A surface nano-gold particle loaded bimetallic nano-cube modified platinum-doped graphene nanocomposite, a preparation method and application thereof

Abstract

The application relates to the field of nanomaterials, in particular to a platinum-doped graphene nanocomposite material modified by surface nanogold particles and double-metal nanocubes and a preparation method and application thereof. A novel Cu / Zn double-metal organic framework modified platinum-doped graphene nanocomposite material Pt-G@Cu / Zn-MOFs is prepared by taking copper nitrate trihydrate, zinc nitrate hexahydrate and 2-methyl imidazole as monomers, taking platinum-doped graphene as a complex, taking hexadecyl trimethyl ammonium bromide as a template agent and taking deionized water as a solvent. Subsequently, a novel Cu / Zn double-metal nanocube modified platinum-doped graphene nanomaterial Pt-G@Cu5Zn8C is obtained through high-temperature calcination. Finally, Pt-G@Cu5Zn8C@Au composite nanomaterial is obtained through surface modification of nanogold particles. The Pt-G@Cu5Zn8C@Au has good laser resolution / ionization efficiency and has important application value in detection of clinically high-toxicity Klebsiella pneumoniae.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of nanomaterials, and particularly to a platinum-doped graphene nanocomposite material modified by surface nanogold particles loaded bimetallic nanocubes as well as a preparation method and application thereof. BACKGROUND

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

[0003] Metabolomics is a research that systematically identifies and quantifies metabolites in living organisms. In recent years, the complete microbial cell metabolic fingerprint extracted by nano-assisted laser desorption / ionization mass spectrometry (LDI-MS) has become an attractive candidate method for distinguishing closely related bacterial species or drug-resistant strains. Bimetallic nanoparticles exhibit special synergistic phenomena, which can significantly improve simultaneous light conversion and physical and chemical stability, and have high value as a matrix for desorption / ionization processes. Metal-organic frameworks (MOFs) are a class of porous materials composed of organic ligands and metal cations, 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 common agglomeration problems. It has been reported that dispersing MOFs in materials with a significant specific surface area can effectively prevent unnecessary aggregation of MOF particles during high-temperature processes. Therefore, it is expected to construct a new type of bimetallic nanomatrix using platinum-doped graphene as a carrier to achieve rapid detection of hypervirulent Klebsiella pneumoniae. SUMMARY

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

[0005] To achieve the above-mentioned purpose, the technical solution adopted by the present application is as follows:

[0006] The first aspect of the present application provides a preparation method of a platinum-doped graphene nanocomposite modified by surface nanogold particle loaded bimetallic nanocubes, comprising the following steps:

[0007] S1, respectively, take platinum-doped graphene nanomaterial, copper nitrate trihydrate, zinc nitrate hexahydrate, cetyltrimethylammonium bromide and 2-methyl imidazole; the platinum-doped graphene nanomaterial, the copper nitrate trihydrate, the zinc nitrate hexahydrate and the cetyltrimethylammonium bromide are dispersed into deionized water and subjected to shock treatment to prepare a first solution; the 2-methyl imidazole is dissolved in deionized water to prepare a second solution;

[0008] S2, the first solution and the second solution are mixed for reaction, and the reaction product is sequentially subjected to washing treatment and drying treatment to obtain a platinum-doped graphene nanocomposite modified by copper-zinc bimetallic organic framework Pt-G@Cu / Zn-MOFs;

[0009] S3, Pt-G@Cu / Zn-MOFs is placed in a tube furnace, inert gas is introduced for high-temperature calcination to obtain a platinum-doped graphene nanocomposite modified by copper-zinc bimetallic carbide nanocubes Pt-G@Cu5Zn8C;

[0010] S4, after Pt-G@Cu5Zn8C is dispersed into nanogold glue solution and subjected to shock treatment, the product is sequentially subjected to washing treatment and drying treatment to obtain the platinum-doped graphene nanocomposite modified by surface nanogold particle loaded bimetallic nanocubes Pt-G@Cu5Zn8C@Au.

[0011] Preferably, 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 cetyltrimethylammonium bromide and the 2-methyl imidazole 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 25-30 DEG C, and the reaction time is 1-2 h.

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

[0014] Preferably, in step S3, the temperature of high-temperature calcination is 500-700 DEG C, and the time is 1-2 h.

[0015] Preferably, the washing treatment in steps S2 and S4 is that deionized water and ethanol are used for washing for several times.

