Ultra-small high-performance near-infrared long-afterglow nanoparticle, and preparation method therefor and use thereof

Abstract

Disclosed in the present invention are an ultra-small high-performance near-infrared long-afterglow nanoparticle, and a preparation method therefor and a use thereof. The preparation method comprises the following steps: S1, adding gallium acetylacetonate, zinc acetylacetonate, chromium acetylacetonate, and a long-chain alkyl diol to a mixed solution containing oleic acid, oleylamine, and octadecene, and carrying out stirring, vacuumizing and heating to 50-110°C, wherein the long-chain alkyl diol contains 10-18 carbon atoms; S2, heating to 160-240°C under nitrogen protection and maintaining the temperature; and S3, continuing heating to 260-340°C, maintaining the temperature, and carrying out post-treatment to obtain the ultra-small high-performance near-infrared long-afterglow nanoparticle. The ultra-small high-performance near-infrared long-afterglow nanoparticle prepared by the present invention has an average diameter of less than 5 nm and an excellent long-afterglow luminescence duration, and has wide prospects for application in the fields of optical imaging and the development of biomedical diagnostic reagents.

Description

Ultra-small high-performance near-infrared long afterglow nanoparticles and preparation method and application thereof TECHNICAL FIELD

[0001] The present application belongs to the technical field of near-infrared long afterglow nanomaterials, and more particularly relates to an ultra-small high-performance near-infrared long afterglow nanoparticle and a preparation method and application thereof. BACKGROUND

[0002] Long afterglow luminescent material is a kind of luminescent material that can continue to emit light for a long time after excitation stops. With its unique super-long life luminescence, near-infrared long afterglow luminescent material can be excited in vitro and then imaged in vivo. Compared with traditional quantum dots and up-conversion luminescent materials, near-infrared long afterglow luminescent material can be excited in vitro, avoiding the interference of biological tissue background fluorescence caused by continuous excitation. At the same time, the emission of near-infrared light is in the biological optical window, with strong penetration. Therefore, near-infrared long afterglow luminescent material has the advantage of ultra-high signal-to-noise ratio in biological optical imaging applications, showing great application prospects.

[0003] The existing preparation strategies for near-infrared long afterglow luminescent materials mainly include high-temperature solid-phase method, sol-gel method, hydrothermal method and silica template method. Among them, the near-infrared long afterglow luminescent material prepared by high-temperature solid-phase method has a large particle size, which is not suitable for biological in vivo imaging; while the sol-gel method and the hydrothermal method can obtain near-infrared long afterglow luminescent nanomaterials with a particle size of less than 100 nanometers, but the prepared nanoparticles are often very agglomerated, easily highly accumulated in organs such as liver, spleen and lung, not only leading to high background signal, but also causing potential toxicity to these organs, limiting its application in in vivo imaging and cell tracking fields. The particle size of the near-infrared long afterglow luminescent material prepared by the silica template method depends on the size of the silica template, and at present it is still impossible to apply this method in silica templates with a size of less than 50 nanometers.

[0004] Many studies have shown that near-infrared long afterglow luminescent nanomaterials with a particle size of less than 5 nm can be excreted through the kidneys, and have higher metabolic efficiency. Therefore, in theory, near-infrared long afterglow luminescent materials with a particle size of less than 5 nm will have smaller background interference and higher biological safety. However, as the particle size of nanomaterials gradually decreases, its luminescent performance generally also gradually decreases. Therefore, how to explore a near-infrared long afterglow luminescent nanomaterial with smaller particle size but better long afterglow continuous luminescence time has become an important problem to be solved.

[0005] Patent publication No. CN105754595A discloses a kind of long afterglow nano material, zinc nitrate solution, gallium nitrate solution, sodium germanate solution and chromium nitrate solution are mixed together stirring rapidly added to ammonia water, adjust the pH of mixed solution to 10;Then the mixed solution is transferred to high-temperature hydrothermal kettle, at 120 DEG C reaction 24h.The long afterglow material size obtained is uniform, size can increase from 7nm to 80nm, under visible light excitation produces high brightness, long duration.However when the long afterglow nano material composition prepared is ZnGa2O4:0.75% Cr, particle size is 7nm, in afterglow decay image, its afterglow time is only 3h, still difficult to meet the actual application demand.

