Responsive microspheres based on three-dimensional magnetic photonic crystals, preparation method and application thereof

Abstract

The present application relates to the technical field of sensing of magnetic nano-optoelectronic materials, and particularly relates to a responsive microsphere based on three-dimensional magnetic photonic crystals, a preparation method and application thereof, wherein magnetic nanoparticles modified by a polyhydroxy compound are arranged in a non-close-packed face-centered cubic or body-centered cubic structure in a spherical polymer to form the responsive microsphere. The responsive microsphere based on three-dimensional magnetic photonic crystals has an easily distinguishable color, is not angle-dependent, does not need to rely on fluorescent dyes or radioactive labels, and can realize real-time and in-situ monitoring through its own optical properties, thus breaking through the bottleneck of sensitivity and resolution of traditional sensors, realizing visual detection, simplifying the detection process, and reducing the cost. The responsive microsphere based on three-dimensional magnetic photonic crystals shortens the diffusion path of substances through its small size, and significantly improves the response speed in combination with a high specific surface area.

Description

Technical Field

[0001] This invention relates to the field of sensing technology of magnetic nano-optoelectronic materials, specifically to a responsive microsphere based on a three-dimensional magnetic photonic crystal, its preparation method, and its application. Background Technology

[0002] Photonic crystals, due to their unique photonic bandgap characteristics and structural colors, show broad application prospects in fields such as sensing, display, and information encryption. Three-dimensional photonic crystal microspheres interact with external target substances through their internally periodically arranged mesoscopic structures. Qualitative and quantitative detection of target analytes can be achieved through optical signals such as photonic bandgap shifts and changes in reflection spectra. Their detection performance is closely related to the material's structural design, functional regulation, and subsequent separation efficiency, making it a key research focus and challenge in the field of functional materials.

[0003] In the existing technology, various technical solutions have been developed for the design and fabrication of photonic crystal microspheres, but significant performance shortcomings still exist, making it difficult to simultaneously meet the application requirements of high detection sensitivity, convenient separation operation, and wide response range:

[0004] Firstly, although non-magnetic photonic crystal microspheres possess basic optical response capabilities, they require separation using traditional methods such as centrifugation and filtration after detection. This process can easily lead to microsphere aggregation or loss. In trace detection systems, the low separation efficiency directly affects the repeatability and accuracy of the results, thus limiting their application in trace analysis.

[0005] To address this separation challenge, some solutions propose designing bifacial magnetic photonic crystal microspheres: these microspheres have optical response capabilities on one side and magnetic capabilities on the other, utilizing the magnetic side for magnetic field-assisted separation. However, this design, which separates magnetic and response functions, requires precise external magnetic field guidance to move the microsphere. Without a magnetic field, the single-sided response surface cannot fully contact the analyte, leading to a significant decrease in detection efficiency and sensitivity, failing to meet the requirements for high-precision detection.

[0006] Secondly, another technique involves coating magnetic nanoparticles with a silica shell and then using the coated particles to prepare photonic crystal microspheres, giving the microspheres both magnetic and responsive properties. However, in this technique, the particles are densely packed inside the microspheres, which not only hinders the effective diffusion of analytes into the microspheres but also compresses the adjustable space of the photonic crystal structure. This results in a significant reduction in the optical response range of the microspheres, making it difficult to achieve a broad-spectrum response to different concentrations and types of analytes, further limiting its applicability in complex detection systems.

[0007] In summary, there is an irreconcilable technical contradiction between current photonic crystal microspheres in terms of separation efficiency, detection sensitivity, and response range. There is an urgent need to develop a novel photonic crystal microsphere that combines high separation performance, high detection sensitivity, and wide response range in order to break through the existing technical bottlenecks and meet the high-performance requirements of functional materials in the field of analytical testing. Summary of the Invention

[0008] One of the objectives of this invention is to provide a responsive microsphere based on a three-dimensional magnetic photonic crystal, which has a higher reflectivity than a one-dimensional photonic crystal, breaking through the bottlenecks of sensitivity and resolution of traditional microspheres and enabling visual detection.

[0009] The second objective of this invention is to provide a method for preparing responsive microspheres based on three-dimensional magnetic photonic crystals, which is simple to operate, easy to control, and produces non-toxic and harmless products that are environmentally friendly.

[0010] The third objective of this invention is to provide an application of responsive microspheres based on three-dimensional magnetic photonic crystals.

[0011] One of the technical solutions adopted to achieve the objective of this invention is: a responsive microsphere based on a three-dimensional magnetic photonic crystal, which is formed by magnetic nanoparticles modified with polyhydroxy compounds arranged in a non-closely packed face-centered cubic or body-centered cubic structure in a spherical polymer.

[0012] Preferably, the magnetic nanoparticles are magnetic nanoparticles modified with polyhydroxy compounds after being treated with an alkaline solution, which are used to improve the electrostatic repulsion of the particle surface.

[0013] Preferably, the magnetic nanoparticles include at least one of the magnetic elements selected from iron, cobalt, nickel, manganese, vanadium, terbium, europium, and gadolinium, which are present on their surface or in themselves.

[0014] Preferably, the magnetic nanoparticles have a particle size of 60-300 nm.

[0015] Preferably, the non-close packing refers to the absence of substantial contact between adjacent magnetic nanoparticles, i.e., the polymer constitutes a continuous phase, while the magnetic nanoparticles constitute a discontinuous phase.

[0016] Preferably, the polyhydroxy compound includes at least one of tannic acid, catechin, epigallocatechin gallate, epigallocatechin gallate, benzotriazole, gluconic acid, glucose, gluconate, dopamine, chlorogenic acid, neochlorogenic acid, and lignin compounds.