[0016] The second aspect of the present application provides a platinum-doped graphene nanocomposite modified by surface nanogold particle loaded bimetallic nanocubes prepared by the above preparation method.

[0017] The third aspect of the present application provides an application of the platinum-doped graphene nanocomposite modified by surface nanogold particle loaded bimetallic nanocubes prepared by the above preparation method or the platinum-doped graphene nanocomposite modified by surface nanogold particle loaded bimetallic nanocubes in detecting Klebsiella pneumoniae.

[0018] Preferably, the Klebsiella pneumoniae is high virulence Klebsiella pneumoniae.

[0019] The present application has the following technical effects compared with the prior art by adopting the above technical scheme:

[0020] The present application prepares a novel platinum-doped graphene nanocomposite modified by Cu / Zn bimetallic organic framework by taking copper nitrate trihydrate, zinc nitrate hexahydrate and 2-methyl imidazole as monomers, platinum-doped graphene as a complex, cetyltrimethylammonium bromide as a template agent and deionized water as a solvent; then obtains a novel platinum-doped graphene nanomaterial modified by Cu / Zn bimetallic nanocubes by high-temperature calcination, and finally obtains Pt-G@Cu5Zn8C@Au composite nanomaterial by surface modification of nanogold particles; Pt-G@Cu5Zn8C@Au has good laser desorption / ionization efficiency and has important application value in detection of high virulence Klebsiella pneumoniae in clinical infection. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 It is a scanning electron microscope photo of a Pt-G@Cu5Zn8C@Au matrix;

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

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

[0024] Figure 4 It is a mass spectrometry metabolic fingerprint comparison diagram of classical Klebsiella pneumoniae and high virulence Klebsiella pneumoniae based on a Pt-G@Cu5Zn8C@Au matrix;

[0025] Figure 5 It is a performance of different machine learning algorithms in distinguishing classical Klebsiella pneumoniae and high virulence Klebsiella pneumoniae;

[0026] Figure 6A score chart for prediction of high virulence Klebsiella pneumoniae based on the LDA model;

[0027] Figure 7 A confusion matrix for classic Klebsiella pneumoniae and high virulence Klebsiella pneumoniae based on the LDA model. DETAILED DESCRIPTION

[0028] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0029] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0030] The present application will be further described below with reference to the drawings and specific embodiments, but not as a limitation of the present application.

[0031] Embodiment 1

[0032] The embodiment provides a preparation method of a platinum-doped graphene nanocomposite modified by surface nanogold particle loaded bimetallic nanocubes, and steps include:

[0033] S1, weigh 15 mg of platinum-doped graphene nanomaterial, 86 mg of copper nitrate trihydrate, 178 mg of zinc nitrate hexahydrate, 7.5 mg of cetyltrimethylammonium bromide, and 4.54 g of 2-methylimidazole; the platinum-doped graphene nanomaterial, the copper nitrate trihydrate, the zinc nitrate hexahydrate, and the cetyltrimethylammonium bromide are dispersed into 15 mL of deionized water and subjected to shock treatment to prepare a first solution; the 2-methylimidazole is dissolved in 70 mL of deionized water to prepare a second solution;

[0034] S2, after mixing the first solution and the second solution, place them in a constant-temperature magnetic stirring oil bath, react at 25℃ for 1 h, after the reaction is completed, wash the reaction product several times with deionized water and ethanol, remove impurities and raw material monomers on the surface of the reaction product, and then place it in a vacuum drying box and dry at 50℃ overnight to obtain a platinum-doped graphene nanocomposite modified by copper-zinc bimetallic organic frameworks Pt-G@Cu / Zn-MOFs;

[0035] S3, place the Pt-G@Cu / Zn-MOFs in a tube furnace, pass nitrogen gas, heat at a heating rate of 1℃ / min to 600℃, and calcine for 2 h to obtain a platinum-doped graphene nanocomposite modified by copper-zinc bimetallic carbide nanocubes Pt-G@Cu5Zn8C.

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

[0037] The morphology of Pt-G@Cu5Zn8C@Au was examined using a scanning electron microscope (20KV, Philips XL30 electron microscope, Netherlands). The results are as follows: Figure 1 As shown, cubic particles are modified on the surface of platinum-doped graphene.

