Cysteine functionalized molybdenum disulfide antibacterial material as well as preparation method and application thereof

Abstract

The invention discloses a cysteine functionalized molybdenum disulfide antibacterial material as well as a preparation method and application thereof. The preparation method comprises the following steps: S1, uniformly mixing a MoS2 nanosheet suspension and a cysteine solution to obtain a mixed solution; and S2, carrying out a hydrothermal reaction on the mixed solution prepared in the step S1, naturally cooling to room temperature after the reaction is finished, and carrying out centrifugal washing and drying to obtain the cysteine functionalized molybdenum disulfide nano material. The method has the characteristics of simple process and convenient synthesis, is easy to realize large-scale production, and provides reliable technical support for industrial application. The cysteine functionalized molybdenum disulfide (MoS2-Cys) nano material prepared by the preparation method disclosed by the invention shows excellent antibacterial property, good biocompatibility, photo-thermal conversion property and near-infrared light response characteristic.

Description

Technical Field

[0001] The invention belongs to the field of medical nanomaterials and relates to a cysteine-functionalized molybdenum disulfide antibacterial material and a preparation method and application thereof. Background Art

[0002] Antibiotic-resistant bacterial infections are spreading around the world and have become a major public health issue threatening human health. The development of new antibacterial strategies to replace traditional antibiotics is urgent. In recent years, nanomaterials have shown great application potential in the antibacterial field due to their unique physicochemical properties and excellent catalytic performance. This type of material can achieve broad-spectrum bactericidal effects by catalytically producing reactive oxygen species (ROS) and is considered to be a very promising antibacterial method. However, existing nanomaterials often require higher concentrations to achieve the ideal bactericidal effect, which not only increases the cost of use, but also may bring potential biological toxicity risks, seriously restricting their practical application in the antibacterial field. Therefore, how to reduce the use concentration of nanomaterials while ensuring antibacterial effects has become a key scientific issue that needs to be urgently addressed in the current research field of nano-antibacterial materials.

[0003] Molybdenum disulfide (MoS2), as a typical transition metal sulfide, has attracted much attention due to its unique physical properties and potential application in the field of photocatalysis. Studies have shown that MoS2 nanosheets have a significant photothermal effect, which can be applied in the antibacterial field. However, the surface structure of MoS2 has an important influence on its photothermal effect, which in turn determines the quality of its antibacterial performance. At present, the photothermal effect sterilization technology of MoS2 still faces several challenges: first, its photothermal conversion efficiency needs to be further improved; second, some heat-resistant strains show strong tolerance to the photothermal effect; finally, the MoS2 application concentration required by the existing technology is relatively high, which to a certain extent limits its practical application.

[0004] Recent studies have shown that cysteine exhibits significant antibacterial activity, primarily through direct or indirect action on the bacterial cell wall membrane. Its mechanism of action involves disrupting the composition of membrane surface substances or inhibiting related biosynthetic processes, thereby inhibiting bacterial growth. Experimental data showed that at a high concentration of 12 mg / mL, cysteine had an inhibition rate of 60% against Escherichia coli. It is worth noting that its antibacterial activity is highly dependent on the cell wall membrane target, and this spatial structure-specific recognition mechanism limits its antibacterial efficacy to a certain extent. Summary of the Invention

[0005] The purpose of the present invention is to provide a cysteine functionalized molybdenum disulfide (MoS2-Cys) antibacterial material and its preparation method and use, in order to solve the above-mentioned technical problems.

[0006] To solve the above technical problems, the present invention provides a preparation method of a cysteine-functionalized molybdenum disulfide antibacterial material, comprising the following steps:

[0007] S1. Mix the MoS2 nanosheet suspension and the cysteine solution evenly to obtain a mixed solution;

[0008] S2. Perform a hydrothermal reaction on the mixed solution prepared in step S1, naturally cool to room temperature after the reaction is completed, centrifuge and wash, and dry to obtain the cysteine-functionalized molybdenum disulfide nanomaterial.

[0009] Further, the preparation method of the MoS2 nanosheet suspension in step S1 is: ultrasonically treat the MoS2 nanosheets with ultrapure water for 18 - 22 min to prepare a suspension with a concentration of 0.1 - 1 mg / mL, and adjust the pH.

[0010] Further, glacial acetic acid is used to adjust the pH to 7.0.

[0011] Further, the preparation method of the cysteine solution in step S1 is: dissolve cysteine powder with ultrapure water, ultrasonically treat for 18 - 22 min, and prepare a cysteine solution with a concentration of 15 - 18 mg / mL.

