Fluorescent hollow glass bead and preparation method thereof

Abstract

The invention relates to the technical field of luminescent materials, in particular to a fluorescent hollow glass bead and a preparation method thereof. The fluorescent hollow glass bead comprises a hollow glass bead and hydrogel coating the surface of the hollow glass bead, the hydrogel is prepared from raw materials including N-(2-aminoethyl) methacrylamide hydrochloride and azido-containing polymeric monomers through an addition polymerization reaction; amino groups in the hydrogel and epoxy groups in the hollow glass beads modified by the epoxy groups are grafted on the surfaces of the hollow glass beads through epoxy-amine ring-opening reaction, and fluorescent molecules containing alkynyl groups are grafted on the hydrogel through click chemical reaction between the alkynyl groups and azide groups in the hydrogel. The hydrogel with the three-dimensional network structure is chemically grafted on the surfaces of the hollow glass beads, so that binding sites are increased, the binding force with the beads is improved, the binding density of fluorescent molecules is improved, the three-dimensional network structure protects the fluorescent molecules from being quenched or oxidized, and the fluorescence intensity and stability are further improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of light-emitting materials, in particular to a fluorescent hollow glass microsphere and a preparation method thereof. BACKGROUND

[0002] Fluorescent microspheres are micro-nano particles composed of organic polymers or inorganic materials (such as silicon dioxide), which have fluorescent dyes, quantum dots (QDs) or rare earth fluorescent materials loaded inside or on the surface. Due to their excellent fluorescent properties, good monodispersity and functional modification characteristics, fluorescent microspheres have important application value in the fields of biological labeling, in vitro diagnosis (IVD), cell imaging and drug delivery.

[0003] The performance of fluorescent microspheres mainly depends on the preparation method, and different synthesis strategies will affect the particle size, fluorescence intensity, stability and surface chemical properties of the microspheres. The common preparation method of fluorescent microspheres is to combine fluorescent chemicals to the surface of the microspheres through chemical bonds to realize the connection of fluorescent substances and microspheres. The fluorescence intensity and stability of this fluorescent microsphere are higher than those of the fluorescent microsphere prepared by adsorption of fluorescent chemicals, and it can selectively bind multiple fluorescent substances.

[0004] For example, the Chinese patent application with the application publication number CN118895119A published on November 5, 2024 discloses a novel organic-inorganic composite fluorescent silica nanomicrosphere and a preparation method thereof. First, 1,8-naphthalimide fluorescent monomer and isocyanate silane coupling agent are reacted to obtain NAP-silane precursor (i.e. fluorescent coupling agent) which has both fluorescent function and hydrolysis bonding function. The abundant silanol groups (Si-OH) on the surface of nanosilica can covalently fix the fluorescent coupling agent at high density, and the obtained fluorescent microspheres have good dispersity, large specific surface area, high fluorescence intensity and stability.

[0005] However, in actual application process, the fluorescent microspheres have problems such as fluorescence intensity value attenuation and unstable combination of fluorescent molecules. SUMMARY

[0006] The purpose of the present application is to provide a fluorescent hollow glass microsphere to solve the problems of low fluorescence intensity and poor stability of existing fluorescent microspheres.

[0007] The second purpose of the present application is to provide a preparation method of a fluorescent hollow glass microsphere to solve the problems of low fluorescence intensity and poor stability of existing fluorescent microspheres.

[0008] In order to solve the above technical problems, the technical scheme of the fluorescent hollow glass microsphere of the present application is as follows: The fluorescent hollow glass microsphere comprises a hollow glass microsphere and a hydrogel coated on the surface of the hollow glass microsphere; the hydrogel is obtained through polyaddition reaction of raw materials comprising N-(2-aminoethyl) methacrylamide hydrochloride and an azido-containing polymer monomer; the amino group in the hydrogel is grafted on the surface of the hollow glass microsphere through epoxy-amine ring-opening reaction with the epoxy group in the hollow glass microsphere modified by the epoxy group; and the alkyne-containing fluorescent molecule is grafted on the hydrogel through click chemistry reaction with the azido group in the hydrogel.

