Hierarchical pore fluorescent monolithic material as well as preparation method and application thereof

Abstract

The invention discloses a hierarchical pore fluorescent monolithic material as well as a preparation method and application thereof, and belongs to the technical field of fluorescent monolithic materials. The preparation method disclosed by the invention comprises the following steps: mixing a fluorescent compound which contains a multi-aldehyde functional group and has aggregation-induced emission, a compound containing an amino functional group and a solvent to obtain a homogeneous solution; introducing the homogeneous solution into a capillary tube, and then putting the capillary tube into a heating device for heating reaction to obtain a solid product; the solid product is subjected to post-treatment, and the hierarchical pore fluorescent monolithic material is obtained.The method solves the technical problems that an existing fluorescent material is poor in universality, and a separation unit and a sensing unit are difficult to connect in series.

Description

Technical Field

[0001] The present invention belongs to the technical field of fluorescent monolithic materials, and in particular relates to a multi-level porous fluorescent monolithic material and a preparation method and application thereof. Background Art

[0002] As a portable device, highly sensitive fluorescent sensors have shown significant advantages in environmental analysis, food safety monitoring (such as meat freshness assessment), and public safety (such as illegal drugs, chemical warfare agents, and explosives detection). However, with the complexity of actual application scenarios and the increasingly stringent standards of related industries, fluorescent sensing technology still faces many challenges in the differential detection of complex samples. First, traditional fluorescent sensing media (such as random fluorescent powder materials or fluorescent substances coated on the surface of substrates such as glass plates) have significant limitations: their physical form is difficult to achieve standardized filling, resulting in low device integration; at the same time, these materials are easily disturbed by environmental factors (such as temperature, humidity, light, etc.), resulting in fluorescence quenching or signal drift, which seriously affects the stability and reproducibility of detection. In addition, due to the lack of effective front-end separation media, traditional fluorescent sensors are difficult to achieve specific identification and differential detection of multi-component mixed samples in complex matrices. To address the above challenges, researchers have developed two main strategies: principal component analysis (PCA) and sensor array technology. PCA, as a multivariate statistical analysis method, can extract characteristic information from fluorescence response data by dimensionality reduction processing, but this method is highly dependent on the quality and integrity of the original data. The matrix effect and environmental variables (such as humidity fluctuations, coexisting interferents, etc.) in the actual sample will significantly affect the reliability of the data, resulting in large deviations in the quantitative analysis results. Sensor array technology achieves differentiated detection by constructing a multi-channel detection system and using the differences in the response patterns of different sensor units to the target object, but it also faces problems such as environmental interference and signal crosstalk, and the data processing process is complex, making it difficult to meet the needs of rapid on-site detection. In recent years, the development of new fluorescent sensing materials has provided a possibility to break through these technical bottlenecks. For example, metal-organic framework materials (MOFs) and covalent organic framework materials (COFs) with regular pore structures have shown great potential in front-end separation and specific identification of complex samples due to their tunable fluorescence properties and excellent selective adsorption capabilities. In addition, intelligent sensing systems based on machine learning algorithms are emerging, which are expected to achieve accurate quantitative detection of trace targets in complex environments by establishing a nonlinear mapping relationship between multidimensional response signals and target concentrations. In the future, the development of fluorescence sensing technology will focus on improving the anti-interference ability of materials, optimizing device integration processes, and developing more advanced signal processing algorithms to meet higher requirements for sensitivity, selectivity, and reliability in actual application scenarios.

[0003] Fluorescence sensors have shown good application prospects in various fields, but in practical applications, technical problems such as difficult molding and processing of fluorescent materials, difficult mass transfer process, and poor universality must be solved. Therefore, the molding of fluorescent materials and the series connection of separation units and sensing units are crucial to the practical application of fluorescent sensors. It is the main way to solve the poor discrimination and recognition of mixtures by the sensing medium in fluorescent sensors. Summary of the invention

[0004] The purpose of the present invention is to provide a multi-level porous fluorescent integral material and a preparation method and application thereof, so as to solve the technical problems that the existing fluorescent materials have poor universality and it is difficult to connect the separation unit and the sensor unit in series.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] The present invention discloses a method for preparing a multi-level porous fluorescent monolithic material, comprising the following steps:

[0007] A fluorescent compound having a polyaldehyde functional group and having aggregation-induced emission, a compound having an amino functional group and a solvent are mixed to obtain a homogeneous solution;

[0008] The homogeneous solution is introduced into the capillary and then placed in a heating device for heating reaction to obtain a solid product; the solid product is post-processed to obtain a multi-level porous fluorescent monolithic material.