[0012] Further, the volume ratio of the MoS2 nanosheet suspension to the cysteine solution in step S1 is 2:(1 - 10), and the mixing is carried out by shaking for at least 20 min.

[0013] Further, the hydrothermal reaction in step S2 is carried out at a temperature of 80 - 160 °C for a time of 5 - 24 h.

[0014] Further, the reaction in step S2 is carried out sealed in a polytetrafluoroethylene-lined reaction kettle.

[0015] Further, the centrifugation time in step S2 is at least 10 minutes, the centrifugation rate is at least 15000 rpm, and the washing is carried out with anhydrous ethanol and deionized water at least three times respectively. After washing, the supernatant is discarded, and the drying is carried out by vacuum freeze-drying.

[0016] The present invention also provides a cysteine-functionalized molybdenum disulfide antibacterial material prepared by the above preparation method.

[0017] The present invention also provides the application of the above cysteine-functionalized molybdenum disulfide antibacterial material in antibacterial.

[0018] Compared with the prior art, the beneficial effects of the present invention are:

[0019] This invention innovatively designs and develops a novel photoresponsive molybdenum disulfide nanocomposite, and also provides its preparation method and application solutions. Through functional modification, this complex can significantly improve its photothermal conversion efficiency and catalytic performance. By utilizing the synergistic mechanism of photothermal effect and catalysis, it achieves highly effective antibacterial properties at low concentrations, providing new ideas and methods for the development of novel nano-antibacterial materials. Specifically:

[0020] (1) The present invention adopts a one-step hydrothermal method to prepare cysteine-functionalized molybdenum disulfide. This method has the characteristics of simple process and convenient synthesis, and is easy to achieve large-scale production, providing reliable technical support for industrial application.

[0021] (2) The near-infrared light-responsive cysteine-functionalized molybdenum disulfide (MoS2-Cys) nanomaterial prepared by the present invention exhibits excellent performance. Under the assistance of 808nm near-infrared light, the material exhibits significant antibacterial effects at low concentrations (10mg / L) and has good biocompatibility. These properties give it broad application prospects in the fields of medical antibacterial and environmental sanitation disinfection.

[0022] (3) The MoS2-Cys nanomaterial of the present invention has excellent photothermal conversion performance, and its photothermal conversion efficiency is as high as 55.5%. This performance index provides a reliable guarantee for related applications.

[0023] (4) The MoS2-Cys nanomaterial prepared by the present invention has excellent near-infrared light response characteristics, and the light power density required to achieve complete sterilization is only 1.35W / cm 2 This characteristic significantly improves the practicality and application value of the material. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0025] Figure 1 Schematic diagram of the reaction principle of the preparation method of the present invention;

[0026] Figure 2 The antibacterial action pathway of the cysteine-functionalized molybdenum disulfide antibacterial material (MoS2-Cys) of the present invention;

[0027] Figure 3Transmission electron microscopy images of MoS2 (a), MoS2-Cys (b), and high-resolution transmission electron microscopy image of MoS2-Cys (c);

[0028] Figure 4 EDS energy spectrum analysis and elemental distribution maps of MoS2-Cys and control group MoS2;

[0029] Figure 5 UV absorption curves of MoS2-Cys and its control samples MoS2 and Cys;

[0030] Figure 6 Band gap diagrams of MoS2-Cys and its control sample MoS2;

[0031] Figure 7 Fourier transform infrared spectra of MoS2-Cys and its control samples MoS2 and Cys;

[0032] Figure 8 Zeta potential diagrams of MoS2-Cys and its control samples MoS2 and Cys;

[0033] Figure 9 Photothermal heating curves of MoS2, Cys, and MoS2-Cys;

[0034] Figure 10 Photothermal heating curves of MoS2-Cys at different concentrations;

[0035] Figure 11 Photothermal heating curves of MoS2-Cys at different optical powers;

[0036] Figure 12 Photothermal cycling diagram of MoS2-Cys of the present invention;

[0037] Figure 13 Photothermal conversion rate curve diagram of MoS2-Cys of the present invention;

[0038] Figure 14 Photothermal conversion rate curve diagram of MoS2-Cys of the present invention;

[0039] Figure 15 Antibacterial (E. coli) plate test results and significance analysis diagrams of blank control group, MoS2, Cys, and MoS2-Cys;

