A surface-modified aluminum-based metal-organic framework-titanium dioxide composite material with gold nanoparticles, its preparation method and application

Abstract

This invention relates to the field of nanomaterials, and more particularly to an aluminum-based metal-organic framework-titanium dioxide composite material modified with surface gold nanoparticles, its preparation method, and its application. The invention prepares a novel aluminum-based metal-organic framework-titanium dioxide cubic nanomaterial precursor (Al-MOF / TiO2) using aluminum trichloride hexahydrate and 3,5-pyrazole dicarboxylic acid as monomers, titanium dioxide as the composite, and deionized water as the solvent. Subsequently, gold nanoparticles are modified onto the Al-MOF / TiO2 surface to obtain the Al-MOF / TiO2@Au cubic composite nanomaterial. The synthesis process is simple and environmentally friendly. Al-MOF / TiO2@Au exhibits a large specific surface area and excellent optical properties, demonstrating its great potential in the study of metabolic fingerprint extraction of drug-resistant bacteria.

Description

Technical Field

[0001] This invention relates to the field of nanomaterials, and more particularly to an aluminum-based metal-organic framework-titanium dioxide composite material modified with surface nano-gold particles, its preparation method, and its application. Background Technology

[0002] With the widespread clinical use of carbapenems, bacterial resistance has gradually increased. In the past two decades, carbapenem-resistant Klebsiella pneumoniae (CRKP) has emerged and spread rapidly worldwide. The primary resistance mechanism of CRKP is the production of carbapenemases by bacteria, which hydrolyze carbapenem antibiotics, thus leading to resistance. Different genotypes of carbapenemase CRKP exhibit varying antibiotic activity, resulting in different infection mortality rates. Therefore, there is an urgent clinical need to develop an efficient, convenient, and highly specific detection method for rapid identification of CRKP and determination of drug-resistant genotypes.

[0003] Matrix-assisted laser desorption / ionization mass spectrometry (MALDI-MS) has significant applications in microbial species identification due to its advantages such as high throughput, high precision, and rapid analysis speed. In the analysis of microbial cell metabolites, the desorption / ionization of small metabolic molecules by nanomatrices is a crucial step, directly affecting the sensitivity, specificity, and stability of the detection. Some nanomaterial matrices, such as amorphous silicon and metal nanoparticles, have been successfully used to extract metabolic fingerprints from clinically infected bacterial cells. However, the sensitivity of single nanomaterials is limited, and there are problems such as difficulty in distinguishing similar bacterial species or strains and drug-resistant strains. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of existing technologies by providing an aluminum-based metal-organic framework-titanium dioxide composite material with surface-modified gold nanoparticles, its preparation method, and its application.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] The first aspect of this invention is to provide a method for preparing an aluminum-based metal-organic framework-titanium dioxide composite material modified with surface-gold nanoparticles, the steps of which include:

[0007] S1. Weigh titanium dioxide, disperse it in deionized water, and shake it to obtain the first solution;

[0008] S2. Weigh out chlorine trioxide hexahydrate, 3,5-pyrazole dicarboxylic acid monohydrate and sodium hydroxide, dissolve them in deionized water to prepare the second solution;

[0009] S3. The first solution and the second solution are mixed and reacted. After the reaction is completed, the reaction product is washed and dried to obtain an aluminum-based metal-organic framework-titanium dioxide composite material.

[0010] S4. The aluminum-based metal-organic framework-titanium dioxide composite material is dispersed in a nano-gold glue solution and shaken. The shaken product is then washed and dried to obtain the aluminum-based metal-organic framework-titanium dioxide composite material modified with nano-gold particles on the surface.

[0011] Preferably, in step S2, the concentration ratio of the chlorine trioxide hexahydrate, the 3,5-pyrazole dicarboxylic acid monohydrate, and the sodium hydroxide in the second solution is 1:(0.9-1.2):(1.0-2.0).

[0012] Preferably, in step S3, the reaction temperature of the first solution and the second solution is 80℃-100℃, and the reaction time is 8h-12h.

[0013] Preferably, in steps S3 and S4, the washing process includes: thorough washing with deionized water and ethanol.

[0014] A second aspect of the present invention is to provide an aluminum-based metal-organic framework-titanium dioxide composite material modified with surface gold nanoparticles prepared by the above-described preparation method.

[0015] A third aspect of the present invention is to provide an application of an aluminum-based metal-organic framework-titanium dioxide composite material modified with surface gold nanoparticles prepared by the above preparation method in bacterial mass spectrometry metabolic fingerprint extraction.

[0016] Preferably, the bacteria are drug-resistant.

[0017] More preferably, the drug-resistant bacteria is carbapenem-resistant Klebsiella pneumoniae.

