Gold nanoparticle modified covalent organic framework material with hollow structure as well as preparation method and application of gold nanoparticle modified covalent organic framework material

Abstract

The invention belongs to the technical field of nano materials, and particularly relates to a gold nanoparticle modified covalent organic framework material with a hollow structure as well as a preparation method and application of the gold nanoparticle modified covalent organic framework material. The preparation method comprises the following steps: dissolving 1, 3, 5-tri (4-aminophenyl) benzene and m-benzenetricarboxaldehyde in an organic solvent, adding glacial acetic acid, and reacting to obtain a covalent organic framework precursor; then dispersing the covalent organic framework in a mixed solvent of 1, 4-dioxane and mesitylene, and adding glacial acetic acid and water to react in an oil bath to obtain a covalent organic framework with a hollow structure; and finally, dissolving in a mixed solution of water and ethanol, placing in an ice bath, adding a chloroauric acid hydrate for reaction, adding sodium borohydride for continuous reaction, and obtaining the gold nanoparticle modified covalent organic framework material with the hollow structure after the reaction is finished. The invention further provides the hollow covalent organic framework material modified by the gold nanoparticles, and the hollow covalent organic framework material can be used as a matrix, has high salt tolerance, can efficiently extract metabolites in urine and provides a high-sensitivity detection result.

Description

Technical Field

[0001] The present application belongs to the technical field of nanomaterials, and specifically relates to a hollow structure covalent organic framework material modified by gold nanoparticles, and a preparation method and application thereof. Background Art

[0002] In recent years, rapid screening and diagnosis of infectious diseases has become a major challenge in public health and clinical treatment. Although traditional PCR testing has high sensitivity and specificity, it is difficult to meet the needs of large-scale screening due to its long detection time, high cost, and the need for professional equipment. Therefore, the development of a high-throughput, low-cost, rapid, and non-invasive detection method is of great significance for the early diagnosis and prevention and control of COVID-19 and other infectious diseases.

[0003] Currently, urine metabolite analysis, as a biomarker detection method with great potential, has attracted widespread attention due to its simple, non-invasive and repeatable specimen collection characteristics. Studies have shown that COVID-19 infection may cause acute kidney injury, and urine-based metabolic analysis is expected to achieve rapid diagnosis.

[0004] Metabolomics is an emerging "omics" following genomics, proteomics, and transcriptomics, which can perform qualitative and quantitative evaluation of small molecule metabolites in body fluids. Currently, metabolomics has been widely used in body fluid metabolism analysis. Mass spectrometry has the characteristics of high resolution and high sensitivity. With the rapid development of various mass spectrometry technologies such as liquid chromatography-mass spectrometry (LC MS) and gas chromatography-mass spectrometry (GCMS), it will play an important role in clinical diagnosis and treatment monitoring.

[0005] Existing mass spectrometry analysis methods for body fluids mainly rely on LC or GC for sample pretreatment, resulting in slow analysis speed and low throughput. They are not suitable for rapid analysis of batch samples and cannot meet the growing clinical testing needs.

[0006] Laser desorption / ionization mass spectrometry (LDI MS) is a high-throughput mass spectrometry technology that has outstanding advantages in analysis speed, sensitivity and ease of operation. This technology uses matrix materials to assist in absorbing laser energy to promote thermal desorption and ionization of the molecules to be tested, which plays a key role in the analysis results. However, due to the high salt concentration in body fluids such as urine, traditional organic small molecule matrices have poor stability, poor salt tolerance, and complex background signals, making them difficult to use for body fluid analysis and detection. Summary of the invention

[0007] The purpose of the present invention is to solve the deficiencies of the prior art and provide a hollow structure covalent organic framework material modified by gold nanoparticles and a preparation method and application thereof, specifically adopting the following technical scheme: In a first aspect, the present invention provides a method for preparing a hollow structure covalent organic framework material modified with gold nanoparticles, characterized in that it comprises the following steps: S1: dissolving 1,3,5-tri(4-aminophenyl)benzene and isophthalic acid in an organic solvent, stirring evenly, adding glacial acetic acid, reacting, centrifuging, washing, and obtaining a covalent organic framework precursor; S2: dispersing the covalent organic framework precursor in a mixed solvent of 1,4-dioxane and mesitylene, mixing, adding glacial acetic acid and water, placing in an oil bath for heating and reacting, centrifuging and washing after the reaction to obtain a hollow structure covalent organic framework; S3: The hollow structure covalent organic framework is dissolved in a mixed solution of water and ethanol, stirred evenly, placed in an ice bath and tetrachloroauric acid hydrate is added to react. After reacting for 3 h-4 h, sodium borohydride is added to continue the reaction. After the reaction is completed, centrifuge and wash to obtain the hollow structure covalent organic framework material modified with gold nanoparticles.