[0040] Figure 16 Antibacterial (E. coli) plate test results and significance analysis diagrams of untreated (control group), H2O2, NIR, and NIR + H2O2;

[0041] Figure 17Antibacterial (MRSA) plate experiment results and significance analysis diagrams of MoS2-Cys and the control group under the conditions of no treatment, H2O2, NIR, and NIR + H2O2;

[0042] Figure 18 Antibacterial (E.coli) plate test results of MoS2, Cys, MoS2-Cys, and the control group at different concentrations under the conditions of no treatment, H2O2, NIR, and NIR + H2O2;

[0043] Figure 19 Significance analysis diagram of antibacterial (E.coli) of MoS2-Cys at different concentrations under the condition of NIR + H2O2;

[0044] Figure 20 Significance analysis diagram of antibacterial (E.coli) of MoS2-Cys (1mg / L) and the control group under the conditions of no treatment, H2O2, NIR, and NIR + H2O2;

[0045] Figure 21 Control diagram of antibacterial effects of MoS2-Cys in the present invention with or without free radical quenching;

[0046] Figure 22 Control diagram of the production of hydroxyl radicals by electron paramagnetic resonance determination of MoS2-Cys in the present invention under the conditions of near-infrared light irradiation and no near-infrared light irradiation;

[0047] Figure 23 Using OPD as a probe to detect the fluorescence generation under different treatment methods;

[0048] Figure 24 Based on Figure 23 Fluorescence quantification;

[0049] Figure 25 Using TMB as a probe molecule to detect the relative production amount of hydroxyl radicals under different treatment methods;

[0050] Figure 26 Biocompatibility results of MoS2-Cys at different concentrations. Specific implementation mode

[0051] In order to make the technical problems, technical solutions, and beneficial effects to be solved by the present invention clearer and more understandable, the present invention will be further described in detail below in conjunction with embodiments and drawings. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0052] In an embodiment of the present invention, the present invention provides a preparation method of a cysteine-functionalized molybdenum disulfide antibacterial material, including the following steps:

[0053] S1. Mix the MoS2 nanosheet suspension and the cysteine solution evenly to obtain a mixed solution;

[0054] S2. Perform a hydrothermal reaction on the mixed solution prepared in step S1. After the reaction is completed, naturally cool it to room temperature, centrifuge, wash, and dry to obtain the cysteine-functionalized molybdenum disulfide nanomaterial.

[0055] Specifically, the MoS2 nanosheets in step S1 are of the 2H phase.

[0056] Specifically, the preparation method of the MoS2 nanosheet suspension in step S1 is: ultrasonicate the MoS2 nanosheets with ultrapure water for 18 - 22 min to prepare a suspension with a concentration of 0.1 - 1 mg / mL, and adjust the pH.

[0057] Preferably, the ultrasonication time is 20 min, and the concentration of the suspension is 0.1 mg / mL.

[0058] Specifically, glacial acetic acid is used to adjust the pH to 7.0.

[0059] Specifically, the preparation method of the cysteine solution in step S1 is: dissolve cysteine powder with ultrapure water, ultrasonicate for 18 - 22 min, and prepare a cysteine solution with a concentration of 15 - 18 mg / mL.

[0060] Preferably, the concentration of the cysteine solution is 16.7 mg / mL, and the ultrasonication time is 20 min.

[0061] Specifically, the volume ratio of the MoS2 nanosheet suspension to the cysteine solution in step S1 is 2:(1 - 10), preferably 1:1. The mixing is carried out by shaking for not less than 20 min, preferably 30 min.

[0062] Specifically, the reaction in step S2 is carried out in a sealed polytetrafluoroethylene-lined reaction kettle.

[0063] Specifically, the hydrothermal reaction in step S2 is carried out at a temperature of 80 - 160 °C for 5 - 24 h.

[0064] Preferably, the hydrothermal reaction in step S2 is carried out at a temperature of 100 ± 5 °C for not less than 12 h.

[0065] Specifically, the centrifugation time in step S2 is at least 1 minute, the centrifugation rate is at least 15000 rpm. Wash with anhydrous ethanol and deionized water at least three times in sequence, discard the supernatant after washing, and the drying is carried out by vacuum freeze-drying.

[0066] An embodiment of the present invention also provides a cysteine-functionalized molybdenum disulfide antibacterial material, which is prepared by the above preparation method.

[0067] An embodiment of the present invention also provides the application of the above cysteine-functionalized molybdenum disulfide antibacterial material in antibacterial.