[0009] The present application is an improvement on the prior art, and provides a fluorescent hollow glass microsphere, wherein a hydrogel is coated on the surface of the hollow glass microsphere, the hydrogel is connected by chemical bonds, the binding force is stronger, and the hydrogel is not easy to fall off; and the three-dimensional network structure of the hydrogel forms a three-dimensional structure on the surface of the microsphere, the reaction sites on the unit area are increased, there are not only chemical bond combination, but also hydrogen bond and intermolecular force, so that the number of fluorescent molecules that can be grafted on the surface of the microsphere is more, the density of the fluorescent molecules on the surface of the microsphere is higher, and the fluorescent intensity is higher; in addition, the three-dimensional network structure of the hydrogel can protect the fluorescent molecules, the hydrogel network can block oxygen, free radicals or other quenchers from contacting the fluorescent molecules, slow down the oxidation or fluorescent intensity decay, prolong the fluorescent molecule decay period, and make the fluorescence more stable. At the same time, due to the low density of the hollow glass microsphere, the prepared fluorescent microspheres are not easy to settle.

[0010] In order to further improve the binding sites, improve the binding capacity, and improve the density of the combined fluorescent molecules, preferably, the azido-containing polymer monomer is azido acrylamide; the raw materials comprise acrylamide; and the mass ratio of acrylamide, azido acrylamide and N-(2-aminoethyl) methacrylamide hydrochloride is (80-90):(5-15):5.

[0011] The technical scheme of the preparation method of the fluorescent hollow glass microsphere of the present application is as follows: The preparation method of the fluorescent hollow glass microsphere comprises the following steps: obtaining a hydrogel through polyaddition reaction of raw materials comprising N-(2-aminoethyl) methacrylamide hydrochloride and an azido-containing polymer monomer; performing epoxy-amine ring-opening reaction between the epoxy group modified hollow glass microsphere and the hydrogel to obtain the hollow glass microsphere coated with the hydrogel; or performing reaction between the epoxy group modified hollow glass microsphere and the raw materials comprising N-(2-aminoethyl) methacrylamide hydrochloride and the azido-containing polymer monomer in a solvent under the action of an initiator to obtain the hollow glass microsphere coated with the hydrogel; and then performing click chemistry reaction between the hollow glass microsphere coated with the hydrogel and the alkyne-containing fluorescent molecule to obtain the fluorescent hollow glass microsphere.

[0012] The application provides a preparation method of the fluorescent hollow glass microbeads.

[0013] To further improve the bonding strength of the hydrogel and the microbeads, preferably, in the two preparation methods of the hydrogel-coated hollow glass microbeads, the azide group-containing polymer monomer is azide acrylamide; the raw material comprises acrylamide; and the mass ratio of the acrylamide, the azide acrylamide and N-(2-aminoethyl) methacrylamide hydrochloride is (80-90):(5-15):5. The acrylamide polymer monomer is used, so that the hydrophilicity of the prepared hydrogel is improved, the water solubility is increased, and the grafting of the microbeads and the grafting of the fluorescent molecules are carried out in a water system, so that the reaction activity is further improved, and the grafting efficiency is improved.

[0014] To further improve the fluorescent intensity and stability, preferably, in the epoxy-amine ring-opening reaction, the mass ratio of the epoxy group-modified hollow glass microbeads and the hydrogel is (20-30):1; or in the reaction of the epoxy group-modified hollow glass microbeads and the raw material under the action of the initiator, the mass ratio of the epoxy group-modified hollow glass microbeads and the raw material is (20-50):1.

[0015] To further improve the grafting rate of the fluorescent molecules, preferably, the mass ratio of the hydrogel-coated hollow glass microbeads and the fluorescent molecules containing the alkyne group is (2000-5000):1; the temperature of the click chemistry reaction is 60-80 DEG C, and the time of the click chemistry reaction is 20-30 min.

[0016] To further improve the bonding capacity of the hydrogel and the microbeads, preferably, the epoxy group-modified hollow glass microbeads are subjected to surface treatment in a silane coupling agent solution with an epoxy group, and the mass ratio of the silane coupling agent with the epoxy group and the hollow glass microbeads is (1-2):100.

