Application of molybdenum dioxide-copper manganese bimetallic composite material in prevention and treatment of tobacco bacterial wilt

Abstract

The invention discloses an application of a molybdenum dioxide-copper manganese double-metal composite material in preventing and treating tobacco bacterial wilt, and the molybdenum dioxide-copper manganese double-metal composite material comprises molybdenum dioxide, a copper nano material and a manganese nano material, the copper nano material and the manganese nano material are loaded on the molybdenum dioxide to form the molybdenum dioxide-copper manganese bimetallic composite material. The composite material not only can effectively inhibit the growth and reproduction of germs, but also can improve and prolong the nutritional quality of plants under the illness condition.

Description

Technical Field

[0001] The present invention relates to the application of a molybdenum dioxide - copper - manganese bimetallic composite material in controlling tobacco bacterial wilt, belonging to the technical field of agricultural plant protection. Background Art

[0002] Ralstonia solanacearum, abbreviated as bacterial wilt pathogen, has a wide distribution range and more than 200 hosts in more than 50 families, including common ones such as potato, peanut, tobacco, papaya, tomato, etc. It is reported that the pathogen attaches to the roots of plants and then aggregates on the xylem vessels, over - secreting cell wall - degrading enzymes and exopolysaccharides to block the vascular system, ultimately leading to the death of the host. This disease easily causes large - area crop production reduction or even crop failure, and is a devastating soil - borne disease, which has seriously threatened the sustainable development of solanaceous crops.

[0003] In recent years, due to the unique optical and physicochemical properties of nanoparticles as antibacterial and antifungal agents in agriculture, nanotechnology has attracted great attention. Copper nanomaterials have received high attention due to their significant lethal activity against Gram - positive and Gram - negative bacteria; while manganese nanomaterials, as micronutrients, are often used in research on improving the nutritional quality of plants. Currently, bimetallic nanoparticles have received more attention than monometallic nanoparticles because bimetallic nanoparticles have combined functions and the efficacy of 1 + 1>2. Molybdenum disulfide has been widely used in eliminating many drug - resistant bacteria, photothermal therapy, and drug delivery due to its large surface area, high biocompatibility, strong near - infrared (NIR) absorption, and low cytotoxicity. However, there is currently no literature reporting the method of loading bimetals on molybdenum disulfide to control bacterial wilt. Summary of the Invention

[0004] Based on the above, the present invention provides the application of a molybdenum dioxide - copper - manganese bimetallic composite material in controlling tobacco bacterial wilt, which can further improve the control effect on bacterial wilt.

[0005] The technical solution of the present invention is as follows:

[0006] In the first aspect, the present invention provides the application of a molybdenum dioxide - copper - manganese bimetallic composite material in controlling tobacco bacterial wilt. The molybdenum dioxide - copper - manganese bimetallic composite material includes molybdenum dioxide, copper nanomaterials, and manganese nanomaterials, and the copper nanomaterials and manganese nanomaterials are loaded on the molybdenum dioxide to form a molybdenum dioxide - copper - manganese bimetallic composite material.

[0007] Preferably, the use concentration of the molybdenum dioxide - copper - manganese bimetallic composite material ≥12.5 mg / L.

[0008] In the second aspect, the present invention provides a method for preparing the molybdenum dioxide - copper - manganese bimetallic composite material, and this method includes:

[0009] S1 Mix ammonium molybdate, thioacetamide, manganese nitrate hexahydrate, and copper nitrate trihydrate with water, and ultrasonically oscillate to prepare a suspension for later use;

[0010] S2 Add the suspension to a reaction kettle and heat for a fixed period of time;

[0011] S3 After heating, cool to room temperature, centrifuge the reaction solution, and collect the precipitate;

[0012] S4 Dry the obtained precipitate at low temperature to finally obtain a MoS2 composite material loaded with Cu and Mn bimetals.

[0013] Preferably, in step S1, 0.003 mol of ammonium molybdate, 0.013 mol of thioacetamide, 0.0005 mol of manganese nitrate hexahydrate, 0.0005 mol of copper nitrate trihydrate, and 30 mL of water are used.

[0014] Preferably, in step S2, the suspension is heated to 200 °C for 24 h.

[0015] Advantages of the present invention: In the present invention, copper nanomaterials and manganese nanomaterials are loaded on molybdenum disulfide for preventing and controlling bacterial wilt. After the Cu and Mn bimetals are combined with MoS2, a stable composite structure is formed. The large specific surface area of MoS2 can adsorb pathogenic bacteria, increasing the contact probability between pathogenic bacteria and metal ions, while Cu 2+ and Mn 2+ can interfere with the structure and function of the cell membrane of pathogenic bacteria, destroy its integrity, inhibit cell wall synthesis, block the energy metabolism and material transport of pathogenic bacteria, thereby effectively inhibiting the growth and reproduction of pathogenic bacteria. In addition, this composite material can also improve and prolong the nutritional quality of plants under diseased conditions. Description of the Drawings

[0016] Figure 1 is the TEM image of the molybdenum dioxide-copper manganese bimetal composite material;

[0017] Figure 2 is the SEM image of the molybdenum dioxide-copper manganese bimetal composite material;

