A Zr-MOF / Fe3O4 composite material, its preparation method and application

Abstract

The application belongs to the field of in vitro diagnosis, and particularly relates to a Zr-MOF / Fe3O4 composite material, a preparation method and application. The application provides a preparation method of a Zr-MOF / Fe3O4 composite material. FeNPs are prepared by a solvothermal method, 2D MOF nanosheets are prepared, ZMF (Zr-MOF / FeNPs) nanosheets are prepared by an in-situ growth method, Zr-MOF flowers are prepared by a dielectric barrier discharge method (DBD), and finally, ZMF flowers, namely the Zr-MOF / Fe3O4 composite material, are prepared by the in-situ growth method. The Zr-MOF / Fe3O4 composite material has a stable structure, the structure also has light energy and thermal energy binding functions, can guarantee the detection intensity and comprehensiveness of signals, and can also widen the application in metabolite detection.

Description

Technical Field

[0001] This invention belongs to the field of in vitro diagnostics, specifically relating to a Zr-MOF / Fe3O4 composite material, its preparation method, and its application. Background Technology

[0002] Heart failure (HF) and heart failure with myocardial infarction (HFMI) are common cardiac diseases with high incidence and mortality. In the context of treating patients with acute or chronic HF and HFMI, clinicians need to rapidly and accurately implement different treatment strategies to improve survival. However, the similarity of symptoms often complicates clinical judgment. Common non-invasive diagnostic markers, such as cardiac troponin (cTn), B-type brain natriuretic peptide (BNP), and electrocardiogram (ECG), while highly sensitive, often lack specificity, leading to a high false-positive rate. This not only leads to unnecessary misdiagnosis but also increases the risk of delaying critical treatment. Although echocardiography and angiography can improve diagnostic accuracy, their widespread application is limited by factors such as experience, invasiveness, and cost. Blood metabolites reflect physiological states and show promising potential as potential biomarkers for disease diagnosis. Metabolomics, focusing on disease phenotypes, offers the potential for fluid-based metabolic characterization analysis to diagnose complex diseases. However, conventional metabolic detection methods (such as nuclear magnetic resonance, high performance liquid chromatography, and tandem mass spectrometry) face limitations in terms of sensitivity, complexity, cost, and throughput, which necessitates addressing the problem of high-throughput, low-cost, and accurate analysis of body fluid metabolic characteristics.

[0003] Since the Nobel Prize was awarded for nano-assisted laser desorption / ionization mass spectrometry (MALDI-MS), laser desorption / ionization mass spectrometry (LDI-MS) has received widespread attention due to its high throughput and ease of operation. In recent years, methods for detecting small molecule metabolites using nanomatrices instead of organic matrices have flourished to reduce matrix background interference. The rational engineering design of the nanomatrix and its interaction with the target small molecule determine the detection performance. Currently, the rational design of nanomatrices based on the LDI-MS mechanism mainly focuses on improving ionization efficiency and enhancing the desorption process. Strategies include introducing nanoscale modifications, such as tips, heterojunctions, and noble metals, to enhance ionization intensity, constructing metal centers, or introducing high photothermal components to improve thermal desorption capacity. Although these methods have made some progress, further improvements are still needed to fully utilize nanomatrices for comprehensive analysis of a large number of complex biological fluids. This includes addressing issues such as weak ionization due to insufficient light absorption, decreased desorption capacity due to rapid heat dissipation, and simplifying the complex preparation of nanomatrices; therefore, there is an urgent need for a nanomatrix and its preparation method that can overcome these shortcomings for accurate metabolite analysis and detection of various cardiac diseases. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a method for preparing a Zr-MOF / Fe3O4 composite material, comprising the following steps:

[0005] S1: FeCl3·6H2O, sodium citrate, sodium acetate and solvent are mixed and stirred to obtain a mixed liquid. The mixture is then subjected to an oxygen-free high-pressure reaction in a reactor. The FeNPs material is obtained by magnetic separation and washing.

