Molybdenum disulfide quantum dot with peroxidase-like catalytic performance and preparation method and application thereof

Abstract

The invention provides a molybdenum disulfide quantum dot with peroxidase-like catalytic performance and a preparation method and application of the molybdenum disulfide quantum dot, and belongs to the technical field of nanometer material preparation. The molybdenum disulfide quantum dots with peroxidase-like catalytic performance are obtained, the operation is convenient, and the steps are simple. Uniform sulfur vacancies exist in lattice stripes of the prepared molybdenum disulfide quantum dots, meanwhile, the quantum dots further comprise a small amount of oxidized molybdenum and oxidized sulfur, the interplanar spacing ranges from 0.15 nm to 0.22 nm, the particle size ranges from 2 nm to 4 nm, and the ultraviolet absorption spectrum has absorption peaks at the positions of 390 nm to 450 nm, 600 nm to 620 nm and 660 nm to 680 nm. The molybdenum disulfide quantum dot can catalyze hydrogen peroxide to be quickly decomposed and generate hydroxyl radicals with strong oxidizing property, and has a better effect in concentration detection of hypoxanthine and enzyme-like catalytic antibacterial application.

Description

Technical Field

[0001] The invention relates to the technical field of nano material preparation, and in particular to molybdenum disulfide quantum dots with peroxidase-like catalytic performance, and a preparation method and application thereof. Background Art

[0002] Biological enzymes are organic substances with catalytic effects produced by living cells. They often have characteristics such as high efficiency and high specificity, and the reaction conditions are relatively mild. They play an important role in the fields of biology, medicine, chemical industry, and environment. However, the storage and reaction conditions of natural biological enzymes are relatively strict, and the synthesis process is relatively complicated, resulting in high application costs and limited application scope. Therefore, since Yan Xiyun's research group successfully synthesized the peroxidase-like properties of ferroferric oxide magnetic nanoparticles in 2007, the research on artificial enzyme simulations has remained hot.

[0003] At present, researchers have found that transition metal oxides, metal molybdenum sulfide and inorganic carbon materials all have peroxidase-like activity, and have successfully prepared many nanozymes, such as molybdenum disulfide nanosheets, gold nanoparticles, graphene oxide (GO) nanosheets and polypyrrole nanoparticles, etc., while there are relatively few studies on the preparation of quantum dot artificial enzymes. In the existing technology, the catalytic activity of a single quantum dot material is weak, and the combination of quantum dots and other catalytic materials can achieve better results, but the synthesis steps of such composite materials are complicated and cumbersome, the cost is high, and it is difficult to industrialize them for the time being.

[0004] In view of this, it is necessary to study molybdenum disulfide quantum dots with peroxidase-like catalytic properties and their preparation methods and applications to solve the above technical problems. Summary of the invention

[0005] In view of the technical problems existing in the background technology, the present application provides a molybdenum disulfide quantum dots with peroxidase-like catalytic properties and a preparation method and application thereof. The dispersion of molybdenum disulfide is treated in a one-step method using an ultrasonic cell disruptor to obtain molybdenum disulfide quantum dots with peroxidase-like catalytic properties. Not only is the preparation step simple, but the obtained molybdenum disulfide quantum dots have good peroxidase-like catalytic properties and can be used for hypoxanthine concentration detection and enzyme-like catalytic antibacterial.

[0006] In the first aspect, an embodiment of the present application provides a molybdenum disulfide quantum dot with peroxidase-like catalytic properties, wherein the molybdenum disulfide quantum dots are prepared by ultrasonically treating a dispersion of molybdenum disulfide with an ultrasonic cell disruptor; uniform sulfur vacancies exist in the lattice fringes of the molybdenum disulfide quantum dots, so that the ratio of molybdenum to sulfur is greater than 1:2; the crystal plane spacing of the molybdenum disulfide quantum dots is 0.15-0.22nm, and the particle size is 2-4nm; the molybdenum disulfide quantum dots also include a small amount of oxidized molybdenum and oxidized sulfur; the ultraviolet absorption spectrum of the molybdenum disulfide quantum dots has absorption peaks at 390-450nm, 600-620nm and 660-680nm.

[0007] Furthermore, the ultraviolet absorption spectrum of the molybdenum disulfide quantum dots has obvious absorption peaks at 400nm, 443nm, 610nm and 670nm; the ratio of molybdenum to sulfur in the molybdenum disulfide quantum dots is 1:(1.4-1.8); the molybdenum disulfide quantum dots have peroxidase-like catalytic properties, which can catalyze the rapid decomposition of hydrogen peroxide to produce hydroxyl radicals.

[0008] In the second aspect, the embodiment of the present application provides a method for preparing molybdenum disulfide quantum dots with peroxidase-like catalytic properties, using an ultrasonic cell disruptor to ultrasonically treat a dispersion of molybdenum disulfide under preset parameters, so that part of the sulfur in the molybdenum disulfide falls off under the action of shear force and cavitation, thereby causing sulfur vacancies to appear in the lattice fringes of the molybdenum disulfide, and at the same time, part of the molybdenum and sulfur are oxidized to obtain molybdenum disulfide quantum dots with peroxidase-like catalytic properties; specifically, the preparation method comprises the following steps:

[0009] S1, adding molybdenum disulfide powder to an organic solvent, and uniformly dispersing it by magnetic stirring to obtain a molybdenum disulfide dispersion with a concentration of 0.005-0.05 g / mL;

[0010] S2, using an ultrasonic cell disruptor to ultrasonically treat the molybdenum disulfide dispersion obtained in step S1 at a power of 100-800 W for 8-18 hours to obtain a molybdenum disulfide quantum dot solution;

[0011] S3, removing the organic solvent by vacuum distillation or rotary evaporation, adding water to uniformly disperse again, filtering, and obtaining a molybdenum disulfide quantum dot aqueous solution.

[0012] Further, the size of the molybdenum disulfide powder is 12 - 16 μm; the organic solvent is N,N-dimethylformamide, N-methylpyrrolidone, absolute ethanol, acetonitrile, acetone or dimethyl sulfoxide; the rotation speed of the magnetic stirring is 400 - 1000 r / min, and the stirring time is 10 - 30 min; in step S3, the filtration uses a 0.22-μm filter head; in step S2, further, the power of the ultrasonic treatment using an ultrasonic cell disruptor is 400 - 800 W, and the ultrasonic treatment time is 10 - 15 h.