[0009] Furthermore, when the compound containing an amino functional group is solid, the specific steps are:

[0010] Mixing a fluorescent compound containing a polyaldehyde functional group and having aggregation-induced emission with a solvent to obtain a mixed solution A;

[0011] Mixing the compound containing an amino functional group and a solvent to obtain a mixed solution B;

[0012] Mixing the mixed solution A and the mixed solution B to obtain a homogeneous solution; introducing the homogeneous solution into a capillary and then placing it in a heating device for heating reaction to obtain a solid product; post-treating the solid product to obtain a multi-level porous fluorescent monolithic material;

[0013] When the compound containing amino functional groups is liquid, the specific steps are:

[0014] A fluorescent compound containing a polyaldehyde functional group and having aggregation-induced emission is mixed with a solvent to obtain a mixed solution A; an amino functional group is added to the mixed solution A to obtain a homogeneous solution; the homogeneous solution is introduced into a capillary and then placed in a heating device for heating reaction to obtain a solid product; the solid product is post-processed to obtain a multi-level porous fluorescent monolithic material.

[0015] Furthermore, the solvent is an organic solvent or a mixture of an organic solvent and water; the compound containing an aldehyde functional group and having aggregation-induced emission fluorescent compound is tetraaldehyde tetraphenylethylene;

[0016] The compound containing amino functional groups is trans-1,2-cyclohexanediamine, 1,4-butanediamine, 1,4-cyclohexanediamine, p-phenylenediamine, m-phenylenediamine, o-phenylenediamine or hydrazine hydrate.

[0017] Furthermore, the usage ratio of the fluorescent compound containing polyaldehyde functional groups and having aggregation-induced emission to the solvent is 91.6 mg: (426-535) μL.

[0018] Furthermore, the ratio of the amino functional group-containing compound to the solvent is (25-47) mg: (426-535) μL.

[0019] Furthermore, the heating device is a water bath; the temperature of the heating reaction is 40 to 80° C., and the time is 4 to 12 hours.

[0020] Furthermore, the post-treatment includes washing and drying treatments performed sequentially.

[0021] Furthermore, the washing is performed by washing with ethanol and n-hexane in sequence.

[0022] The invention also discloses a method for preparing a multi-level porous fluorescent integral material prepared by the above-mentioned preparation method.

[0023] The invention also discloses a method for preparing the multi-level porous fluorescent integral material.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] The invention discloses a method for preparing a multi-level porous fluorescent monolithic material. A fluorescent compound containing a polyaldehyde functional group and having aggregation-induced emission, a compound containing an amino functional group, a solvent and the like are mixed and introduced into a capillary, and the multi-level porous fluorescent monolithic material is controllably prepared in situ in the capillary. Since the polyaldehyde functional group compound has the property of aggregation-induced emission, the formed solid multi-level porous fluorescent monolithic material exhibits ideal fluorescent properties, and at the same time, its rigid skeleton gives the fluorescent monolithic material a higher specific surface area and a multi-level porous structure. The fluorescent materials synthesized in the prior art are all random fluorescent powder materials or fluorescent substances are coated on the surface of a substrate such as a glass plate, which results in the inability to form and fill them in practical applications, and the inability to separate mixed samples. The capillary used above plays the role of a medium filling carrier, and realizes the series connection of a separation unit and a sensing unit. The multi-level pores in the multi-level porous fluorescent monolithic material can improve the mass transfer process and adsorb and separate the sample. At the same time, the fluorescent property enables it to be used as a sensing medium to realize the differentiated detection of mixed samples. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 The actual pictures and fluorescence emission pictures of the multi-level porous fluorescent monolithic materials prepared in different embodiments of the present invention;

[0027] Figure 2 The fluorescence emission spectra of the multi-level porous fluorescent monolithic materials prepared in different embodiments of the present invention;

[0028] Figure 3 The actual image and fluorescence luminescence image of the capillary monolithic column prepared in Example 1 of the present invention;