[0006] S2: 1,3,5-Benzotricarboxylic acid and zirconium chloride are used as raw materials for organic ligands. They are added to a mixed solvent and mixed. The clear liquid after mixing is loaded into a polytetrafluoroethylene reactor and subjected to an oxygen-free high-pressure reaction. After the reaction, the mixture is centrifuged and washed to obtain 2D MOF nanosheets.

[0007] S3: The 2D MOF nanosheets obtained in S2 were added to a mixed solution of ethylene glycol containing ferric chloride, 1,6-hexanediamine and sodium acetate, stirred at room temperature, and after high-temperature anaerobic reaction, 2D ZMF nanosheets were obtained by magnetic separation and washing.

[0008] S4: 1,3,5-Benzotricarboxylic acid and zirconium chloride, as raw materials for organic ligands, are mixed with a mixed solvent. The clear liquid is then loaded into a dielectric barrier discharge reactor. After centrifugation and washing, 3D MOF flower materials are obtained.

[0009] S5: The Zr-MOF flowers obtained in S4 were added to a mixed solution of ethylene glycol containing ferric chloride, 1,6-hexanediamine and sodium acetate. The mixture was stirred at room temperature and reacted under an oxygen-free high-pressure environment. After magnetic separation and washing, ZMF flowers, i.e. Zr-MOF / Fe3O4 composite material, were obtained.

[0010] Furthermore, the solvent in S1 is ethylene glycol, the stirring time is 1 hour, the high-pressure anaerobic reaction time is 12 hours, the temperature is 200°C, and the washing solution is ethanol and deionized water.

[0011] Furthermore, the high-pressure anaerobic reaction time in S2 is 12 hours, the temperature is 120°C, and the washing solution is DMF, ethanol, and deionized water.

[0012] Furthermore, the stirring time in S3 is 1 hour, the high-pressure anaerobic reaction time is 6 hours, and the temperature is 200°C.

[0013] Furthermore, the dielectric barrier discharge reaction process in S4 lasts for 20 minutes, and the washing solution consists of DMF, ethanol, and deionized water; the mixed solvent consists of N,N-dimethylformamide, deionized water, and formic acid.

[0014] Furthermore, the stirring time in S5 is 1 hour, the high-pressure anaerobic reaction time is 6 hours, the temperature is 200°C, and the washing solution is ethanol and deionized water.

[0015] A Zr-MOF / Fe3O4 composite material, wherein the Zr-MOF / Fe3O4 composite material has a three-dimensional flower-like Zr-MOF nanoskeleton structure.

[0016] An application of a Zr-MOF / Fe3O4 composite material, wherein the Zr-MOF / Fe3O4 composite material is used in the preparation of nanochips for the detection of metabolites of diseases.

[0017] Beneficial effects

[0018] The present invention provides a method for preparing a Zr-MOF / Fe3O4 composite material. By employing the discharge arc method, Fe3O4 can be grown in situ in MOF to obtain a Zr-MOF / Fe3O4 composite material. This material has a stable structure that also provides light and heat confinement functions, which can reduce overall heat loss and ensure signal detection intensity and comprehensiveness. Furthermore, it can be widely used in the detection of metabolites in cardiac diseases. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort. In the drawings:

[0020] Figure 1 This is a diagram illustrating the preparation process of Example 1 of the present invention;

[0021] Figure 2 The images show the SEM images of the morphology of FeNPs, ZMF sheets, and ZMF flowers (Zr-MOF / Fe3O4 composite material) in Example 1 of this invention.

[0022] Figure 3 This is a standard metabolite intensity diagram of Example 1 of the present invention;

[0023] Figure 4 This is a background image of the matrix in Embodiment 1 of the present invention;

[0024] Figure 5 This is an intensity diagram of mixed standard metabolites under high protein and high salt conditions in Example 1 of the present invention;

[0025] Figure 6 This is a serum test image of different samples from Example 1 of the present invention. Detailed Implementation

[0026] The following will refer to Embodiment 1 of the present invention and the appendix. Figures 1-6 The technical solutions of the present invention have been clearly and completely described. It is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] Combination Figure 1 The preparation process diagram shows the specific preparation method of the present invention.