[0017] Preferably, the alkaline solution is a solution with a pH greater than 7, including but not limited to at least one of sodium hydroxide solution, sodium tetraborate decahydrate solution, sodium carbonate solution, sodium bicarbonate solution, sodium acetate solution, and sodium phosphate solution.

[0018] The second objective of this invention is achieved through the following technical solution: a method for preparing responsive microspheres based on a three-dimensional magnetic photonic crystal, comprising the following steps:

[0019] (1) Magnetic nanoparticles are dispersed in a prepolymer liquid containing polymerizable monomers to obtain a mixed solution;

[0020] (2) The mixed solution obtained in step (1) is used as phase A, the poor solvent of phase A is used as phase B, phase A is dispersed into small droplets by phase B, and then polymerization is initiated to obtain the responsive microspheres based on the three-dimensional magnetic photonic crystal.

[0021] Preferably, in step (1), the concentration of magnetic nanoparticles in the prepolymer solution is 1wt%-75wt%.

[0022] Preferably, in step (1), the prepolymer liquid includes a polymerizable monomer, an initiator, and a solvent; the polymerizable monomer is of at least one type, and at least one of the polymerizable monomers has a polymerizable group number greater than or equal to 2, and the molar percentage of the polymerizable monomer in the prepolymer liquid is 0.5%-100%; the initiator includes at least one of a photoinitiator and a thermal initiator, and its content is 0-30% of the total molar amount of the polymerizable monomer.

[0023] Preferably, in step (1), the polymerizable monomer includes at least one of the following groups: acrylate group, carboxylic acid, amino group, hydrazone group, acetal group, ketal group, amide group, imine group, sulfonic acid group, hydroxyl group, pyridyl group, phosphoric acid, phosphate ester, quinone group, thiol group, phenylboronic acid, borate ester, crown ether, disulfide group, selenide group, peptide group, glycosidic group, thioether group, and tellurium ether group.

[0024] Preferably, the solvent in the prepolymer liquid includes at least one of carbonates, carboxylic esters, ethers, alkanols, pyrrolidones, acetonitrile, dimethyl sulfoxide, deionized water, acetone, and N,N-dimethylformamide, with a mass percentage of 0-90%.

[0025] Preferably, the carbonates include at least one of cyclic carbonates (such as ethylene carbonate, propylene carbonate), chain carbonates (such as dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate), and fluorocarbonates; the carboxylic acid esters include at least one of γ-butyrolactone, ethyl acetate, and methyl formate; the ethers include at least one of tetrahydrofuran, 2-methyltetrahydrofuran, dimethoxymethane, and 1,2-dimethoxyethane; the alkanols include at least one of methanol, ethanol, and isopropanol; and the pyrrolidones include at least one of N-methylpyrrolidone, 1-epoxy-2-pyrrolidone, N-octylpyrrolidone, 1-acetyl-2-pyrrolidone, 4-hydroxy-2-pyrrolidone, 2-pyrrolidone, and 1-methyl-2-pyrrolidone. The fluorocarbonates include fluorocyclic carbonates (such as fluoroethylene carbonate: fluoroethylene carbonate, difluoroethylene carbonate, trifluoromethyl ethylene carbonate, fluoropropylene carbonate: trifluoromethyl propylene carbonate, etc.) and fluorochain carbonates (such as dimethyl fluorocarbonate, methyl ethyl fluorocarbonate, diethyl fluorocarbonate, etc.).

[0026] Preferably, the polymerizable monomers react to form a three-dimensional polymer through a polymerization reaction, wherein the polymerization reaction includes free radical polymerization or ionic polymerization.

[0027] Preferably, the polymerizable monomers include, but are not limited to, ethoxylated trimethylolpropane triacrylate (ETPTA), ethylene glycol dimethacrylate (EGDMA), N,N′-methylenebisacrylamide (BIS), polyethylene glycol diacrylate (PEGDA), acrylic acid (AA), methacrylic acid (MAA), methyl methacrylate, acrylamide acrylic acid, styrene-benzene sulfonic acid, methacrylic acid sulfonic acid, acrylic acid sulfuric acid, N... Hydroxyethylacrylamide, N,N-methyleneacrylamide, (N Isopropylacrylamide), (N Isopropylmethacrylamide), N,N Diethylacrylamide, hydroxyethyl methacrylate, methyl methacrylate, 3 Acrylamidophenylboronic acid, 3-methylacrylamidophenylboronic acid, 4 At least one of vinylphenylboronic acid, ethyleneimine, glycine, leucine, etc.

[0028] Preferably, the polymerizable monomer includes a responsive polymerizable monomer that can be polymerized into a polymer with responsive functions, wherein the responsiveness includes at least one of magnetic response, pH response, ionic response, solvent response, sugar response, and electric field response.

[0029] Preferably, the responsive polymerizable monomers include, but are not limited to, acrylic acid (AA), methacrylic acid (MAA), methyl methacrylate, acrylamide acrylic acid, styrene-benzenesulfonic acid, methacrylic acid sulfonic acid, acrylic acid sulfuric acid, and N-methyl methacrylate. Hydroxyethylacrylamide, (N Isopropylacrylamide), (N Isopropylmethacrylamide), N,N Diethylacrylamide hydroxyethyl methacrylate, methyl methacrylate, 3 Acrylamidophenylboronic acid, 3-methylacrylamidophenylboronic acid, 4 At least one of vinylphenylboronic acid, etc.

