Platinum-doped graphene nano composite material modified by surface nano gold particle loaded bimetallic nano cube and preparation method and application of platinum-doped graphene nano composite material

Abstract

The invention relates to the field of nano materials, in particular to a platinum-doped graphene nano composite material modified by surface nano gold particle loaded bimetallic nano cubes and a preparation method and application of the platinum-doped graphene nano composite material. According to the preparation method, copper nitrate trihydrate, zinc nitrate hexahydrate and 2-methylimidazole are taken as monomers, platinum-doped graphene is taken as a compound, hexadecyl trimethyl ammonium bromide is taken as a template agent, and deionized water is taken as a solvent, so that the novel Cu / Zn bimetal organic framework modified platinum-doped graphene nanocomposite Pt-G-Cu / Zn-MOFs is prepared; the preparation method comprises the following steps: preparing a platinum-doped graphene nanomaterial Pt-G-coated Cu5Zn8C, then calcining at a high temperature to obtain a novel Cu / Zn bimetallic nanocube modified platinum-doped graphene nanomaterial Pt-G-coated Cu5Zn8C, and finally modifying nano gold particles on the surface to obtain the Pt-G-coated Cu5Zn8C-coated Au composite nanomaterial. The Pt-G (at) Cu5Zn8C (at) Au has good laser desorption / ionization efficiency, and has important application value in clinical detection of high-toxicity klebsiella pneumoniae infection.

Description

Technical Field

[0001] The invention relates to the field of nanomaterials, and in particular to a platinum-doped graphene nanocomposite material modified by surface nanogold particles loaded with bimetallic nanocubes, and a preparation method and application thereof. Background Art

[0002] Klebsiella pneumoniae is a highly diverse human pathogen and the leading cause of antibiotic resistance-related deaths worldwide. The bacterium is divided into two major categories: classical Klebsiella pneumoniae (cKP) and hypervirulent Klebsiella pneumoniae (hvKP). In the past two decades, clinical hypervirulent Klebsiella pneumoniae infections have attracted worldwide attention because they can cause severe and invasive infections (mainly community-acquired infections) in healthy individuals. In addition, although most hypervirulent Klebsiella pneumoniae strains are sensitive to antibiotics (except ampicillin), the mortality rate of hypervirulent Klebsiella pneumoniae infections is as high as 3% to 42%. Therefore, there is an urgent need to develop an efficient and simple detection method for rapid detection of hypervirulent Klebsiella pneumoniae in clinical practice.

[0003] Metabolomics is the study of systematically identifying and quantifying metabolites in living organisms. In recent years, metabolic fingerprints of intact microbial cells extracted by nano-assisted laser desorption / ionization mass spectrometry (LDI-MS) have become attractive candidates for distinguishing closely related bacterial species or drug-resistant strains. Bimetallic nanoparticles exhibit special synergistic phenomena that can significantly improve simultaneous photoconversion and physicochemical stability, and are highly valuable as matrices for desorption / ionization processes. Metal-organic frameworks (MOFs) are a class of porous materials composed of organic ligands and metal anodes, which are often used as sacrificial agents for the preparation of metal / carbon nanocomposites. So far, researchers have successfully prepared a variety of bimetallic carbon composites using MOFs as templates. However, high-temperature calcination often leads to the common agglomeration problem. It has been reported that dispersing MOFs in materials with significant specific surface area can effectively prevent the unwanted aggregation of MOFs particles during high-temperature processes. Therefore, using platinum-doped graphene as a carrier is expected to construct a new type of bimetallic nanomatrix for rapid detection of highly virulent Klebsiella pneumoniae. Summary of the invention

[0004] The purpose of the present invention is to provide a platinum-doped graphene nanocomposite material modified by surface nano-gold particles loaded with bimetallic nanocubes and a preparation method and application thereof in view of the deficiencies in the prior art.