[0017] To further improve the bonding capacity of the hydrogel and the microbeads, preferably, the temperature of the surface treatment is 80-100 DEG C, and the time is 4-8 h.

[0018] To further complete the reaction, preferably, in the reaction of the epoxy group-modified hollow glass microbeads and the raw material under the action of the initiator, the temperature is 40-60 DEG C, and the time is 2-3 h.

[0019] In order to further make the reaction complete, preferably, the temperature of the polyaddition reaction is 40-60 DEG C, the time of the polyaddition reaction is 2-3h; the temperature of the epoxy-amine ring-opening reaction is 50-70 DEG C, and the time is 1-2h. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 The flow chart of the preparation method of the fluorescent hollow glass microspheres of the embodiment 1 of the present application is shown in the figure. Figure 2 The fluorescent intensity value change curve of the fluorescent hollow glass microspheres under different storage times is shown in the figure. DETAILED DESCRIPTION

[0021] The technical concept of the fluorescent hollow glass microspheres provided by the present application is as follows: The prior art grafts fluorescent molecules on the silane coupling agent, and then grafts the fluorescent molecules on the hollow glass microspheres through the hydrolysis of the silane coupling agent to obtain the fluorescent hollow glass microspheres. However, the structure of the silane coupling agent is single, the density of the grafted fluorescent molecules is low, and the fluorescent molecules are easily quenched, resulting in poor fluorescent intensity and stability.

[0022] The present application grafts the hydrogel with a three-dimensional network structure on the surface of the hollow glass microspheres, increases the combination sites, improves the combination with the microspheres, increases the combination density of the fluorescent molecules, and the three-dimensional network structure can protect the fluorescent molecules from being quenched or oxidized, thereby improving the fluorescent intensity and stability.

[0023] The preparation method of the fluorescent hollow glass microspheres provided by the present application comprises the following steps: (1) The epoxy group modified hollow glass microspheres: the epoxy group modified hollow glass microspheres are surface treated in the silane coupling agent solution with epoxy groups at 80-100 DEG C for 4-8h, and the mass ratio of the silane coupling agent with epoxy groups to the hollow glass microspheres is (1-2):100.

[0024] Specifically, the silane coupling agent with epoxy groups is γ-glycidoxypropyltrimethoxysilane.

[0025] Specifically, in the silane coupling agent solution with epoxy groups, the mass ratio of the silane coupling agent with epoxy groups to the first solvent is (5-8):(100-110).

[0026] Specifically, in the silane coupling agent solution with epoxy groups, the first solvent is composed of ethanol and water; and the mass ratio of the silane coupling agent with epoxy groups, ethanol and water is 5-8:100-110:0.5-1.

[0027] Specifically, the hollow glass microspheres before surface treatment are subjected to hydroxylation treatment, the hydroxylation treatment is plasma treatment, the temperature of the plasma treatment is 80-100℃, the time of the plasma treatment is 10-30min, and the power of the plasma is 300-500W.

[0028] Specifically, a condensation reflux reaction is adopted during surface treatment.

[0029] (2) Surface-grafted hydrogel: The first mode: acrylamide, azido acrylamide and N-(2-aminoethyl) methacrylamide hydrochloride with a mass ratio of (80-90):(5-15):5 are subjected to polyaddition reaction to obtain a hydrogel; epoxy group modified hollow glass microspheres and the hydrogel with a mass ratio of (20-30):1 are subjected to epoxy-amine ring-opening reaction to obtain hollow glass microspheres coated with hydrogel.

[0030] Specifically, the temperature of the polyaddition reaction is 40-60℃, and the time of the polyaddition reaction is 2-3h.

[0031] Specifically, the polyaddition reaction is carried out by reacting acrylamide, azido acrylamide and N-(2-aminoethyl) methacrylamide hydrochloride in a second solvent under the action of a first initiator; the second solvent is water; the first initiator is azobisdimethylaminoformamidine hydrochloride; and sodium hydroxide solution is added for quenching after the reaction is completed.