[0029] Figure 4 This is a scanning electron microscope image of the capillary monolithic column prepared in Example 1 of the present invention;

[0030] Among them: a-morphology of multi-level pore fluorescent monolithic material; b-enlarged image of the multi-level pore fluorescent monolithic material fitting with the inner wall of the capillary;

[0031] Figure 5 This is a macropore size distribution diagram of the multi-level porous fluorescent monolithic material prepared in Example 1 of the present invention;

[0032] Figure 6 This is a micropore physical adsorption test diagram of the multi-level porous fluorescent monolithic material prepared in Example 1 of the present invention;

[0033] Figure 7 This is a micropore physical adsorption test diagram of the multi-level porous fluorescent monolithic material prepared in Example 7 of the present invention. DETAILED DESCRIPTION

[0034] In order to enable those skilled in the art to understand the characteristics and effects of the present invention, the following is a general description and definition of the terms and expressions mentioned in the specification and claims. Unless otherwise specified, all technical and scientific terms used in the text are the common meanings understood by those skilled in the art for the present invention. In the event of a conflict, the definition in this specification shall prevail.

[0035] The theories or mechanisms described and disclosed herein, whether correct or incorrect, should not limit the scope of the present invention in any way, that is, the present invention can be implemented without being limited by any specific theory or mechanism.

[0036] Herein, all features such as values, quantities, contents and concentrations defined in the form of numerical ranges or percentage ranges are for simplicity and convenience only. Accordingly, the description of numerical ranges or percentage ranges should be considered to have included and specifically disclosed all possible secondary ranges and individual values ​​within the range (including integers and fractions).

[0037] In this document, unless otherwise specified, “includes,” “including,” “contains,” “has,” or similar terms cover the meanings of “consisting of” and “mainly consisting of,” for example, “A includes a” covers the meanings of “A includes a and other” and “A only includes a.”

[0038] In this document, in order to make the description concise, not all possible combinations of various technical features in various embodiments or examples are described. Therefore, as long as there is no contradiction in the combination of these technical features, the various technical features in various embodiments or examples can be combined arbitrarily, and all possible combinations should be considered to be within the scope of this specification.

[0039] The present invention provides a method for preparing a multi-level porous fluorescent monolithic material, comprising the following steps:

[0040] Firstly, a fluorescent compound containing a polyaldehyde functional group and having aggregation-induced emission, a compound containing an aldehyde functional group and having aggregation-induced emission characteristics, an organic solvent and water are uniformly mixed, and then the homogeneous solution is placed in a heating device for heating reaction to obtain a solid product, and finally the solid product is rinsed and dried to obtain a multi-level porous fluorescent monolithic material;

[0041] The specific steps are:

[0042] Step 1: uniformly mix a fluorescent compound containing a polyaldehyde functional group and having aggregation-induced emission and an organic solvent, or uniformly mix a fluorescent compound containing a polyaldehyde functional group and having aggregation-induced emission, an organic solvent and water to obtain a mixed solution A;

[0043] Step 2: uniformly mixing the compound containing an amino functional group and an organic solvent, or uniformly mixing the compound containing an amino functional group, an organic solvent and water to obtain a mixed solution B;

[0044] Step 3: Mix the mixed solution A and the mixed solution B to obtain a homogeneous solution;

[0045] Step 4: Pour the homogeneous solution C into the capillary and place it in a heating device for heating reaction to obtain a solid product; post-treat the solid product to obtain a multi-level pore fluorescent monolithic material (multi-level pore capillary monolithic column).

[0046] The present invention is based on a polymerization-induced phase separation method, and adopts a one-pot method to prepare in situ in a capillary a multi-level porous fluorescent monolithic material having both separation performance and sensing performance, thereby realizing the series connection of a separation unit and a sensing unit. The multi-level pore structure of the fluorescent monolithic material can selectively adsorb and separate complex samples, and the fluorescent properties of the fluorescent monolithic material can be detected to achieve the purpose of integrated adsorption, separation and detection. The problem of difficulty in distinguishing and identifying mixtures is solved, and mixtures can be detected in real time and quickly. The present invention selects a capillary as a medium filling carrier, and constructs in situ in the capillary a dual-functional material having both separation performance and sensing properties, namely a multi-level porous fluorescent monolithic material, thereby realizing the series connection of a separation unit and a sensing unit.

