently, various synthetic methods have been developed for synthesizing rare earth nanoparticles, such as thermal decomposition, solvothermal methods, and coprecipitation. Rare earth nanoparticles synthesized using thermal decomposition methods are of high quality and have excellent optical properties, but require the prior synthesis of precursors, and toxic substances are generated during the high-temperature decomposition process; additionally, the synthesis conditions are relatively strict. The solvothermal method has a relatively low synthesis temperature (below 200℃), but the obtained nanoparticles usually have a large size distribution, and the surface may retain surfactants that are difficult to remove. Although the coprecipitation method has general applicability and significant improvements over thermal decomposition and solvothermal methods, the synthesis process is time-consuming and continuous, typically requiring more than 5 hours, and precise control of the morphology is difficult.
[0003] Rare earth borate nanoparticles contain both rare earth elements used for imaging and boron elements used in boron neutron capture therapy (BNCT), possessing the potential for image-guided BNCT. However, most current methods for synthesizing nanoscale rare earth borate nanoparticles require prolonged high temperatures and are generally carried out in aqueous reaction systems, resulting in uncontrollable morphology and size of the prepared nanoparticles. The size of nanoparticles is crucial for their metabolic and distribution behavior in vivo. Therefore, improving the synthesis of rare earth borate nanoparticles to obtain nanoparticles with uniform size and regular morphology is of great significance for better application in BNCT. Summary of the Invention
[0004] The purpose of this invention is to provide a novel method for synthesizing rare earth borate nanoparticles, which does not require high temperatures and can be carried out in an organic phase, thereby preparing neodymium borate nanoparticles with regular morphology and uniform size.
[0005] The technical solution of this invention is as follows: a method for synthesizing rare earth borate nanoparticles, comprising the following steps:
[0006] After heating the boron precursor in a nitrogen atmosphere, the rare earth metal precursor is rapidly injected, and the temperature is rapidly raised to 280-310℃ and maintained for a period of time to form uniform rare earth borate nanoparticles.
[0007] The rare earth metal precursor is an organic solution containing rare earth acetate hydrate and oleic acid; the boron precursor is an organic solution containing tributyl borate.
[0008] Preferably, the rare earth acetate hydrate is selected from neodymium acetate hydrate, lanthanum acetate hydrate, gadolinium acetate hydrate, or europium acetate hydrate.
[0009] Preferably, the rare earth metal precursor is rapidly injected after the boron precursor is slowly heated to above 240°C in a nitrogen atmosphere.
[0010] Preferably, after rapidly injecting the rare earth metal precursor into the boron precursor, the temperature is rapidly increased at a rate of 10°C / min or higher.
[0011] Preferably, the rare earth metal precursor is prepared by uniformly mixing rare earth acetate hydrate, oleic acid and octadecene, heating at 140-160°C for 30-60 minutes and then cooling to room temperature.
[0012] Preferably, the boron precursor is prepared by uniformly mixing tributyl borate and octadecene.
[0013] Preferably, the molar ratio of rare earth metal to boron in the rare earth metal precursor and the boron precursor is 30:15-90.
[0014] Preferably, the rare earth metal concentration in the rare earth metal precursor is 30-90 mM.
[0015] Preferably, the boron concentration in the boron precursor is 30-90 mM.
[0016] Preferably, the rare earth borate nanoparticles are formed by ethanol precipitation and centrifugation, followed by resuspending in an organic solvent. This process is repeated 3-4 times to finally obtain rare earth borate nanoparticles dispersed in an organic solvent, which are then transferred to a sample vial and sealed for storage.
[0017] The advantages of this invention are:
[0018] 1. Based on the wide applications of rare earth elements and existing synthesis methods, the limitations of current rare earth borate nanoparticle synthesis methods, and their application prospects in boron neutron capture therapy, this invention first innovatively improves the synthesis method of rare earth borate nanoparticles. Oleate rare earth metals and tributyl borate are pyrolyzed at high temperature to form core sites and grow into uniform rare earth borate nanoparticles, preparing neodymium borate nanoparticles with regular morphology and uniform size. Optical performance characterization shows that they possess the potential for near-infrared II imaging-guided BNCT. Subsequently, we further successfully controlled the size of neodymium borate nanoparticles by adjusting the ratio of neodymium precursor to boron precursor. Finally, we successfully synthesized various rare earth borate nanoparticles using this synthetic route, demonstrating the universality of this method.