[0013] In a third aspect, the embodiment of the present application provides an application of the molybdenum disulfide quantum dots with peroxidase-like catalytic performance described in any one of the foregoing technical solutions or the molybdenum disulfide quantum dots with peroxidase-like catalytic performance prepared by the preparation method described in any one of them, including the concentration detection of hypoxanthine and enzyme-like catalytic antibacterial; wherein,

[0014] The concentration detection of hypoxanthine means that after the sample to be tested is pretreated, xanthine oxidase is added and incubated for a period of time to decompose hypoxanthine to produce hydrogen peroxide, then the pH is adjusted, molybdenum disulfide quantum dots and 3,3',5,5'-tetramethylbenzidine hydrochloride (TMB) are added, and after incubation for a period of time, a solution to be tested is obtained. The molybdenum disulfide quantum dots catalyze the rapid decomposition of hydrogen peroxide to produce hydroxyl radicals, and the hydroxyl radicals further oxidize the solution containing TMB to blue. Finally, the ultraviolet spectrum of the solution to be tested is measured, and the concentration of hypoxanthine in the sample to be tested is calculated according to the linear relationship between the absorbance and the hypoxanthine concentration within the detectable range; the detectable range of the hypoxanthine concentration is 5 - 80 μM;

[0015] The enzyme-like catalytic antibacterial means that the molybdenum disulfide quantum dot aqueous solution is mixed with a hydrogen peroxide solution, and the molybdenum disulfide quantum dots catalyze the rapid decomposition of hydrogen peroxide to produce hydroxyl radicals, and the strong oxidizing property of the hydroxyl radicals inactivates bacteria.

[0016] Further, the concentration detection of hypoxanthine includes the following steps:

[0017] S1, prepare a xanthine oxidase solution and a hypoxanthine solution respectively, then take n portions of the xanthine oxidase solution of the same volume and n portions of the hypoxanthine solution of different volumes, add n portions of the hypoxanthine solution to n portions of the xanthine oxidase solution respectively, incubate at 37°C for 10 minutes, add a molybdenum disulfide quantum dot aqueous solution and a 3,3',5,5'-tetramethylbenzidine hydrochloride aqueous solution, then, dilute with acetate buffer to obtain a fixed volume solution, incubate at 25-65°C for 5-30 minutes to obtain a test solution, test the ultraviolet absorption spectrum of the test solution respectively, and establish a standard curve equation with the absorbance of the oxidized state 3,3',5,5'-tetramethylbenzidine hydrochloride at the maximum absorption wavelength of 652nm as the ordinate and the concentration of hypoxanthine as the abscissa; n≥5;

[0018] S2, pretreating the sample to be tested, adding xanthine oxidase solution, incubating at 37°C for 10 minutes, adding molybdenum disulfide quantum dot aqueous solution and 3,3',5,5'-tetramethylbenzidine hydrochloride aqueous solution, and then diluting with acetate buffer to obtain a fixed volume solution, incubating at 25-65°C for 5-30 minutes to obtain a test solution, measuring the ultraviolet absorption spectrum of the test solution, and substituting the obtained absorbance into the standard curve equation obtained in step S1 to calculate the hypoxanthine concentration in the sample to be tested.

[0019] Furthermore, in step S1 and step S2, the concentration of xanthine oxidase in the constant volume solution is 2.5-3U / mL, the concentration of the molybdenum disulfide quantum dot aqueous solution is 40-50μg / mL, and the concentration of the 3,3',5,5'-tetramethylbenzidine hydrochloride aqueous solution is 1-1.5mM; in step S1, the concentration of hypoxanthine in the constant volume solution is 5-140μM.

[0020] Furthermore, in step S1, the mass ratio of molybdenum disulfide quantum dots to hypoxanthine, xanthine oxidase and TMB is 40:(0.68-19.1):50:310; in step S2, the mass ratio of molybdenum disulfide quantum dots to the sample to be tested, xanthine oxidase and 3,3',5,5'-tetramethylbenzidine hydrochloride is 4:200000:1:31; in step S2, the pretreatment includes one or more of grinding, water bath heating, dilution, centrifugation and filtration; in the pretreatment, acetate buffer with pH=7 is used for dilution.

[0021] Furthermore, in step S1 and step S2, the solvents of the xanthine oxidase solution and the hypoxanthine solution are both acetate buffer with a pH of 7; the pH value of the acetate buffer used for volume adjustment in step S1 and step S2 is 2-8.

[0022] Furthermore, the bacteria suitable for the enzyme-catalyzed antibacterial activity include Escherichia coli and Staphylococcus aureus.

[0023] The beneficial effects of this application are as follows:

[0024] The present application provides a molybdenum disulfide quantum dot with peroxidase-like catalytic performance and its preparation method and application, wherein a dispersion of molybdenum disulfide is treated with an ultrasonic cell disruptor in one step to obtain molybdenum disulfide quantum dots with peroxidase-like catalytic performance. The quantum dots can be used for hypoxanthine concentration detection and enzyme-like catalytic antibacterial.

[0025] (1) The preparation method of molybdenum disulfide quantum dots provided in the present application utilizes the cavitation effect and strong shear force of an ultrasonic cell disruptor to cause partial sulfur shedding and oxidation of sulfur and molybdenum from molybdenum disulfide during the ultrasonic process, thereby obtaining molybdenum disulfide quantum dots with enzyme-like catalytic properties. The preparation method is easy to operate and has simple steps.

[0026] (2) The lattice fringes of the molybdenum disulfide quantum dots provided by the present application have uniform sulfur vacancies, so that the ratio of molybdenum to sulfur is 1: (1.4-1.8), and at the same time, the molybdenum disulfide quantum dots also include a small amount of oxidized molybdenum and oxidized sulfur. The interplanar spacing of the molybdenum disulfide quantum dots is 0.15-0.22nm, the particle size is 2-4nm, and the ultraviolet absorption spectrum has obvious absorption peaks at 400nm, 443nm, 610nm and 670nm.

[0027] (3) The molybdenum disulfide quantum dots provided in this application have good enzyme-like catalytic properties, can catalyze the rapid decomposition of hydrogen peroxide and produce hydroxyl free radicals, and have good effects in the detection of hypoxanthine concentration and enzyme-like catalytic antibacterial applications.

[0028] a. In the detection of hypoxanthine concentration, hypoxanthine is first decomposed by xanthine enzyme to produce hydrogen peroxide, and then the peroxidase-like catalytic performance of molybdenum disulfide quantum dots is used to quickly decompose hydrogen peroxide into hydroxyl radicals with extremely strong oxidizing properties. Hydroxyl radicals can oxidize TMB solution to turn blue, thereby increasing the absorbance at 652nm. Hypoxanthine is detected by monitoring the absorbance change of the reaction solution at 652nm, and the detectable concentration range is 5-80μM.

