Preparation and application of copper-based nano-enzyme bactericide

Abstract

The invention relates to the technical field of agriculture, and discloses preparation and application of a copper-based nano-enzyme bactericide, the copper-based nano-enzyme bactericide is simple in preparation method, is formed by self-assembly of soluble copper ion salt and cholate bio-based surfactant, and has an excellent bactericidal effect. In consideration of prevention and treatment scenes of plant bacterial diseases, the copper-based nano-enzyme bactericide can realize efficient deposition on the surfaces of crop leaves, and the pesticide utilization rate is increased; meanwhile, leaf chlorophyll content is increased, and crop growth is promoted; and after residual in the soil, the subsequent seed germination is not influenced, and the method is environment-friendly. Compared with the prior art, the bactericide prepared by the invention has a wide application prospect in the field of pesticides.

Description

Technical Field

[0001] The present invention relates to the field of agricultural technology, and in particular to the preparation and application of a copper-based nanoenzyme fungicide. Background Art

[0002] Plant bacterial diseases refer to a series of physiological changes in plant cells and tissues caused by pathogenic bacteria that infect crops. Bacterial diseases are characterized by widespread occurrence, prolonged damage, and severe losses, making them a primary target of prevention and control in agricultural production.

[0003] Copper preparations are one of the main active ingredients of pesticides for preventing and controlling plant bacterial diseases. They are divided into inorganic copper and organic copper. Their bactericidal mechanism is mainly as follows: (1) copper ions are released after application, which come into direct contact with the cell membrane of pathogenic bacteria, denaturing the cell membrane protein and causing physical damage; (2) copper ions and the physiological reactions they induce cause the cell membrane of pathogenic bacteria to rupture, membrane potential to change, cell contents to flow out, and cell integrity to be destroyed; (3) copper ions induce plants to produce reactive oxygen species, which further damages pathogenic bacteria; (4) copper ions induce oxidative stress reactions, causing lipid peroxidation, protein oxidation and DNA degradation in pathogenic bacteria, thereby achieving the effect of inhibiting growth or killing bacteria.

[0004] However, inorganic copper preparations are often applied at high concentrations, causing crop damage and easily remaining in the soil, polluting the farmland ecosystem. Nanozymes, as enzyme mimics, not only possess many of the characteristics of nanomaterials but also possess catalytic functions. They are among the top ten emerging technologies in chemistry for 2022. Copper-based nanozymes are widely available, inexpensive, and possess enzyme-like activity. They can be prepared as copper-based nanozyme fungicides, achieving high bactericidal properties at low concentrations for the prevention and control of bacterial plant diseases. Meanwhile, while organic copper preparations have diverse structures, they often need to be prepared into pesticide suspensions, wettable powders, water-dispersible granules, and other formulations that are diluted with water before use. The resulting suspensions have poor surface activity and tend to bounce, roll, aggregate, and slide off the surface of crop leaves, reducing pesticide utilization and diminishing control effectiveness. Due to their small size, copper-based nanozymes can be embedded within the micro- and nanostructures of plant leaves, effectively improving their target deposition and achieving better bactericidal properties.

[0005] Invention patent application CN114306382A discloses a copper-based nanozyme and its preparation method and application. The copper-based nanozyme is simple and efficient in design. It is formed by self-assembly of water-soluble copper ion salts and phenolic compounds as precursors to form copper-phenol nanozymes, which are then combined with polydopamine nanoparticles. Based on the photothermal conversion ability of polydopamine and the peroxidase-like activity of copper-phenol nanozymes, the copper-based nanozyme material shows excellent in vitro antibacterial effects of enzyme-like catalysis and photothermal action, and exhibits significant in vitro antibacterial therapeutic effects on common bacterial infections. However, the copper-based nanozyme prepared by this patent needs to be irradiated with near-infrared light and hydrogen peroxide added in a suitable pH buffer system to have excellent bactericidal properties, and the use process is relatively complicated.

[0006] Invention patent application CN115501339A discloses a copper-based nanoenzyme active material for repairing a variety of difficult-to-heal wounds, its application, and wound repair gel. The materials used to prepare the copper-based nanoenzyme are mainly nanosheets, nanowires, nanospheres, or microflowers assembled from nanosheets containing copper ions. At 40°C, it can not only effectively inhibit bacterial infection but also significantly promote wound repair. It can be applied to the repair of a variety of difficult-to-heal wounds, such as bacterial-infected wounds, diabetic wounds, and deep burn wounds. However, this patent requires the preparation of a 0.5% copper-based sheet-like nanoenzyme sodium alginate hydrogel. On the one hand, the high copper ion concentration can easily cause phytotoxicity, and on the other hand, the hydrogel system is not conducive to use in farmland.