[0028] Example 1

[0029] S1: Prepared using a solvothermal method, the reaction raw materials include 2.43g of ferric chloride (FeCl3·6H2O), 0.45g of sodium citrate and 3.6g of sodium acetate, and 60ml of ethylene glycol as solvent. The raw materials are mixed and stirred at room temperature for 1 hour. Then, the mixture is loaded into a polytetrafluoroethylene reactor and reacted at 200℃ under high pressure and oxygen-free conditions for 12 hours. After the reaction, the mixture is separated by magnetic force and washed with ethanol and deionized water to obtain FeNPs material.

[0030] S2: 12.3 mg of 1,3,5-benzenetricarboxylic acid (H3BTB) and 10.1 mg of zirconium chloride (ZrCl4) were used as raw materials for the organic ligand; the mixed solvent was 5 mL of N,N-dimethylformamide (DMF), 0.06 mL of deionized water and 0.9 mL of formic acid; the mixed clear liquid was placed in a polytetrafluoroethylene reactor and subjected to high pressure reaction at 120 °C under anaerobic conditions for 12 hours; after the reaction, the material was centrifuged and washed with DMF, ethanol and deionized water to obtain 2D MOF nanosheets;

[0031] S3: ZMF nanosheets were prepared by in-situ growth method. 30 mg of 2D MOF nanosheets were added to a mixed solution (18 mL) of ethylene glycol containing 90 mg of ferric chloride, 324 mg of 1,6-hexanediamine and 360 mg of sodium acetate. The mixture was stirred at room temperature for 1 hour, and then reacted under high pressure and anaerobic environment at 200 °C for 6 hours. The mixture was separated by magnetic force and washed with ethanol and deionized water to obtain 2D ZMF nanosheets.

[0032] S4: Zr-MOF flowers were prepared using the discharge arc method. 12.3 mg of 1,3,5-benzenetricarboxylic acid and 10.1 mg of zirconium chloride were used as raw materials for the organic ligands. The mixed solvent consisted of 5 mL of N,N-dimethylformamide, 0.06 mL of deionized water, and 0.9 mL of formic acid. After mixing, the clear liquid was loaded into a DBD reactor, and a sufficiently high AC voltage (37–50 V, 1.27–3 A) was applied between the two electrodes for 20 minutes to prepare flower-like MOF materials. After centrifugation and washing with DMF, ethanol, and deionized water, 3D MOF flower materials were obtained.

[0033] S5: ZMF flowers were prepared by in-situ growth. Initially, 30 mg of Zr-MOF flowers were added to a mixed solution (18 mL) of ethylene glycol containing 90 mg of ferric chloride, 324 mg of 1,6-hexanediamine and 360 mg of sodium acetate. The mixture was stirred at room temperature for 1 hour and then reacted at 200 °C for 6 hours under anaerobic high pressure to obtain 3D ZMF flowers. The obtained 3D ZMF flowers were separated by magnetic force and washed with ethanol and deionized water to obtain Zr-MOF / Fe3O4 composite material.

[0034] Combination Figure 2 It can be seen from the SEM images of the FeNPs, ZMF sheets, and ZMF flowers prepared by this invention that the material has been successfully generated. Combined with... Figure 3 It was found that glucose, tryptophan, phenylalanine, arginine, and lysine were used as standard samples. The strength comparison between nanomatrices systematically explored LDI enhancement. Five small molecule metabolites—glucose, tryptophan, phenylalanine, arginine, and lysine—were selected as standard samples to evaluate the performance of the nanomaterials, and ZMF flowers were found to have the highest strength. In scanning electron microscopy images, uniformly distributed two-dimensional sheets and three-dimensional flower-like Zr-MOF nanoframeworks were clearly observed. The nanosheets showed independent distribution, and the flower structure grew from multiple dispersed sheets. The thicknesses of the two nanoframeworks were 10 nm and 5 nm, respectively. FeNPs were regular spheres of 200–300 nm, and the ZMF nanosheets and ZMF flowers maintained their original two-dimensional and three-dimensional spatial structures. FeNPs were uniformly distributed on the Zr-MOF nanoframework. The ZMF flowers had a diameter of 5 μm and exhibited a regular flower shape.