[0029] b. In enzyme-like catalytic antibacterial activities, molybdenum disulfide quantum dots catalyze hydrogen peroxide to produce hydroxyl radicals, which use the strong oxidizing property of hydroxyl radicals to inactivate Escherichia coli or Staphylococcus aureus, thereby achieving catalytic antibacterial activity.

[0030] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solution of the present application, the following is a brief introduction to the drawings used in the present application. Obviously, the drawings described below are only some embodiments of the present application, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0032] Figure 1 This is a transmission electron microscope (TEM) image of molybdenum disulfide quantum dots prepared in Example 1 of the present application;

[0033] Figure 2 This is an X-ray photoelectron spectrum (XPS) of the molybdenum disulfide quantum dots prepared in Example 1 of the present application;

[0034] Figure 3 This is the ultraviolet absorption spectrum of molybdenum disulfide quantum dots prepared in Example 1 of the present application;

[0035] Figure 4 This is an electron paramagnetic resonance (EPR) spectrum related to sulfur vacancies in molybdenum disulfide quantum dots prepared in Example 1 of the present application;

[0036] Figure 5 This is a TEM image of molybdenum disulfide quantum dots prepared in Comparative Example 1 of the present application;

[0037] Figure 6 This is a TEM image of molybdenum disulfide quantum dots prepared in Comparative Example 2 of the present application;

[0038] Figure 7 This is a TEM image of molybdenum disulfide quantum dots prepared in Comparative Example 3 of the present application;

[0039] Figure 8 The ultraviolet absorption spectrum obtained by the test of Application Example 1 of this application (left) and the linear relationship diagram of the absorbance of the test solution changing with the hypoxanthine concentration (right);

[0040] Fig. 9 This is the antibacterial effect diagram obtained by using the coating plate method to test the application example 2-3 of this application;

[0041] Fig.10 This is a comparison chart of the peroxidase-like catalytic activity of molybdenum disulfide quantum dots prepared in Example 1 of the present application and Comparative Examples 1-3. DETAILED DESCRIPTION

[0042] The following embodiments of the technical solution of the present application are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0043] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0044] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0045] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0046] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0047] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0048] In the existing technology, there are relatively few studies on quantum dots artificially mimicking enzymes, and the catalytic activity of single quantum dot materials is relatively weak. Combining quantum dots with other catalytic materials can achieve better results, but the synthesis steps of such composite materials are complicated and cumbersome, and the cost is high, making it difficult to apply them industrially for the time being.

[0049] In order to solve the technical problems that the catalytic activity of a single quantum dot material is weak, it needs to be compounded with other catalytic materials to achieve catalysis, and the synthesis steps are complicated and cumbersome, and the preparation cost is high, the present application provides a molybdenum disulfide quantum dot with peroxidase-like catalytic properties and its preparation method and application. Among them, the dispersion of molybdenum disulfide is treated with an ultrasonic cell disruptor in one step to obtain molybdenum disulfide quantum dots with peroxidase-like catalytic properties. Under the synergistic effect of cavitation and strong shear force, part of the sulfur of molybdenum disulfide falls off, so that there are uniform sulfur vacancies in the lattice fringes of the quantum dots. At the same time, part of the molybdenum and sulfur are oxidized during the ultrasonic treatment process. The preparation method provided by the present application is simple, and the obtained molybdenum disulfide quantum dots can catalyze the rapid decomposition of hydrogen peroxide and produce hydroxyl radicals, which are suitable for hypoxanthine concentration detection and enzyme-like catalytic antibacterial.

[0050] The present application provides a molybdenum disulfide quantum dot with peroxidase-like catalytic performance, which is prepared by ultrasonically treating a dispersion of molybdenum disulfide with an ultrasonic cell disruptor. The molybdenum disulfide quantum dot has uniform sulfur vacancies in its lattice fringes, so that its molybdenum to sulfur ratio is greater than 1:2, and further, the molybdenum to sulfur ratio is 1:(1.4-1.8).

[0051] In some embodiments, the molybdenum disulfide quantum dots have a crystal plane spacing of 0.15-0.22 nm, a particle size of 2-4 nm, and an ultraviolet absorption spectrum with absorption peaks at 390-450 nm, 600-620 nm, and 660-680 nm, and further, obvious absorption peaks at 400 nm, 443 nm, 610 nm, and 670 nm.

[0052] In some embodiments, the molybdenum disulfide quantum dots further include a small amount of oxidized molybdenum and oxidized sulfur.

[0053] The molybdenum disulfide quantum dots provided in the embodiments of the present application have peroxidase-like catalytic properties and can catalyze the rapid decomposition of hydrogen peroxide to produce hydroxyl radicals.

[0054] In the second aspect, the embodiment of the present application provides a method for preparing molybdenum disulfide quantum dots with peroxidase-like catalytic properties, using an ultrasonic cell disruptor to ultrasonically treat a dispersion of molybdenum disulfide under preset parameters, so that part of the sulfur in the molybdenum disulfide falls off under the action of shear force and cavitation, thereby causing sulfur vacancies to appear in the lattice fringes of the molybdenum disulfide, and at the same time, part of the molybdenum and sulfur are oxidized to obtain molybdenum disulfide quantum dots with peroxidase-like catalytic properties. Specifically, the preparation method comprises the following steps:

[0055] S1, adding molybdenum disulfide powder to an organic solvent, and uniformly dispersing the powder by magnetic stirring to obtain a molybdenum disulfide dispersion having a concentration of 0.005-0.05 g / mL.

[0056] In some embodiments, the organic solvent is DMF, NMP, anhydrous ethanol, acetonitrile, acetone or DMSO. The speed of magnetic stirring is 400-1000 r / min, and the stirring time is 10-30 min.

[0057] In some embodiments, the molybdenum disulfide powder has a size of 12-16 μm.

[0058] S2, using an ultrasonic cell disruptor to ultrasonically treat the molybdenum disulfide dispersion obtained in step S1 at a power of 100-800 W for 8-18 hours to obtain a molybdenum disulfide quantum dot solution.

[0059] In some embodiments, the ultrasonic treatment power of the ultrasonic cell disruptor is 400-800 W, preferably 400 W, and the ultrasonic treatment time is 10-15 h.

[0060] S3, removing the organic solvent by vacuum distillation or rotary evaporation, adding water to re-disperse uniformly, filtering with a 0.22 μm filter head to obtain a molybdenum disulfide quantum dot aqueous solution, wherein the concentration of the molybdenum disulfide quantum dot aqueous solution is 0.5-3 mg / mL.