[0030] Preferably, the responsive polymers, such as pH-responsive polymers, include, but are not limited to, polyacrylic acid (PAA), polymethacrylic acid (PMAA), polymethyl methacrylate, and poly(N-methyl methacrylate). At least one of acrylamide-based acrylic acid, etc.; ion-responsive polymers including but not limited to at least one of PAA, PMAA, polystyrene-benzenesulfonic acid, polymethyl methacrylate sulfonic acid, polyacrylic acid sulfuric acid, etc.; temperature-responsive polymers including but not limited to poly(N-methyl- ... Hydroxyethylacrylamide, poly(N) Isopropylacrylamide (PNIPAM), poly(N) Isopropyl methacrylamide), poly(N,N) At least one of diethylacrylamide, etc.; solvent-responsive polymers including but not limited to at least one of polyhydroxyethyl methacrylate (PHEMA), polymethyl methacrylate, etc.; sugar-responsive polymers including but not limited to poly(3-ethylhexyl methacrylate) Acrylamidophenylboronic acid (PAAPBA), poly(3-methacrylamidophenylboronic acid), poly(4-methacrylamidophenylboronic acid) At least one of vinylphenylboronic acid, etc.; electric field responsive polymers include, but are not limited to, PAA, PMAA, PHEMA, polymethyl methacrylate, poly(N-methyl methacrylate), etc. At least one of acrylamide-based acrylic acid, etc.

[0031] Preferably, the photoinitiator includes at least one of 2-hydroxy-2-methyl-1-phenylpropanone (HMPP), 2-hydroxy-2-methyl-1-[4-(2-hydroxyethoxy)phenyl]-1-propanone, and the thermal initiator includes at least one of azobisisobutyronitrile, azobisisobutyronitrile, ammonium persulfate, and so on.

[0032] Preferably, the magnetic nanoparticles are magnetic nanoparticles modified with polyhydroxy compounds after treatment with an alkaline solution, in order to improve the electrostatic repulsion on the particle surface.

[0033] Preferably, in step (2), the volume ratio of phase A to phase B is 1:5-50. The specific process of using phase B to disperse phase A into small droplets is as follows: after mixing phase A and phase B, phase A is dispersed into small droplets by stirring or microfluidic control. Phase B includes at least one of mineral oil, silicone oil, alkanes, and halogenated hydrocarbons.

[0034] Preferably, the silicone oil includes at least one of the following: linear silicone oil (such as dimethyl silicone oil / polydimethylsiloxane, benzyl silicone oil, methyl silicone oil, fluorinated silicone oil), cyclic silicone oil (such as octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane), branched silicone oil (such as methyltriethoxysilane modified silicone oil, vinyl branched silicone oil).

[0035] Preferably, the alkane may include liquid alkane or solid alkane that is soluble in liquid alkane or can be converted into liquid by methods such as heating (temperature below 60°C).

[0036] Preferably, the alkane has between 5 and 25 carbon atoms.

[0037] Preferably, the alkane is at least one of straight-chain alkanes (such as n-pentane, n-dodecane, hexadecane, etc.), cycloalkanes (such as cyclohexane, cyclooctane, etc.), and isoalkanes (such as isopentane, isooctane, etc.).

[0038] Preferably, the halohydrocarbon is a liquid halohydrocarbon with less than 15 carbon atoms.

[0039] Preferably, the halogenated hydrocarbon includes at least one of saturated halogenated hydrocarbons (such as 2-chloropropane, 1-bromobutane, 3-chloropentane, etc.), unsaturated halogenated hydrocarbons (such as vinyl chloride, 3-bromopropene, p-bromostyrene, etc.), and aromatic halogenated hydrocarbons (such as chlorobenzene, o-dichlorobenzene, p-bromophenol, o-bromobenzaldehyde, m-dichlorobenzene, etc.).

[0040] The third objective of this invention is achieved through the following technical solution: an application of the responsive microspheres based on three-dimensional magnetic photonic crystals, which are applied to biomedical detection or diagnosis, environmental monitoring, chemical sensing, smart display, optical devices, and flexible wearable devices.

[0041] The aforementioned responsive microspheres based on three-dimensional magnetic photonic crystals, by integrating materials science, photonics, and micro / nano fabrication technologies, provide a breakthrough solution for innovation in fields such as intelligent sensing, precision medicine, and green energy. Their core value lies in encapsulating complex optical response mechanisms at the microsphere scale, combining high performance, low cost, and potential for large-scale production, thus possessing broad market application prospects.

[0042] The present invention has the following advantages:

[0043] The responsive microspheres based on three-dimensional magnetic photonic crystals of the present invention can achieve rapid directional collection of microspheres through gentle magnetic interaction, effectively preserving the integrity of the microspheres and the trace amounts of substances to be detected bound thereto, avoiding signal loss or "false negative" results caused by separation operations; at the same time, it eliminates the forced dependence on external magnetic fields, adapts to the detection needs under magnetic field-free conditions, and significantly broadens the application scenarios.

[0044] The responsive microspheres based on three-dimensional magnetic photonic crystals of the present invention enable high-precision analysis in trace analysis scenarios. The weak optical signals generated by the interaction between the substance to be detected and the microspheres can also be efficiently transmitted and amplified through the complete photonic crystal structure, which greatly improves the detection accuracy, meets the requirements of high-precision analysis, and ensures the accuracy and repeatability of the detection results.

[0045] The responsive microspheres based on three-dimensional magnetic photonic crystals of the present invention can expand the contact area between the substance to be detected and the photonic crystal structure, reduce diffusion resistance, achieve broad-spectrum response to different concentrations and types of substances to be detected (such as trace pollutants in the environment and trace biomarkers in biological body fluids), adapt to complex detection systems, and improve the applicability of the technology.

