A luminescent nanoparticle based on activated alkyne click reaction and preparation method thereof

Abstract

The present invention discloses a luminescent nanoparticle based on activated alkyne click reaction and a preparation method thereof, wherein the surface of mesoporous silica nanoparticles is amino-modified, and then covalently bound with activated alkyne-modified aggregation-induced luminescence dye to form a stable silica nanoparticle loaded with aggregation-induced luminescence dye, and finally tannic acid is coated on the surface of the nanoparticles to improve the water solubility, stability and biocompatibility of the aggregation-induced luminescence nanoparticles. Compared with traditional fluorescent microspheres, the aggregation-induced luminescence nanoparticles prepared by the present invention have extremely high stability and avoid dye leakage.

Description

Technical Field

[0001] The invention belongs to the fields of nano material synthesis, food safety detection and biomedical testing, and specifically relates to luminescent nanoparticles based on activated alkyne click reaction and a preparation method thereof. Background Art

[0002] Aggregation-induced emission (AIE) refers to a phenomenon in which a class of molecules in a solution that do not emit light or emit light weakly significantly enhance their light emission after aggregation. It was first proposed by the research group of Academician Tang Benzhong. The aggregation-induced emission phenomenon overcomes the problem of fluorescence quenching caused by traditional fluorescent dyes in an aggregated state and is hailed as a "paradigm shift" in the field of fluorescence. The use of aggregation-induced emission dyes to prepare fluorescent probes is not limited by the amount of dye loaded, which greatly improves the performance of the probes.

[0003] Mesoporous silica nanoparticles have the characteristics of large surface area, good surface properties and biocompatibility, and have gradually become carriers in the fields of biomedical testing, drug delivery, etc.

[0004] At present, the main methods for synthesizing aggregation-induced luminescence microspheres are microemulsion method and swelling method. Among them, the microemulsion method (CN109749326B) assembles tetramethyl tetraphenylene acid fluorescent microspheres through hydrophilic-hydrophobic interactions. This synthesis method is simple and fast, but it is difficult to synthesize fluorescent microspheres with a narrow particle size distribution. The swelling method (CN110982512A) first swells the polystyrene template microspheres, and then loads the dye into the template microspheres according to the concentration difference. Although the above methods are simple to synthesize, they are all loaded through weak forces such as electrostatic effects and hydrophilic-hydrophobic balance interactions, and the problem of dye leakage is inevitable. Summary of the invention

[0005] In view of the shortcomings and difficulties in the prior art, the present invention aims to provide a luminescent nanoparticle based on activated alkyne click reaction and a preparation method thereof, and proposes a method of loading aggregation-induced luminescence dye by covalently bonding amino groups and activated alkynes. Since mesoporous silica nanoparticles have a large surface area, the surface amino loading capacity can be increased, thereby increasing the dye loading capacity. The prepared aggregation-induced luminescence microspheres have the characteristics of narrow particle size distribution and high sphericity.

[0006] In order to solve the problem of low loading amount of aggregation-induced luminescence microspheres loaded with silica nanoparticles, the present invention proposes a method for loading aggregation-induced luminescence dyes with mesoporous silica nanoparticles. The surface of mesoporous silica nanoparticles is loose and porous, and has a high surface area. By using mesoporous silica nanoparticles, the amount of aggregation-induced luminescence dyes can be greatly increased, and high-performance fluorescent nanoparticles are expected to be obtained. Wrapping the tannic acid layer on the outside can increase the water solubility and stability of the nanoparticles as a whole, and provide functional groups for further modification.