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

[0006] The first aspect of the present invention is to provide a method for preparing a platinum-doped graphene nanocomposite material modified by surface nano-gold particles loaded with bimetallic nanocubes, the steps comprising:

[0007] S1. Weigh platinum-doped graphene nanomaterials, copper nitrate trihydrate, zinc nitrate hexahydrate, hexadecyltrimethylammonium bromide and 2-methylimidazole respectively; disperse the platinum-doped graphene nanomaterials, the copper nitrate trihydrate, the zinc nitrate hexahydrate and the hexadecyltrimethylammonium bromide in deionized water and shake them to obtain a first solution; dissolve the 2-methylimidazole in deionized water to obtain a second solution;

[0008] S2, mixing the first solution and the second solution to react, and washing and drying the reaction product in sequence to obtain a copper-zinc bimetallic organic framework modified platinum-doped graphene nanocomposite material Pt-G@Cu / Zn-MOFs;

[0009] S3, placing Pt-G@Cu / Zn-MOFs in a tube furnace, introducing inert gas for high-temperature calcination, and obtaining copper-zinc bimetallic carbide nanocube-modified platinum-doped graphene nanocomposite material Pt-G@Cu5Zn8C;

[0010] S4. After dispersing Pt-G@Cu5Zn8C in a nano-gold colloid solution and shaking it, the product is washed and dried in sequence to obtain the platinum-doped graphene nanocomposite material Pt-G@Cu5Zn8C@Au modified by the surface nano-gold particles loaded with bimetallic nanocubes.

[0011] Preferably, in the mixture of the first solution and the second solution, the concentration ratio of the copper nitrate trihydrate, the zinc nitrate hexahydrate, the hexadecyltrimethylammonium bromide and the 2-methylimidazole is 1:1:(0.02-0.04):(80-100).

[0012] Preferably, in step S2, the reaction temperature of the first solution and the second solution is 25°C-30°C, and the reaction time is 1h-2h.

[0013] Preferably, in step S3, the inert gas is nitrogen.

[0014] Preferably, in step S3, the high temperature calcination is carried out at a temperature of 500°C-700°C and for a time of 1h-2h.

[0015] Preferably, the washing treatments in step S2 and step S4 are both: washing with deionized water and ethanol for several times.

[0016] The second aspect of the present invention is to provide a platinum-doped graphene nanocomposite material modified by surface nano-gold particles loaded with bimetallic nanocubes prepared by the above preparation method.

[0017] The third aspect of the present invention is to provide a platinum-doped graphene nanocomposite material modified by bimetallic nanocubes loaded on the surface of gold nanoparticles prepared by the above preparation method or the use of the platinum-doped graphene nanocomposite material modified by bimetallic nanocubes loaded on the surface of gold nanoparticles in the detection of Klebsiella pneumoniae.

[0018] Preferably, the Klebsiella pneumoniae is highly virulent Klebsiella pneumoniae.

[0019] The present invention adopts the above technical solution, and has the following technical effects compared with the prior art:

[0020] The invention uses copper nitrate trihydrate, zinc nitrate hexahydrate and 2-methylimidazole as monomers, platinum-doped graphene as a composite, hexadecyltrimethylammonium bromide as a template and deionized water as a solvent to prepare a novel Cu / Zn bimetallic organic framework modified platinum-doped graphene nanocomposite material Pt-G@Cu / Zn-MOFs; subsequently, high-temperature calcination is performed to obtain a novel Cu / Zn bimetallic nanocube modified platinum-doped graphene nanomaterial Pt-G@Cu5Zn8C; finally, surface modification with nano-gold particles is performed to obtain a Pt-G@Cu5Zn8C@Au composite nanomaterial; Pt-G@Cu5Zn8C@Au has good laser desorption / ionization efficiency and has important application value in the detection of highly virulent Klebsiella pneumoniae in clinical infection. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a scanning electron microscope image of the Pt-G@Cu5Zn8C@Au matrix;

[0022] Figure 2 is the nitrogen isothermal adsorption-desorption curve of Pt-G@Cu5Zn8C@Au matrix;

[0023] Figure 3 This is the pore size distribution diagram of Pt-G@Cu5Zn8C@Au matrix;

[0024] Figure 4 Comparison of mass spectrometry metabolic fingerprints of classical Klebsiella pneumoniae and highly virulent Klebsiella pneumoniae based on Pt-G@Cu5Zn8C@Au matrix;

[0025] Figure 5 To show the performance of different machine learning algorithms in distinguishing between classical Klebsiella pneumoniae and highly virulent Klebsiella pneumoniae;

[0026] Figure 6This is the prediction score diagram of highly virulent Klebsiella pneumoniae based on the LDA model;

[0027] Figure 7 The confusion matrix of classical Klebsiella pneumoniae and highly virulent Klebsiella pneumoniae based on the LDA model. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0030] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, but they are not intended to limit the present invention.