[0047] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall within the scope limited by the appended claims of the application equally.

[0048] The following examples use conventional instruments and equipment in the art. The experimental methods in the following examples that do not specify specific conditions are usually carried out under conventional conditions or under conditions recommended by the manufacturer. The various raw materials used in the following examples, unless otherwise specified, are conventional commercially available products, and their specifications are conventional specifications in the art. In the specification of the present invention and the following examples, unless otherwise specified, "%" means weight percentage, "part" means weight part, and ratio means weight ratio.

[0049] Example 1

[0050] A method for preparing a multi-level porous fluorescent monolithic material comprises the following steps:

[0051] Step 1: Add 91.6 mg of tetraaldehyde tetraphenylethylene, 321 μL of dimethyl sulfoxide and 214 μL of N,N-dimethylformamide into a glass bottle to obtain a mixed solution A;

[0052] Step 2: Ultrasonicate the mixed solution A at room temperature for 2 min;

[0053] Step 3: Add 49.5 μL of trans-1,2-cyclohexanediamine to the mixed solution A, and perform ultrasonication to form a homogeneous solution to obtain a homogeneous solution;

[0054] Step 4: After the homogeneous solution is introduced into the capillary, it is transferred to a water bath at 80°C for reaction for 12 hours to obtain a capillary monolithic column; the capillary monolithic column is rinsed with ethanol and n-hexane in sequence, and then dried with nitrogen to obtain a multi-level pore fluorescent monolithic material.

[0055] Example 2

[0056] A method for preparing a multi-level porous fluorescent monolithic material comprises the following steps:

[0057] Step 1: Add 91.6 mg of tetraaldehyde tetraphenylethylene, 295 μL of dimethyl sulfoxide and 197 μL of N,N-dimethylformamide into a glass bottle to obtain a mixed solution A;

[0058] Step 2: Ultrasonicate the mixed solution A at room temperature for 2 min;

[0059] Step 3: Add 40 μL of 1,4-butanediamine to the mixed solution A, and perform ultrasonication to form a homogeneous solution to obtain a homogeneous solution;

[0060] Step 4: After the homogeneous solution is introduced into the capillary, it is transferred to a 40°C water bath for reaction for 4 hours to obtain a solid product; the solid product is rinsed with ethanol and n-hexane in sequence, and then dried with nitrogen to obtain a multi-level porous fluorescent monolithic material.

[0061] Example 3

[0062] A method for preparing a multi-level porous fluorescent monolithic material comprises the following steps:

[0063] Step 1: Add 91.6 mg of tetraaldehyde tetraphenylethylene and 499 μL of dimethyl sulfoxide into a glass bottle to obtain a mixed solution A;

[0064] Step 2: Ultrasonicate the mixed solution A at room temperature for 2 min;

[0065] Step 3: Add 50.8 μL of 1,4-cyclohexanediamine to the mixed solution A, and perform ultrasound to form a homogeneous solution to obtain a homogeneous solution;

[0066] Step 4: After the homogeneous solution is introduced into the capillary, it is transferred to a 40°C water bath for reaction for 6 hours to obtain a solid product; the solid product is rinsed with ethanol and n-hexane in sequence, and then blown dry with nitrogen to obtain a multi-level porous fluorescent monolithic material.

[0067] Example 4

[0068] A method for preparing a multi-level porous fluorescent monolithic material comprises the following steps:

[0069] Step 1: Add 91.6 mg of tetraaldehyde tetraphenylethylene and 235.5 μL of dimethylbenzene into a glass bottle to obtain a mixed solution A;

[0070] Step 2: Add 44.1 mg of p-phenylenediamine, 235.5 μL of dimethylbenzene and 25 μL of water into a glass bottle to obtain a mixed solution B;

[0071] Step 3: respectively sonicate the mixed solution A and the mixed solution B at room temperature for 2 minutes, then add the mixed solution B to the mixed solution A, and continue sonicating to form a homogeneous solution, thereby obtaining a homogeneous solution;

[0072] Step 4: After the homogeneous solution is introduced into the capillary, it is transferred to a 60°C water bath for reaction for 6 hours to obtain a solid product; the solid product is rinsed with ethanol and n-hexane in sequence, and then blown dry with nitrogen to obtain a multi-level porous fluorescent monolithic material.