[0068] The following is a specific introduction to the present invention in combination with specific embodiments:

[0069] Example 1

[0070] Preparation of cysteine-functionalized molybdenum disulfide antibacterial material:

[0071] (1) Ultrasonic MoS2 nanosheets in ultrapure water for 20 min to prepare a suspension with a concentration of 0.1 mg / mL, and adjust the pH to 7.0 with glacial acetic acid;

[0072] (2) Weigh 0.667 g of cysteine powder into a conical flask, add 40 mL of ultrapure water, and ultrasonic for 20 min to prepare a cysteine solution;

[0073] (3) Mix the suspension prepared in (1) and the solution prepared in (2) according to a volume ratio of 1:1 and shake for 30 min;

[0074] (4) Transfer the mixture prepared in (3) into a 100 mL polytetrafluoroethylene-lined reaction kettle, seal it, react at 100 °C for 12 h, naturally cool to room temperature after the reaction, centrifuge and wash, and freeze-dry to obtain the cysteine-functionalized molybdenum disulfide nanomaterial.

[0075] Example 2

[0076] In this example, the cysteine-functionalized molybdenum disulfide nanosheets (MoS2-Cys) prepared in Example 1 were used for multiple detections. The following are the detection results of MoS2-Cys prepared in Example 1, its control MoS2 and Cys.

[0077] Figure 3 Figures (a), (b) and (c) are the transmission electron microscope images of MoS2, MoS2-Cys and the high-resolution transmission electron microscope image of MoS2-Cys, respectively. It can be seen from the figures that molybdenum disulfide is nanosheets, and the functionalized sample MoS2-Cys still maintains the nanosheet structure of MoS2, and significantly improves the dispersion performance of the nanomaterial.

[0078] Figure 4 Figures are the EDS energy spectrum distribution and element distribution diagrams of MoS2-Cys and the control group MoS2. It can be seen from the figures that MoS2-Cys is mainly composed of Mo, S, N, O, and C elements, confirming that Cys is successfully modified on the surface of molybdenum disulfide nanosheets.

[0079] Figure 5 The ultraviolet absorption spectra of MoS2-Cys and its control samples MoS2 and Cys Figure 6 The band gap diagram of MoS2-Cys and its control sample MoS2. It can be seen from the figure that the absorption of MoS2-Cys in the near-infrared region is significantly enhanced, and its band gap is 2.28 eV, lower than that of pure MoS2 nanosheets, which confirms the enhancement effect of cysteine functionalization on the near-infrared light absorption performance.

[0080] Figure 7 The Fourier transform infrared spectra of MoS2-Cys and its control samples MoS2 and Cys. It can be seen from the figure that MoS2-Cys shows absorption peaks similar to those of Cys, indicating that Cys has been successfully modified on the surface of molybdenum disulfide nanosheets. At the same time, the Mo-S bond in the MoS2 sample has absorption at 940 cm -1 At this position, while the vibration wavenumber of the Mo-S bond in MoS2-Cys shows a blue shift, indicating that cysteine has been successfully bonded through disulfide bonds.

[0081] Figure 8 The Zeta potential diagrams of MoS2-Cys and its control samples MoS2 and Cys. It can be seen from the figure that the modification of cysteine makes MoS2-Cys have a higher surface positive charge, significantly changing the surface potential of molybdenum disulfide nanosheets, further proving the successful modification of cysteine.

[0082] Example 3 Photothermal Performance Test

[0083] In this example, the MoS2-Cys composite material prepared in Example 1 was used, and MoS2 and Cys were used as control samples for photothermal performance testing.

[0084] Cys, MoS2-Cys, and MoS2 were respectively dispersed in deionized water, and the photothermal effect was tested under 808 nm near-infrared light irradiation. The results are as Figures 9 - 14 shown.

[0085] From Figure 9 it can be seen that after irradiating with near-infrared light at a fixed concentration (10 mg / L) and light power density (1.35 w / cm 2 ) for 20 minutes, the temperatures of pure water, Cys, MoS2, and MoS2-Cys increased by 18 °C, 20 °C, 27 °C, and 50 °C respectively. The results show that cysteine functionalization significantly enhances the photothermal effect of the nanomaterials.

[0086] From Figure 10 it can be seen that at a fixed power density (1.35 w / cm 2)Under the condition of , the photothermal effect of MoS2-Cys nanomaterials increases significantly with the increase of concentration (2.5mg / mL, 5mg / mL, 10mg / mL, 20mg / mL, 40mg / mL).