[0006] SUMMARY

[0007] For the above existing technical problems, the primary purpose of the present application is to provide a kind of preparation method of super-small high-performance near-infrared long afterglow nano particles, the average diameter of near-infrared long afterglow nano particles obtained by preparation is less than 5 nanometers, can produce the near-infrared long afterglow emission with wavelength between 600 nanometers and 800 nanometers, and the long afterglow light duration can be more than 5 hours.

[0008] The second purpose of the present application is to provide a kind of preparation method of super-small high-performance near-infrared long afterglow nano particles, and the super-small high-performance near-infrared long afterglow nano particles obtained by preparation.

[0009] The third purpose of the present application is to provide the application of super-small high-performance near-infrared long afterglow nano particles in biological optical imaging, molecular labeling or in the preparation of medical diagnosis and treatment reagent.

[0010] In order to achieve the above-mentioned purpose, the present application is realized by the following technical scheme:

[0011] The present application claims a kind of preparation method of super-small high-performance near-infrared long afterglow nano particles, comprising the following steps:

[0012] S1.acetylacetone gallium, acetylacetone zinc, acetylacetone chromium and long-chain alkyl diol are added to the mixed solution containing oleic acid, oleylamine and octadecene, stirring, vacuumizing, heating to 50~110 DEG C, and keeping temperature;The long-chain alkyl diol contains 10~18 carbon atoms;

[0013] S2.under nitrogen protection, temperature is raised to 160~240 DEG C, and keeping temperature;

[0014] S3.continuously heating to 260~340 DEG C, keeping temperature, post-processing, and obtaining the super-small high-performance near-infrared long afterglow nano particles.

[0015] The present application uses a mixed solvent of oleic acid, oleylamine and octadecene as a reaction system, limits the growth of near-infrared long afterglow nanoparticles, and at the same time uses the organic groups attached to the surface of the nanoparticles to improve the dispersibility of the nanoparticles. The prepared nanoparticles not only have smaller particle size, but also reduce the agglomeration of the nanoparticles. The introduction of long-chain alkyl glycol can promote the decomposition of acetylacetone salt raw material, improve the crystallinity of near-infrared long afterglow nanoparticles, and thus improve the near-infrared long afterglow performance. If a low-boiling short-chain alkyl diol is introduced into the reaction system, the heating temperature in step S3 cannot be increased to the optimal reaction temperature, and the ultra-small high-performance near-infrared long afterglow nanoparticles of the present application cannot be prepared.

[0016] Further, the present application uses a three-stage heating to prepare the ultra-small high-performance near-infrared long afterglow nanoparticles, wherein the first stage of heating is to completely dissolve the acetylacetone salt in the mixed solvent of oleic acid, oleylamine and octadecene; the second stage of heating is to promote the decomposition of acetylacetone salt to form small crystal grains; and the third stage of heating is to help the growth of crystal grains, and finally to prepare the high-performance infrared long afterglow nanoparticles. The long afterglow nanoparticles prepared by the present application not only have smaller average diameter, but also have more excellent long afterglow light duration.

[0017] Preferably, in the step S1, the molar ratio of the acetylacetone gallium, acetylacetone zinc, acetylacetone chromium and long-chain diol is 2:(0.6-1.4):(1x10 -4 -2x10 -3 ):(1-40). Further preferably, the molar ratio of the acetylacetone gallium, acetylacetone zinc, acetylacetone chromium and long-chain diol is 2:(1.0-1.1):(1x10 -3 -1.5x10 -3 ): (5-15). Further preferably, the molar ratio of the acetylacetone gallium, acetylacetone zinc, acetylacetone chromium and long-chain diol is 2:1:1.42x10 -3 :10. Under the above preferred range, the prepared ultra-small high-performance near-infrared long afterglow nanoparticles have higher luminous intensity.

[0018] Preferably, in the step S1, the volume ratio of the oleic acid, oleylamine and octadecene is 1:(0.5-1.5):(1-4). Further preferably, the volume ratio of the oleic acid, oleylamine and octadecene is 1:(0.8-1.2):(1.5-2.5).