[0008] The present invention uses 1,3,5-tris(4-aminophenyl)benzene and isophthalic acid as raw materials, synthesizes a covalent organic framework (COF) precursor through a polymerization reaction initiated by glacial acetic acid, then transforms the structure of the COF precursor through a dynamic imine exchange reaction to obtain a hollow structure covalent organic framework (HCOFs), and finally performs an in-situ chloroauric acid reduction treatment on the HCOFs to generate gold nanoparticles on the surface to obtain a hollow structure covalent organic framework (HCOFs-Au) material modified with nano-gold particles. The hollow structure COF prepared by the method is conducive to increasing the reflection and refraction of laser inside the material, and compared with the solid structure COF, the light absorption efficiency is significantly improved.

[0009] As a further preferred embodiment, the usage ratio of the above-mentioned 1,3,5-tris(4-aminophenyl)benzene, isophthalic acid aldehyde, organic solvent and glacial acetic acid is 70 mg:32.5 mg:25 mL:2.5 mL.

[0010] As a further preferred embodiment, the organic solvent is acetonitrile.

[0011] As a further preferred embodiment, the volume ratio of 1,4-dioxane to mesitylene in S2 is 4:1.

[0012] As a further preferred embodiment, the volume ratio of water to ethanol in S3 is 1:1.

[0013] As a further preferred embodiment, the mass ratio of tetrachloroauric acid hydrate to sodium borohydride in S3 is 1: 1. In the above preparation, the sodium borohydride is excessive in molar ratio to ensure that the chloroauric acid is fully reduced.

[0014] As a further preferred embodiment, the heating temperature in the oil bath is 65° C.-70° C. In the above preparation process, if the temperature is too low, the dynamic imine exchange reaction may be insufficient and the hollow structure cannot be formed; if the temperature is too high, the hollow shell structure may collapse.

[0015] In a second aspect, the present invention provides a hollow structure covalent organic framework material modified with gold nanoparticles for detecting urine metabolites. The hollow structure covalent organic framework material is prepared by the above-mentioned preparation method.

[0016] As a further preferred embodiment, the hollow structure covalent organic framework material is used for urine metabolite detection to distinguish between common pneumonia and pneumonia caused by new coronavirus infection.

[0017] In a third aspect, the present invention also provides the use of the above-mentioned hollow structure covalent organic framework material modified with gold nanoparticles for urine metabolite detection in the preparation of a matrix material for laser desorption / ionization mass spectrometry.

[0018] The beneficial effects of the present invention are: (1) The present invention provides a method for preparing a hollow covalent organic framework material HCOFs-Au modified with gold nanoparticles. (2) The present invention also provides a hollow covalent organic framework material HCOFs-Au modified with gold nanoparticles, which can be used as a matrix for laser desorption / ionization mass spectrometry (LDI MS). The material has high salt tolerance, can efficiently extract metabolites in urine, and provide highly sensitive detection results. Compared with traditional small molecule matrices, the detection sensitivity is improved by an order of magnitude. (3) The present invention can use HCOFs-Au as a matrix to detect urine samples, which has low detection cost and is suitable for large-scale screening, with the advantages of low cost and high throughput; (4) The present invention can quickly analyze and screen metabolite markers to achieve rapid differentiation of patients infected with the new coronavirus. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0020] Figure 1 Shown is a transmission electron microscope image of HCOFs-Au prepared in Example 1; Figure 2Shown is the UV-visible absorption spectra of the hollow covalent organic framework material HCOFs prepared in Example 1 and the hollow covalent organic framework material HCOFs-Au modified with gold nanoparticles; Figure 3 Shown are the test results of standard small molecule metabolites of the prepared gold nanoparticle-modified hollow covalent organic framework material HCOFs-Au; Figure 4 Shown are representative metabolite characteristic profiles of urine in patients with common pneumonia and pneumonia caused by novel coronavirus infection; Figure 5 Shown is a heat map of 7 key metabolic markers between patients with common pneumonia and patients with pneumonia caused by the new coronavirus infection; Figure 6 Shown is a performance graph for distinguishing common pneumonia patients from pneumonia patients caused by novel coronavirus infection using 7 key metabolic markers; Figure 7 Shown is a comparison of the signal intensities of creatinine in urine specimens detected using HCOFs-Au matrix solution, HCOFs, COFs, and CHCA. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0022] Example 1 A method for preparing a hollow structure covalent organic framework material modified by gold nanoparticles comprises the following steps: (1) 70 mg of 1,3,5-tris(4-aminophenyl)benzene and 32.5 mg of isophthalic acid were dissolved in 25 mL of acetonitrile. After being thoroughly stirred and mixed, 2.5 mL of glacial acetic acid was added. The reaction system was stirred at room temperature for 6 hours to obtain a yellow precipitate. The intermediate product 1 (covalent organic framework (COF) precursor) was obtained by centrifugation and ethanol washing. (2) The intermediate product 1 was fully dispersed in a mixed solvent of 1,4-dioxane and mesitylene in a volume ratio of 4:1. After stirring and mixing, glacial acetic acid and deionized water in a volume ratio of 1:1 were added. The reaction system was placed in an oil bath at 70°C and heated and stirred for 48 hours. After the reaction was completed, the product was centrifuged and washed with tetrahydrofuran to obtain the intermediate product 2 (hollow structure covalent organic framework (HCOFs)). (3) The intermediate product 2 was dissolved in water and ethanol in a volume ratio of 1:1. After being stirred and thoroughly mixed, it was placed in an ice bath. 2 mg of tetrachloroauric acid hydrate was added. After continuous stirring for 4 hours, 2 mg of sodium borohydride was added. After reacting for 30 minutes, the product was centrifuged and washed with ethanol and deionized water to obtain a hollow covalent organic framework material modified with gold nanoparticles (HCOFs-Au).