[0087] It can be seen from Figure 11 that when the concentration of MoS2-Cys nanomaterials is fixed (10mg / mL), the photothermal effect increases with the increase of the light power density (0.25w / cm 2 , 1.35w / cm 2 , 2.56w / cm 2 ).

[0088] It can be seen from Figure 12 that after five photothermal cooling cycles of MoS2-Cys, its photothermal effect does not show an obvious decrease, indicating good stability.

[0089] It can be seen from Figure 13 and Figure 14 that the photothermal conversion efficiency of MoS2-Cys prepared in Example 1 is as high as 55.5%, further confirming its excellent photothermal performance.

[0090] Photothermal antibacterial performance test of Example 4

[0091] In this example, the MoS2-Cys composite material prepared in Example 1 was used, and MoS2 and Cys were used as control samples for the photothermal antibacterial performance test.

[0092] After incubating MoS2, Cys, and MoS2-Cys with Escherichia coli respectively, they were treated under 808nm near-infrared light (NIR) with a power density of 1.35W / cm 2 for 20 minutes, and 200μM H2O2 was added. Then the mixture was evenly coated on the agar solid medium for cultivation. The experimental results are as Figure 15 shown. It can be seen from the figure that Cys did not show an obvious antibacterial effect under near-infrared light irradiation, while MoS2 showed a relatively significant antibacterial effect, and MoS2-Cys almost reached an antibacterial efficiency of 100%. In the case of not adding MoS2, Cys, or MoS2-Cys, neither H2O2 alone, near-infrared light (NIR) alone, nor their combination had an obvious effect on bacterial growth. See Figure 16 . This antibacterial effect is also applicable to methicillin-resistant Staphylococcus aureus (MRSA). See Figure 17When MoS2-Cys is added, it has a certain antibacterial effect without H2O2 or near-infrared light (NIR) treatment. H2O2 or near-infrared light (NIR) alone also has a stronger antibacterial effect, and the combination of the two can completely inhibit bacterial growth.

[0093] like Figure 20 As shown in the figure, in the presence of near-infrared light and H2O2, MoS2-Cys exhibited significant antibacterial effects even at extremely low concentrations (1 mg / L). In the absence of H2O2 and near-infrared light (NIR), MoS2-Cys alone also exhibited significant antibacterial effects, with an E. coli survival rate of 72.8%. However, under the action of H2O2 or near-infrared light alone, the survival rates of E. coli dropped to 62.1% and 38.1%, respectively. Figure 19 As shown in the figure, with the increase of MoS2-Cys concentration, its antibacterial effect is further enhanced. When the concentration increases to 10 mg / L, almost no colonies are formed on the agar plate, and the bactericidal rate is close to 100%.

[0094] Example 5 Photothermal Enhancement of Catalytic Performance

[0095] This example uses the MoS2-Cys composite material prepared in Example 1 to conduct a systematic test of its photothermal enhanced catalytic performance.

[0096] Figure 21 This is a comparison chart of the antibacterial effects of the MoS2-Cys free radical quenching or not of the present invention. It can be seen from the figure that since the addition of IPA can quench the ·OH produced in the system, the bacterial survival rate of Group II with the addition of IPA is greatly improved, and the difference is very significant. In the control group and Group I, the addition of IPA has no significant effect on the bacterial survival rate, indicating that ·OH plays a key role in the process of the MoS2-Cys composite material prepared in Example 1 of the present invention exerting a high-efficiency antibacterial effect.

[0097] Figure 22 This is a comparison chart of the hydroxyl radical generation of MoS2-Cys under near-infrared light irradiation and without near-infrared light irradiation by electron paramagnetic resonance. It can be seen from the figure that without near-infrared light irradiation, there is no obvious ·OH in the system. After adding NIR irradiation, the ·OH signal is obvious, indicating that NIR greatly promotes the generation of ·OH.

[0098] OPD is used as a probe molecule to detect ·OH in the system. Since OPD itself has no fluorescence, ·OH can oxidize OPD into a substance with a fluorescent effect. The results are as follows: Figure 23 As shown in the figure, it can be seen that the fluorescence signal intensity of the MoS2-Cys+H2O2+NIR system is significantly enhanced. Figure 24 Based on Figure 23The quantitative results of fluorescence intensity further prove the near-infrared enhanced peroxidase activity of the examples of the present invention.