[0019] Specifically, the long-chain alkyl diol in the present application can contain 10 carbon atoms, 11 carbon atoms, 12 carbon atoms, 13 carbon atoms, 14 carbon atoms, 15 carbon atoms, 16 carbon atoms, 17 carbon atoms, 18 carbon atoms, etc., or an interval range formed by any of the above values, such as 10-14 carbon atoms, 12-18 carbon atoms, etc., and the present application is not limited thereto.

[0020] Preferably, the long-chain alkyl diol contains 12-16 carbon atoms. Further preferably, the long-chain alkyl diol is selected from one or more of 1,2-dodecanediol, 1,2-tetradecanediol, or 1,2-hexadecanediol. Further preferably, the long-chain alkyl diol is 1,2-tetradecanediol.

[0021] Preferably, in the step S2, the holding time is 0.5-3h. Further preferably, the holding time is 0.8-1.5h.

[0022] Specifically, in the step S2, the temperature is raised to 160℃, 170℃, 180℃, 190℃, 200℃, 210℃, 220℃, 230℃, 240℃, etc., or an interval range formed by any of the above values, such as 160℃-190℃, 170℃-210℃, etc., and the present application is not limited thereto. Further preferably, in the step S2, the temperature is raised to 180-220℃.

[0023] Preferably, in the step S3, the holding time is 0.5-5h. Further preferably, the holding time is 1-3h.

[0024] Specifically, in the step S3, the temperature is further raised to 260℃, 270℃, 280℃, 290℃, 300℃, 310℃, 320℃, 330℃, 340℃, etc., or an interval range formed by any of the above values, such as 260℃-290℃, 270℃-310℃, etc., and the present application is not limited thereto. Further preferably, in the step S3, the temperature is further raised to 290-320℃.

[0025] Preferably, in the step S1, the holding time is 0.4-2h. Further preferably, the holding time is 0.6-1h.

[0026] Further preferably, in the step S1, the temperature is raised to 70-90℃.

[0027] Preferably, the post-treatment includes centrifugation, resuspension, and washing.

[0028] Further, the present application claims the ultra-small high-performance near-infrared long-afterglow nanoparticles prepared by the above-mentioned preparation method of ultra-small high-performance near-infrared long-afterglow nanoparticles.

[0029] Preferably, the average diameter of the ultra-small high-performance near-infrared long-persistence nanometer particles is less than 5 nm. Further preferably, the average diameter of the ultra-small high-performance near-infrared long-persistence nanometer particles is 3.5-4.5 nm.

[0030] Preferably, the chemical formula of the ultra-small high-performance near-infrared long-persistence nanometer particles is Zn y Ga2Cr x O4, wherein 1x10 -4 ≤x≤2x10 -3 , 0.6≤y≤1.4. Wherein, Zn y Ga2O4 is the matrix, and Cr 3+ is the activating ion. Preferably, 0.0005≤x≤0.002, 0.8≤y≤1.2. Further preferably, 0.001≤x≤0.0015, 1.0≤y≤1.1.

[0031] Further, the application claims an application of the ultra-small high-performance near-infrared long-persistence nanometer particles in optical imaging of a living body, molecular labeling or in preparation of medical diagnosis and treatment reagents.

[0032] The ultra-small high-performance near-infrared long-persistence nanometer particles provided by the application have an average diameter of less than 5 nm and a long-persistence luminescence performance with a luminescence duration of more than 4 hours. After proper functional modification, the nanometer particles can also be used in subcellular organelle imaging, molecular labeling and living body fine optical imaging, and therefore the application in the above fields should also be within the protection scope of the application.