[0046] The responsive microspheres based on three-dimensional magnetic photonic crystals of this invention provide an efficient and multifunctional platform solution for innovation in fields such as intelligent sensing, precision medicine, and green energy. Its core value lies in encapsulating complex photonic manipulation mechanisms at the microsphere scale, achieving a leapfrog breakthrough from laboratory research to practical applications. Attached Figure Description

[0047] Figure 1 This is a schematic diagram of the structure of the three-dimensional magnetic photonic crystal microsphere in this invention;

[0048] Figure 2 The images shown are SEM images and magnified views of the three-dimensional magnetic photonic crystal microspheres prepared in Example 1, where a is an SEM image of the three-dimensional magnetic photonic crystal microspheres, b is a magnified view of the part enclosed in a, and c is a magnified view of the part enclosed in b.

[0049] Figure 3 An optical microscope image of the microspheres based on a three-dimensional magnetic photonic crystal prepared in Example 1 of this invention;

[0050] Figure 4 The image shows the reflection spectrum of the three-dimensional magnetic photonic crystal microspheres prepared in Example 1 of this invention in a 200 mM glucose solution.

[0051] Figure 5 The image shows the reflection spectrum of the three-dimensional magnetic photonic crystal microspheres prepared in Example 2 of this invention in a 200 mM glucose solution.

[0052] Figure 6 This is a comparison chart of the reflectance of the microspheres prepared in Example 1 and Example 2 of the present invention in propylene carbonate solution;

[0053] Figure 7 The image shows the reflectance spectrum of the pH-responsive microspheres based on a three-dimensional magnetic photonic crystal prepared in Example 4 of this invention in Na2CO3 solution.

[0054] Figure 8 The reflection spectra of the temperature-responsive microspheres based on the three-dimensional magnetic photonic crystal in Embodiment 7 of the present invention at 25°C and 60°C;

[0055] Figure 9 This is a physical image of the temperature-responsive microspheres based on a three-dimensional magnetic photonic crystal prepared in Example 9 of the present invention, as the temperature is increased from 25°C to 50°C.

[0056] Figure 10 The image shows the reflectance spectra of the ion-responsive microspheres based on a three-dimensional magnetic photonic crystal prepared in Example 10 of this invention in solutions with ion intensities of 150 mmol / L and 1000 mmol / L, respectively.

[0057] Figure 11 The image shows the reflection spectra of the solvent-responsive microspheres based on a three-dimensional magnetic photonic crystal prepared in Example 12 of this invention in aqueous and ethanol solutions. Detailed Implementation

[0058] The present invention will be further described below with reference to the embodiments and accompanying drawings, but the content of the present invention is not limited to the following embodiments.

[0059] The responsive polymer materials used in the embodiments of this invention are all materials disclosed in the prior art, and all can achieve the inventive purpose of this application, but do not only include the responsive materials described in this embodiment.

[0060] Example 1 (Glucose Response)

[0061] (1) Add a 10 mg / ml tannic acid / propylene carbonate (TA / PC) solution to Fe3O4 particles, disperse by ultrasonication, and wash with propylene carbonate solution 1-2 times to obtain Fe3O4@TA particles; (2) Take 3 g of 3-acrylamide phenylboronic acid, 0.03 g of ETPTA (ethoxylated trimethylolpropane triacrylate), 0.02 g of azobisisoheptanenitrile, and 1 ml of propylene carbonate and mix them evenly by ultrasonication to prepare a prepolymer solution; take 40 mg of Fe3O4@TA particles and mix them evenly with 100 μL of prepolymer solution by ultrasonication to obtain a mixed solution; (3) Take the mixed solution as phase A and mineral oil as phase B, mix phase A and phase B, disperse phase A into small droplets by mechanical stirring, and thermally initiate polymerization to obtain glucose-responsive microspheres based on three-dimensional magnetic photonic crystals.

[0062] Figure 1 The diagram shown is a schematic diagram of the structure of the three-dimensional photonic crystal microsphere in Embodiment 1 of the present invention. The three-dimensional photonic crystal microsphere of the present invention is formed by non-closely packed magnetic nanoparticles into a spherical shape. Figure 2 The images show SEM images and magnified views of the three-dimensional magnetic photonic crystal microspheres prepared in this embodiment. As can be seen from the images, the prepared microspheres are arranged in a spherical shape by non-close packing of magnetic nanoparticles. That is, the polymer constitutes a continuous phase, and the magnetic nanoparticles are non-closely packed in the polymer with gaps between adjacent nanoparticles.

[0063] Figure 3 The image shown is an optical microscope image of the three-dimensional magnetic photonic crystal microspheres prepared in this embodiment. As can be seen from the image, the prepared microspheres exhibit bright structural colors and uniform color.

[0064] Figure 4 The figure shows the reflection spectrum of the three-dimensional magnetic photonic crystal microspheres prepared in this embodiment in a 200mM glucose solution. As can be seen from the figure, the reflection peak position shifted from 641nm to 718nm before and after the addition of glucose solution, which is a shift of 77nm.

[0065] Example 2 (Glucose Response)

[0066] (1) Add a 10 mg / ml tannic acid / propylene carbonate (TA / PC) solution to Fe3O4 particles, disperse by ultrasonication, and wash with propylene carbonate solution 1-2 times to obtain Fe3O4@TA particles; (2) Take the particles from step (1) and add a 12.5 mg / ml sodium tetraborate decahydrate aqueous solution and a 5-10 mg / ml tannic acid aqueous solution respectively; (3) Wash the product from step (2) twice with deionized water and ethanol respectively, and disperse it in propylene carbonate for later use. (4) Take 3g of 3-acrylamide phenylboronic acid, 0.03g of ETPTA, 0.02g of azobisisoheptanenitrile and 1ml of propylene carbonate and mix them evenly by ultrasonication to prepare a prepolymer solution; take 40mg of Fe3O4@TA particles treated with alkali solution and mix them evenly with 100μL of prepolymer solution by ultrasonication to obtain a mixed solution; (5) take the mixed solution as phase A and mineral oil as phase B, mix phase A and phase B and disperse phase A into small droplets by mechanical stirring, and thermally initiate polymerization to obtain glucose-responsive microspheres based on three-dimensional magnetic photonic crystals.