[0018] Figure 3 is the in vitro antibacterial plate image (the upper figure is treated with the molybdenum dioxide-copper manganese bimetal composite material, and the lower figure is treated with the MoS2 sample);

[0019] Figure 4 is the image of the disease situation of potted tobacco plants (the left figure is treated with the MoS2 sample, and the right figure is treated with the molybdenum dioxide-copper manganese bimetal composite material). Detailed Embodiments

[0020] To make the above objects, features, and advantages of the present invention more apparent and understandable, the following provides a detailed description of the specific embodiments of the present invention in conjunction with the accompanying drawings. Many specific details are set forth in the following description to facilitate a thorough understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the essence of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0021] Example 1: Preparation of Molybdenum Dioxide-Copper Manganese Bimetallic Composite

[0022] Synthesized by the one-pot method, specifically including the following steps:

[0023] S1 Add 0.003 mol of ammonium molybdate, 0.013 mol of thioacetamide, 0.0005 mol of manganese nitrate hexahydrate, and 0.0005 mol of copper nitrate trihydrate to 30 mL of water, and ultrasonically oscillate for 30 min to prepare a suspension for later use;

[0024] S2 Add the suspension to a 50 mL reaction kettle, heat to 200 °C, and maintain for 24 h;

[0025] S3 After heating, cool to room temperature, centrifuge the reaction solution, and collect the precipitate;

[0026] S4 Dry the obtained precipitate overnight at 40 °C to finally obtain the MoS2 composite material loaded with Cu and Mn bimetals. Figure 1 and Figure 2 are the TEM image and SEM image of the composite material respectively, indicating that the Cu and Mn bimetals are successfully loaded on MoS2.

[0027] Example 2: In Vitro Antibacterial Activity Experiment

[0028] Culture the Ralstonia solanacearum strain overnight in Medium B, collect the fresh bacterial suspension (OD 600 = 1), which is equivalent to approximately 1×10 9 colony-forming units (CFU) / mL, and then dilute the bacterial suspension to 1×10 5 CFU / mL.

[0029] Add the molybdenum dioxide-copper manganese bimetallic composite material and MoS2 sample in Example 1 to the bacterial suspension respectively to obtain the following concentration samples: 0, 1.5625, 3.125, 6.25, 12.5, 25 mg / L, with no addition as the control. After culturing the Ralstonia solanacearum cells at 30 °C for 24 h, monitor the viable bacteria by counting the number of CFUs on the casein peptone glucose (CPG) agar medium plate. The obtained data are as Figure 3 shown, and analyze Figure 3From the in vitro antibacterial plate results, it can be seen that the antibacterial effect depends on the antibacterial concentration. As the concentration increases, the antibacterial effect gradually enhances. However, when the concentration reaches 12.5 mg / L, the antibacterial effect of the implemented composite material is significantly better than that of MoS2. Especially when the concentration reaches 25 mg / L, the effect of the implemented composite material in inhibiting Ralstonia solanacearum is extremely significant, with only a few colonies remaining.

[0030] Example 3: Potted plant control experiment

[0031] The molybdenum dioxide - copper manganese bimetallic composite material and the MoS2 sample were respectively made into liquids with a concentration of 12.5 mg / L, and then sprayed onto the potted tobacco plants suffering from Ralstonia solanacearum. After two weeks, the appearance of the tobacco plants is as shown in Figure 4 It is found that the control effect of spraying the molybdenum dioxide - copper manganese bimetallic composite material is significantly better than that of spraying the MoS2 sample.

[0032] The above - mentioned embodiments only represent several implementation manners of the present invention. Their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the patent of the present invention. It should be pointed out that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention should be subject to the appended claims.

Claims

1. Application of molybdenum dioxide - copper - manganese bimetallic composite material in preventing and controlling tobacco bacterial wilt, wherein the molybdenum dioxide - copper - manganese bimetallic composite material comprises molybdenum dioxide, copper nanomaterial and manganese nanomaterial, and the copper nanomaterial and manganese nanomaterial are loaded on the molybdenum dioxide to form the molybdenum dioxide - copper - manganese bimetallic composite material.

2. The application according to claim 1, characterized in that, The use concentration of the molybdenum dioxide - copper - manganese bimetallic composite material is ≥ 12.5 mg / L.

3. A method for preparing the molybdenum dioxide - copper manganese bimetallic composite material described in claim 1, characterized in that, This method includes: S1 Mix ammonium molybdate, thioacetamide, manganese nitrate hexahydrate and copper nitrate trihydrate with water, and perform ultrasonic oscillation to prepare a suspension for use; S2 Add the suspension into a reaction kettle and heat for a fixed duration; S3 After heating, cool to room temperature, centrifuge the reaction solution and collect the precipitate; S4 Dry the obtained precipitate at low temperature to finally obtain the MoS2 composite material loaded with Cu and Mn bimetals.

4. The method according to claim 3, wherein In step S1, 0.003 mol of ammonium molybdate, 0.013 mol of thioacetamide, 0.0005 mol of manganese nitrate hexahydrate, 0.0005 mol of copper nitrate trihydrate and 30 mL of water are used.

5. The method according to claim 3, characterized in that In step S2, the suspension is heated to 200 °C for 24 h.

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