[0032] Specifically, the amount of the first initiator added is 1-2% of the total mass of the three polymerization monomers of acrylamide, azido acrylamide and N-(2-aminoethyl) methacrylamide hydrochloride.

[0033] Specifically, the temperature of the epoxy-amine ring-opening reaction is 50-70℃, and the time is 1-2h.

[0034] Specifically, the epoxy-amine ring-opening reaction is carried out by reacting epoxy group modified hollow glass microspheres and the hydrogel in a third solvent under the action of a catalyst. The catalyst is pentamethyldiethylene triamine, and the third solvent is water.

[0035] Specifically, the epoxy-amine ring-opening reaction is carried out by adding the epoxy group modified hollow glass microspheres to a hydrogel solution under the action of a catalyst; the hydrogel solution is obtained by dispersing the hydrogel in a third solvent, 100-110 parts of the third solvent are added for every 1 part of the hydrogel; and the amount of the catalyst added is 1-2% of the mass of the hydrogel solution.

[0036] The second way is that the epoxy group modified hollow glass microspheres, acrylamide, azido acrylamide and N-(2-aminoethyl) methacrylamide hydrochloride are reacted in a fourth solvent under the action of a second initiator at 40-60℃ for 2-3h to obtain the hydrogel coated hollow glass microspheres. The fourth solvent is water. After the reaction is completed, a sodium hydroxide solution is added for quenching.

[0037] Specifically, the mass ratio of acrylamide, azido acrylamide and N-(2-aminoethyl) methacrylamide hydrochloride is (80-90):(5-15):5; the mass ratio of the epoxy group modified hollow glass microspheres to the total mass of acrylamide, azido acrylamide and N-(2-aminoethyl) methacrylamide hydrochloride is (20-50):1.

[0038] Specifically, the second initiator is azobisdimethylamidinum hydrochloride; the addition amount of the second initiator is 1-2% of the total mass of acrylamide, azido acrylamide and N-(2-aminoethyl) methacrylamide hydrochloride.

[0039] 3) Fluorescent molecule grafting: the hydrogel coated hollow glass microspheres are subjected to click chemistry reaction with the fluorescent molecule containing an alkyne group to obtain the fluorescent hollow glass microspheres.

[0040] Specifically, the mass ratio of the hydrogel coated hollow glass microspheres to the fluorescent molecule containing an alkyne group is (2000-5000):1.

[0041] Specifically, the click chemistry reaction is that the hydrogel coated hollow glass microspheres and the fluorescent molecule containing an alkyne group are reacted in a fifth solvent under the action of a catalyst at 60-80℃ for 20-30min; the catalyst includes copper sulfate and sodium ascorbate; the fifth solvent is water. The addition amount of the catalyst is 1-3% of the mass of the fluorescent molecule, and the catalyst includes copper sulfate and sodium ascorbate with a mass ratio of (1-2):(1-2).

[0042] The embodiments of the present application are further described below in combination with specific examples. The chemical reagents involved in the following examples are all commercially available conventional goods unless otherwise specified.

[0043] I. Specific examples of the fluorescent hollow glass microspheres and the preparation method thereof Example 1 The fluorescent hollow glass microspheres of the embodiment comprise hollow glass microspheres and hydrogel coated on the surface of the hollow glass microspheres; the hydrogel is obtained by polyaddition reaction of acrylamide, azidoacrylamide and N-(2-aminoethyl) methacrylamide hydrochloride with a mass ratio of 85:10:5; the amino groups in the hydrogel are grafted on the surface of the hollow glass microspheres by epoxy-amine ring-opening reaction with the epoxy groups in the hollow glass microspheres modified by epoxy groups, and the fluorescent molecules containing alkynyl groups are grafted on the hydrogel by click chemistry reaction with the azido groups in the hydrogel.