[0019] 2. Aqueous reaction systems typically require holding at temperatures of several hundred degrees Celsius for several hours and must be carried out in specific reactor equipment. Furthermore, the morphology and size of the prepared nanoparticles are uncontrollable. In contrast, the synthesis method proposed in this invention can be achieved in the laboratory using a flask and heating device, and the synthesized nanoparticles have controllable morphology and adjustable size. Attached Figure Description
[0020] Figure 1 This is a schematic diagram illustrating the synthesis of rare earth borate nanoparticles via the thermal decomposition of multi-source precursors (MSP).
[0021] Figure 2 The images show (a) a TEM image of the NdBO3 nanoparticles in Example 1, (b) the corresponding particle size distribution histogram (scale bar 100 nm), (c) the ultraviolet absorption spectrum, and (d) the emission spectrum (808 nm excitation). Figure 2 The data provided by c / d show that NdBO3 nanoparticles have emission peaks in the near-infrared II region under 808nm excitation, at 1060nm and 1350nm respectively, which is sufficient to demonstrate that they can be used for near-infrared II imaging.
[0022] Figure 3 The images show (a) the full XPS spectrum, (b) the Nd 3d partial spectrum, and (c) the B 1s partial spectrum of the NdBO3 nanoparticles in Example 1. Figure 3 The XPS data provided indicate that the nanoparticles contain both Nd and B, suggesting their potential use in near-infrared II imaging-guided BNCT.
[0023] Figure 4 The images show NdBO3 nanoparticles synthesized with different feed ratios in Example 2. (a) TEM image and (d) corresponding particle size distribution histogram of nanoparticles with a feed ratio of Nd:B = 30:15 (the molar ratio of rare earth metal to boron in the rare earth metal precursor to boron precursor is 30:15); (b) TEM image and (e) corresponding particle size distribution histogram of nanoparticles with a feed ratio of Nd:B = 30:30 (the molar ratio of rare earth metal to boron in the rare earth metal precursor to boron precursor is 30:30); (c) TEM image and (f) corresponding particle size distribution histogram of nanoparticles with a feed ratio of Nd:B = 30:90 (the molar ratio of rare earth metal to boron in the rare earth metal precursor to boron precursor is 30:90) (scale bar is 200 nm).
[0024] Figure 5 The images show (a) a TEM image and (b) a corresponding particle size distribution histogram (scale bar 100 nm) of the LaBO3 nanoparticles in Example 3, (c) a UV absorption spectrum, and (d) an excitation spectrum and an emission spectrum.
[0025] Figure 6 The images shown are (a) a TEM image and (b) a corresponding particle size distribution histogram of the GdBO3 nanoparticles in Example 4 (scale bar is 100 nm).
[0026] Figure 7 The images show (a) a TEM image and (b) a corresponding particle size distribution histogram (scale bar 100 nm) of the EuBO3 nanoparticles in Example 5, (c) an ultraviolet absorption spectrum, and (d) an excitation spectrum and an emission spectrum. Specific Implementation
[0027] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments described are not intended to limit the present invention.
[0028] Example 1:
[0029] This embodiment relates to the synthesis and characterization of neodymium borate nanoparticles (NdBO3).
[0030] NdBO3 nanoparticles were prepared by decomposing a mixed solution of boron and neodymium precursors at high temperature. The neodymium precursor was prepared by uniformly mixing 144.6 mg of neodymium acetate hydrate, 3 mL of oleic acid, and 12 mL of octadecene, then heating at 150 °C for 40 min and cooling to room temperature (neodymium concentration: 30 mM). The boron precursor was prepared by uniformly mixing 85 μL of tributyl borate and 10415 μL of octadecene (boron concentration: 30 mM). The boron precursor was slowly heated to 240 °C under a nitrogen atmosphere, and then the neodymium precursor was rapidly injected. The temperature was rapidly increased (10 °C / min) to 280 °C and maintained for 20 min to form uniform nanoparticles. After natural cooling to room temperature, the precipitate was obtained by ethanol precipitation and centrifugation, and then resuspended in cyclohexane. This washing process was repeated 3-4 times to remove excess ligands. The final NdBO3 nanoparticles were dispersed in 5 mL of cyclohexane, transferred to sample vials, and sealed for storage.
[0031] The characterization methods for NdBO3 nanoparticles are as follows: To determine the morphology and size of NdBO3 nanoparticles, the solution was diluted to an appropriate concentration and dropped onto a copper mesh. After air drying, TEM images were captured using a Talos F200S G2 transmission electron microscope at an accelerating voltage of 200 kV. The particle size distribution of the nanoparticles in the TEM images was statistically analyzed using ImageJ software. To characterize the optical properties of NdBO3 nanoparticles, the absorption spectrum was measured using a UV spectrophotometer after diluting the solution to an appropriate concentration, followed by emission spectrum measurement using a fluorescence spectrometer under 808 nm excitation. Simultaneously, to characterize the elemental composition of NdBO3 nanoparticles, X-ray photoelectron spectroscopy was performed after high-temperature calcination.