[0035] Combination Figure 4 It can be seen that ZMF flower materials have no background interference peaks compared to traditional organic matrices, combined with Figure 5 Intensity maps of mixed standard metabolites under high protein and high salt conditions can be obtained. ZMF flowers not only obtained the highest signal intensity but also detected the largest number of signals. Figure 6The serum test images from different samples show that ZMF flowers can effectively detect metabolite signals in serum.

[0036] The steps for further fabricating ZMF flowers into a chip for metabolite detection include: sample preparation and LDI-MS analysis. First, a standard metabolite solution containing Glu, Arg, Try, Phe, or Lys is prepared using deionized water. To improve protein and salt tolerance, BSA and NaCl are mixed with typical small metabolites Glu, Arg, Try, Phe, and Lys, with a concentration of 1 ng / nL for each metabolite. All blood samples are inserted into empty tubes via venipuncture and allowed to clot within 1 hour at room temperature. Blood samples are centrifuged for 10 min, and serum is collected and immediately stored at -80℃ for further analysis. Different materials are prepared into 1 ng / nL aqueous suspensions, where Glu, Arg, Try, Phe, or Lys represents glucose, arginine, tryptophan, phenylalanine, and lysine, respectively.

[0037] LDI-MS analysis was performed using MALDI-TOF / TOF mass spectrometry (Shimadzu, AXIMA-Performance) in positive ion mode, equipped with a nitrogen laser (337 nm). Parameters were set including 200 laser scans per sample, a laser intensity of 65%, and a molecular weight range of 100 to 1000 Da. The instrument was calibrated with standard samples before each use, with standard metabolite solutions or serum samples pipetted onto the target plate. After drying at room temperature, the matrix was transferred to cover the previously dried spots. Samples were then dried at room temperature before analysis on the MALDI-TOF / TOF MS. For each sample, including small molecules and biological samples, five independent LDI-MS experiments were performed to ensure the reproducibility and reliability of the results.

[0038] The preparation method used in this invention enables the in-situ growth of iron oxide in MOF to obtain a stable structure. This structure also provides light and heat confinement functions, which can reduce overall heat loss and ensure signal detection intensity and comprehensiveness. The prepared ZMF flower can broaden its application in the detection of metabolites in heart diseases.

Claims

1. A method for preparing a Zr-MOF / Fe3O4 composite material, characterized in that, Includes the following steps: S1: 1,3,5-tris(4-carboxyphenyl)benzene and zirconium chloride, as raw materials for organic ligands, are mixed with a mixed solvent. The clear liquid is then loaded into a dielectric barrier discharge reactor. After centrifugation and washing, 3D MOF flower materials are obtained. The dielectric barrier discharge reaction process lasted 20 minutes. The washing solution consisted of DMF, ethanol, and deionized water. The mixed solvent consisted of N,N-dimethylformamide, deionized water, and formic acid. The AC voltage during the dielectric barrier discharge process was 37–50 V, and the current was 1.27–3 A. S2: The Zr-MOF flowers obtained in S1 were added to a mixed solution of ethylene glycol containing ferric chloride, 1,6-hexanediamine and sodium acetate. The mixture was stirred at room temperature and reacted under an oxygen-free high-pressure environment. After magnetic separation and washing, ZMF flowers, i.e. Zr-MOF / Fe3O4 composite material, were obtained.

2. The method for preparing a Zr-MOF / Fe3O4 composite material according to claim 1, characterized in that, The stirring time described in S2 is 1 hour, the high-pressure anaerobic reaction time is 6 hours, the temperature is 200°C, and the washing solution is ethanol and deionized water.

3. A Zr-MOF / Fe3O4 composite material obtained by the preparation method according to any one of claims 1 to 2, characterized in that, The Zr-MOF / Fe3O4 composite material has a three-dimensional flower-like structure.

4. The application of the Zr-MOF / Fe3O4 composite material according to claim 3, characterized in that, The Zr-MOF / Fe3O4 composite material is used in the preparation of nanochips for the detection of disease metabolites.

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