[0044] The flow chart of the preparation method of the fluorescent hollow glass microspheres of the embodiment is shown in Figure 1 The specific method is as follows: (1) Hollow glass microspheres modified by epoxy groups First, surface hydroxylation is performed: the hollow glass microspheres are treated by a rotary plasma device, the power of the rotary plasma device is 300 W, the treatment time is 10 min, and the treatment temperature is 80℃, to obtain hollow glass microspheres with high-density hydroxyl groups. Then, silane coupling agent is grafted: γ-glycidoxypropyltrimethoxysilane (GPTMS) is added to a mixed solvent of ethanol and water to obtain a silane coupling agent solution, the mass ratio of γ-glycidoxypropyltrimethoxysilane, ethanol and water is 5:100:0.5, hollow glass microspheres with surface hydroxylation are added to the silane coupling agent solution, the mass ratio of γ-glycidoxypropyltrimethoxysilane and hollow glass microspheres is 1:100, 80℃ condensation reflux reaction for 4h, pure water, ethanol washing, 105℃ drying, the hydroxyl groups on the surface of the hollow glass microspheres react with the silicon hydroxyl groups generated by the hydrolysis of the silane coupling agent, so that the silane coupling agent containing epoxy groups is grafted on the surface of the hollow glass microspheres, and hollow glass microspheres modified by epoxy groups are obtained.

[0045] (2) Synthesis of hydrogel Azidopropyl acrylamide (Formula I) (purchased from Ziyue Biological AzPMA), acrylamide (Formula II) and N-(2-aminoethyl) methacrylamide hydrochloride (Formula III) are first dissolved in deionized water in a round-bottomed flask according to a mass ratio of 10:85:5, an initiator azobisdimethylaminoformamide hydrochloride (AIBA, 1% of the total mass of the three polymerization monomers) is added under a nitrogen atmosphere, and the reaction is carried out at 40℃ for 2h. The polymerization reaction is quenched with NaOH aqueous solution to form a hydrogel polymer. The hydrogel polymer with azido groups and amino groups (Formula V) is obtained by purification and freeze-drying, and the reaction equation is as follows: ; wherein x:y:z=85:10:5. x, y and z are represented by the addition amount of the three polymerization monomers.

[0046] (3) Hollow glass microspheres coated with hydrogel The hydrogel polymer obtained in step (2) was diluted 100 times with water to obtain a hydrogel polymer solution. Then, the epoxy group-modified hollow glass microspheres obtained in step (1) were added and mixed. The mass ratio of the hydrogel polymer to the epoxy group-modified hollow glass microspheres was 1:20. Then, 1% of the mass of the hydrogel polymer solution was added as a catalyst, pentamethyldiethylenetriamine (PMDETA). The reaction was carried out at 50°C for 1 hour. The amino group of the hydrogel (the amino group in -NH2·HCl of formula V) and the epoxy group underwent an epoxy-amine ring-opening reaction. After centrifugation, washing, and vacuum low-temperature drying, the hydrogel-coated hollow glass microspheres were obtained.

[0047] (4) Grafting of fluorescent molecules The hollow glass microspheres coated with hydrogel obtained in step (3) were added to pure water, followed by the addition of copper sulfate catalyst and sodium ascorbate (the amount of catalyst added was 1% of the mass of the fluorescent molecule, and the proportions of copper sulfate and sodium ascorbate were 0.5% each), and the fluorescent molecule CY7-anlyne with an alkyne group (molecular formula: C 40 H 47 N3O7S2 (CAS: 2183440-55-1) The mass ratio of hydrogel-coated hollow glass microspheres to fluorescent molecules is 2000:1. After being mixed evenly, the mixture is heated to 60℃ for 20 min. The alkyne groups in the fluorescent molecules undergo a "click chemistry" reaction with the azide groups in the hydrogel. Click chemistry is characterized by rapid reaction, high efficiency, and strong binding force of fluorescent molecules. After centrifugation, washing, and vacuum low-temperature drying, fluorescent hollow glass microspheres are obtained.

[0048] Example 2 The fluorescent hollow glass microspheres of this embodiment include hollow glass microspheres and hydrogels coated on the surface of the hollow glass microspheres; the hydrogel is obtained by addition polymerization of acrylamide, azidoacrylamide and N-(2-aminoethyl)methacrylamide hydrochloride in a mass ratio of 85:10:5; the amino groups in the hydrogel are grafted onto the surface of the hollow glass microspheres through an epoxy-amine ring-opening reaction with the epoxy groups modified by the epoxy groups; and the fluorescent molecules containing alkynyl groups are grafted onto the hydrogel through a click chemical reaction between the alkynyl groups and the azido groups in the hydrogel.