[0033] Compared with the prior art, the application has the following beneficial effects:

[0034] The application provides a preparation method of ultra-small high-performance near-infrared long-persistence nanometer particles. The method uses a mixed solution of oleic acid, oleylamine and octadecene as a reaction medium, uses a long-chain dihydric alcohol as a reaction control reagent, and uses a specific amount of zinc acetylacetone and chromium acetylacetone and reaction temperature and time to prepare ultra-small high-performance near-infrared long-persistence nanometer particles with an average diameter of less than 5 nm and good dispersibility, which can effectively avoid high aggregation in organs such as liver, spleen and lung. The nanometer particles also have excellent long-persistence luminescence performance, can be effectively excited by 265 nm ultraviolet light to produce near-infrared long-persistence emission with a wavelength of 600-800 nm, the maximum long-persistence luminescence duration is more than 5 hours, better living body imaging effect can be achieved, and the nanometer particles have a wide application prospect in the fields of optical imaging and biomedical diagnosis and treatment reagent development. BRIEF DESCRIPTION OF DRAWINGS

[0035] Figure 1 is a TEM image of the ultra-small high-performance near-infrared long- persistence nanocrystals provided in Example 1.

[0036] Figure 2 is a particle size distribution graph of the ultra-small high-performance near-infrared long-persistence nanocrystals provided in Example 1.

[0037] Figure 3 is an XRD graph of the ultra-small high-performance near-infrared long- persistence nanocrystals provided in Example 1.

[0038] Figure 4 is an excitation and emission spectrum graph of the ultra-small high- performance near-infrared long-persistence nanocrystals provided in Example 1, in which the dashed line is the excitation spectrum and the solid line is the emission spectrum.

[0039] Figure 5 is an emission spectrum graph of the ultra-small high-performance near- infrared long-persistence nanocrystals provided in Examples 1-5 with different Zn 2+ contents.

[0040] Figure 6 is an emission spectrum graph of the ultra-small high-performance near- infrared long-persistence nanocrystals provided in Examples 1 and 6-10 with different Cr 3+ contents.

[0041] Figure 7 is an emission spectrum graph of the ultra-small high-performance near- infrared long-persistence nanocrystals provided in Comparative Example 1, Example 1, and Examples 11-14 with different contents of 1,2-tetradecanediol.

[0042] Figure 8 is an emission spectrum graph of the ultra-small high-performance near- infrared long-persistence nanocrystals provided in Example 1 and Examples 15-19 with different reaction temperatures.

[0043] Figure 9 is a long-persistence luminescence decay curve graph and a long-persistence emission spectrum graph of the ultra-small high-performance near-infrared long- persistence nanocrystals provided in Example 1.

[0044] Figure 10 is a TEM image and a persistence decay imaging graph of the ultra-small high-performance near-infrared long-persistence nanocrystals provided in Example 1 and Examples 11-14 with different contents of 1,2-tetradecanediol. DETAILED DESCRIPTION

[0045] The present application is further illustrated by the following description with reference to the accompanying drawings and specific examples, which are not intended to limit the present application in any way. Unless otherwise defined, the reagents, methods, and equipment employed in the present application are those conventional in the art.

[0046] Example 1 A method for preparing ultra-small high-performance near-infrared long- persistence nanocrystals

[0047] (1) Gallium acetylacetonate, zinc acetylacetonate, chromium acetylacetonate and 1,2-tetradecanediol (molar ratio of 2:1:0.00142:10) were added to a three-necked flask containing a mixed solution of 10 mL of oleic acid, 10 mL of oleylamine and 20 mL of octadecene, heated to 80°C under vacuum while stirring and maintained for 0.5 hours.

[0048] (2) The reaction product of step (1) was heated to 200°C under nitrogen protection and maintained for 1 hour.

[0049] (3) The temperature was continuously increased to 310°C and maintained for 2 hours.

[0050] (4) The reaction product of step (3) was cooled, centrifuged, resuspended and washed multiple times to obtain ultra-small high-performance near-infrared long-afterglow nanoparticles.

[0051] Example 2 to 5: A method for preparing ultra-small high-performance near-infrared long-afterglow nanoparticles

[0052] Example 2 and Example 1 differ in that the molar ratio of gallium acetylacetonate, zinc acetylacetonate, chromium acetylacetonate and 1,2-tetradecanediol is 2:0.8:0.00142:10.

[0053] Example 3 and Example 1 differ in that the molar ratio of gallium acetylacetonate, zinc acetylacetonate, chromium acetylacetonate and 1,2-tetradecanediol is 2:0.9:0.00142:10.

[0054] Example 4 and Example 1 differ in that the molar ratio of gallium acetylacetonate, zinc acetylacetonate, chromium acetylacetonate and 1,2-tetradecanediol is 2:1.1:0.00142:10.