[0061] In a third aspect, an embodiment of the present application provides an application of molybdenum disulfide quantum dots having peroxidase-like catalytic properties in the aforementioned scheme, including hypoxanthine concentration detection and enzyme-like catalytic antibacterial.

[0062] Among them, the concentration detection of hypoxanthine refers to pre-treating the sample to be tested, adding xanthine oxidase and incubating for a period of time to decompose hypoxanthine to produce hydrogen peroxide, then adjusting the pH, adding molybdenum disulfide quantum dots and 3,3',5,5'-tetramethylbenzidine hydrochloride (TMB), incubating for a period of time to obtain a test solution, allowing the molybdenum disulfide quantum dots to catalyze the rapid decomposition of hydrogen peroxide to obtain hydroxyl radicals, which further oxidize the solution containing TMB to blue, and finally testing the ultraviolet spectrum of the test solution, and calculating the hypoxanthine concentration in the test sample based on the linear relationship between absorbance and hypoxanthine concentration within the detectable range. The detectable range of hypoxanthine concentration is 5-80μM.

[0063] Specifically, the detection of hypoxanthine concentration includes the following steps:

[0064] S1, prepare a xanthine oxidase solution and a hypoxanthine solution respectively, then take n parts of the same volume of the xanthine oxidase solution and n parts of the hypoxanthine solution of different volumes, add the n parts of the hypoxanthine solution to the n parts of the xanthine oxidase solution respectively, incubate at 37°C for 10 minutes, add a molybdenum disulfide quantum dot aqueous solution and a TMB aqueous solution, and then make up the volume with an acetate buffer, so that in the final obtained n parts of the fixed volume solution, the concentration of hypoxanthine increases gradually within the range of 5-140 μM, the concentration of xanthine oxidase is 2.5-3 U / mL, the concentration of molybdenum disulfide quantum dots is 40-50 μg / mL, and the concentration of TMB is 1-1.5 mM. Next, n portions of the fixed volume solution are incubated at 25-65° C. for 5-30 minutes to obtain n portions of the test solution, and their UV absorption spectra are tested respectively, and the absorbance of the oxidized TMB at the maximum absorption wavelength of 652 nm is used as the ordinate and the concentration of hypoxanthine is used as the abscissa to establish a standard curve equation;

[0065] In some embodiments, in step S1, the mass ratio of molybdenum disulfide quantum dots to hypoxanthine, xanthine oxidase and TMB is 40:(0.68-19.1):50:310.

[0066] In some embodiments, n≥5, preferably 5≤n≤15; more preferably, n=11, at this time, the concentration of hypoxanthine is 5μM, 10μM, 20μM, 30μM, 40μM, 50μM, 60μM, 80μM, 100μM, 120μM, 140μM, and the standard curve equation is Y=0.007X+0.179, R 2 =0.975.

[0067] S2, pre-treat the sample to be tested, add xanthine oxidase solution, incubate at 37°C for 10 minutes, add molybdenum disulfide quantum dot aqueous solution and TMB aqueous solution, and then dilute with acetate buffer, so that the final dilute solution has a xanthine oxidase concentration of 2.5-3U / mL, a molybdenum disulfide quantum dot concentration of 40-50μg / mL, and a TMB concentration of 1-1.5mM. Then, incubate the dilute solution at 25-65°C for 5-30 minutes to obtain a test solution, measure the ultraviolet absorption spectrum of the test solution, and substitute the obtained absorbance into the standard curve equation obtained in step S1 to calculate the hypoxanthine concentration in the sample to be tested.

[0068] In some embodiments, the pretreatment in step S2 includes one or more of grinding, water bath heating, dilution, centrifugation, and filtration, wherein the dilution is performed using an acetate buffer having a pH of 7.

[0069] In some embodiments, in step S2, the mass ratio of molybdenum disulfide quantum dots to the sample to be tested, xanthine oxidase and TMB is 4:200000:1:31.

[0070] In some embodiments, the samples to be tested include meat, fish, shrimp, shellfish, beans and nuts.

[0071] In some embodiments, in step S1 and step S2, the solvents of the xanthine oxidase solution and the hypoxanthine solution are both acetate buffer with a pH of 7; the pH value of the acetate buffer used for volume adjustment in step S1 and step S2 is 2-8.

[0072] Enzyme-like catalytic antibacterial method refers to mixing an aqueous solution of molybdenum disulfide quantum dots with a hydrogen peroxide solution. The molybdenum disulfide quantum dots catalyze the rapid decomposition of hydrogen peroxide and produce hydroxyl free radicals, which inactivate the bacteria through the strong oxidizing property of hydroxyl free radicals.

[0073] In some embodiments, the bacteria include Escherichia coli and Staphylococcus aureus.

[0074] Some specific embodiments are listed below. It should be noted that the embodiments described below are exemplary and are only used to explain the present application, and should not be construed as limiting the present application. If specific techniques or conditions are not specified in the embodiments, the techniques or conditions described in the literature in this area or the product specifications are used. The reagents or instruments used without specifying the manufacturer are all conventional products that can be obtained commercially.

[0075] In the examples of the present application, the particle size of the molybdenum disulfide powder used in preparing molybdenum disulfide quantum dots is 12-16 μm, and the ultrasonic cell disruptor used is SCIENTZ-ⅡD.

[0076] Example 1

[0077] Example 1 provides a method for preparing molybdenum disulfide quantum dots having peroxidase-like catalytic properties, comprising the following steps:

[0078] S1, add 0.4g molybdenum disulfide powder to 40mL DMF, stir magnetically for 20min (500r / min), disperse the molybdenum disulfide evenly, and obtain a molybdenum disulfide dispersion with a concentration of 0.01g / mL;

[0079] S2, using an ultrasonic cell disruptor to ultrasonically treat the molybdenum disulfide dispersion obtained in step S1 at a power of 400 W for 15 hours to obtain a molybdenum disulfide quantum dot solution;

[0080] S3, removing DMF from the molybdenum disulfide quantum dot solution obtained in step S2 by reduced pressure distillation, adding water to disperse it uniformly again, filtering with a 0.22 μm needle, and obtaining an aqueous solution of molybdenum disulfide quantum dots with enzyme-like catalytic properties, with a concentration of 1.7 mg / mL.

[0081] The crystal structure of the MoS2 quantum dots prepared in Example 1 was tested and analyzed using a transmission electron microscope (TEM). The size of the quantum dots was found to be 3.2 nm. Figure 1 As shown, it can be seen that the interplanar spacing (dhkl) of MoS2 quantum dots is 0.16nm, and the lattice fringes are discontinuous, with uniform sulfur vacancies. This is because the ultrasonic cell disruptor not only has cavitation effects on MoS2 quantum dots during the ultrasonic process, but also has strong shear forces. Part of the sulfur falls off under the synergistic effect of the two strong forces, resulting in uniform sulfur vacancies on the lattice fringes, and thus making the molybdenum-sulfur ratio in the MoS2 quantum dots greater than 1:2.