[0018] The present invention adopts the above technical solution and has the following technical effects compared with the prior art:

[0019] This invention prepares a novel aluminum-based metal-organic framework-titanium dioxide cubic nanomaterial precursor (Al-MOF / TiO2) using aluminum trichloride hexahydrate and 3,5-pyrazole dicarboxylic acid as monomers, titanium dioxide as a composite, and deionized water as a solvent. Subsequently, gold nanoparticles are modified on the surface of Al-MOF / TiO2 to obtain Al-MOF / TiO2@Au cubic composite nanomaterials. The synthesis process is simple and environmentally friendly. Al-MOF / TiO2@Au has a large specific surface area and excellent optical properties, indicating its great potential in the study of metabolic fingerprint extraction of drug-resistant bacteria. Attached Figure Description

[0020] Figure 1 Scanning electron microscope image of an aluminum-based metal-organic framework-titanium dioxide composite matrix modified with surface gold nanoparticles;

[0021] Figure 2 Nitrogen isothermal adsorption-desorption curves of aluminum-based metal-organic framework-titanium dioxide composite matrix modified with surface gold nanoparticles.

[0022] Figure 3 The ultraviolet absorption spectrum of the aluminum-based metal-organic framework-titanium dioxide composite matrix modified with surface gold nanoparticles;

[0023] Figure 4 Mass spectrometry metabolic fingerprints of different clinically infectious bacteria based on aluminum-based metal-organic framework-titanium dioxide composite matrix modified with surface gold nanoparticles are compared.

[0024] Figure 5 Mass spectrometry metabolic fingerprints of clinical Klebsiella pneumoniae drug-resistant and drug-sensitive strains based on aluminum-based metal-organic framework-titanium dioxide composite matrix modified with surface gold nanoparticles are compared.

[0025] Figure 6 Mass spectrometry metabolic fingerprints of different carbapenemase-resistant Klebsiella pneumoniae genotypes based on aluminum-based metal-organic framework-titanium dioxide composite matrix modified with surface gold nanoparticles.

[0026] Figure 7 OPLS-DA model score plots for three clinically infectious bacteria;

[0027] Figure 8 OPLS-DA model score plots for clinically resistant and susceptible Klebsiella pneumoniae strains;

[0028] Figure 9 OPLS-DA model score plots for Klebsiella pneumoniae with different carbapenemase-resistant genotypes. Detailed Implementation

[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. 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.

[0030] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0031] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but this is not intended to limit the scope of the invention.

[0032] Example 1

[0033] This embodiment provides a method for preparing an aluminum-based metal-organic framework-titanium dioxide composite material modified with surface-gold nanoparticles, the steps of which include:

[0034] S1. Weigh 100 mg of titanium dioxide, disperse it in 75 mL of deionized water, and shake at a constant temperature for 30 min to obtain the first solution;

[0035] S2. Weigh 1.06 g of chlorine trioxide hexahydrate (4.39 mmol), 76 mg of 3,5-pyrazole dicarboxylic acid monohydrate (4.39 mmol), and 270 mg of sodium hydroxide (6.75 mmol), dissolve them in 75 mL of deionized water to prepare the second solution;

[0036] S3. The first solution and the second solution are mixed and placed in a constant temperature magnetic stirring oil bath. The reaction is carried out at 90°C for 10 hours. After the reaction is completed, the reaction product is thoroughly washed with deionized water and ethanol to remove impurities and raw material monomers from the surface of the product. After washing, the product is placed in a vacuum drying oven and dried at 50°C overnight to obtain aluminum-based metal-organic framework-titanium dioxide composite material.

[0037] S4. Disperse 30 mg of the aluminum-based metal-organic framework-titanium dioxide composite material into 20 mL of nano-gold glue solution, shake at a constant temperature for 2 h, wash the shaken product thoroughly with deionized water and ethanol, and then dry the product in a vacuum dryer to obtain the aluminum-based metal-organic framework-titanium dioxide composite material modified with nano-gold particles on the surface.

[0038] Scanning electron microscope (SEM) images of the resulting aluminum-based metal-organic framework-titanium dioxide composite matrix modified with surface gold nanoparticles (20 kV, Philips XL30 electron microscope, Netherlands) are shown below. Figure 1 As shown, the product exhibits a uniform cubic morphology with an average size of approximately 1 μm.

[0039] Studies using nitrogen isothermal adsorption-desorption curves (Micromeritics ASAP-2010, USA) indicate that the product has a large specific surface area. Figure 2 Studies using ultraviolet absorption spectroscopy (Shimadzu UV-1900, Japan) showed that, compared to the aluminum-based metal-organic framework-titanium dioxide precursor (product 1), the resulting aluminum-based metal-organic framework-titanium dioxide composite matrix modified with surface gold nanoparticles (product 2) exhibited stronger ultraviolet-visible (UV-vis) absorbance at 355 nm. Figure 3 ).