[0055] Example 5 and Example 1 differ in that the molar ratio of gallium acetylacetonate, zinc acetylacetonate, chromium acetylacetonate and 1,2-tetradecanediol is 2:1.2:0.00142:10.

[0056] Example 6 to 10: A method for preparing ultra-small high-performance near-infrared long-afterglow nanoparticles

[0057] Example 6 and Example 1 differ in that the molar ratio of gallium acetylacetonate, zinc acetylacetonate, chromium acetylacetonate and 1,2-tetradecanediol is 2:1:0.00058:10.

[0058] Example 7 and Example 1 differ in that the molar ratio of gallium acetylacetonate, zinc acetylacetonate, chromium acetylacetonate and 1,2-tetradecanediol is 2:1:0.00086:10.

[0059] Example 8 differs from Example 1 in that the molar ratio of gallium acetylacetonate, zinc acetylacetonate, chromium acetylacetonate and 1,2-tetradecanediol is 2:1:0.00114:10.

[0060] Example 9 differs from Example 1 in that the molar ratio of gallium acetylacetonate, zinc acetylacetonate, chromium acetylacetonate and 1,2-tetradecanediol is 2:1:0.00172:10.

[0061] Example 10 differs from Example 1 in that the molar ratio of gallium acetylacetonate, zinc acetylacetonate, chromium acetylacetonate and 1,2-tetradecanediol is 2:1:0.002:10.

[0062] Example 11-14 A method for preparing super-small high-performance near-infrared long-persistence nanoparticles

[0063] Example 11 differs from Example 1 in that the molar ratio of gallium acetylacetonate, zinc acetylacetonate, chromium acetylacetonate and 1,2-tetradecanediol is 2:1:0.00142:2.

[0064] Example 12 differs from Example 1 in that the molar ratio of gallium acetylacetonate, zinc acetylacetonate, chromium acetylacetonate and 1,2-tetradecanediol is 2:1:0.00142:5.

[0065] Example 13 differs from Example 1 in that the molar ratio of gallium acetylacetonate, zinc acetylacetonate, chromium acetylacetonate and 1,2-tetradecanediol is 2:1:0.00142:15.

[0066] Example 14 differs from Example 1 in that the molar ratio of gallium acetylacetonate, zinc acetylacetonate, chromium acetylacetonate and 1,2-tetradecanediol is 2:1:0.00142:20.

[0067] Example 15-19 A method for preparing super-small high-performance near-infrared long-persistence nanoparticles

[0068] Example 15 differs from Example 1 in that in step (3), the temperature is continued to be raised to 290°C.

[0069] Example 16 differs from Example 1 in that in step (3), the temperature is continued to be raised to 300°C.

[0070] Example 17 differs from Example 1 in that in step (3), the temperature is continued to be raised to 320°C.

[0071] Example 18 differs from Example 1 in that in step (3), the temperature is continued to be raised to 330°C.

[0072] Example 19 differs from Example 1 in that in step (3), the temperature is continued to be raised to 340°C.

[0073] Comparative Example 1

[0074] The difference between Comparative Example 1 and Example 1 is that the molar ratio of gallium acetylacetonate, zinc acetylacetonate, chromium acetylacetonate and 1,2-tetradecanediol is 2:1:0.00142:0, that is, 1,2-tetradecanediol is not added in Comparative Example 1.

[0075] Characterization and performance test of the ultra-small high-performance near-infrared long afterglow nanoparticles of Test Example 1

[0076] The ultra-small high-performance near-infrared long afterglow nanoparticles prepared in Example 1 were dissolved in a cyclohexane solution and dropped on a copper mesh, and the morphology and size of the nanoparticles were observed by transmission electron microscopy. FIG. 1 is a TEM image of the ultra-small high-performance near-infrared long afterglow nanoparticles provided in Example 1. As can be seen from FIG. 1, the ultra-small high-performance near-infrared long afterglow nanoparticles with an average diameter of less than 5 nanometers were successfully prepared in Example 1, and had excellent dispersibility.

