Ternary metal hydrotalcite nano material and preparation method and application thereof

Abstract

The invention discloses a ternary metal hydrotalcite nano material as well as a preparation method and application thereof, and belongs to the field of nano materials. The preparation method disclosed by the invention comprises the following steps: (1) taking Fe (NO3) 3.9 H2O, Co (NO3) 2.6 H2O and (NH4) 6Mo7O24. 4H2O as metal sources, adding a solvent deionized water, adding a precipitator NaOH solution in a nitrogen atmosphere, and adjusting the pH value to 9.0-10.5 to obtain a reaction solution; and (2) stirring the reaction solution, carrying out a crystallization reaction, washing after the reaction is finished, and drying to obtain the ternary metal hydrotalcite nano material. The preparation method has the advantages of mild reaction conditions, cheap and easily available raw materials, simple preparation process and easy realization of industrial popularization. The prepared ternary metal hydrotalcite nano material is stable in structure and regular and controllable in morphology, and has relatively high peroxidase-like catalytic activity.

Description

Technical Field

[0001] The present invention relates to the field of nanomaterials, and in particular to a ternary metal hydrotalcite nanomaterial, a preparation method and an application thereof. Background Art

[0002] With the increasing problem of drug-resistant bacteria caused by overuse of antibiotics, the development of novel non-antibiotic antimicrobial materials has become a research hotspot. Nanoenzymes are nanomaterials with biocatalytic properties that mimic the catalytic activity of natural enzymes while offering increased stability and broader potential for application. Among these, peroxidase-like nanomaterials (such as CoFe-LDH) can catalyze the decomposition of H₂O₂ to produce ROS, which has a potent antibacterial effect on bacteria.

[0003] Mo has excellent redox properties and electron transfer capabilities, and doping with Mo can further enhance the catalytic activity and structural stability of hydrotalcite. Therefore, the construction of CoFeMo ternary synergistic LDH nanomaterials is expected to prepare an efficient and stable nanozyme antibacterial platform. Summary of the Invention

[0004] In view of the above shortcomings of the prior art, the purpose of the present invention is to provide a ternary metal hydrotalcite nanomaterial and its preparation method and application. The prepared ternary metal hydrotalcite nanomaterial has high peroxidase-like catalytic activity and antibacterial effect, which effectively solves the problems of the prior art.

[0005] In order to achieve the above purpose or other purposes, the present invention is implemented through the following technical solutions.

[0006] A method for preparing a ternary metal hydrotalcite nanomaterial comprises the following steps:

[0007] (1) Using Fe(NO3)3·9H2O, Co(NO3)2·6H2O and (NH4)6Mo7O 24 4H2O is used as a metal source, deionized water is added as a solvent, and a precipitant NaOH solution is added under a nitrogen atmosphere, and the pH is adjusted to 9.0-10.5 to obtain a reaction solution;

[0008] (2) After stirring the reaction solution, a crystallization reaction is carried out, and after the reaction is completed, the ternary metal hydrotalcite nanomaterial is obtained by washing and drying.

[0009] In one example of the present invention, Fe(NO3)3·9H2O, Co(NO3)2·6H2O, (NH4)6Mo7O 24 The molar ratio of 4H2O is based on the molar ratio of metal ions: Fe 3+ 、Co 2+ 、Mo 6+The molar ratio is (0.6~1.4):(5~30):(50~150).

[0010] In one embodiment of the present invention, a precipitant NaOH solution is added in step (1) to adjust the pH. Preferably, the concentration of the sodium hydroxide solution can be a conventional solubility, the purpose of which is to adjust the pH of the solution, including but not limited to: the concentration of the sodium hydroxide solution is 40 mg·mL-1.

[0011] In one example of the present invention, the amount of deionized water used in step (1) is the same as the mass of the deionized water used in step (1) and the amount of metal salts added (such as Fe(NO3)3·9H2O, Co(NO3)2·6H2O and (NH4)6Mo7O). 24 The total mass ratio of water to the solvent is (5-100):1. Within this range, the raw materials can be fully dissolved and a uniform reaction system can be formed. This avoids excessively high concentrations in certain areas of the solvent, which can lead to uneven precipitation, and excessively low concentrations in the reaction, which can affect the product crystal structure.

[0012] In one example of the present invention, the stirring time in step (2) is 0.2 h to 2 h, and the stirring temperature is 15° C. to 30° C.

[0013] In one example of the present invention, the crystallization reaction temperature in step (2) is 60° C. to 100° C., and the crystallization reaction time is 8 h to 36 h.

[0014] In one example of the present invention, after the reaction in step (2) is completed, washing is performed with deionized water and ethanol in sequence. During the washing process, deionized water and ethanol are used alternately for 2 to 5 times.