[0031] Example 1

[0032] This embodiment provides a method for preparing a platinum-doped graphene nanocomposite material modified with bimetallic nanocubes loaded with surface nanogold particles, the steps comprising:

[0033] S1, weighing 15 mg of platinum-doped graphene nanomaterial, 86 mg of copper nitrate trihydrate, 178 mg of zinc nitrate hexahydrate, 7.5 mg of hexadecyltrimethylammonium bromide and 4.54 g of 2-methylimidazole; dispersing the platinum-doped graphene nanomaterial, the copper nitrate trihydrate, the zinc nitrate hexahydrate and the hexadecyltrimethylammonium bromide into 15 mL of deionized water and shaking to obtain a first solution; dissolving the 2-methylimidazole in 70 mL of deionized water to obtain a second solution;

[0034] S2, mixing the first solution and the second solution and placing them in a constant temperature magnetic stirring oil bath pot, reacting at 25° C. for 1 hour, after the reaction is completed, washing the reaction product several times with deionized water and ethanol to remove impurities and raw material monomers on the surface of the reaction product, placing it in a vacuum drying oven, drying it at 50° C. overnight, and obtaining a copper-zinc bimetallic organic framework modified platinum-doped graphene nanocomposite material Pt-G@Cu / Zn-MOFs;

[0035] S3, placing Pt-G@Cu / Zn-MOFs in a tube furnace, introducing nitrogen, heating to 600°C at a heating rate of 1°C / min, and calcining for 2h to obtain copper-zinc bimetallic carbide nanocube-modified platinum-doped graphene nanocomposite material Pt-G@Cu5Zn8C;

[0036] S4. Disperse 30 mg of Pt-G@Cu5Zn8C into 20 mL of nano-gold colloid solution, shake at a constant temperature for 2 hours, wash the shaken product several times with deionized water and ethanol, and place the washed product in a vacuum dryer for drying to obtain the platinum-doped graphene nanocomposite material Pt-G@Cu5Zn8C@Au modified by surface nano-gold particles loaded with bimetallic nanocubes.

[0037] The morphology of Pt-G@Cu5Zn8C@Au was detected by scanning electron microscopy (20KV, Philips XL30 electron microscope, Netherlands). Figure 1 As shown, cubic particles are modified on the surface of Pt-doped graphene.

[0038] The results of nitrogen isothermal adsorption-desorption curve (Micromeritics ASAP-2010, USA) are as follows: Figure 2-3 As shown in Figure 2, the specific surface area of ​​Pt-G@Cu5Zn8C@Au is 24.2 m 2 / g, pore volume is 0.06cm 3 / g( Figure 2 ), the pore size is 11.3nm ( Figure 3 ).

[0039] Example 2

[0040] This example provides the use of Pt-G@Cu5Zn8C@Au prepared by the preparation method described in Example 1 in the detection of Klebsiella pneumoniae.

[0041] (1) Sample preparation

[0042] 1 mg of Pt-G@Cu5Zn8C@Au nanomaterials were dispersed in 1 mL of deionized water, and clinical classical Klebsiella pneumoniae (cKP, 82 strains) and highly virulent Klebsiella pneumoniae (hvKP, 52 strains) were collected and resuspended in deionized water after liquid culture at a concentration of about 1×10 10 CFU / mL.

[0043] (2) Mass spectrometry

[0044] 1 μL of Pt-G@Cu5Zn8C@Au nanomaterial was deposited on the MALDI target plate, and 1 μL of different Klebsiella pneumoniae suspensions were spotted on the Pt-G@Cu5Zn8C@Au nanomaterial. Then, cell wall lysates including formic acid (0.5 μL, 70% aqueous solution), 1-butanol (0.5 μL) and salicylic acid (1 μL, 1 mg / mL aqueous solution) were deposited on the above target. After natural drying, laser desorption ionization mass spectrometry analysis was performed using a Bruker MicroFlex LRF mass spectrometer with a 355nm Nd:YAG laser light source, a laser frequency of 2000 Hz, and an acceleration voltage of 20 kV. The acquisition mode was a cation reflector mode, and the mass-to-charge ratio range was 100 Da-1000 Da. Mass spectrometry data were obtained from FlexControl 3.4, and the data were exported in flexAnalysis 3.4 to obtain rich metabolite mass spectrometry spectra of different bacteria.

[0045] Figure 4 Comparison of mass spectrometry metabolic fingerprints of clinical classical Klebsiella pneumoniae and highly virulent Klebsiella pneumoniae extracted from Pt-G@Cu5Zn8C@Au nanomaterial matrix.