[0067] (2) Figure 5 The figure shows the reflection spectrum of the three-dimensional magnetic photonic crystal microspheres prepared in this embodiment in a 200mM glucose solution. As can be seen from the figure, the reflection peak position shifted from 587nm to 718nm before and after the addition of glucose solution, which is a shift of 131nm, and the change from yellow to red.

[0068] Figure 6 The image shows a comparison of the reflectance of particles in propylene carbonate solution before and after alkali treatment in Examples 1 and 2. It can be seen that the reflectance of the particles improved after alkali treatment. Figure 4 and Figure 5 The response results also show that the enhancement of electrostatic repulsion on the particle surface is beneficial for the visualization research of magnetic nanoparticles in sensing applications.

[0069] Example 3 (Glucose Response)

[0070] (1) Add a 10 mg / ml tannic acid / propylene carbonate (TA / PC) solution to γ-Fe2O3 particles, disperse by ultrasonication, and wash with propylene carbonate solution 1-2 times to obtain γ-Fe2O3@TA particles; (2) Take 0.3 g of 3-methylacrylamidophenylboronic acid, 0.03 g of EGDMA, 0.03 g of azobisisoheptanenitrile, and 1 ml of propylene carbonate, mix them evenly by ultrasonication to prepare a prepolymer solution; take 40 mg of γ-Fe2O3@TA particles and 100 μL of prepolymer solution, mix them evenly by ultrasonication to obtain a mixed solution; (3) Take the mixed solution as phase A and mineral oil as phase B, mix phase A and phase B, disperse phase A into small droplets by mechanical stirring, and thermally initiate polymerization to obtain glucose-responsive microspheres based on three-dimensional magnetic photonic crystals. The prepared microspheres showed a 62 nm shift in the reflection peak position before and after the addition of glucose solution.

[0071] Example 4 (pH response)

[0072] (1) Add a 10 mg / ml tannic acid / propylene carbonate (TA / PC) solution to Fe3O4 particles, disperse by ultrasonication, and wash with propylene carbonate solution 1-2 times to obtain Fe3O4@TA particles; (2) Take the particles from step (1) and add a 12.5 mg / ml sodium tetraborate decahydrate aqueous solution and a 5-10 mg / ml tannic acid aqueous solution respectively; (3) Wash the product from step (2) twice with deionized water and ethanol respectively, and disperse it in propylene carbonate solution. (4) Take 3g of acrylic acid, 0.03g of ETPTA, 0.02g of azobisisoheptanenitrile and 1ml of propylene carbonate and mix them evenly by ultrasonication to prepare a prepolymer solution; take 40mg of Fe3O4@TA particles treated with alkali solution and mix them evenly with 150μL of prepolymer solution by ultrasonication to obtain a mixed solution; (5) take the mixed solution as phase A and mineral oil as phase B, mix phase A and phase B and disperse phase A into small droplets by mechanical stirring, and thermally initiate polymerization to obtain pH-corresponding three-dimensional magnetic photonic crystal microspheres.

[0073] Figure 7The image shows the reflection spectrum of the three-dimensional magnetic photonic crystal microspheres in Na2CO3 aqueous solution in this embodiment. The reflection peak shifted by 59 nm, and the color changed from yellow to red, indicating that the prepared microspheres have a certain degree of responsiveness.

[0074] Example 5 (pH response)

[0075] (1) Add a 12 mg / ml tannic acid / propylene carbonate (TA / PC) solution to NiO particles, disperse by ultrasonication, and wash with propylene carbonate solution 1-2 times to obtain NiO@TA particles; (2) Take 0.3 g methacrylic acid, 0.03 g EGDMA (ethylene glycol dimethacrylate), 0.02 g HMPP, and 1 ml propylene carbonate and mix them evenly by ultrasonication to prepare a prepolymer solution; take 40 mg NiO@TA particles and mix them evenly with 100 μL of prepolymer solution by ultrasonication to obtain a mixed solution; (3) Use the mixed solution as phase A and mineral oil as phase B. Mix phase A and phase B and disperse phase A into small droplets through a microfluidic device. Photoinitiated polymerization is used to obtain pH-responsive microspheres based on three-dimensional magnetic photonic crystals. The reflection peak position of the prepared microspheres in Na2CO3 aqueous solution shifts by 45 nm, indicating that the prepared microspheres have certain response performance.

[0076] Example 6 (pH response)

[0077] (1) Add a 12 mg / ml catechin / propylene carbonate (CA / PC) solution to NiS particles, disperse by ultrasonication, and wash with propylene carbonate solution 1-2 times to obtain NiS@CA particles; (2) Take 3 g acrylic acid, 0.03 g ETPTA, 0.02 g azobisisoheptanenitrile, and 1 ml propylene carbonate and mix them evenly by ultrasonication to prepare a prepolymer solution; take 40 mg NiS@CA particles and mix them evenly with 150 μL of prepolymer solution by ultrasonication to obtain a mixed solution; (3) Use the mixed solution as phase A and mineral oil as phase B, mix phase A and phase B, disperse phase A into small droplets by mechanical stirring, and thermally initiate polymerization to obtain pH-corresponding microspheres based on three-dimensional magnetic photonic crystals. The prepared microspheres showed a 61 nm shift in the reflection peak position in Na2CO3 aqueous solution, and the color changed from yellow to red.