[0049] The preparation method of the fluorescent hollow glass microspheres in this embodiment is as follows: (1) Same as step (1) in Example 1.

[0050] (2) Hydrogel-coated hollow glass microspheres First, azide acrylamide (formula I), acrylamide (formula II) and N-(2-aminoethyl) methacrylamide hydrochloride (formula III) are dissolved in deionized water in a ratio of 10:85:5, added to a round-bottom flask, and an initiator azobisdimethylamide hydrochloride (AIBA, 1% of the total mass of the three polymerization monomers) is added under a nitrogen atmosphere. The epoxy group modified hollow glass microspheres obtained in step (1) are added, and the mass ratio of the epoxy group modified hollow glass microspheres to the total mass of the three polymerization monomers is 20:1. The reaction is stirred at 40°C for 2h, and the polymerization reaction is quenched with an aqueous NaOH solution. After centrifugation, washing and vacuum low-temperature drying, the hydrogel-coated hollow glass microspheres are obtained.

[0051] (3) The same as step (4) of Example 1.

[0052] Example 3 The fluorescent hollow glass microspheres and the preparation method thereof of the present embodiment are basically the same as those of Example 1, except that the x:y:z in the hydrogel polymer is 90:5:5.

[0053] Example 4 The fluorescent hollow glass microspheres and the preparation method thereof of the present embodiment are basically the same as those of Example 1, except that the x:y:z in the hydrogel polymer is 80:15:5.

[0054] Example 5 The fluorescent hollow glass microspheres and the preparation method thereof of the present embodiment are basically the same as those of Example 2, except that the x:y:z in the hydrogel polymer is 90:5:5.

[0055] Example 6 The fluorescent hollow glass microspheres and the preparation method thereof of the present embodiment are basically the same as those of Example 2, except that the x:y:z in the hydrogel polymer is 80:15:5.

[0056] Comparative Example 2 Comparative Example 1 The preparation method of the fluorescent hollow glass microspheres of the present comparative example is as follows: (1) Surface treatment of hollow glass microspheres: The surface of the hollow glass microspheres is cleaned with a sodium hydroxide solution. Specifically, a 0.1M NaOH solution is used, and the reaction is stirred at 60°C for 1h, and then washed with water to neutral.

[0057] (2) Surface adsorption hydrogel: Dissolve azido acrylamide (Formula I), acrylamide (Formula II) and N-(2-aminoethyl) methacrylamide hydrochloride (Formula III) in deionized water according to the mass ratio of 10:85:5, add into a round-bottom flask, and add AIBA and the surface treated hollow glass beads obtained in step (1) under a nitrogen atmosphere, the mass ratio of the total mass of the surface treated hollow glass beads and the three polymerization monomers being 20:1, stir at 40°C for 2h, quench the polymerization reaction with NaOH aqueous solution, centrifuge, wash, and vacuum low-temperature dry to obtain the hollow glass beads coated with hydrogel. The hydrogel polymer is coated on the surface of the hollow glass beads by adsorption (the structure of the hydrogel polymer is referred to Formula V, wherein x:y:z=85:10:5).

[0058] (3) Fluorescent molecule grafting: add the hollow glass beads coated with hydrogel obtained in step (2) into pure water, and then add copper sulfate and sodium ascorbate (the catalyst is added in an amount of 1% of the mass of the fluorescent molecule, and the mass ratio of copper sulfate and sodium ascorbate is 0.5%), and a fluorescent molecule CY7-anlyne with an alkyne group, the mass ratio of the hollow glass beads coated with hydrogel and the fluorescent molecule being 2000:1, mix uniformly, heat at 60°C for 20min, centrifuge, wash, and vacuum low-temperature dry to obtain the fluorescent hollow glass beads.