[0007] The technical solution adopted by the present invention is:

[0008] The present invention provides a method for preparing luminescent nanoparticles based on activated alkyne click reaction: the surface of mesoporous silica nanoparticles is modified with amino groups, and then covalently bonded with activated alkyne-modified aggregation-induced luminescent dyes to form stable silica nanoparticles loaded with aggregation-induced luminescent dyes, and finally tannic acid is coated on the surface of the nanoparticles to improve the water solubility, stability and biocompatibility of the aggregation-induced luminescent nanoparticles;

[0009] Specifically:

[0010] The catalyst triethanolamine, the organic template hexadecyltrimethylammonium bromide and sodium salicylate are dissolved in ultrapure water step by step, and tetraethoxysilane is added for hydrolysis to obtain mesoporous silica nanoparticles. The organic template in the mesoporous silica nanoparticles is removed by acid extraction, and then the surface is modified with 3-aminopropyltriethoxysilane. After centrifugal washing, the amino-modified mesoporous silica nanoparticles are redissolved in ethanol. Subsequently, the activated alkyne aggregation-induced luminescence dye is dissolved in dimethyl sulfoxide, and the mesoporous silica nanoparticles are diluted in ultrapure water. The activated alkyne dye is added dropwise to the ethanol aqueous solution containing mesoporous silica, and ultrasound is continuously applied. The obtained product is washed with an aqueous solution containing sodium dodecyl sulfate, centrifuged, and the dye-loaded mesoporous silica nanoparticles are stored in an ethanol aqueous solution. Subsequently, surface functional group modification is performed, metal ions and tannic acid are dissolved in ultrapure water, and the dye-loaded mesoporous silica nanoparticles are dissolved in the above reagents, and ultrasound is continuously applied. Centrifugation is performed, and the obtained product is stored in ultrapure water.

[0011] The specific steps are:

[0012] (1) adding the catalyst triethanolamine dropwise into a three-necked flask containing ultrapure water and stirring to disperse;

[0013] (2) Add the organic template hexadecyltrimethylammonium bromide and sodium salicylate into a three-necked flask respectively and continue stirring;

[0014] (3) After being fully dissolved, tetraethoxysilane is added to the reaction system, and mesoporous silica nanoparticles are obtained after hydrolysis;

[0015] (4) washing the mesoporous silica nanoparticles obtained in step (3) with ethanol three times;

[0016] (5) extracting the remaining organic template from the mesoporous silica nanoparticles obtained in step (4) with a mixture of methanol and hydrochloric acid, and redispersing the mixture in ethanol;

[0017] (6) transferring the mesoporous silica nanoparticles into a conical flask, adding ammonia water and 3-aminopropyltriethoxysilane respectively, and continuously stirring to obtain modified mesoporous silica nanoparticles;

[0018] (7) re-dispersing the modified mesoporous silica nanoparticles obtained in step (6) in ethanol;

[0019] (8) dissolving the aggregation-induced emission dye in dimethyl sulfoxide;

[0020] (9) diluting the mesoporous silica nanoparticles obtained in step (7) with ultrapure water;

[0021] (10) adding the aggregation-induced emission dye obtained in step (8) dropwise to the reaction system described in step (9) and continuously sonicating;

[0022] (11) adding an aqueous solution of sodium dodecyl sulfate to the reaction system described in step (10), and centrifuging to remove unreacted aggregation-induced emission dye;

[0023] (12) Dissolving metal ions and tannic acid in ultrapure water, and adding the mixture to the mesoporous silica nanoparticles loaded with aggregation-induced emission dye obtained in step (11), and continuously sonicating.

[0024] (13) The product was separated by centrifugation and stored in ultrapure water.

[0025] Preferably, the final concentration of the triethanolamine in step (1) after being dissolved in ultrapure water is 1-20 mg / mL.

[0026] Preferably, the final concentration of the hexadecyltrimethylammonium bromide and sodium salicylate in step (2) after being dissolved in ultrapure water is 1-20 mg / mL.

[0027] Preferably, the final concentration of tetraethoxysilane dissolved in ultrapure water in step (3) is 1-15%.

[0028] Preferably, the ratio of the methanol / hydrochloric acid mixed solution in step (5) is 1:1-50:1, and the extraction time is 6-12 hours.

[0029] Preferably, the ratio of 3-aminopropyltriethoxysilane to tetraethoxysilane in step (6) is 1:1-3:1.