[0078] Example 7 (Temperature Response)

[0079] (1) Add a 10 mg / ml tannic acid / propylene carbonate (TA / PC) solution to MnS particles, disperse by ultrasonication, and wash with propylene carbonate solution 1-2 times to obtain MnS@TA particles; (2) Take the particles from step (1) and add a 12.5 mg / ml sodium tetraborate decahydrate aqueous solution and a 5-10 mg / ml tannic acid aqueous solution respectively; (3) Wash the product from step (2) twice with deionized water and ethanol respectively, and disperse it in propylene carbonate for later use; (4) Take 3g N-isopropylacrylamide and 0.03g ETPTA, 0.02g 2-hydroxy-2-methyl-1-[4-(2-hydroxyethoxy)phenyl]-1-propanone, and 1ml propylene carbonate were ultrasonically mixed to prepare a prepolymer solution; 40mg of alkali-treated MnS@TA particles were ultrasonically mixed with 200μL of the prepolymer solution to obtain a mixed solution; (5) The mixed solution was used as phase A and mineral oil was used as phase B. The phase A and phase B were mixed and dispersed into small droplets by mechanical stirring. Photoinitiated polymerization was used to obtain temperature-responsive microspheres based on three-dimensional magnetic photonic crystals.

[0080] Figure 8 The image shows the reflection spectra of the three-dimensional magnetic photonic crystal microspheres in this embodiment at 25℃ and 60℃. The reflection peak position shifted from 598nm to 673nm, a shift of 75nm, and changed from orange to red.

[0081] Example 8 (Temperature Response)

[0082] (1) Add a 10 mg / ml dopamine / propylene carbonate (DA / PC) solution to γ-Fe2O3 particles, disperse by ultrasonication, and wash with propylene carbonate solution 1-2 times to obtain γ-Fe2O3@DA particles; take 0.3 g N, N Diethylacrylamide, 0.03g EGDMA, 0.03g HMPP, and 1ml propylene carbonate were ultrasonically mixed to prepare a prepolymer solution; 40mg γ-Fe2O3@DA particles were ultrasonically mixed with 100μL of the prepolymer solution to obtain a mixed solution; (2) The mixed solution was used as phase A, and mineral oil was used as phase B. The phase A and phase B were mixed and dispersed into small droplets by a microfluidic device. Photoinitiated polymerization was used to obtain temperature-responsive microspheres based on three-dimensional magnetic photonic crystals. The prepared microspheres shifted by 103nm when heated from 25℃ to 60℃.

[0083] Example 9 (Temperature Response)

[0084] (1) Add a 10 mg / ml tannic acid / propylene carbonate (TA / PC) solution to Fe3O4 particles, disperse by ultrasonication, and wash with propylene carbonate solution 1-2 times to obtain Fe3O4@TA particles; (2) Take 0.3 g N, N Diethylacrylamide, 0.03g ETPT A 0.03g of azobisisoheptane and 1ml of propylene carbonate were ultrasonically mixed to prepare a prepolymer solution; 40mg of Fe3O4@TA particles were ultrasonically mixed with 100μL of the prepolymer solution to obtain a mixed solution; (3) the mixed solution was used as phase A and pentadecane was used as phase B. Pentadecane was dissolved in a 55℃ water bath and phase A was added to mix. The phase A and phase B were mixed and dispersed into small droplets by mechanical stirring. Photoinitiated polymerization was used to obtain temperature-responsive three-dimensional magnetic photonic crystal microspheres. Figure 9 The image shows the changes in the prepared microspheres as the temperature was increased from 25°C to 50°C. It is easy to see that the color of the microspheres changed from red to blue. The reflection peak shifted by 185 nm upon testing.

[0085] Example 10 (Ion Response)

[0086] (1) Add a 10 mg / ml gluconic acid / propylene carbonate (GA / PC) solution to CoS particles, disperse by ultrasonication, and wash with propylene carbonate solution 1-2 times to obtain CoS@GA particles; (2) Take 0.3 g methacrylic acid sulfonic acid, 0.03 g PEGDA (polyethylene glycol diacrylate), 0.03 g HMPP, and 1 ml propylene carbonate and mix them evenly by ultrasonication to prepare a prepolymer solution; take 20 mg CoS@GA particles and mix them evenly with 100 μL of prepolymer solution by ultrasonication to obtain a mixed solution; (3) Take the mixed solution as phase A and mineral oil as phase B, mix phase A and phase B, disperse phase A into small droplets by microfluidic device, and photo-initiated polymerization to obtain ion-responsive three-dimensional magnetic photonic crystal microspheres.

[0087] Figure 10 The image shows the reflection spectra of the three-dimensional magnetic photonic crystal microspheres in this embodiment in solutions with ionic intensities of 150 mmol / L and 1000 mmol / L, respectively. The reflection peak position shifted from 562 nm to 630 nm, a shift of 68 nm, achieving a change from green to red.