[0059] Comparative Example 2 The preparation method of the fluorescent hollow glass beads of the present comparative example is as follows: (1) Azido-modified hollow glass beads: first, perform surface hydroxylation: treat the hollow glass beads by using a rotary plasma device, the power of the rotary plasma device being 300W, the treatment time being 10min, and the treatment temperature being 80°C, to obtain hollow glass beads with high-density hydroxyl groups. Then graft azido silane coupling agent: add (3-azidopropyl) trimethoxysilane (chemical formula: C6H 15 N3O3Si; CAS: 76788-88-0) into a mixed solvent of anhydrous ethanol and triethylamine to obtain an azido silane coupling agent solution, the mass ratio of (3-azidopropyl) trimethoxysilane, anhydrous ethanol and triethylamine being 1:100:0.5, add 1g of the surface-hydroxylated hollow glass beads into the azido silane coupling agent solution, the mass ratio of (3-azidopropyl) trimethoxysilane and the surface-hydroxylated hollow glass beads being 1:100, and condense and reflux at 80°C for 8h, then wash with pure water and ethanol, and dry at 60°C under vacuum to obtain azido-modified hollow glass beads.

[0060] (2) Fluorescent molecule grafting: the azide-modified hollow glass beads obtained in step (1) are added to pure water, and then a catalyst copper sulfate and sodium ascorbate (the catalyst is added in an amount of 1% of the mass of the fluorescent molecule, and the copper sulfate and sodium ascorbate account for 0.5% respectively), a fluorescent molecule CY7-anlyne with an alkyne group are added, the mass ratio of the azide-modified hollow glass beads and the fluorescent molecule is 2000:1, the mixture is uniformly mixed, heated at 60°C for 20 min, centrifuged, washed, vacuum low-temperature dried, and the fluorescent hollow glass beads are obtained.

[0061] Comparative Example 3 The preparation method of the fluorescent hollow glass beads of the present comparative example is basically the same as that of Comparative Example 1, except that the x:y:z in the hydrogel polymer is 90:5:5.

[0062] Comparative Example 4 The preparation method of the fluorescent hollow glass beads of the present comparative example is basically the same as that of Comparative Example 1, except that the x:y:z in the hydrogel polymer is 80:15:5.

[0063] III. Experimental Examples (1) Fluorescent intensity value test The fluorescent intensity of the fluorescent hollow glass beads obtained in the examples and comparative examples is tested, and the difference in fluorescent intensity value is compared as shown in Table 1, with an excitation wavelength of 750 nm.

[0064] Table 1 Fluorescent intensity value of fluorescent hollow glass beads

[0065] As can be seen from Table 1, the fluorescent intensity value of the hollow glass beads grafted with hydrogel on the surface provided by the present application is higher, mainly due to the three-dimensional structure of the hydrogel increasing the surface density of the fluorescent molecules, while different azide ratios have a certain influence on the fluorescent intensity value, and the azide group is not the higher the better, and the intensity value is the highest at a proper ratio.

[0066] (2) Stability test The fluorescent intensity value of the fluorescent hollow glass beads obtained in the examples and comparative examples is tested after being placed for a period of time, and the degree of fluorescence decay is obtained to evaluate the fluorescence stability. The change in fluorescent intensity value at different storage times is shown in Table 2 and Figure 2 .

[0067] Table 2 Fluorescent intensity value at different storage times

[0068] As can be seen from Table 2 and Figure 2It can be seen that the hollow glass beads grafted with the surface hydrogel provided by the present application have a slow fluorescence intensity value decay, while the hydrogel without grafting (comparative example 2) and the hydrogel adsorbed on the surface (comparative example 1) have a fast fluorescence intensity value decay, indicating that the stability is poorer.

[0069] Finally, it should be noted that: the above only for the preferred embodiments of the present application, and not for limiting the present application, although the foregoing detailed description of the present application is made with reference to the foregoing embodiments, for those skilled in the art, it still can be modified, or part of the technical features of the equivalent replacement, within the spirit and principles of the present application, any modification, equivalent replacement, improvement, etc., should be included within the scope of the present application.