[0007] Invention patent application CN119456034A discloses an ultra-dispersed copper-based nanozyme, its preparation method, and application. The copper-based nanozyme is formed by oxidative coupling self-assembly from a copper-containing compound and a polyphenol compound as precursors in the presence of a polymer dispersant and a surfactant. The nanozyme exhibits excellent dispersibility in aqueous solvents, good antioxidant and antibacterial properties, and has broad application prospects in skin care and medical health. However, the patent requires stirring the reaction at 50°C for 3 hours and centrifuging at 10,000 rpm to obtain the ultra-dispersed copper-based nanozyme, resulting in a complex preparation method and high cost.

[0008] Therefore, there is an urgent need for a copper-based nanozyme fungicide suitable for the prevention and control of plant bacterial diseases, which has the characteristics of simple preparation method, stable physical and chemical properties, efficient dosage delivery, and environmental safety and friendliness. It can achieve better prevention and control effects at lower concentrations, improve the effective utilization rate of pesticides, and promote the green and sustainable development of pesticides. Summary of the Invention

[0009] In response to the deficiencies in the prior art, the present invention provides a preparation and application of a copper-based nanozyme fungicide, thereby obtaining a copper-based nanozyme fungicide with a simple preparation method, stable physical and chemical properties, efficient dosage delivery, and environmental safety and friendliness, achieving good prevention and control effects at low concentrations.

[0010] In order to solve the above technical problems, the present invention provides the following technical solutions.

[0011] On the one hand, the present invention provides a copper-based nanozyme bactericide, which is formed by self-assembly of a copper-containing compound and a bile salt bio-based surfactant.

[0012] Furthermore, the copper-containing compound includes one or more of copper sulfate, copper chloride, and copper acetate, preferably copper chloride (CuCl2).

[0013] Furthermore, the bile salt bio-based surfactant includes one or more of sodium cholate, sodium deoxycholate, sodium glycocholate, sodium glycodeoxycholate, sodium taurocholate, and sodium taurodeoxycholate, preferably sodium deoxycholate (NaDC).

[0014] Furthermore, the copper-based nanozyme fungicide has an average particle size range of 40-100 nm, has a Tyndall effect, and has good dispersibility in water.

[0015] Furthermore, the surface tension of the copper-based nanozyme fungicide is in the range of 35-50 mN / m, has good surface activity, and is easy to adhere and deposit on the surface of crop leaves.

[0016] Furthermore, the crop leaves include rice, wheat, corn, potato, etc., preferably rice leaves.

[0017] On the other hand, the present invention provides a method for preparing the copper-based nanozyme fungicide, comprising the following steps:

[0018] (1) dissolving one or more water-soluble copper ion salts in deionized water and stirring to obtain a uniform dispersed solution;

[0019] (2) dissolving one or more bile salt bio-based surfactants in deionized water and stirring to obtain a uniform dispersed solution;

[0020] (3) Copper ion salt solutions of different concentrations are mixed with bile salt bio-based surfactant solutions, stirred, and then allowed to stand to obtain self-assembled bodies in different liquid states.

[0021] Furthermore, in step (1), the molar concentration of the water-soluble copper ions is 0.05-100 mmol / L.

[0022] Furthermore, in step (2), the molar concentration of the bile salt bio-based surfactant is 1-100 mmol / L.

[0023] Furthermore, in steps (1)-(3), the stirring rate is 50-300 rpm, and the stirring time is 10-60 minutes.

[0024] Furthermore, in step (3), the self-assemblies in different liquid states include solutions, sols, gels, flocculent precipitations, etc.

[0025] Furthermore, in step (1), the molar concentration of the water-soluble copper ions is preferably 0.05-1 mmol / L.

[0026] Furthermore, in step (2), the molar concentration of the bile salt bio-based surfactant is preferably 1-50 mmol / L.

[0027] Furthermore, in step (3), the self-assembly in different liquid states is preferably a sol.