[0077] FIG. 2 is a size distribution graph of the ultra-small high-performance near-infrared long afterglow nanoparticles provided in Example 1 (200 nanoparticles were randomly selected for statistics). As can be seen from FIG. 2, the average size of the ultra-small high-performance near-infrared long afterglow nanoparticles prepared in Example 1 was 3.76 nanometers.

[0078] The ultra-small high-performance near-infrared long afterglow nanoparticles prepared in Example 1 were measured by X-ray powder diffractometer. FIG. 3 is an XRD graph of the ultra-small high-performance near-infrared long afterglow nanoparticles provided in Example 1. As can be seen from FIG. 3, the XRD spectrum of the prepared ultra-small high-performance near-infrared long afterglow nanoparticles is consistent with the standard card of ZnGa2O4 (JCPDS: 381240), which is a pure phase.

[0079] The ultra-small high-performance near-infrared long afterglow nanoparticles prepared in Example 1 were measured by fluorescence spectrometer. FIG. 4 is an excitation and emission spectrum graph of the ultra-small high-performance near-infrared long afterglow nanoparticles provided in Example 1. As can be seen from FIG. 4, the emission band of the nanoparticles is between 600 nanometers and 800 nanometers, and the main emission peak is at 695 nanometers.

[0080] The ultra-small high-performance near-infrared long afterglow nanoparticles prepared in each example and comparative example were measured by fluorescence spectrometer.

[0081] FIG. 5 is an emission spectrum graph of the ultra-small high-performance near-infrared long afterglow nanoparticles with different Zn 2+ contents provided in Examples 1-5. As can be seen from FIG. 5, with the increase of the Zn 2+With the increase of the content of Cr, the luminescence intensity of the nanoparticles showed a trend of first increasing and then decreasing, and when the molar ratio of gallium acetylacetonate, zinc acetylacetonate, chromium acetylacetonate and 1,2-tetradecanediol was 2:1:0.00142:10, the optical performance of the nanoparticles was best.

[0082] Figure 6 is an emission spectrum of the super-small high-performance near-infrared long afterglow nanoparticles provided by Examples 1 and 6-10 with different Cr 3+ With the increase of the content of Cr, the luminescence intensity of the nanoparticles showed a trend of first increasing and then decreasing, and when the molar ratio of gallium acetylacetonate, zinc acetylacetonate, chromium acetylacetonate and 1,2-tetradecanediol was 2:1:0.00142:10, the optical performance of the nanoparticles was best. 3+

[0083] Figure 7 is an emission spectrum of the super-small high-performance near-infrared long afterglow nanoparticles prepared by adding different amounts of 1,2-tetradecanediol provided by Comparative Example 1, Example 1 and Examples 11-14. As can be seen from Figure 7, with the increase of the amount of 1,2-tetradecanediol added, the luminescence intensity of the nanoparticles showed a trend of first increasing and then decreasing, and when the amount of 1,2-tetradecanediol added was 10 mmol, the optical performance of the nanoparticles was best, so the optimal amount of 1,2-tetradecanediol added was selected to be 10 mmol.

[0084] Figure 8 is an emission spectrum of the super-small high-performance near-infrared long afterglow nanoparticles prepared by different reaction temperatures provided by Example 1 and Examples 15-19. As can be seen from Figure 8, with the increase of the reaction temperature, the luminescence intensity of the nanoparticles showed a trend of first increasing and then decreasing, and when the reaction temperature was 310°C, the optical performance of the nanoparticles was best, so the optimal reaction temperature was selected to be 310°C.

[0085] The super-small high-performance near-infrared long afterglow nanoparticles prepared by Example 1 were subjected to long afterglow luminescence test, and the specific operation was as follows: after the nanoparticles were irradiated by 265 nm ultraviolet light for 1 minute, the afterglow intensity of the nanoparticles was measured by a small animal optical imaging system to obtain a long afterglow luminescence decay curve; after the nanoparticles were irradiated by 265 nm ultraviolet light for 1 minute, the long afterglow emission spectrum was immediately measured by a fluorescence spectrometer.