[0040] Example 2

[0041] This embodiment provides an application of an aluminum-based metal-organic framework-titanium dioxide composite material modified with surface gold nanoparticles prepared by the method described in Example 1 in the extraction of metabolic fingerprints from different bacteria using mass spectrometry.

[0042] (1) Sample preparation

[0043] 1 mg of Al-MOF / TiO2@Au nanomaterials were dispersed in 1 mL of deionized water. Clinical Escherichia coli (ECO, strain 71), Staphylococcus aureus (SA, strain 76), and Klebsiella pneumoniae (KP, strain 64) were collected, and after liquid culture, they were resuspended in deionized water to a concentration of approximately 1 × 10⁻⁶. 10 CFU / mL.

[0044] (2) Mass spectrometry analysis

[0045] 1 μL of Al-MOF / TiO2@Au nanomaterials was deposited on a MALDI target plate, and 1 μL of different bacterial suspensions were spotted onto the Al-MOF / TiO2@Au nanomaterials. Then, a cell wall lysis buffer containing formic acid (0.5 μL, 70% aqueous solution), 1-butanol (0.5 μL), and salicylic acid (1 μL, 1 mg / mL aqueous solution) was deposited on the target plate. After natural drying, laser desorption / ionization mass spectrometry analysis was performed using a Bruker MicroFlex LRF mass spectrometer with a 355 nm Nd:YAG laser source, a laser frequency of 2000 Hz, and an accelerating voltage of 20 kV. The acquisition mode was cation reflector mode, and the mass-to-charge ratio range was 100-1000 Da. Mass spectrometry data were obtained from FlexControl 3.4 and exported from FlexAnalysis 3.4 to obtain rich metabolite spectra of different bacteria.

[0046] Figure 4 Comparison of mass spectrometry metabolic fingerprints of clinical Escherichia coli, Staphylococcus aureus, and Klebsiella pneumoniae extracted from Al-MOF / TiO2@Au nanomaterial matrix.

[0047] Example 3

[0048] This embodiment provides the application of an aluminum-based metal-organic framework-titanium dioxide composite material modified with surface gold nanoparticles prepared by the method described in Example 1 in the extraction of mass spectrometry metabolic fingerprints of drug-resistant and sensitive strains of Klebsiella pneumoniae.

[0049] (1) Sample preparation

[0050] 1 mg of Al-MOF / TiO2@Au nanomaterials were dispersed in 1 mL of deionized water. Carbapenem-resistant Klebsiella pneumoniae (CRKP, strain 80) and carbapenem-sensitive Klebsiella pneumoniae (CSKP, strain 89) were collected, cultured in liquid, and then resuspended in deionized water to a concentration of approximately 1 × 10⁻⁶. 10 CFU / mL.

[0051] (2) Mass spectrometry analysis

[0052] 1 μL of Al-MOF / TiO2@Au nanomaterials was deposited on a MALDI target plate. 1 μL of Klebsiella pneumoniae suspensions with different drug resistances were spotted onto the Al-MOF / TiO2@Au nanomaterials. Then, a cell wall lysis buffer containing formic acid (0.5 μL, 70% aqueous solution), 1-butanol (0.5 μL), and salicylic acid (1 μL, 1 mg / mL aqueous solution) was deposited on the target site. After natural drying, laser desorption / ionization mass spectrometry (LASIK) analysis was performed using a Bruker MicroFlex LRF mass spectrometer with a 355 nm Nd:YAG laser source, a laser frequency of 2000 Hz, and an accelerating voltage of 20 kV. The acquisition mode was cation reflector mode, and the mass-to-charge ratio range was 100-1000 Da. Mass spectrometry data were obtained from FlexControl 3.4 and exported from FlexAnalysis 3.4 to obtain bacterial metabolic mass spectra.

[0053] Figure 5 Comparison of mass spectrometry metabolic fingerprints of clinically resistant and susceptible Klebsiella pneumoniae strains extracted from Al-MOF / TiO2@Au nanomaterial matrix.

[0054] Example 4

[0055] This embodiment provides the application of an aluminum-based metal-organic framework-titanium dioxide composite material modified with surface gold nanoparticles prepared by the method described in Example 1 in the extraction of mass spectrometry metabolic fingerprints of Klebsiella pneumoniae with different carbapenemase-resistant genotypes.

[0056] (1) Sample preparation

[0057] 1 mg of Al-MOF / TiO2@Au nanomaterials were dispersed in 1 mL of deionized water. Different genotypes of clinically carbapenemase-resistant Klebsiella pneumoniae (IMP, 12 strains; KPC, 12 strains; NDM, 12 strains) were collected, cultured in liquid, and then resuspended in deionized water to a concentration of approximately 1 × 10⁻⁶. 10 CFU / mL.