[0032] Example 2:
[0033] This embodiment relates to the size control of neodymium borate nanoparticles, which is achieved by changing the concentration ratio of neodymium precursor to boron precursor.
[0034] Except for the changes in the preparation of the boron precursor, the preparation of the neodymium precursor and the synthesis of neodymium borate nanoparticles of different sizes are the same as in Example 1. The preparation processes of the boron precursors with different concentrations are as follows: the 15 mM boron precursor is prepared by uniformly mixing 42.5 μL of tributyl borate and 10457.5 μL of octadecene; the 30 mM boron precursor is prepared by uniformly mixing 85 μL of tributyl borate and 10415 μL of octadecene; and the 90 mM boron precursor is prepared by uniformly mixing 255 μL of tributyl borate and 10245 μL of octadecene.
[0035] The morphology and size characterization process for neodymium borate nanoparticles of different sizes is the same as in Example 1.
[0036] Example 3:
[0037] This embodiment relates to the synthesis and characterization of lanthanum borate nanoparticles (LaBO3).
[0038] LaBO3 nanoparticles were prepared by decomposing a mixed solution of boron and lanthanum precursors at high temperature. The lanthanum precursor was prepared by mixing 142.2 mg of lanthanum acetate hydrate, 3 mL of oleic acid, and 12 mL of octadecene, heating at 150 °C for 40 min, and then cooling to room temperature (lanthanum concentration: 30 mM). The boron precursor was prepared by mixing 85 μL of tributyl borate and 10415 μL of octadecene (boron concentration: 30 mM). The boron precursor was slowly heated to 240 °C under a nitrogen atmosphere, followed by rapid injection of the lanthanum precursor. The temperature was then rapidly increased (10 °C / min) to 280 °C and maintained for 20 min to form uniform nanoparticles. After natural cooling to room temperature, the precipitate was obtained by ethanol precipitation and centrifugation, and then resuspended in cyclohexane. This washing process was repeated 3-4 times to remove excess ligands. The final LaBO3 nanoparticles were dispersed in 5 mL of cyclohexane, transferred to sample vials, and sealed for storage.
[0039] The characterization methods for LaBO3 nanoparticles are as follows: To determine the morphology and size of the LaBO3 nanoparticles, the solution was diluted to an appropriate concentration and dropped onto a copper grid. After air drying, TEM images were captured using a Talos F200S G2 transmission electron microscope at an accelerating voltage of 200 kV. The particle size distribution of the nanoparticles in the TEM images was statistically analyzed using ImageJ software. To characterize the optical properties of the LaBO3 nanoparticles, the absorption spectrum was measured using a UV spectrophotometer after diluting the solution to an appropriate concentration, followed by emission spectrum measurement using a fluorescence spectrometer under xenon lamp (370 nm) excitation.
[0040] Example 4:
[0041] This embodiment relates to the synthesis and characterization of gadolinium borate nanoparticles (GdBO3).
[0042] GdBO3 nanoparticles were prepared by decomposing a mixed solution of boron and lanthanum precursors at high temperature. The gadolinium precursor was prepared by mixing 182.9 mg gadolinium acetate hydrate, 3 mL oleic acid, and 12 mL octadecene, heating at 150 °C for 40 min, and then cooling to room temperature (gadolinium concentration: 30 mM). The boron precursor was prepared by mixing 85 μL tributyl borate and 10415 μL octadecene (boron concentration: 30 mM). The boron precursor was slowly heated to 240 °C under a nitrogen atmosphere, and then the gadolinium precursor was rapidly injected. The temperature was rapidly increased (10 °C / min) to 310 °C and maintained for 20 min to form uniform nanoparticles. After natural cooling to room temperature, the precipitate was obtained by ethanol precipitation and centrifugation, and then resuspended in cyclohexane. This washing process was repeated 3-4 times to remove excess ligands. The final GdBO3 nanoparticles were dispersed in 5 mL of cyclohexane, transferred to sample vials, and sealed for storage.
[0043] The characterization method of GdBO3 nanoparticles is as follows: In order to determine the morphology and size of GdBO3 nanoparticles, the solution was diluted to an appropriate concentration and dropped onto a copper grid. After air drying, TEM images were taken using a Talos F200S G2 transmission electron microscope at an accelerating voltage of 200kV. The particle size distribution of nanoparticles in the electron microscope images was statistically analyzed using ImageJ software.