Claims

1. Fluorescent hollow glass microbeads, characterized in that, The hollow glass microsphere comprises a hollow glass microsphere and a hydrogel coated on the surface of the hollow glass microsphere; the hydrogel is obtained by polyaddition reaction of raw materials comprising N-(2-aminoethyl) methacrylamide hydrochloride and an azido-containing polymerizable monomer; the amino group in the hydrogel is grafted on the surface of the hollow glass microsphere through epoxy-amine ring-opening reaction of the epoxy group in the hollow glass microsphere modified by the epoxy group; and the alkyne-containing fluorescent molecule is grafted on the hydrogel through click chemistry reaction of the alkyne group and the azido group in the hydrogel.

2. The fluorescent hollow glass microsphere according to claim 1, wherein The azido-containing polymerizable monomer is azido acrylamide; the raw materials comprise acrylamide; and the mass ratio of acrylamide, azido acrylamide and N-(2-aminoethyl) methacrylamide hydrochloride is (80-90):(5-15):

5.

3. A method of producing fluorescent hollow glass microbeads as claimed in claim 1 or 2, characterized by, The method comprises the following steps: The raw materials comprising N-(2-aminoethyl) methacrylamide hydrochloride and the azido-containing polymerizable monomer are subjected to polyaddition reaction to obtain the hydrogel; and the epoxy group modified hollow glass microsphere and the hydrogel are subjected to epoxy-amine ring-opening reaction to obtain the hollow glass microsphere coated with the hydrogel. Or the epoxy group modified hollow glass microsphere is subjected to reaction with the raw materials comprising N-(2-aminoethyl) methacrylamide hydrochloride and the azido-containing polymerizable monomer in a solvent under the action of an initiator to obtain the hollow glass microsphere coated with the hydrogel. Then, the hollow glass microsphere coated with the hydrogel is subjected to click chemistry reaction with the alkyne-containing fluorescent molecule to obtain the fluorescent hollow glass microsphere.

4. The method of claim 3, wherein the hollow glass microspheres are fluorescent. In the two preparation methods of the hollow glass microsphere coated with the hydrogel, the azido-containing polymerizable monomer is azido acrylamide; the raw materials comprise acrylamide; and the mass ratio of acrylamide, azido acrylamide and N-(2-aminoethyl) methacrylamide hydrochloride is (80-90):(5-15):

5.

5. The method for preparing fluorescent hollow glass microspheres as described in claim 3 or 4, characterized in that, In the epoxy-amine ring-opening reaction, the mass ratio of the epoxy group modified hollow glass microsphere and the hydrogel is (20-30):1; or in the reaction of the epoxy group modified hollow glass microsphere and the raw materials under the action of the initiator, the mass ratio of the epoxy group modified hollow glass microsphere and the raw materials is (20-50):

1.

6. The method of claim 3, wherein the hollow glass microspheres are fluorescent. The mass ratio of the hollow glass microsphere coated with the hydrogel and the alkyne-containing fluorescent molecule is (2000-5000):1; the temperature of the click chemistry reaction is 60-80°C; and the time of the click chemistry reaction is 20-30 min.

7. The method of claim 3, wherein the hollow glass microspheres are fluorescent. The epoxy group modified hollow glass microsphere is obtained by surface treatment of the hollow glass microsphere in a solution of silane coupling agent with an epoxy group, and the mass ratio of the silane coupling agent with the epoxy group and the hollow glass microsphere is (1-2):

100.

8. The method for preparing fluorescent hollow glass microspheres as described in claim 7, characterized in that, The temperature of the surface treatment is 80-100°C, and the time is 4-8 h.

9. The method for preparing fluorescent hollow glass microspheres as described in claim 3 or 4, characterized in that, In the reaction of the epoxy group modified hollow glass microsphere and the raw materials under the action of the initiator, the temperature is 40-60°C, and the time is 2-3 h.

10. The method for preparing fluorescent hollow glass microspheres as described in claim 3 or 4, characterized in that, In the polyaddition reaction, the temperature is 40-60°C, and the time is 2-3 h; and in the epoxy-amine ring-opening reaction, the temperature is 50-70°C, and the time is 1-2 h.

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