[0082] The MoS2 quantum dots prepared in 1 were tested and analyzed using X-ray photoelectron spectroscopy (XPS). Figure 2 The figure below shows the X-ray photoelectron spectroscopy (XPS) of the quantum dots. Analysis shows that the ratio of molybdenum to sulfur in the MoS2 quantum dots is 1:1.49, which deviates from the ratio of molybdenum to sulfur in the original MoS2 powder (1:2), indicating that defects (sulfur vacancies) have occurred in the prepared MoS2 quantum dots. Mo 3d appeared in the high-resolution XPS spectrum. 6+ The characteristic peaks of molybdenum disulfide powder indicate that the original Mo 4+ was partially oxidized; at the same time, S appeared in the high-resolution XPS spectrum of S2p 6+ The presence of sulfur vacancies in the MoS2 quantum dot lattice and the oxidation of Mo and S give the surface of the MoS2 quantum dot different electronic properties and active sites from those of the MoS2 powder, thereby providing new or more catalytic activity centers, giving the MoS2 quantum dots special peroxidase-like catalytic properties.

[0083] See also Figure 3 , is the ultraviolet absorption spectrum of the molybdenum disulfide quantum dot aqueous solution obtained in Example 1. It can be seen that there are obvious absorption peaks at 400nm, 443nm, 610nm and 670nm.

[0084] See also Figure 4, is the electron paramagnetic resonance (EPR) spectrum associated with sulfur vacancies in the MoS2 quantum dots obtained in Example 1. It can be seen from the figure that the MoS2 quantum dots obtained in this example produce strong sulfur vacancy-related electron paramagnetic signals, indicating that uniform sulfur vacancies exist in the lattice fringes of the prepared MoS2 quantum dots.

[0085] Example 2

[0086] Example 2 provides a method for preparing molybdenum disulfide quantum dots with peroxidase-like catalytic properties, comprising the following steps:

[0087] S1, 0.4g molybdenum disulfide powder is added to 40mL NMP, and magnetic stirring is carried out for 20min (500r / min) to uniformly disperse the molybdenum disulfide to obtain a molybdenum disulfide dispersion liquid with a concentration of 0.01g / mL;

[0088] S2, using an ultrasonic cell disruptor to ultrasonically treat the molybdenum disulfide dispersion obtained in step S1 at a power of 600 W for 12 hours to obtain a molybdenum disulfide quantum dot solution;

[0089] S3, removing NMP from the molybdenum disulfide quantum dot solution obtained in step S2 by vacuum distillation, adding water to disperse it uniformly again, filtering with a 0.22 μm needle, and obtaining a molybdenum disulfide quantum dot aqueous solution with enzyme-like catalytic properties.

[0090] The crystal plane structure of the molybdenum disulfide quantum dots prepared in Example 2 was tested and analyzed by TEM, and it was found that the size of the quantum dots was 3.8 nm, the interplanar spacing (dhkl) was 0.19 nm, and uniform sulfur vacancies also existed on the lattice fringes of the quantum dots.

[0091] Example 3

[0092] Example 3 provides a method for preparing molybdenum disulfide quantum dots with peroxidase-like catalytic properties, comprising the following steps:

[0093] S1, 0.4g molybdenum disulfide powder is added in 40mL DMF, magnetic agitation 20min (800r / min), molybdenum disulfide is evenly dispersed, obtains the molybdenum disulfide dispersion liquid that concentration is 0.01g / mL;

[0094] S2, using an ultrasonic cell disruptor to ultrasonically treat the molybdenum disulfide dispersion obtained in step S1 at a power of 800 W for 10 hours to obtain a molybdenum disulfide quantum dot solution;

[0095] S3, removing DMF from the molybdenum disulfide quantum dot solution obtained in step S2 by reduced pressure distillation, adding water to disperse it uniformly again, filtering with a 0.22 μm needle, and obtaining a molybdenum disulfide quantum dot aqueous solution with enzyme-like catalytic properties.

[0096] The crystal plane structure of the molybdenum disulfide quantum dots prepared in Example 3 was tested and analyzed by TEM, and it was found that the size of the quantum dots was 3.5 nm, the interplanar spacing (dhkl) was 0.2 nm, and uniform sulfur vacancies also existed on the lattice fringes of the quantum dots.

[0097] Comparative Example 1

[0098] Comparative Example 1 provides a method for preparing molybdenum disulfide quantum dots by a hydrothermal method, comprising the following steps:

[0099] S1, dissolve 0.125 g of sodium molybdate dihydrate in 40 mL of deionized water, and adjust the pH to 6.5 with 0.1 M HCl aqueous solution;

[0100] S2, 0.25 g of L-cysteine ​​was dissolved in 30 mL of deionized water, and the solution obtained in step S1 was added to obtain a mixture, and then the mixture was stirred for 5 min and transferred to a stainless steel autoclave for reaction at 200° C. for 12 h. The solution after the reaction was naturally cooled to room temperature, centrifuged at 8000 rpm for 10 min, the supernatant was collected, dialyzed with deionized water for 12 h, and then filtered with a 0.22 μm microporous filter membrane to obtain cysteine-functionalized molybdenum disulfide quantum dots.

[0101] See also Figure 5 As shown, the crystal plane structure of the molybdenum disulfide quantum dots prepared in Comparative Example 1 was tested and analyzed using TEM, and the size of the quantum dots was 4.3 nm, and the interplanar spacing (dhkl) was 0.22 nm. Compared with the molybdenum disulfide quantum dots prepared in Examples 1-3, the molybdenum disulfide quantum dots prepared in this comparative example were slightly larger in size, and there was no obvious lattice distortion and defects in the crystal plane. Therefore, there may be no sulfur vacancies on the surface of the quantum dots, which leads to a lack of effective active sites to achieve enzyme-like catalytic performance.