[0023] The above-obtained materials were subjected to characterization tests, and the results are as follows: Figure 1-Figure 2 As shown, Figure 1 This is a transmission electron microscope image of HCOFs-Au; it can be seen from the image that gold nanoparticles are evenly distributed on the surface of HCOFs.

[0024] Figure 2 The UV-visible absorption spectra of the intermediate product 2 and HCOFs-Au; it can be seen from the figure that the modification of precious metal nanoparticles improves the UV absorption of the material.

[0025] Example 2 Verification of the effect of HCOFs-Au as a matrix for testing metabolites in laser desorption / ionization mass spectrometry (LDI MS) (1) Preparation of matrix solution: Disperse the hollow structure covalent organic framework material HCOFs-Au modified with gold nanoparticles prepared in Example 1 in deionized water at a concentration of 5 mg / mL.

[0026] (2) Prepare metabolite standard solution: Dissolve five metabolites including tryptophan (Trp), phenylalanine (Phe), N-acetyl-L-aspartic acid (NA-Asp), lactose and fructose in deionized water at a concentration of 1 mM. Prepare a metabolite standard solution with 0.5 mM NaCl solution and 5 mg / mL bovine serum albumin solution respectively to test the matrix salt resistance and protein resistance.

[0027] (3) After mixing equal volumes (1 μL) of metabolite solution and matrix suspension, add 1 μL of the mixture onto a stainless steel target plate, allow to dry naturally at room temperature, and then perform mass spectrometry detection.

[0028] The mass spectrometer used in the above test process was a Bruker UltrafleXtreme MALDI-TOF MS instrument (BrukerDaltonics, Billerica, MA), equipped with a 355 nm Nd:YAG laser. The data acquisition mode was positive ion reflection mode, the laser beam size was set to "small", and the laser energy was set to 80%.

[0029] The test results are as follows Figure 3As shown in the results, it can be seen that in salt solution, the signal intensity of the metabolite did not weaken, indicating that HCOFs-Au has excellent salt resistance.

[0030] Example 3 HCOFs-Au was used as a matrix to detect urine metabolites to distinguish common pneumonia from pneumonia caused by COVID-19 infection. The specific process is as follows: The sample urine and HCOFs-Au matrix solution (preparation process is the same as in Example 2) were mixed in equal volumes, mixed with a vortex mixer and then tested by target point. The instrument test conditions are the same as in Example 2. A total of 34 urine specimens from patients with common pneumonia and 50 patients with pneumonia caused by new coronavirus infection were tested. Each specimen was tested three times in parallel, and a total of 252 urine metabolic fingerprints were obtained. The data was exported as raw data by flexanalysis software, and then processed by data alignment, normalization, missing value filling and other steps before being imported into the support vector machine (software is Orange).