[0030] Preferably, the final concentration of the aggregation-induced emission dye dissolved in dimethyl sulfoxide in step (8) is 5-50 mg / mL.

[0031] Preferably, the dilution factor of the mesoporous silica nanoparticles in step (9) is 0.5-10 times.

[0032] Preferably, the ultrasonic conditions in step (10) are a power of 50-300 watts and a time of 3-15 minutes.

[0033] Preferably, the concentration of the sodium dodecyl sulfate aqueous solution in step (11) is 1-5 mg / mL.

[0034] Preferably, the metal ions in step (12) are derived from ferric chloride, zirconium oxychloride or europium chloride.

[0035] Preferably, the mass ratio of tannic acid, metal ions and mesoporous silica in step (12) is 10:1:1-80:1:1.

[0036] The present invention also provides a nanoparticle doped with a positive charge aggregation-induced luminescent dye, which is a mesoporous silica luminescent nanoparticle prepared by the above-mentioned preparation method.

[0037] Preferably, the particle size of the mesoporous silica luminescent nanoparticles is 100-400 nm.

[0038] The advantages of the present invention are:

[0039] (1) The aggregation-induced emission dyes were loaded onto mesoporous silica nanoparticles, which greatly increased the dye loading capacity.

[0040] (2) Through the rapid reaction of amino groups and activated alkynes, aggregation-induced emission dyes can be quickly loaded without a catalyst. The covalent bonding of amino groups and activated alkynes greatly improves the stability of dye loading and is not easy to leak. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 It is a scanning electron microscope image of the silicon dioxide luminescent nanoparticles synthesized by the present invention.

[0042] Figure 2 It is a schematic diagram of the principle of synthesizing silicon dioxide luminescent nanoparticles according to the present invention. DETAILED DESCRIPTION

[0043] Example 1: Preparation of amino-modified mesoporous silica nanoparticles

[0044] 130 mg of triethanolamine was added to a three-necked flask containing 50 mL of ultrapure water and stirred at 80 ° C for 30 minutes. Then 600 mg of hexadecyltrimethylammonium bromide and 300 mg of sodium salicylate were added to the above reaction system and stirred for 60 minutes. Then 4 mL of tetraethoxysilane was added to the three-necked flask and hydrolyzed for 3 hours to generate mesoporous silica nanoparticles. The obtained product was washed with ethanol three times to remove excess reactants. Subsequently, the excess organic template was removed by acid extraction, and the mesoporous silica nanoparticles were dispersed in a mixed system of 100 mL of methanol and 6 mL of concentrated hydrochloric acid, and rapidly stirred at 60 ° C for 6 hours and repeated 3 times. Then the surface amino group was modified, and the obtained mesoporous silica nanoparticles were dispersed in 400 mL of ethanol, 6 mL of ammonia water and 2 mL of 3-aminopropyltriethoxysilane were added, and stirred at room temperature for 10 hours. The obtained product was then centrifuged and washed twice and stored in ethanol for later use.

[0045] Example 2: Aminated mesoporous silica nanoparticles loaded with aggregation-induced emission dyes

[0046] Take 2mL of the prepared amino-modified mesoporous silica nanoparticles and dilute them 1-fold with ultrapure water, and dissolve the aggregation-induced emission dye in dimethyl sulfoxide at a concentration of 50mg / mL. Add 100μL of the aggregation-induced emission dye solution to the amino-modified mesoporous silica nanoparticle dilution and sonicate quickly for 5 minutes. Then add 1mL of 4 mg / mL sodium dodecyl sulfate solution to wash away the unreacted dye. Centrifuge and wash 3 times with 1mg / mL sodium dodecyl sulfate solution. Dissolve 5mg of ferric chloride and 300mg of tannic acid in ultrapure water and add them to the obtained dye-loaded mesoporous silica nanoparticles, and sonicate quickly for 5 minutes. Then centrifuge and redissolve the resulting product in ultrapure water.