[0046] Application Examples

[0047] Based on the metabolite mass spectra of classic Klebsiella pneumoniae and highly virulent Klebsiella pneumoniae obtained in Example 2, five machine learning algorithm models were established, and the steps included:

[0048] (1) The urine mass spectra were preprocessed using R language based on MALDIquant and MALDIquantForeign packages, including peak intensity conversion and normalization, peak smoothing, baseline subtraction, peak alignment, peak identification, and peak grouping;

[0049] (2) Based on two groups of Klebsiella pneumoniae mass spectrometry metabolic fingerprint spectra, five machine learning algorithm models (SVM, KNN, NB, LDA, Logi) were constructed using Python to obtain the indicators of different machine learning algorithms in distinguishing classic Klebsiella pneumoniae from highly virulent Klebsiella pneumoniae, including recall rate, precision value, F1 score and accuracy value ( Figure 5 ); Prediction score of highly virulent Klebsiella pneumoniae based on LDA model ( Figure 6 ); Confusion matrix of classical Klebsiella pneumoniae and highly virulent Klebsiella pneumoniae based on LDA model ( Figure 7 ).

[0050] In summary, the surface nano-gold particles loaded bimetallic nanocubes modified platinum-doped graphene nanocomposite material of the present invention has great application potential in the detection of highly virulent Klebsiella pneumoniae.

[0051] The above description is only a preferred embodiment of the present invention, and does not limit the implementation mode and protection scope of the present invention. For those skilled in the art, it should be aware that all solutions obtained by equivalent substitutions and obvious changes made using the description and illustrations of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing a platinum-doped graphene nanocomposite material modified by surface nanogold particles loaded with bimetallic nanocubes, characterized in that the steps include: S1. Weigh platinum-doped graphene nanomaterials, copper nitrate trihydrate, zinc nitrate hexahydrate, hexadecyltrimethylammonium bromide and 2-methylimidazole respectively; The platinum-doped graphene nanomaterial, the copper nitrate trihydrate, the zinc nitrate hexahydrate and the hexadecyltrimethylammonium bromide are dispersed in deionized water and shaken to obtain a first solution; the 2-methylimidazole is dissolved in deionized water to obtain a second solution; S2, mixing the first solution and the second solution to react, and washing and drying the reaction product in sequence to obtain a copper-zinc bimetallic organic framework modified platinum-doped graphene nanocomposite material Pt-G@Cu / Zn-MOFs; S3, placing Pt-G@Cu / Zn-MOFs in a tube furnace, introducing inert gas for high-temperature calcination, and obtaining copper-zinc bimetallic carbide nanocube-modified platinum-doped graphene nanocomposite material Pt-G@Cu5Zn8C; S4. After dispersing Pt-G@Cu5Zn8C in a nano-gold colloid solution and shaking it, the product is washed and dried in sequence to obtain the platinum-doped graphene nanocomposite material Pt-G@Cu5Zn8C@Au modified by the surface nano-gold particles loaded with bimetallic nanocubes.

2. The preparation method according to claim 1, characterized in that: In the mixed solution of the first solution and the second solution, the concentration ratio of the copper nitrate trihydrate, the zinc nitrate hexahydrate, the hexadecyltrimethylammonium bromide and the 2-methylimidazole is 1:1:(0.02-0.04):(80-100).

3. The preparation method according to claim 1, characterized in that: In step S2, the reaction temperature of the first solution and the second solution is 25°C-30°C, and the reaction time is 1h-2h.

4. The preparation method according to claim 1, characterized in that: In step S3, the inert gas is nitrogen.

5. The preparation method according to claim 1, characterized in that: In step S3, the high temperature calcination temperature is 500°C-700°C, and the time is 1h-2h.

6. The preparation method according to claim 1, characterized in that: The washing treatments in step S2 and step S4 are both: washing with deionized water and ethanol for several times.

7. A platinum-doped graphene nanocomposite material modified with bimetallic nanocubes loaded with surface nanogold particles prepared by the preparation method according to any one of claims 1 to 6.

8. Use of a platinum-doped graphene nanocomposite material modified by bimetallic nanocubes loaded on the surface of gold nanoparticles prepared by the preparation method according to any one of claims 1 to 6 or a platinum-doped graphene nanocomposite material modified by bimetallic nanocubes loaded on the surface of gold nanoparticles as claimed in claim 7 in detecting Klebsiella pneumoniae.

9. The use according to claim 8, characterized in that: The Klebsiella pneumoniae is highly virulent Klebsiella pneumoniae.

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