[0073] Example 5

[0074] A method for preparing a multi-level porous fluorescent monolithic material comprises the following steps:

[0075] Step 1: Add 91.6 mg of tetraaldehyde tetraphenylethylene and 235.5 μL of dimethylbenzene into a glass bottle to obtain a mixed solution A;

[0076] Step 2: Add 44.1 mg of m-phenylenediamine, 235.5 μL of dimethylbenzene and 25 μL of water into a glass bottle to obtain a mixed solution B;

[0077] Step 3: respectively sonicate the mixed solution A and the mixed solution B at room temperature for 2 minutes, then add the mixed solution B to the mixed solution A, and continue sonicating to form a homogeneous solution, thereby obtaining a homogeneous solution;

[0078] Step 4: After the homogeneous solution is introduced into the capillary, it is transferred to a water bath at 80°C for reaction for 8 hours to obtain a solid product; the solid product is rinsed with ethanol and n-hexane in sequence, and then dried in a constant temperature box or blown dry with nitrogen to obtain a multi-level porous fluorescent integral material.

[0079] Example 6

[0080] A method for preparing a multi-level porous fluorescent monolithic material comprises the following steps:

[0081] Step 1: Add 91.6 mg of tetraaldehyde tetraphenylethylene and 235.5 μL of dimethylbenzene into a glass bottle to obtain a mixed solution A;

[0082] Step 2: Add 44.1 mg of o-phenylenediamine, 235.5 μL of dimethylbenzene and 25 μL of water into a glass bottle to obtain a mixed solution B;

[0083] Step 3: respectively sonicate the mixed solution A and the mixed solution B at room temperature for 2 minutes, then add the mixed solution B to the mixed solution A, and continue sonicating to form a homogeneous solution, thereby obtaining a homogeneous solution;

[0084] Step 4: After the homogeneous solution is introduced into the capillary, it is transferred to a water bath at 80° C. and reacted for 10 hours to obtain a solid product; the solid product is rinsed with ethanol and n-hexane in sequence, and then blown dry with nitrogen to obtain a multi-level porous fluorescent monolithic material.

[0085] Example 7

[0086] A method for preparing a multi-level porous fluorescent monolithic material comprises the following steps:

[0087] Step 1: Add 91.6 mg of tetraaldehyde tetraphenylethylene, 405 μL of dimethyl sulfoxide and 21 μL of water into a glass bottle to obtain a mixed solution A;

[0088] Step 2: Ultrasonicate the mixed solution A at room temperature for 2 min;

[0089] Step 3: Add 24.3 μL of hydrazine hydrate (mass fraction 85%) to the mixed solution A, and form a homogeneous solution by ultrasonication to obtain a homogeneous solution;

[0090] Step 4: After the homogeneous solution is introduced into the capillary, it is transferred to a water bath at 80°C for reaction for 12 hours to obtain a solid product; the solid product is rinsed with ethanol and n-hexane in sequence, and then dried with nitrogen to obtain a multi-level porous fluorescent monolithic material.

[0091] Figure 1 The actual pictures and fluorescence emission pictures of the multi-level porous fluorescent monolithic materials prepared according to different embodiments of the present invention are shown. From the pictures, it can be seen that multi-level porous fluorescent monolithic materials with different fluorescence properties can be prepared by using different amine functional group compounds.

[0092] Figure 2 The fluorescence emission spectra of the multi-level porous fluorescent monolithic materials prepared in different embodiments of the present invention are shown in the figure. It can be seen from the figure that the fluorescence emission wavelength of the multi-level porous fluorescent monolithic materials synthesized by aniline and hydrazine hydrate has red-shifted, indicating that a conjugated structure has been generated. Figure 1 , which confirmed that different amine functional group compounds can be used to prepare multi-level porous fluorescent monolithic materials with different fluorescent properties.

[0093] Figure 3 The actual image and fluorescence emission image of the capillary monolithic column prepared in Example 1 of the present invention show that the multi-level porous fluorescent monolithic material prepared in the capillary retains good fluorescence properties.

[0094] Figure 4 This is a scanning electron microscope image of the capillary monolithic column prepared in Example 1 of the present invention. It can be seen that the uniform through-hole structure is beneficial to the mass transfer process and adsorption separation, and the material fits tightly to the inner wall of the capillary and is not easy to fall off during use.