[0044] Example 5:
[0045] This embodiment relates to the synthesis and characterization of europium borate nanoparticles (EuBO3).
[0046] EuBO3 nanoparticles were prepared by decomposing a mixed solution of boron and europium precursors at high temperature. The europium precursor was prepared by uniformly mixing 443.7 mg europium acetate hydrate, 3 mL oleic acid, and 12 mL octadecene, then heating at 150 °C for 40 min and cooling to room temperature (europium concentration: 90 mM). The boron precursor was prepared by uniformly mixing 255 μL tributyl borate and 10245 μL octadecene (boron concentration: 90 mM). The boron precursor was slowly heated to 240 °C under a nitrogen atmosphere, followed by rapid injection of the europium precursor. The temperature was then rapidly increased (10 °C / min) to 310 °C and maintained for 20 min to form uniform nanoparticles. After natural cooling to room temperature, the precipitate was obtained by ethanol precipitation and centrifugation, then resuspended in cyclohexane. This washing process was repeated 3-4 times to remove excess ligands. The final EuBO3 nanoparticles were dispersed in 5 mL of cyclohexane, transferred to sample vials, and sealed for storage.
[0047] The characterization methods for EuBO3 nanoparticles are as follows: To determine the morphology and size of the EuBO3 nanoparticles, the solution was diluted to an appropriate concentration and dropped onto a copper mesh. After air drying, TEM images were captured using a Talos F200S G2 transmission electron microscope at an accelerating voltage of 200 kV. The particle size distribution of the nanoparticles in the TEM images was statistically analyzed using ImageJ software. To characterize the optical properties of the EuBO3 nanoparticles, the absorption spectrum of the solution was measured using a UV spectrophotometer after diluting to an appropriate concentration, followed by emission spectrum measurement using a fluorescence spectrometer under xenon lamp (395 nm) excitation.
[0048] The above-described embodiments are merely preferred embodiments provided to fully illustrate the present invention, and the scope of protection of the present invention is not limited thereto. Equivalent substitutions or modifications made by those skilled in the art based on the present invention are all within the scope of protection of the present invention. The scope of protection of the present invention is defined by the claims.
Claims
1. A method for synthesizing rare earth borate nanoparticles, characterized in that, Includes the following steps: After heating the boron precursor in a nitrogen atmosphere, the rare earth metal precursor is rapidly injected, and the temperature is rapidly raised to 280-310℃ and maintained for a period of time to form uniform rare earth borate nanoparticles. The rare earth metal precursor is an organic solution containing rare earth acetate hydrate and oleic acid; the boron precursor is an organic solution containing tributyl borate. The boron precursor was slowly heated to above 240°C in a nitrogen atmosphere, and then the rare earth metal precursor was rapidly injected. After rapidly injecting the rare earth metal precursor into the boron precursor, the temperature is rapidly increased at a rate of 10℃ / min or higher. The rare earth metal precursor is prepared by mixing rare earth acetate hydrate, oleic acid and octadecene evenly, heating at 140-160℃ for 30-60 min and then cooling to room temperature.
2. The method for synthesizing rare earth borate nanoparticles according to claim 1, characterized in that, The rare earth acetate hydrate is selected from neodymium acetate hydrate, lanthanum acetate hydrate, gadolinium acetate hydrate, or europium acetate hydrate.
3. The method for synthesizing rare earth borate nanoparticles according to claim 1, characterized in that, The boron precursor is prepared by uniformly mixing tributyl borate and octadecene.
4. The method for synthesizing rare earth borate nanoparticles according to claim 1, characterized in that, The molar ratio of rare earth metal to boron in the rare earth metal precursor and the boron precursor is 30:15-90.
5. The method for synthesizing rare earth borate nanoparticles according to claim 1, characterized in that, The rare earth metal concentration in the rare earth metal precursor is 30-90 mM.
6. The method for synthesizing rare earth borate nanoparticles according to claim 1, characterized in that, The boron concentration in the boron precursor is 30-90 mM.
7. The method for synthesizing rare earth borate nanoparticles according to claim 1, characterized in that, Rare earth borate nanoparticles were formed by ethanol precipitation and centrifugation. The precipitate was then resuspended in an organic solvent and repeated 3-4 times to finally obtain rare earth borate nanoparticles dispersed in an organic solvent. The precipitate was then transferred to a sample vial and sealed for storage.