[0102] Comparative Example 2

[0103] Comparative Example 2 provides a method for preparing molybdenum disulfide quantum dots, using ultrasound (ultrasonic cell disruptor) + hydrothermal method, comprising the following steps:

[0104] S1, add 0.4g molybdenum disulfide powder to 40mL DMF, stir magnetically for 20min (500r / min), disperse the molybdenum disulfide evenly, and obtain a molybdenum disulfide dispersion with a concentration of 0.01g / mL;

[0105] S2, using an ultrasonic cell disruptor to ultrasonically treat the molybdenum disulfide dispersion obtained in step S1 at a power of 400 W for 15 hours to obtain a molybdenum disulfide quantum dot solution;

[0106] S3, placing the molybdenum disulfide quantum dot solution obtained in step S2 in a polytetrafluoroethylene-lined high-pressure reactor for hydrothermal reaction at 150° C. for 6 hours, and then naturally cooling to room temperature;

[0107] S4, removing DMF from the solution obtained after the hydrothermal reaction in step S3 by reduced pressure distillation, adding water to disperse it uniformly again, and filtering with a 0.22 μm needle to obtain a molybdenum disulfide quantum dot aqueous solution.

[0108] Figure 6 The crystal plane structure of the molybdenum disulfide quantum dots prepared in Comparative Example 2 was tested and analyzed by TEM, and the size of the quantum dots was 4.0 nm, and the interplanar spacing (dhkl) was 0.24 nm. Compared with the molybdenum disulfide quantum dots prepared in Examples 1-3, the size of the molybdenum disulfide quantum dots prepared in this comparative example was also slightly larger, and there were only a very small number of defects (sulfur vacancies) in its crystal plane. Therefore, there were only a few effective active sites on the surface of the quantum dots to achieve enzyme-like catalytic performance. The reason why the molybdenum disulfide quantum dots prepared by ultrasound + hydrothermal method have fewer defects may be that the high temperature and high pressure conditions in the hydrothermal process cause the atoms in the lattice to rearrange, promote the recrystallization of the lattice and the repair of lattice defects, and the disappearance of such defects may cause the enzyme-like catalytic performance of the molybdenum disulfide quantum dots to decrease.

[0109] Comparative Example 3

[0110] Comparative Example 3 provides a method for preparing molybdenum disulfide quantum dots, in which the ultrasonic cell disruptor is replaced with a common ultrasonic cleaning instrument G-12A, comprising the following steps:

[0111] S1, 0.4g molybdenum disulfide powder is added to 40mL anhydrous ethanol, and magnetic stirring is carried out for 20min (500r / min) to uniformly disperse the molybdenum disulfide to obtain a molybdenum disulfide dispersion liquid with a concentration of 0.01g / mL;

[0112] S2, using a common ultrasonic cleaner to ultrasonically treat the molybdenum disulfide dispersion obtained in step S1 at a power of 400 W for 15 hours to obtain a molybdenum disulfide quantum dot solution;

[0113] S3, removing the anhydrous ethanol in the molybdenum disulfide quantum dot solution obtained in step S2 by rotary evaporation, adding water to disperse it uniformly again, and filtering with a 0.22 μm needle to obtain a molybdenum disulfide quantum dot aqueous solution.

[0114] Figure 7TEM was used to test and analyze the crystal structure of the molybdenum disulfide quantum dots prepared in Comparative Example 3, and the size of the quantum dots was found to be 3.0 nm, and the interplanar spacing (dhkl) was 0.204 nm. Compared with the molybdenum disulfide quantum dots prepared in Examples 1-3, the molybdenum disulfide quantum dots prepared in this comparative example also had only a very small number of defects (sulfur vacancies) in the crystal plane. Therefore, there were fewer effective active sites on the surface of the quantum dots to achieve enzyme-like catalytic performance.

[0115] Application Example 1

[0116] Application Example 1 provides an application of molybdenum disulfide quantum dots with peroxidase-like catalytic properties in detecting hypoxanthine concentration, comprising the following steps:

[0117] S1, take 11 portions of 100 μL 50U / mL xanthine oxidase solution (solvent is acetate buffer at pH = 7), add 0.5, 1, 2, 3, 4, 5, 6, 8, 10, 12, 14 μL of 50mM hypoxanthine solution (solvent is acetate buffer at pH = 7), incubate at 37°C for 10 min, then add 0.5mL 160μg / mL molybdenum disulfide quantum dot aqueous solution and 0.2mL 10mM TMB aqueous solution, then the above solutions were diluted to 2mL with pH=4 acetate buffer, so that the final concentration of xanthine oxidase was 2.5U / mL, the final concentration of hypoxanthine was 5μM, 10μM, 20μM, 30μM, 40μM, 50μM, 60μM, 80μM, 100μM, 120μM, 140μM, the final concentration of molybdenum disulfide quantum dots was 40μg / mL, the final concentration of TMB was 1mM, and then incubated at 45°C for 15min to obtain the test solution. Finally, the UV absorption spectra of the 11 test solutions were tested respectively, and the absorbance A of TMB at 652nm was used. 652 The standard curve equation was established by taking the concentration of hypoxanthine as the ordinate and the concentration of hypoxanthine as the abscissa;

[0118] See also Figure 8 As shown in FIG. 1 , the ultraviolet absorption spectrum obtained in step S1 and the linear relationship diagram of the absorbance of 11 solutions with the change of hypoxanthine concentration. It can be seen that as the concentration of hypoxanthine increases from 5 μM to 140 μM, the absorbance of the solution increases, and has a good linear relationship in the range of 5-80 μM. The standard curve equation Y=0.007X+0.179, R 2 =0.975.

[0119] S2, take 2g of three samples to be tested (fish, shrimp, clam) respectively, add them to 5mL pH=7 acetate buffer and grind them into homogenate, then centrifuge at 7000rpm for 10min, filter the supernatant to obtain three sample solutions. Then, treat the three sample solutions as follows:

[0120] Take 8 μL of sample solution, add 100 μL of 50U / mL xanthine oxidase solution (solvent is acetate buffer at pH=7), incubate at 37°C for 10 min, add 0.5 mL of 160 μg / mL molybdenum disulfide quantum dot aqueous solution and 0.2 mL of 10 mM TMB aqueous solution, then dilute the above solutions to 2 mL with acetate buffer at pH=4, incubate at 25-65°C for 5-30 min to obtain the test solution, measure the ultraviolet absorption spectrum of the test solution, and substitute the absorbance at 652 nm into the standard curve equation obtained in step S1 to calculate the hypoxanthine concentration in the test sample.

[0121] Application Example 2

[0122] Application Example 2 provides an application of molybdenum disulfide quantum dots having peroxidase-like catalytic properties, wherein the molybdenum disulfide quantum dots prepared in Example 1 are used for enzyme-like catalytic antibacterial treatment, comprising the following steps:

[0123] S1, prepare a blank control solution (phosphate buffer solution with pH = 7.4), a 160 μg / mL aqueous solution of molybdenum disulfide quantum dots, a 500 μM aqueous solution of hydrogen peroxide, and a mixed aqueous solution of molybdenum disulfide quantum dots and hydrogen peroxide (the concentration of molybdenum disulfide quantum dots is 160 μg / mL, and the concentration of hydrogen peroxide is 500 μM).