[0086] Figure 9 is a long afterglow luminescence decay curve and a long afterglow emission spectrum of the super-small high-performance near-infrared long afterglow nanoparticles provided by Example 1. As can be seen from Figure 9, the long afterglow emission spectrum of the nanoparticles was basically consistent with the spectrum shape of the emission spectrum in Figure 1, the afterglow emission band was between 600 nm and 800 nm, the main emission peak was slightly shifted to 705 nm, and the long afterglow luminescence duration was more than 5 hours.

[0087] ​Figure 10 is TEM images and afterglow decay images of the super-small high-performance near-infrared long afterglow nanoparticles prepared with different contents of 1,2-tetradecanediol according to Example 1 and Examples 11-14. The average diameter and long afterglow luminescence duration of the super-small high-performance near-infrared long afterglow nanoparticles prepared according to Example 1 and Examples 11-14 are shown in Table 1 below.

[0088] Table 1

[0089] As can be seen from Figure 10 and Table 1, the average diameter of the super-small high-performance near-infrared long afterglow nanoparticles provided by the present application is less than 5 nanometers, and the long afterglow luminescence duration is more than 4 hours. Among them, the long afterglow luminescence duration of the super-small high-performance near-infrared long afterglow nanoparticles prepared according to Example 1 is more than 5 hours.

[0090] The foregoing examples are illustrative only and are not intended to limit the scope of the methods described herein. The appended claims are intended to claim as broad a range as is allowed under the rules of patent law, and the examples presented herein are intended to demonstrate the scope of the application. Thus, the applicant expressly reserves the right to amend its claims to affirmatively reflect the scope of the application as fully as possible, under the rules of patent law. Some of the numerical ranges recited in the claims are inclusive of the endpoints, but not exclusive of any other sub-range falling within the recited ranges. Changes in these ranges that would not materially affect the performance of the application are intended to be construed as allowed under the foregoing proviso.

Claims

1. A method for preparing ultra-small, high-performance near-infrared long-lasting glow nanoparticles, characterized in that: The following steps are involved: S1. Gallium acetylacetonate, zinc acetylacetonate, chromium acetylacetonate and a long-chain alkyl glycol are added to a mixed solution containing oleic acid, oleylamine and octadecene, stirred, evacuated, heated to 50 to 110 ° C, and kept warm; the long-chain alkyl glycol contains 10 to 18 carbon atoms; S2. Raise the temperature to 160-240°C under nitrogen protection and keep warm; S3. Continue to raise the temperature to 260-340° C., keep the temperature, and perform post-processing to obtain the ultra-small, high-performance near-infrared long-afterglow nanoparticles.

2. The preparation method according to claim 1, characterized in that In the step S1, the molar ratio of gallium acetylacetonate, zinc acetylacetonate, chromium acetylacetonate and long-chain alkyl glycol is 2: (0.6-1.4): (1×10 -4 ~2×10 -3 ):(1~40).

3. The preparation method according to claim 1, characterized in that: In the step S1, the volume ratio of oleic acid, oleylamine and octadecene is 1:(0.5-1.5):(1-4).

4. The preparation method according to claim 1, characterized in that The long-chain alkyl glycol contains 12 to 16 carbon atoms.

5. The preparation method according to claim 1, characterized in that: In step S2, the insulation time is 0.5 to 3 hours.

6. The preparation method according to claim 1, characterized in that: In step S3, the insulation time is 0.5 to 5 hours.

7. Ultra-small, high-performance near-infrared long-afterglow nanoparticles prepared by the preparation method according to any one of claims 1 to 6.

8. The ultra-small, high-performance near-infrared long-afterglow nanoparticles according to claim 7, characterized in that: The average diameter of the ultra-small high-performance near-infrared long-afterglow nanoparticles is 3.5-4.5 nm.

9. The ultra-small, high-performance near-infrared long-afterglow nanoparticles according to claim 7 or 8, characterized in that: The chemical formula of the ultra-small high-performance near-infrared long-lasting nanoparticles is Zn y Ga2Cr x O4; among them, 1×10 -4 ≤x≤2×10 -3 , 0.6≤y≤1.

4.

10. Use of the ultra-small, high-performance near-infrared long-afterglow nanoparticles according to any one of claims 7 to 9 in in vivo optical imaging, molecular labeling, or in the preparation of medical diagnostic reagents.

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