[0028] In another aspect, the present invention also includes the use of the copper-based nanozyme fungicide in preventing and controlling plant bacterial diseases. For plant bacterial disease prevention and control scenarios, the copper-based nanozyme fungicide can be effectively deposited on the surface of crop leaves through stem and leaf spraying, destroying bacterial structures by generating highly toxic reactive oxygen species or activating catalase-like activity to cause bacterial oxidative damage. At the same time, bile salt-based biosurfactants can promote crop growth. The copper-based nanozyme fungicide residue in the soil does not affect seed germination.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] (1) The present invention provides a copper-based nanozyme bactericide, which is prepared by stirring one or more copper-containing compounds with one or more bile salt surfactants at room temperature, and obtains a system that is stably dispersed in an aqueous solution through self-assembly.

[0031] (2) The copper-based nanozyme fungicide prepared by the present invention has a small average particle size and can be well dispersed in water, and has a low surface tension, which can enable the droplets to effectively adhere to the surface of crop leaves, thereby achieving efficient dosage delivery.

[0032] (3) The copper-based nanozyme fungicide prepared by the present invention can simulate the activity of peroxidase and oxidase-like enzymes, destroy the bacterial structure by generating highly toxic reactive oxygen species, activate the activity of catalase-like enzymes to form bacterial oxidation losses, and effectively prevent and control plant bacterial diseases at lower concentrations.

[0033] (4) The copper-based nanozyme fungicide prepared by the present invention can promote crop growth, increase leaf chlorophyll content, and increase plant fresh weight after degradation of bile salt surfactants.

[0034] (5) The copper-based nanozyme fungicide prepared by the present invention does not affect subsequent seed germination after remaining in the soil, and has good environmental safety.

[0035] (6) The present invention comprehensively considers the prevention and control scenarios of plant bacterial diseases and proposes a simple and efficient method for preparing a copper-based nanozyme fungicide, which has the characteristics of stable physical and chemical properties, efficient dosage delivery, and environmental safety and friendliness. It achieves better prevention and control effects at lower concentrations, which is conducive to its promotion and use in farmland. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 The phase diagram of the self-assembly obtained after mixing sodium deoxycholate with copper chloride at different concentrations;

[0037] Figure 2 This is the microscopic morphology of the copper-based nanozyme fungicide;

[0038] Figure 3 Characterization of POD enzyme activity of copper-based nanozyme fungicides;

[0039] Figure 4 Fluorescence spectrometer was used to detect the production of ·OH by copper-based nanozyme bactericide;

[0040] Figure 5 Characterization of OXD enzyme activity of copper-based nanozyme fungicides;

[0041] Figure 6 The deposition process of copper-based nanozyme fungicide on the surface of rice leaves;

[0042] Figure 7 The deposition effect of copper-based nanozyme fungicide on the surface of rice leaves;

[0043] Figure 8 The antibacterial effect of copper-based nanozyme fungicide on bacterial blight pathogen;

[0044] Figure 9 The antibacterial effect of copper-based nanozyme fungicide on rice blast fungus;

[0045] Figure 10 The growth-promoting effect of copper-based nanozyme fungicide on rice plants;

[0046] Figure 11 Effects of copper-based nanozyme fungicides on the germination rate of rice seeds. DETAILED DESCRIPTION

[0047] In order to make the technical problems, technical solutions and advantages to be solved by the present invention clearer, a detailed description will be given below with reference to the accompanying drawings and specific embodiments.

[0048] The materials and reagents used in the following examples can all be obtained from commercial sources.

[0049] Example 1: Prepare 0.2mmol / L copper chloride solution and 20mmol / L sodium deoxycholate in 100ml volumetric flasks respectively, mix them in a round bottom flask at a volume ratio of 1:1, and stir mechanically at 100rpm for 30 minutes to form a self-assembled body. Figure 1 As shown, at this time the self-assembly is in the green area, in a sol state, has good stability, and exhibits a Tyndall effect, with a translucent appearance.

[0050] Example 2: 0.8 mmol / L copper chloride solution and 20 mmol / L sodium glycodeoxycholate were prepared in 100 ml volumetric flasks, respectively, and mixed in a round-bottom flask at a volume ratio of 1:1. The mixture was mechanically stirred at 100 rpm for 30 minutes to form a self-assembled sol state with good stability.

[0051] Example 3: 1.6 mmol / L copper chloride solution and 20 mmol / L sodium taurodeoxycholate were prepared in 100 ml volumetric flasks respectively, mixed in a round-bottom flask at a volume ratio of 1:1, and mechanically stirred at 100 rpm for 30 minutes to form a self-assembled sol state with good stability.