[0124] S2, take 1 mL of each of the four solutions obtained in step S1 and add them to four tubes of 10 5 CFU / mL of Escherichia coli solution and cultured at 37°C for 30 min.

[0125] S3, using the coating plate method to test the antibacterial effect of the four solutions added in step S2.

[0126] Application Example 3

[0127] The difference between Application Example 3 and Application Example 2 is that the Escherichia coli solution in step S2 is replaced with Staphylococcus aureus. The rest is basically the same as Application Example 2 and will not be described again.

[0128] See also Fig. 9As shown, the antibacterial effect diagrams of the blank control, molybdenum disulfide quantum dots, hydrogen peroxide, and molybdenum disulfide quantum dots + hydrogen peroxide obtained by the coating plate method in Application Example 2-3. It can be seen that the addition of molybdenum disulfide quantum dots aqueous solution alone has basically no antibacterial function; the number of bacteria is reduced after the addition of hydrogen peroxide aqueous solution alone, but the antibacterial effect is not obvious; after adding the mixed aqueous solution of molybdenum disulfide quantum dots and hydrogen peroxide, the number of bacteria is significantly reduced, and an excellent antibacterial effect is obtained. This is because molybdenum disulfide quantum dots catalyze hydrogen peroxide to generate strongly oxidizing hydroxyl radicals, which make Escherichia coli and Staphylococcus aureus lose their activity under the action of hydroxyl radicals.

[0129] The peroxidase-like catalytic activity of the molybdenum disulfide quantum dots prepared in Example 1 and Comparative Examples 1-3 was tested, and the specific steps were as follows:

[0130] The molybdenum disulfide quantum dots prepared in Example 1 and Comparative Examples 1-3 were respectively used to prepare 50 μL of 0.1 mg / mL aqueous solution of molybdenum disulfide quantum dots, and then 200 μL of 10 mM TMB aqueous solution was added, and then 100 μL of 10 mM H 2 O 2 For aqueous solution, dilute to 2 mL with ultrapure water, let stand for 10 min, and measure the absorbance of the solution at 652 nm. See the table below for details.

[0131] See also Fig.10 As shown, it is a comparison chart of the peroxidase-like catalytic activity of the molybdenum disulfide quantum dots prepared in Example 1 and Comparative Examples 1-3. It can be seen that the absorbance value at 652nm obtained by testing the molybdenum disulfide quantum dots prepared in Example 1 is significantly higher than the absorbance value measured by the molybdenum disulfide quantum dots prepared in Comparative Examples 1-3 (Example 1: MoS 2 QDs (DMF) ultrasonic cell disruptor ultrasound; Comparative Example 1: MoS 2 QDs (hydrothermal); Comparative Example 2: MoS 2 QDs (DMF) ultrasonic cell disruptor ultrasound + hydrothermal; Comparative Example 3: MoS 2 QDs (anhydrous ethanol) ultrasonic cleaning instrument ultrasound), which shows that the molybdenum disulfide quantum dots synthesized by the preparation method of Example 1 have more excellent enzyme-like catalytic performance, that is, the synthesis method using ultrasonic cell disruptor ultrasound and DMF as solvent is significantly better.

[0132] Among them, the enzyme-like catalytic effect of molybdenum disulfide quantum dots prepared by ultrasonic cell disruptor is significantly better than that prepared by ultrasonic cleaning instrument. This may be because ultrasonic cell disruptor usually has higher power and more concentrated energy output, which can produce stronger mechanical vibration and cavitation effect, so that the crystal structure of molybdenum disulfide is subjected to more violent impact, thereby more effectively stripping out quantum dots with smaller size and more defects. Ordinary ultrasonic cleaning instruments have relatively low power, and the energy distribution is more uniform but not concentrated enough. They mainly play a cleaning and simple dispersion role, and the degree of damage to the crystal structure of molybdenum disulfide is limited, so it is difficult to produce a large number of quantum dots with high catalytic activity.

[0133] In summary, the present application provides a molybdenum disulfide quantum dot with peroxidase-like catalytic properties, and a preparation method and application thereof. The molybdenum disulfide quantum dots with peroxidase-like catalytic properties are obtained by treating the molybdenum disulfide dispersion with an ultrasonic cell disruptor in one step. The preparation steps provided in the present application are simple, and the obtained molybdenum disulfide quantum dots have good peroxidase-like catalytic properties, which can be used for hypoxanthine concentration detection and enzyme-like catalytic antibacterial.

[0134] It should be noted that the present application is not limited to the above-mentioned embodiments. The above-mentioned embodiments are only examples, and the embodiments having the same structure as the technical idea and exerting the same effect within the scope of the technical solution of the present application are all included in the technical scope of the present application. In addition, without departing from the scope of the main purpose of the present application, various modifications that can be thought of by those skilled in the art to the embodiments and other methods of combining some of the constituent elements in the embodiments are also included in the scope of the present application.

Claims

1. A molybdenum disulfide quantum dot having peroxidase-like catalytic properties, characterized in that: The molybdenum disulfide quantum dots are prepared by ultrasonically treating a dispersion of molybdenum disulfide with an ultrasonic cell disruptor; uniform sulfur vacancies exist in the lattice stripes of the molybdenum disulfide quantum dots, so that the ratio of molybdenum to sulfur is greater than 1:2; the interplanar spacing of the molybdenum disulfide quantum dots is 0.15-0.22nm, and the particle size is 2-4nm; the molybdenum disulfide quantum dots also include a small amount of oxidized molybdenum and oxidized sulfur; the ultraviolet absorption spectrum of the molybdenum disulfide quantum dots has absorption peaks at 390-450nm, 600-620nm and 660-680nm.

2. The molybdenum disulfide quantum dots having peroxidase-like catalytic properties according to claim 1, characterized in that: The ultraviolet absorption spectrum of the molybdenum disulfide quantum dots has obvious absorption peaks at 400nm, 443nm, 610nm and 670nm; the ratio of molybdenum to sulfur in the molybdenum disulfide quantum dots is 1:(1.4-1.8); the molybdenum disulfide quantum dots have peroxidase-like catalytic properties, can catalyze the rapid decomposition of hydrogen peroxide, and produce hydroxyl radicals.