[0031] After processing by the machine learning model, 7 characteristic metabolites were screened out, including 7 key m / z features: Pseudouridine, 8-hydroxyguanine (8-HdG), Creatinine, Methylhistidine (MHis), Pterin-6-carboxylic acid, 3-hydroxysalicylic acid (3-HHA) and PAGln. The screening conditions for the metabolite markers are: frequency greater than 50%, p value less than 0.05, and AUC value greater than 0.7.

[0032] The results are as follows Figure 5-6 As shown; Figure 5 The figure shows a heat map comparison of the above 7 characteristic metabolites between patients with common pneumonia and those with pneumonia caused by the new coronavirus infection. The results show that there are significant differences in these 7 key metabolites between the two groups.

[0033] Figure 6 This is a performance curve for diagnosing patients with pneumonia caused by the new coronavirus infection using the above 7 characteristic metabolites. From the results, it can be seen that patients with pneumonia caused by the new coronavirus infection can be accurately distinguished from patients with common pneumonia.

[0034] Example 4 The detection effect of HCOFs-Au as a matrix for detecting actual urine metabolites was verified, and the detection effects of its precursor material HCOFs, solid COFs material and the commonly used organic matrix CHCA were compared. The specific process is as follows: The same urine sample was mixed with equal volumes of HCOFs-Au matrix solution, HCOFs, COFs, and CHCA (the preparation process was the same as in Example 2), and then mixed with a vortex mixer and then tested by spotting.

[0035] The test results are as follows Figure 7 As shown in the figure, from the statistical results of urine creatinine signal intensity, it can be seen that the prepared material HCOFs-Au has the best detection effect. Compared with the small molecule matrix CHCA, the detection sensitivity of HCOFs-Au to metabolites is improved by an order of magnitude.

[0037] The embodiments of the present application are described above in conjunction with the accompanying drawings. Specific examples are used herein to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the core idea of ​​the present application, but the present application is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the inspiration of the present application, ordinary technicians in this field can also make many forms without departing from the scope of protection of the purpose of the present application and the claims, all of which are within the protection of the present application.

Claims

1. A method for preparing a hollow structure covalent organic framework material modified with gold nanoparticles, characterized in that: The following steps are involved: S1: dissolving 1,3,5-tri(4-aminophenyl)benzene and isophthalic acid in an organic solvent, stirring evenly, adding glacial acetic acid, reacting, centrifuging, washing, and obtaining a covalent organic framework precursor; S2: dispersing the covalent organic framework precursor in a mixed solvent of 1,4-dioxane and mesitylene, mixing, adding glacial acetic acid and water, placing in an oil bath for heating and reacting, centrifuging and washing after the reaction to obtain a hollow structure covalent organic framework; S3: dissolving the hollow structure covalent organic framework in a mixed solution of water and ethanol, stirring evenly, placing in an ice bath and adding tetrachloroauric acid hydrate to react, adding sodium borohydride after reacting for 3h-4h to continue the reaction, and after the reaction is completed, centrifuging and washing to obtain the hollow structure covalent organic framework material modified with gold nanoparticles.

2. The preparation method according to claim 1, characterized in that: The usage ratio of the 1,3,5-tris(4-aminophenyl)benzene, the isophthalic acid aldehyde, the organic solvent and the glacial acetic acid is 70 mg:32.5 mg:25 mL:2.5 mL.

3. The preparation method according to claim 2, characterized in that: The organic solvent is acetonitrile.

4. The preparation method according to claim 1, characterized in that: The volume ratio of 1,4-dioxane to mesitylene in S2 is 4:

1.

5. The preparation method according to claim 1, characterized in that: The volume ratio of water to ethanol in S3 is 1:

1.

6. The preparation method according to claim 5, characterized in that: The mass ratio of tetrachloroauric acid hydrate to sodium borohydride in S3 is 1:

1.

7. The preparation method according to claim 1, characterized in that: The heating temperature in the oil bath is 65°C-70°C.

8. A hollow structure covalent organic framework material modified with gold nanoparticles for detecting urine metabolites, characterized in that: The hollow structure covalent organic framework material is prepared by the preparation method according to any one of claims 1 to 7.

9. The hollow structure covalent organic framework material according to claim 8, characterized in that: The hollow structure covalent organic framework material is used for urine metabolite detection to distinguish between common pneumonia and pneumonia caused by new coronavirus infection.

10. Use of the hollow structure covalent organic framework material modified with gold nanoparticles for urine metabolite detection according to claim 8 in the preparation of a matrix material for laser desorption / ionization mass spectrometry.

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