[0058] (2) Mass spectrometry analysis

[0059] 1 μL of Al-MOF / TiO2@Au nanomaterials was deposited on a MALDI target plate, and 1 μL of cell suspension was spotted onto the Al-MOF / TiO2@Au nanomaterials. Then, a cell wall lysis buffer containing formic acid (0.5 μL, 70% aqueous solution), 1-butanol (0.5 μL), and salicylic acid (1 μL, 1 mg / mL aqueous solution) was deposited on the target site. After natural drying, laser desorption / ionization mass spectrometry analysis was performed using a Bruker MicroFlex LRF mass spectrometer with a 355 nm Nd:YAG laser source, a laser frequency of 2000 Hz, and an accelerating voltage of 20 kV. The acquisition mode was cation reflector mode, and the mass-to-charge ratio range was 100-1000 Da. Mass spectrometry data were obtained from FlexControl 3.4 and exported from FlexAnalysis 3.4 to obtain bacterial metabolic mass spectra.

[0060] Figure 6 Comparison of mass spectrometry metabolic fingerprints of different carbapenemase-resistant Klebsiella pneumoniae genotypes extracted from Al-MOF / TiO2@Au nanomaterial matrix.

[0061] Application Examples

[0062] Based on the bacterial metabolic mass spectra obtained in Examples 2-4, an orthogonal partial least squares discriminant analysis (OPLS-DA) model was established, including the following steps:

[0063] (1) The urine mass spectra were preprocessed using R language based on the MALDIquant and MALDIquantForeign packages, including peak intensity conversion and normalization, peak smoothing, baseline subtraction, peak alignment, peak identification and peak grouping.

[0064] (2) Based on bacterial metabolic mass spectrometry, SIMCA software (version 14.1, Umetrics) was used. Sweden constructed an OPLS-DA model to distinguish between different bacterial species. Figure 7 Differentiation between carbapenem-resistant and susceptible strains of Klebsiella pneumoniae. Figure 8 Differentiation of Klebsiella pneumoniae with different carbapenemase genotypes ( Figure 9 ).

[0065] In summary, the aluminum-based metal-organic framework-titanium dioxide composite material modified with surface gold nanoparticles of the present invention has great potential in the study of metabolic fingerprint extraction of drug-resistant bacteria.

[0066] The above description is merely a preferred embodiment of the present invention and does not limit the implementation and protection scope of the present invention. Those skilled in the art should realize that any equivalent substitutions and obvious changes made based on the description and illustrations of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing an aluminum-based metal-organic framework-titanium dioxide composite material modified with surface-gold nanoparticles, characterized in that the steps include... include: S1. Weigh titanium dioxide, disperse it in deionized water, and shake it to obtain the first solution; S2. Weigh out chlorine trioxide hexahydrate, 3,5-pyrazole dicarboxylic acid monohydrate and sodium hydroxide, dissolve them in deionized water to prepare the second solution; S3. The first solution and the second solution are mixed and reacted. After the reaction is completed, the reaction product is washed and dried to obtain an aluminum-based metal-organic framework-titanium dioxide composite material. S4. The aluminum-based metal-organic framework-titanium dioxide composite material is dispersed in a nano-gold glue solution and shaken. The shaken product is then washed and dried to obtain the aluminum-based metal-organic framework-titanium dioxide composite material modified with nano-gold particles on the surface.

2. The preparation method according to claim 1, characterized in that, In step S2, the concentration ratio of chlorine trioxide hexahydrate, 3,5-pyrazole dicarboxylic acid monohydrate and sodium hydroxide in the second solution is 1:(0.9-1.2):(1.0-2.0).

3. The preparation method according to claim 1, characterized in that, In step S3, the reaction temperature of the first solution and the second solution is 80℃-100℃, and the reaction time is 8h-12h.

4. The preparation method according to claim 1, characterized in that, In steps S3 and S4, the washing process includes: thorough washing with deionized water and ethanol.

5. An aluminum-based metal-organic framework-titanium dioxide composite material with surface-modified gold nanoparticles, prepared by the preparation method according to any one of claims 1-4.

6. The application of an aluminum-based metal-organic framework-titanium dioxide composite material modified with surface gold nanoparticles prepared by any one of claims 1-4 in bacterial mass spectrometry metabolic fingerprint extraction.

7. The application according to claim 6, characterized in that, The bacteria in question are drug-resistant.

8. The application according to claim 7, characterized in that, The drug-resistant bacteria is carbapenem-resistant Klebsiella pneumoniae.

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