[0088] Example 11 (Ion Response)

[0089] (1) Add a 10 mg / ml gluconic acid / propylene carbonate (GA / PC) solution to CoS particles, disperse them by ultrasonication, and wash them 1-2 times with propylene carbonate solution to obtain CoS@GA particles; (2) Take the particles from step (1) and add them to a 0.1 mol / L sodium hydroxide aqueous solution; (3) Wash the product from step (2) twice with deionized water and ethanol, and disperse it in propylene carbonate for later use; (4) Take 0.3 g methacrylic acid sulfonic acid, 0.03 g PEGDA (polyethylene glycol diacrylate), 0.03 g HMPP, and 1 ml propylene carbonate and mix them evenly by ultrasonication to prepare a prepolymer solution; Take 20 mg of CoS@GA particles treated with alkali solution and mix them evenly with 100 μL of prepolymer solution by ultrasonication to obtain a mixed solution; (5) Take the mixed solution as phase A and mineral oil as phase B, mix phase A and phase B, disperse phase A into small droplets through a microfluidic device, and photo-initiated polymerization to obtain ion-responsive three-dimensional magnetic photonic crystal microspheres. The prepared microspheres showed a 48 nm shift in their reflection peak when the solution with an ionic strength of 150 mmol / L was changed to a solution with an ionic strength of 1000 mmol / L.

[0090] Example 12 (Solvent Response)

[0091] (1) Add a 10 mg / ml gluconic acid / propylene carbonate (GA / PC) solution to CoO particles, disperse by ultrasonication, and wash with propylene carbonate solution 1-2 times to obtain CoO@GA particles; (2) Take 0.3 g butyl methacrylate, 0.03 g PEGDA (polyethylene glycol diacrylate), 0.03 g 2-hydroxy-2-methyl-1-[4-(2-hydroxyethoxy)phenyl]-1-propanone, and 1 ml propylene carbonate and mix them evenly by ultrasonication to prepare a prepolymer solution; take 40 mg CoO@GA particles and mix them evenly with 150 μL of prepolymer solution by ultrasonication to obtain a mixed solution; (3) Take the mixed solution as phase A and mineral oil as phase B, mix phase A and phase B, disperse phase A into small droplets by microfluidic device, and photo-initiated polymerization to obtain solvent-responsive microspheres based on three-dimensional magnetic photonic crystals.

[0092] Figure 11 The image shows the reflection spectra of the three-dimensional magnetic photonic crystal microspheres in aqueous and ethanol solutions in this embodiment. The reflection peak position shifted from 585nm to 659nm, a shift of 74nm, and the color changed from yellow to red.

[0093] Example 13 (Solvent Response)

[0094] (1) Add a 10 mg / ml gluconic acid / propylene carbonate (GA / PC) solution to the CoO particles, disperse by ultrasonication, and wash with propylene carbonate solution 1-2 times to obtain CoO@GA particles; (2) Take the particles from step (1) and add them to a 0.1 mol / L sodium hydroxide aqueous solution; (3) Wash the product from step (2) twice with deionized water and ethanol, and disperse it in propylene carbonate for later use; (4) Take 0.3 g butyl methacrylate and 0.03 g PEGDA (polyethylene glycol) (5) 0.03 g of 2-hydroxy-2-methyl-1-[4-(2-hydroxyethoxy)phenyl]-1-propanone and 1 ml of propylene carbonate were ultrasonically mixed to prepare a prepolymer solution; 40 mg of alkali-treated CoO@GA particles were ultrasonically mixed with 150 μL of the prepolymer solution to obtain a mixed solution; (6) The mixed solution was used as phase A and mineral oil as phase B. The phase A and phase B were mixed and dispersed into small droplets by a microfluidic device. Photoinitiated polymerization was used to obtain solvent-responsive microspheres based on three-dimensional magnetic photonic crystals. The prepared microspheres were converted from aqueous solution to ethanol solution, and the reflection peak position shifted by 90 nm.

[0095] Example 14 (Magnetic Response)

[0096] (1) Add a 10 mg / ml tannic acid / propylene carbonate (TA / PC) solution to Fe3O4 particles, disperse by ultrasonication, and wash with propylene carbonate solution 1-2 times to obtain Fe3O4@TA particles; (2) Take the particles from step (1) and add a 12.5 mg / ml sodium tetraborate decahydrate aqueous solution and a 5-10 mg / ml tannic acid aqueous solution respectively; (3) Wash the product from step (2) twice with deionized water and ethanol respectively, and disperse in (4) Take 1g ETPTA, 0.03g azobisisovalerate, and 1ml propylene carbonate and mix them evenly by ultrasonication to prepare a prepolymer solution; take 40mg of alkali-treated Fe3O4@TA nanoparticles and mix them evenly with 200μL of prepolymer solution by ultrasonication to obtain a mixed solution; (5) Take the mixed solution as phase A and mineral oil as phase B, mix phase A and phase B, disperse phase A into small droplets by a microfluidic device, and thermally initiate polymerization to obtain magnetically responsive microspheres based on three-dimensional magnetic photonic crystals. When a magnetic field is applied to the prepared microspheres, their reflectivity decreases from 67 to 48, proving that the microspheres have magnetic response properties.

[0097] Example 15 (Magnetic Response)

[0098] (1) Add a tannic acid / propylene carbonate (TA / PC) solution with a concentration of 10 mg / ml to Fe3O4 particles, disperse by ultrasonication, and wash with propylene carbonate solution 1-2 times to obtain Fe3O4@TA particles; (2) Take the particles from step (1) and add sodium tetraborate decahydrate aqueous solution with a concentration of 12.5 mg / ml and tannic acid aqueous solution with a concentration of 5-10 mg / ml respectively; (3) Wash the product from step (2) twice with deionized water and ethanol respectively, and disperse it in propylene carbonate for later use; (4) Take 1g ETPTA and 0.03g azobisisovalerate and mix them evenly by ultrasonication to prepare a prepolymer solution; Take 40mg of Fe3O4@TA particles treated with alkali solution and mix them evenly with 200μL of prepolymer solution by ultrasonication to obtain a mixed solution; (5) Take the mixed solution as phase A and mineral oil as phase B, mix phase A and phase B and disperse phase A into small droplets by microfluidic device, and thermally initiate polymerization to obtain magnetically responsive three-dimensional magnetic photonic crystal microspheres. The reflectivity of the prepared microspheres decreased by 21% before and after the application of a magnetic field, proving that the prepared microspheres have magnetic responsiveness.