[0052] The physical and chemical properties of the prepared Examples 1-3 were tested, including micromorphology, particle size, Zeta potential, surface tension and viscosity. The relevant testing methods are as follows.

[0053] Microscopic morphology measurement: 10 μL of the copper-based nanozyme bactericide sol system of Example 1-3 was dropped onto a copper mesh. After natural drying, its appearance morphology was observed by transmission electron microscopy at a voltage of 80 kV.

[0054] Particle size determination: The particle size and distribution (PDI index) of Examples 1-3 were measured using a Malvern Nano ZS90 dynamic light scattering instrument at 25±0.1° C., and each sample was tested 5 times to obtain the average value.

[0055] Zeta potential measurement: The zeta potential of Examples 1-3 was measured using a Malvern Nano ZS90 dynamic light scattering instrument at 25±0.1° C., and each sample was tested 5 times to obtain the average value.

[0056] Determination of surface tension: The equilibrium surface tension of the sol was measured at 25±0.1°C using the hanging plate method and a DCAT21 surface tension meter. Each sample was tested 5 times and the average value was taken.

[0057] Viscosity determination: Shear viscosity was measured at 25±0.1°C using a DV2T viscometer at 100 rpm. Each sample was tested 5 times and the average value was taken.

[0058] As attached Figure 2As shown in the figure, the microscopic morphology of the copper-based nanozyme fungicide is a regular spherical or quasi-spherical structure with a particle size of less than 100 nm; at the same time, the surface of the spherical structure is smooth and there is no obvious agglomeration phenomenon, indicating that the system has good thermodynamic stability.

[0059] The particle size, PDI index, Zeta potential, surface tension and viscosity of Examples 1-3 are shown in Table 1.

[0060] Table 1 Rational properties of copper-based nanozyme fungicides

[0061]

[0062]

[0063] The particle size of copper-based nanozymes is in the range of 40-80 nm. Figure 2 Transmission electron microscopy revealed consistent particle size, indicating that the Brownian motion of the particles can resist the influence of gravity and achieve a kinetically stable state. The PDI index of the particle size distribution was less than 0.20, indicating low polydispersity and uniform particle size of the nanozyme particles, further reducing instability factors caused by Ostwald ripening. The zeta potential was less than -50 mV, indicating strong electrostatic repulsion between nanozyme particles, further reducing precipitation caused by agglomeration or flocculation. The surface tension was approximately 45 mN / m, indicating good surface activity, allowing for wetting, spreading, and deposition on the target surface. The viscosity was approximately 1 cP, comparable to that of water, facilitating atomization and spraying by spraying equipment during stem and leaf spraying.

[0064] The biomimetic enzyme activity of the nanozymes prepared in Examples 1-3 was tested, and the relevant test methods are as follows.

[0065] In the presence of H2O2, TMB was selected as a chromogenic substrate to assess POD-like activity. The absorbance spectra of the solutions were measured at wavelengths of 400-800 nm using a UV-visible spectrophotometer, and the changes in TMB absorbance after the addition of the copper-based nanozyme fungicide and varying concentrations of H2O2 were compared. A 5 mmol / L TPA solution was prepared in a 2 mmol / L NaOH solution. The copper-based nanozyme fungicide and H2O2 were mixed in a pH 6 acetate buffer and incubated for 12 hours at room temperature under visible light with gentle shaking.

[0066] Fluorescence spectra were measured using a fluorescence spectrometer with an excitation wavelength of 332 nm and an emission peak at 445 nm. Several free radicals were monitored using an ESR spectrometer, with DMPO selected as a scavenger. The characteristic peak intensity ratios of the ESR were observed to identify the characteristic peaks of free radical generation.

[0067] In the presence of H2O2, nanozymes catalyze the conversion of H2O2 into ·OH, and the generated ·OH further converts colorless TMB into blue oxidized TMB (TMBox), indicating that nanozymes can exhibit peroxidase-like catalytic activity. Figure 3 As shown in the figure, the maximum characteristic absorbance was observed at 652nm using a UV-visible absorption spectrophotometer. By comparing the changes in the absorbance of TMBox at 652nm, it was found that the absorbance intensity of TMBox increased with the increase of H2O2 concentration. This means that the peroxidase-like activity of the nanozyme is enhanced with the increase of H2O2 concentration. When TPA-Na reacts with OH, an obvious fluorescence peak appears at 445nm under the excitation of 322nm excitation light. Figure 4 The results of the fluorescence experiment of copper-based nanozymes based on TPA-Na to detect ·OH are shown. In the presence of H2O2, the fluorescence intensity of TPA-Na is significantly enhanced after the addition of copper-based nanozymes, and the fluorescence intensity increases with the increase of Cu ion concentration in the nanozymes. ESR spectroscopy further confirms that ·OH is produced during the reaction of copper-based nanozymes. As shown in the attached figure Figure 5 As shown in Figure 3, when DMPO is used as the capture agent, the characteristic peak intensity ratio of ESR is 1:2:2:1, which belongs to the characteristic peak generated by DMPO / ·OH, indicating that the nanozyme has OXD enzyme activity.