[0038] The results were obtained through nitrogen isothermal adsorption-desorption curve analysis (Micromeritics ASAP-2010, USA). Figures 2-3 As shown, the specific surface area of ​​Pt-G@Cu5Zn8C@Au is 24.2 m². 2 / g, pore volume is 0.06cm 3 / g( Figure 2 ), with an aperture size of 11.3 nm ( Figure 3 ).

[0039] Example 2

[0040] This embodiment provides the application of Pt-G@Cu5Zn8C@Au prepared by the 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. Clinically classic Klebsiella pneumoniae (cKP, strain 82) and highly virulent Klebsiella pneumoniae (hvKP, strain 52) were collected, cultured in liquid, and then resuspended in deionized water to a concentration of approximately 1 × 10⁻⁶. 10 CFU / mL.

[0043] (2) Mass spectrometry analysis

[0044] 1 μL of Pt-G@Cu5Zn8C@Au nanomaterials was deposited on a MALDI target plate. 1 μL of suspensions of different Klebsiella pneumoniae strains were spotted onto the Pt-G@Cu5Zn8C@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 Da-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.

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

[0046] Application Examples

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

[0048] (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.

[0049] (2) Based on the two sets of Klebsiella pneumoniae mass spectrometry metabolic fingerprints, five machine learning algorithm models (SVM, KNN, NB, LDA, Logi) were constructed using Python. The indicators of different machine learning algorithms in distinguishing between classic Klebsiella pneumoniae and highly virulent Klebsiella pneumoniae were obtained, including recall, precision, F1 score, and accuracy. Figure 5 ); Predicted score of highly virulent Klebsiella pneumoniae based on LDA model ( Figure 6 ); Confusion matrix of classic Klebsiella pneumoniae and highly virulent Klebsiella pneumoniae based on LDA model ( Figure 7 ).

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

[0051] The above merely describes preferred embodiments of the present application, and is not intended to limit the implementation and protection scope of the present application. Those skilled in the art should be able to understand that any equivalent substitutions and obvious changes made according to the present application description and drawings should be included in the protection scope of the present application.

Claims

1. A preparation method of a surface nanogold particle loaded bimetallic nanocube modified platinum doped graphene nanocomposite, characterized by the steps of The application relates to a preparation method of a surface nano-gold particle loaded bimetallic nanocube modified platinum-doped graphene nanocomposite material. S1, respectively, take platinum-doped graphene nanomaterials, copper nitrate trihydrate, zinc nitrate hexahydrate, cetyltrimethylammonium bromide and 2-methyl imidazole; The platinum-doped graphene nanomaterials, the copper nitrate trihydrate, the zinc nitrate hexahydrate and the cetyltrimethylammonium bromide are dispersed into deionized water and subjected to shock treatment to prepare a first solution; the 2-methyl imidazole is dissolved in deionized water to prepare a second solution; S2, the first solution and the second solution are mixed to react, and the reaction product is subjected to washing treatment and drying treatment in sequence to obtain the copper-zinc bimetallic organic framework modified platinum-doped graphene nanocomposite material Pt-G@Cu / Zn-MOFs; S3, the Pt-G@Cu / Zn-MOFs are placed in a tube furnace, inert gas is introduced to perform high-temperature calcination, and the copper-zinc bimetallic carbide nanocube modified platinum-doped graphene nanocomposite material Pt-G@Cu5Zn8C is obtained; S4, the Pt-G@Cu5Zn8C is dispersed into a nano-gold colloid solution and subjected to shock treatment, and then the product is subjected to washing treatment and drying treatment in sequence to obtain the surface nano-gold particle loaded bimetallic nanocube modified platinum-doped graphene nanocomposite material Pt-G@Cu5Zn8C@Au.

2. The production method according to claim 1, characterized by, 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 cetyltrimethylammonium bromide and the 2-methyl imidazole 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 25-30 DEG C, and the reaction time is 1-2 h.

4. The method of claim 1, wherein, 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 500-700 DEG C, and the time is 1-2 h.

6. The method of claim 1, wherein, In step S2 and step S4, the washing treatment is carried out by using deionized water and ethanol for several times. 7.A surface nano-gold particle loaded bimetallic nanocube modified platinum-doped graphene nanocomposite material prepared by the preparation method in any one of claims 1-6. 8.A use of the surface nano-gold particle loaded bimetallic nanocube modified platinum-doped graphene nanocomposite material in claim 7 in detection of Klebsiella pneumoniae.

9. Use according to claim 8, characterized in that, The Klebsiella pneumoniae is high-toxicity Klebsiella pneumoniae.

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