[0047] The above embodiments of the present invention are intended to illustrate the present invention rather than to limit the present invention. Any changes within the meaning and scope equivalent to the claims of the present invention should be considered to be included within the scope of the claims.

Claims

1. A method for preparing luminescent nanoparticles based on activated alkyne click reaction, characterized in that: Loading aggregation-induced luminescence dye on mesoporous silica nanoparticles to obtain mesoporous silica luminescent nanoparticles, wherein the aggregation-induced luminescence dye has an activated alkyne group; The preparation method of the mesoporous silica nanoparticles comprises the following steps: dissolving a catalyst triethanolamine, an organic template hexadecyltrimethylammonium bromide and sodium salicylate in ultrapure water, adding tetraethoxysilane for hydrolysis, and obtaining mesoporous silica nanoparticles; removing the organic template in the mesoporous silica nanoparticles by an acid extraction method, and then modifying the surface with 3-aminopropyltriethoxysilane; After centrifugal washing, the amino-modified mesoporous silica nanoparticles were redissolved in ethanol; The preparation method of the silica luminescent nanoparticles comprises the following steps: dissolving an activated alkyne aggregation-induced luminescent dye in dimethyl sulfoxide and diluting mesoporous silica nanoparticles in ultrapure water; dropping the activated alkyne dye into an ethanol aqueous solution containing mesoporous silica, and continuously ultrasonicating; washing the obtained product with an aqueous solution containing sodium dodecyl sulfate, centrifuging, and storing the mesoporous silica nanoparticles loaded with the dye in an ethanol aqueous solution; then performing surface functional group modification, dissolving metal ions and tannic acid in ultrapure water, dissolving the mesoporous silica nanoparticles loaded with the dye in the above reagent, and continuously ultrasonicating; After centrifugation, the product was stored in ultrapure water.

2. The method for preparing luminescent nanoparticles based on activated alkyne click reaction according to claim 1, characterized in that: The final concentration of the triethanolamine, hexadecyltrimethylammonium bromide and sodium salicylate dissolved in ultrapure water is 1-20 mg / mL; the final concentration of the tetraethoxysilane dissolved in ultrapure water is 1-15%.

3. The method for preparing luminescent nanoparticles based on activated alkyne click reaction according to claim 1, characterized in that: The reagent used in the acid extraction method is a methanol / hydrochloric acid mixed solution, the ratio of which is 1:1-50:1, and the extraction time is 6-12 hours; the reagent used in the surface modification is 3-aminopropyltriethoxysilane, and the ratio of 3-aminopropyltriethoxysilane to tetraethoxysilane is 1:1-3:

1.

4. The method for preparing luminescent nanoparticles based on activated alkyne click reaction according to claim 1, characterized in that: The final concentration of the dye dissolved in dimethyl sulfoxide is 5-50 mg / mL; the dilution multiple of the mesoporous silica nanoparticles is 0.5-10 times; and the concentration of the sodium dodecyl sulfate aqueous solution is 1-5 mg / mL.

5. The method for preparing luminescent nanoparticles based on activated alkyne click reaction according to claim 1, characterized in that: The ultrasonic power is 50-300 watts, and the ultrasonic time is 3-15 minutes.

6. The method for preparing luminescent nanoparticles based on activated alkyne click reaction according to claim 1, characterized in that: The metal ions are derived from ferric chloride, zirconium oxychloride and europium chloride; the mass ratio of tannic acid, metal ions and mesoporous silica is 10:1:1-80:1:

1.

7. A luminescent nanoparticle based on activated alkyne click reaction, characterized in that: The mesoporous silicon dioxide luminescent nanoparticle is prepared by the luminescent nanoparticle preparation method based on activated alkyne click reaction as described in any one of claims 1 to 6.

8. The luminescent nanoparticles based on activated alkyne click reaction according to claim 7, characterized in that: The particle size of the mesoporous silica luminescent nanoparticles is 100-400 nm.

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