[0068] In order to compare and analyze the bactericidal performance of copper-based nanozymes with Examples 1-3, Comparative Examples 1-3 were prepared for control studies.

[0069] Comparative Example 1: Nano copper hydroxide fungicide purchased on the market was diluted with water to a copper ion concentration of 0.1 mmol / L, and compared with Example 1.

[0070] Comparative Example 2: Nano copper hydroxide fungicide purchased on the market was diluted with water to a copper ion concentration of 0.4 mmol / L, and compared with Example 2.

[0071] Comparative Example 3: Nano copper hydroxide fungicide purchased on the market was diluted with water to a copper ion concentration of 0.8 mmol / L, and compared with Example 3.

[0072] The contact angle and deposition process of the pesticide solutions of Examples 1-3 and Comparative Examples 1-3 on the surface of rice leaves were studied, and the relevant testing methods are as follows.

[0073] Contact angle: The static contact angle was measured at 25±0.1°C using the sessile drop method using an OCA 20 fully automatic optical contact angle meter. Each sample was tested five times and the average value was taken.

[0074] Deposition process: The dynamic deposition process of droplets on the surface of rice leaves was recorded using an i-SPEED 220 high-speed camera. Each experiment was repeated at least five times, and the video data was kinematically analyzed using i-SPEED Suite professional software. The microscopic morphology of the deposited pesticide solution was observed using a scanning electron microscope.

[0075] Table 2 shows the contact angles of Examples 1-3 and Comparative Examples 1-3 on the surface of rice leaves compared to water (surface tension of about 72 mN / m). The results show that the contact angle of water on the superhydrophobic rice leaf surface exceeds 150°. Examples 1-3 can reduce the contact angle by more than 20°, while the contact angles of Comparative Examples 1-3 are comparable to that of water, indicating that Examples 1-3 have good surface activity and are conducive to deposition on the surface of rice leaves. Figure 6 As shown, water and comparative example 2 could not be deposited on the surface of rice leaves, while examples 1-3 could all be deposited on the surface of rice leaves (as shown in the attached Figure 7 ), with better dose delivery efficiency.

[0076] Table 2 Contact angles of water, Examples 1-3 and Comparative Examples 1-3 on rice leaves

[0077]

[0078] The fungicidal performance of the pesticide solutions of Examples 1-3 and Comparative Examples 1-3 against bacterial disease bacterial blight and fungal disease rice blast was compared and the relevant test methods are as follows.

[0079] For bacterial bacterial blight, a copper-based fungicide was dissolved in NA medium and the pathogen suspension was evenly inoculated using a coating method. After incubation at 28°C in the dark for 3 days, the antibacterial activity was analyzed by observing the number of colonies and morphological changes. For the fungus Rice blast, the prepared nanozyme was dissolved in PDA medium and poured into a Petri dish. After solidification, a 7mm rice blast cake was inoculated in the center of the plate and incubated at 28°C in the dark for 10 days. The growth diameter of the cake was observed to calculate the inhibition rate and evaluate the antibacterial effect.

[0080] Table 3 shows the fungicidal performance of Examples 1-3 and Comparative Examples 1-3 against bacterial blight and rice blast. Compared with Comparative Examples 1-3, Examples 1-3 have better control effects on bacterial diseases such as bacterial blight, exceeding 90%. Figure 8 At the same time, because of their nanozyme activity, Examples 1-3 also have a certain control effect on the fungal disease rice blast, exceeding 80%, as shown in the attached Figure 9 shown.

[0081] Table 3 Bactericidal performance of Examples 1-3 and Comparative Examples 1-3 against bacterial blight and rice blast

[0082]

[0083]

[0084] Because copper-based nanozyme fungicides contain bile salt bio-based surfactants, which have the ability to promote crop growth, the fresh weight, dry weight, plant height, root length and total chlorophyll content of rice plants were measured. The relevant test methods are as follows.