[0099] Figure 25 To detect the generation of ·OH by MoS2-Cys prepared in Example 1 of the present invention and MoS2 of the control group under different treatment methods using TMB as a probe molecule, it can be seen from the figure that there is no significant difference in the ultraviolet absorption at a wavelength of 652 nm among Group I, Group II, and Group III, indicating that there is no obvious difference in the amount of ·OH generated by MoS2 and MoS2-Cys without NIR irradiation, while there is a significant difference in Group IV, further indicating that MoS2-Cys prepared in Example 1 has good NIR activity and can significantly enhance the ability to catalytically generate ·OH under NIR conditions.

[0100] Example 6 Biocompatibility

[0101] In this example, the MoS2-Cys composite material prepared in Example 1 was used to detect its biocompatibility, and the results are as Figure 26 shown.

[0102] From Figure 26 it can be seen that the MoS2-Cys nanomaterial prepared in Example 1 has excellent biocompatibility. Even when the concentration of the nanomaterial reaches 10 mg / L, no obvious cytotoxicity is observed, indicating the potential safety of this material in biomedical applications. This result further supports the practical application potential of MoS2-Cys in antibacterial therapy.

[0103] As can be seen from the above examples, the MoS2-Cys composite material prepared by the present invention exhibits excellent antibacterial performance. After cysteine functionalization, the surface of the MoS2-Cys material is positively charged, which can effectively promote the interaction between the nanomaterial and the negative charge on the bacterial surface, and at the same time significantly enhance the absorption ability of near-infrared light. This enhancement effect brings double advantages: on the one hand, the photothermal effect of the material is significantly improved; on the other hand, the hot electrons generated by light excitation accelerate the catalytic reaction and promote the generation of more reactive oxygen species (ROS), thereby synergistically enhancing the antibacterial performance. The MoS2-Cys prepared by the present invention has broad-spectrum antibacterial performance and can be widely applied to the treatment of various pathogenic bacterial infections and the field of environmental disinfection.

[0104] The above description is only a description of the preferred embodiments of the present invention and does not limit the scope of the present invention in any way. Any changes and modifications made by those of ordinary skill in the art of the present invention according to the above disclosure shall fall within the protection scope of the claims.

Claims

1. A preparation method of a cysteine-functionalized molybdenum disulfide antibacterial material, characterized in that It includes the following steps: S1. Mix the MoS2 nanosheet suspension and the cysteine solution evenly to obtain a mixed solution; S2. Carry out a hydrothermal reaction on the mixed solution prepared in step S1. After the reaction is completed, naturally cool it to room temperature, centrifuge and wash, and dry to obtain the cysteine-functionalized molybdenum disulfide nanomaterial.

2. The preparation method according to claim 1, characterized in that, The preparation method of the MoS2 nanosheet suspension in step S1 is: ultrasonicate the MoS2 nanosheets with ultrapure water for 18 - 22 min to prepare a suspension with a concentration of 0.1 - 1 mg / mL, and adjust the pH.

3. The preparation method according to claim 2, wherein Adjust the pH using glacial acetic acid to pH 7.

0.

4. The preparation method according to claim 1, wherein The preparation method of the cysteine solution in step S1 is: dissolve cysteine powder with ultrapure water, ultrasonically treat it for 18 - 22 min to prepare a cysteine solution with a concentration of 15 - 18 mg / mL.

5. The preparation method according to claim 1, characterized in that, In step S1, the volume ratio of the MoS2 nanosheet suspension to the cysteine solution is 2:(1 - 10), and the mixing is carried out by shaking for no less than 20 min.

6. The preparation method according to claim 1, characterized in that, The hydrothermal reaction in step S2 is carried out at a temperature of 80 - 160 °C for a time of 5 - 24 h.

7. The preparation method according to claim 1, wherein The reaction in step S2 is carried out sealed in a polytetrafluoroethylene-lined reaction kettle.

8. The preparation method according to claim 1, characterized in that, In step S2, the centrifugation time is at least 10 minutes, the centrifugation rate is at least 15000 rpm, and it is washed with absolute ethanol and deionized water at least three times in sequence. After washing, discard the supernatant. The drying is carried out by vacuum freeze-drying.

9. A cysteine-functionalized molybdenum disulfide antibacterial material, characterized in that, It is prepared by using the preparation method described in any one of claims 1 - 8.

10. The application of the cysteine-functionalized molybdenum disulfide antibacterial material described in claim 9 in antibacterial.

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