3. A method for preparing molybdenum disulfide quantum dots with peroxidase-like catalytic properties, characterized in that: The dispersion of molybdenum disulfide is ultrasonically treated with an ultrasonic cell disruptor under preset parameters, so that part of the sulfur in the molybdenum disulfide falls off under the action of shear force and cavitation, thereby causing sulfur vacancies to appear in the lattice fringes of the molybdenum disulfide, and part of the molybdenum and sulfur are oxidized, thereby obtaining molybdenum disulfide quantum dots with peroxidase-like catalytic properties; specifically, the preparation method comprises the following steps: S1, adding molybdenum disulfide powder to an organic solvent, and uniformly dispersing it by magnetic stirring to obtain a molybdenum disulfide dispersion with a concentration of 0.005-0.05 g / mL; S2, using an ultrasonic cell disruptor to ultrasonically treat the molybdenum disulfide dispersion obtained in step S1 at a power of 100-800 W for 8-18 hours to obtain a molybdenum disulfide quantum dot solution; S3, removing the organic solvent by vacuum distillation or rotary evaporation, adding water to uniformly disperse again, filtering, and obtaining a molybdenum disulfide quantum dot aqueous solution.

4. The method for preparing molybdenum disulfide quantum dots having peroxidase-like catalytic properties according to claim 3, characterized in that: The size of the molybdenum disulfide powder is 12-16 μm; the organic solvent is N,N-dimethylformamide, N-methylpyrrolidone, anhydrous ethanol, acetonitrile, acetone or dimethyl sulfoxide; the rotation speed of the magnetic stirring is 400-1000 r / min, and the stirring time is 10-30 min; in step S3, a 0.22 μm filter head is used for filtration; in step S2, further, the ultrasonic cell disruptor is used for ultrasonic treatment with a power of 400-800 W and a time of ultrasonic treatment of 10-15 h.

5. Use of the molybdenum disulfide quantum dots with peroxidase-like catalytic properties according to any one of claims 1 to 2 or the molybdenum disulfide quantum dots with peroxidase-like catalytic properties obtained by the preparation method according to any one of claims 3 to 4, characterized in that: Including hypoxanthine concentration detection and enzyme-catalyzed antibacterial; among them, The hypoxanthine concentration detection refers to pre-treating the sample to be tested, adding xanthine oxidase and incubating for a period of time to decompose hypoxanthine to produce hydrogen peroxide, then adjusting the pH, adding molybdenum disulfide quantum dots and 3,3',5,5'-tetramethylbenzidine hydrochloride, incubating for a period of time to obtain a test solution, allowing the molybdenum disulfide quantum dots to catalyze the rapid decomposition of hydrogen peroxide to obtain hydroxyl radicals, and the hydroxyl radicals further oxidize the solution containing 3,3',5,5'-tetramethylbenzidine hydrochloride to blue, and finally testing the ultraviolet spectrum of the test solution, and calculating the hypoxanthine concentration in the test sample according to the linear relationship between absorbance and hypoxanthine concentration within the detectable range; the detectable range of the hypoxanthine concentration is 5-80 μM; The enzyme-like catalytic antibacterial means that the molybdenum disulfide quantum dot aqueous solution is mixed with a hydrogen peroxide solution, and the molybdenum disulfide quantum dots catalyze the rapid decomposition of hydrogen peroxide and produce hydroxyl free radicals, and the bacteria are inactivated by the strong oxidizing property of the hydroxyl free radicals.

6. The use of molybdenum disulfide quantum dots having peroxidase-like catalytic properties according to claim 5, characterized in that: The concentration detection of hypoxanthine comprises the following steps: S1, prepare a xanthine oxidase solution and a hypoxanthine solution respectively, then take n portions of the xanthine oxidase solution of the same volume and n portions of the hypoxanthine solution of different volumes, add n portions of the hypoxanthine solution to n portions of the xanthine oxidase solution respectively, incubate at 37°C for 10 minutes, add a molybdenum disulfide quantum dot aqueous solution and a 3,3',5,5'-tetramethylbenzidine hydrochloride aqueous solution, then, dilute with acetate buffer to obtain a fixed volume solution, incubate at 25-65°C for 5-30 minutes to obtain a test solution, test the ultraviolet absorption spectrum of the test solution respectively, and establish a standard curve equation with the absorbance of the oxidized state 3,3',5,5'-tetramethylbenzidine hydrochloride at the maximum absorption wavelength of 652nm as the ordinate and the concentration of hypoxanthine as the abscissa; n≥5; S2, pretreating the sample to be tested, adding xanthine oxidase solution, incubating at 37°C for 10 minutes, adding molybdenum disulfide quantum dot aqueous solution and 3,3',5,5'-tetramethylbenzidine hydrochloride aqueous solution, and then diluting with acetate buffer to obtain a fixed volume solution, incubating at 25-65°C for 5-30 minutes to obtain a test solution, measuring the ultraviolet absorption spectrum of the test solution, and substituting the obtained absorbance into the standard curve equation obtained in step S1 to calculate the hypoxanthine concentration in the sample to be tested.

7. The use of molybdenum disulfide quantum dots having peroxidase-like catalytic properties according to claim 6, characterized in that: In step S1 and step S2, the concentration of xanthine oxidase in the constant volume solution is 2.5-3U / mL, the concentration of the molybdenum disulfide quantum dot aqueous solution is 40-50μg / mL, and the concentration of the 3,3',5,5'-tetramethylbenzidine hydrochloride aqueous solution is 1-1.5mM; in step S1, the concentration of hypoxanthine in the constant volume solution is 5-140μM.

8. The use of molybdenum disulfide quantum dots having peroxidase-like catalytic properties according to claim 7, characterized in that: In step S1, the mass ratio of molybdenum disulfide quantum dots to hypoxanthine, xanthine oxidase and TMB is 40:(0.68-19.1):50:310; in step S2, the mass ratio of molybdenum disulfide quantum dots to the sample to be tested, xanthine oxidase and 3,3',5,5'-tetramethylbenzidine hydrochloride is 4:200000:1:31; in step S2, the pretreatment includes one or more of grinding, water bath heating, dilution, centrifugation and filtration; in the pretreatment, acetate buffer with pH=7 is used for dilution.

9. The use of molybdenum disulfide quantum dots having peroxidase-like catalytic properties according to claim 8, characterized in that: In step S1 and step S2, the solvents of the xanthine oxidase solution and the hypoxanthine solution are both acetate buffer with a pH of 7; the pH value of the acetate buffer used for volume determination in step S1 and step S2 is 2-8.

10. The use of molybdenum disulfide quantum dots having peroxidase-like catalytic properties according to claim 5, characterized in that: The bacteria suitable for the enzyme-catalyzed antibacterial activity include Escherichia coli and Staphylococcus aureus.

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