[0085] Fresh and dry weight determination: Rice plants were sprayed with a copper-based fungicide and then incubated in an artificial climate incubator for 10 days. Light conditions were set to 16 hours during the day and 8 hours at night, and the temperature was set at 28°C during the day and 24°C at night. The fresh and dry weights of the entire rice plant were measured, and the average of five tests for each sample was used.

[0086] Determination of plant height and root length: Under the above conditions, the plant height and root length of rice plants cultured with different copper-based fungicides were measured, and each sample was tested 5 times and the average value was taken.

[0087] Determination of total chlorophyll content: Spectrophotometry was used to measure the absorbance at the maximum absorption wavelength (663 nm for chlorophyll a and 645 nm for chlorophyll b) and calculate the chlorophyll content.

[0088] As shown in Table 4, the presence of bile salt bio-based surfactants promotes the growth of rice plants. Figure 10 The growth-promoting effects of Examples 1-3 can be intuitively felt.

[0089] Table 4 Growth-promoting effects of Examples 1-3 and Comparative Examples 1-3 on rice plants

[0090]

[0091]

[0092] Currently, the effective utilization rate of pesticides is about 42% or more. It is inevitable that some pesticide liquid will be lost to the environment, causing ecological and environmental safety in farmland. The effects of Examples 1-3 and Comparative Examples 1-3 on seed germination in soil were compared to observe whether they are environmentally friendly. The relevant test methods are as follows.

[0093] Rice seeds were soaked in 70% ethanol for 2 minutes, then soaked in 5% sodium hypochlorite for 30 minutes, and finally rinsed several times with sterile water. Fifteen seeds were placed in three 9 cm Petri dishes. 5 mL of the fungicide solution from Examples 1-3 and Comparative Examples 1-3 was added to each dish. The Petri dishes containing the seeds were placed in an incubator and incubated in the dark. Germination was recorded after 3 days.

[0094] As attached Figure 11 As shown, Examples 1-3 can all make the seeds germinate, with a germination rate of 100%, and are environmentally friendly.

[0095] In summary, the present invention comprehensively considers the plant bacterial disease prevention and control scenarios, proposes a simple and efficient copper-based nanozyme fungicide preparation method, and has the characteristics of stable physical and chemical properties, efficient dosage delivery, and environmental safety and friendliness. It achieves better prevention and control effects at lower concentrations, which is conducive to its promotion and use in farmland, improving the effective utilization rate of pesticides while promoting the green and sustainable development of pesticides.

[0096] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A copper-based nanozyme bactericide, characterized in that: The copper-based nanozyme bactericide is formed by self-assembly of a copper-containing compound and a bile salt bio-based surfactant.

2. The copper-based nanozyme bactericide according to claim 1, characterized in that The copper-containing compound includes one or more of copper sulfate, copper chloride, and copper acetate; the bile salt bio-based surfactant includes one or more of sodium cholate, sodium deoxycholate, sodium glycocholate, sodium glycodeoxycholate, sodium taurocholate, and sodium taurodeoxycholate.

3. The method for preparing the copper-based nanozyme fungicide according to claim 1, characterized in that: The following steps are involved: (1) dissolving one or more water-soluble copper ion salts in deionized water and stirring to obtain a uniform dispersed solution; (2) dissolving one or more bile salt bio-based surfactants in deionized water and stirring to obtain a uniform dispersed solution; (3) Copper ion salt solutions of different concentrations are mixed with bile salt bio-based surfactant solutions, stirred, and then allowed to stand to obtain self-assembled bodies in different liquid states.

4. The method for preparing the copper-based nanozyme bactericide according to claim 3, characterized in that: The molar concentration of the water-soluble copper ion in step (1) is 0.05-100 mmol / L; the molar concentration of the bile salt bio-based surfactant in step (2) is 1-100 mmol / L; the stirring rate in steps (1)-(3) is 50-300 rpm, and the stirring time is 10-60 minutes; the self-assembly in different liquid states in step (3) includes a solution, a sol, a gel or a flocculent precipitate.

5. The method for preparing the copper-based nanozyme bactericide according to claim 4, characterized in that: The self-assembly of different liquid states is a sol.

6. The use of the copper-based nanozyme bactericide according to claim 1, characterized in that: Copper-based nanozyme fungicides are mainly used to prevent and control bacterial diseases in farmland, and can also prevent and control fungal diseases in farmland; at the same time, they can promote crop production and are environmentally safe and friendly.

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