[0099] Example 16 (Magnetic Response)

[0100] (1) Add a 10 mg / ml tannic acid / propylene carbonate (TA / PC) solution to Fe3O4 particles, disperse by ultrasonication, and wash with propylene carbonate solution 1-2 times to obtain Fe3O4@TA particles; (2) Take 0.3 g methyl methacrylate and 1 ml propylene carbonate, mix them evenly by ultrasonication to prepare a prepolymer solution; take 40 mg Fe3O4@TA particles and 200 μL prepolymer solution, mix them evenly by ultrasonication to obtain a mixed solution; (3) Use the mixed solution as phase A and mineral oil as phase B, mix phase A and phase B, disperse phase A into small droplets through a microfluidic device, and polymerize at 180 °C to obtain magnetically responsive microspheres based on three-dimensional magnetic photonic crystals. The reflectivity of the prepared microspheres decreased by 22% before and after the application of a magnetic field, proving that the prepared microspheres have magnetic responsiveness.

[0101] The above description is merely a preferred embodiment of the present invention, and should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A responsive microsphere based on a three-dimensional magnetic photonic crystal, characterized in that: Magnetic nanoparticles modified with polyhydroxy compounds are arranged in a non-close-packed face-centered cubic or body-centered cubic structure in a spherical polymer. The magnetic nanoparticles are magnetic nanoparticles modified with polyhydroxy compounds after being treated with an alkaline solution. The magnetic nanoparticles include those with at least one of the magnetic elements of iron, cobalt, nickel, and manganese on their surface or in themselves, and the particle size of the magnetic nanoparticles is 60-300 nm. The method for preparing the responsive microspheres based on the three-dimensional magnetic photonic crystal includes the following steps: (1) Magnetic nanoparticles are dispersed in a prepolymer liquid containing polymerizable monomers to obtain a mixed solution; (2) The mixed solution obtained in step (1) is used as phase A, the poor solvent of phase A is used as phase B, phase A is dispersed into small droplets by phase B, and then polymerization is initiated to obtain the responsive microspheres based on the three-dimensional magnetic photonic crystal.

2. The responsive microspheres based on a three-dimensional magnetic photonic crystal according to claim 1, characterized in that: The polyhydroxy compound includes at least one of tannic acid, catechin, epigallocatechin gallate, epigallocatechin gallate, pyrogallol, gluconic acid, glucose, gluconate, dopamine, chlorogenic acid, neochlorogenic acid, and lignin compounds.

3. A method for preparing responsive microspheres based on a three-dimensional magnetic photonic crystal according to any one of claims 1-2, characterized in that, Includes the following steps: (1) Magnetic nanoparticles are dispersed in a prepolymer liquid containing polymerizable monomers to obtain a mixed solution; (2) The mixed solution obtained in step (1) is used as phase A, the poor solvent of phase A is used as phase B, phase A is dispersed into small droplets by phase B, and then polymerization is initiated to obtain the responsive microspheres based on the three-dimensional magnetic photonic crystal.

4. The method for preparing responsive microspheres based on a three-dimensional magnetic photonic crystal according to claim 3, characterized in that: In step (1), the concentration of magnetic nanoparticles in the prepolymer solution is 1wt%-75wt%.

5. The method for preparing responsive microspheres based on a three-dimensional magnetic photonic crystal according to claim 3, characterized in that: In step (1), the prepolymer liquid includes polymerizable monomers, initiators, and solvents; at least one of the polymerizable monomers has a polymerizable group number greater than or equal to 2, and the molar percentage of polymerizable monomers in the prepolymer liquid is 0.5%-100%; the initiator includes at least one of photoinitiators and thermal initiators, and its content is 0-30% of the total molar amount of polymerizable monomers; the solvent includes at least one of carbonates, carboxylic esters, ethers, alkanols, pyrrolidones, acetonitrile, dimethyl sulfoxide, deionized water, acetone, and N,N-dimethylformamide.

6. The method for preparing responsive microspheres based on a three-dimensional magnetic photonic crystal according to claim 3, characterized in that: In step (1), the polymerizable monomer includes at least one of the following groups: acrylate group, carboxylic acid, amino group, hydrazone group, acetal group, ketal group, amide group, imine group, sulfonic acid group, hydroxyl group, pyridyl group, phosphoric acid, phosphate ester, quinone group, thiol group, phenylboronic acid, borate ester, crown ether, disulfide group, selenide group, peptide group, glycosidic group, thioether group, and tellurium ether group.

7. The method for preparing responsive microspheres based on three-dimensional magnetic photonic crystals according to claim 3, characterized in that: In step (2), the volume ratio of phase A to phase B is 1:5-50. The specific process of using phase B to disperse phase A into small droplets is as follows: after mixing phase A and phase B, phase A is dispersed into small droplets by stirring or microfluidic control. Phase B includes at least one of mineral oil, silicone oil, alkanes, and halogenated hydrocarbons.

8. The application of a responsive microsphere based on a three-dimensional magnetic photonic crystal according to any one of claims 1-2 or a responsive microsphere based on a three-dimensional magnetic photonic crystal prepared by the preparation method according to any one of claims 3-7, characterized in that: The responsive microspheres based on three-dimensional magnetic photonic crystals are applied to the fields of biomedical detection or diagnosis, environmental monitoring, chemical sensing, smart display, optical devices, and flexible wearable devices, wherein the biomedical detection or diagnosis is for non-disease diagnosis purposes.

Images