[0095] Figure 5 This is a macropore size distribution diagram of the multi-level porous fluorescent monolithic material prepared in Example 1 of the present invention. It can be seen from the figure that the macropore size is 0.6 μm.

[0096] Figure 6This is a micropore physical adsorption test diagram of the multi-level porous fluorescent monolithic material prepared in Example 1. It can be seen from the figure that the specific surface area of ​​the fluorescent monolithic material is 399 m 2 / g, micropore diameters are 0.8, 1.27, 1.7nm. Figure 5 It shows that the synthesized fluorescent monolithic material has a multi-level pore structure of macropores and micropores.

[0097] Figure 7 This is a micropore physical adsorption test diagram of the multi-level porous fluorescent monolithic material prepared in Example 7. It can be seen from the figure that the specific surface area of ​​the fluorescent monolithic material is 530 m 2 / g, and the micropore diameter is 0.5nm.

[0098] The above contents are only for explaining the technical idea of ​​the present invention and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution in accordance with the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.

Claims

1. A method for preparing a multi-level porous fluorescent monolithic material, characterized in that: The following steps are involved: A fluorescent compound having a polyaldehyde functional group and having aggregation-induced emission, a compound having an amino functional group and a solvent are mixed to obtain a homogeneous solution; The homogeneous solution is introduced into the capillary and then placed in a heating device for heating reaction to obtain a solid product; The solid product is post-processed to obtain a multi-level porous fluorescent monolithic material.

2. The method for preparing a multi-level porous fluorescent monolithic material according to claim 1, characterized in that: When the compound containing amino functional group is solid, the specific steps are: Mixing a fluorescent compound containing a polyaldehyde functional group and having aggregation-induced emission with a solvent to obtain a mixed solution A; Mixing the compound containing an amino functional group and a solvent to obtain a mixed solution B; Mixing the mixed solution A and the mixed solution B to obtain a homogeneous solution; The homogeneous solution is introduced into the capillary and then placed in a heating device for heating reaction to obtain a solid product; Post-processing the solid product to obtain a multi-level porous fluorescent monolithic material; When the compound containing amino functional groups is liquid, the specific steps are: A fluorescent compound containing polyaldehyde functional groups and having aggregation-induced emission is mixed with a solvent to obtain a mixed solution A; an amino functional group is added to the mixed solution A to obtain a homogeneous solution; the homogeneous solution is introduced into a capillary and then placed in a heating device for heating reaction to obtain a solid product; The solid product is post-processed to obtain a multi-level porous fluorescent monolithic material.

3. The method for preparing a multi-level porous fluorescent monolithic material according to claim 1, characterized in that: The solvent is an organic solvent or a mixture of an organic solvent and water; the compound containing an aldehyde functional group and having aggregation-induced luminescence fluorescent compound is tetraaldehyde tetraphenylethylene; The compound containing amino functional groups is trans-1,2-cyclohexanediamine, 1,4-butanediamine, 1,4-cyclohexanediamine, p-phenylenediamine, m-phenylenediamine, o-phenylenediamine or hydrazine hydrate.

4. The method for preparing a multi-level porous fluorescent monolithic material according to claim 1, characterized in that: The usage ratio of the fluorescent compound containing polyaldehyde functional groups and having aggregation-induced luminescence to the solvent is 91.6 mg: (426-535) μL.

5. The method for preparing a multi-level porous fluorescent monolithic material according to claim 1, characterized in that: The usage ratio of the compound containing amino functional group to the solvent is (25-47) mg: (426-535) μL.

6. The method for preparing a multi-level porous fluorescent monolithic material according to claim 1, characterized in that: The heating device is a water bath; the temperature of the heating reaction is 40-80° C., and the time is 4-12 hours.

7. The method for preparing a multi-level porous fluorescent monolithic material according to claim 1, characterized in that: The post-treatment includes washing and drying processes performed sequentially.

8. The method for preparing a multi-level porous fluorescent monolithic material according to claim 7, characterized in that: The washing is performed by washing with ethanol and n-hexane in sequence.

9. A multi-level porous fluorescent monolithic material, characterized in that: The preparation method is described in any one of claims 1 to 8.

10. Use of the multi-level porous fluorescent monolithic material according to claim 9 in a fluorescent sensor.

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