[0015] In one example of the present invention, the drying temperature in step (2) is 30°C to 120°C.

[0016] The present invention also protects a ternary metal hydrotalcite nanomaterial (abbreviated as CoFeMo-LDH material) prepared using the above-mentioned preparation method. The ternary metal hydrotalcite nanomaterial prepared by the present invention has a nanosheet structure with a size of 30nm to 100nm, a uniform structure, and a regular morphology. It has excellent peroxidase-like catalytic activity and can catalyze the decomposition of H2O2 under acidic conditions to produce hydroxyl radicals, thereby oxidizing TMB to produce a blue product, which can kill bacteria such as Staphylococcus aureus and Escherichia coli.

[0017] A third aspect of the present invention also discloses the application of the aforementioned ternary metal hydrotalcite nanomaterial in the antibacterial field. The ternary metal hydrotalcite nanomaterial can be applied to antibacterial treatments, including but not limited to: adjunctive treatment of infected wounds, antibacterial coatings on medical device surfaces, composite antibacterial systems with biomedical materials (such as hydrogels and wound dressings), and the preparation of antibacterial dressings or topical antibacterial carriers.

[0018] The preparation method disclosed in the present invention has mild reaction conditions, uses inexpensive and readily available raw materials, and has a simple preparation process, making it easy to industrialize and promote. The ternary metal hydrotalcite nanomaterial prepared using the method of the present invention not only has a stable structure and a regularly controllable morphology, but also has good dispersibility and processability. Due to the doping of the metals Mo, Fe, and Co, the synergistic effect of the three metals gives the hydrotalcite nanomaterial high peroxidase-like catalytic activity, capable of catalyzing peroxides to produce reactive oxygen free radicals under physiological conditions, achieving a broad-spectrum antibacterial effect without antibiotics. It has potential clinical application prospects, especially for combating drug-resistant bacterial infections, and has good application prospects in the antibacterial field. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is the powder X-ray diffraction spectrum of the ternary CoFeMo hydrotalcite nanomaterial prepared in Example 1 of the present invention.

[0020] Figure 2 This is the transmission electron microscope (TEM) spectrum of the ternary CoFeMo hydrotalcite nanomaterial prepared in Example 1 of the present invention.

[0021] Figure 3 This is a peroxidase-like activity test of the materials prepared in Examples 1-4 and Comparative Examples 1-4 of the present invention.

[0022] Figure 4 These are the antibacterial performance test results of the materials prepared in Examples 1-4 and Comparative Examples 1-4 of the present invention. DETAILED DESCRIPTION

[0023] The following describes the embodiments of the present invention through specific examples. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the following examples and the features in the examples can be combined with each other unless they conflict. It should also be understood that the terms used in the examples of the present invention are for the purpose of describing specific embodiments, not for the purpose of limiting the scope of protection of the present invention. The test methods for which specific conditions are not specified in the following examples are generally carried out under conventional conditions or under the conditions recommended by the manufacturers.

[0024] It should be noted that the terms such as "upper", "lower", "left", "right", "middle" and "one" cited in this specification are only for the convenience of description and are not used to limit the scope of implementation of the present invention. Changes or adjustments to their relative relationships should be regarded as the scope of implementation of the present invention without substantially changing the technical content.

[0025] The technical scheme of the present invention is described in detail below through several specific examples and comparative examples. Unless otherwise specified, the raw materials and reagents used in the following examples are commercially available or can be prepared by conventional methods in the art. Unless otherwise specified, the detection methods used in the examples of the present invention are conventional detection methods in the industry.

[0026] Example 1

[0027] Combine Fe(NO3)3·9H2O (0.05mmol), Co(NO3)2·6H2O (0.95mmol) and (NH4)6Mo7O 24 4H2O (0.714 mmol) was dissolved in deionized water (70 mL) as solution A; NaOH solution (40 mg mL -1 ) was added to Solution A until the pH reached 9.8. The mixture was then stirred at room temperature (30°C) for 0.5 h before being transferred to a reactor for crystallization at 80°C for 24 h. Finally, the CoFeMo-LDH nanosheets were washed with deionized water and anhydrous ethanol.

[0028] Example 2

[0029] Combine Fe(NO3)3·9H2O (0.05mmol), Co(NO3)2·6H2O (0.95mmol) and (NH4)6Mo7O 24 4H2O (0.357 mmol) was dissolved in deionized water (70 mL) as solution A. NaOH solution (40 mg mL⁻¹) was added to solution A under a nitrogen atmosphere until the pH reached 9.8. The mixture was then stirred at 20°C for 0.5 h before being transferred to a reactor and crystallized at 80°C for 24 h. Finally, CoFeMo-LDH nanosheets were obtained after washing with deionized water and anhydrous ethanol.

[0030] Example 3

[0031] Combine Fe(NO3)3·9H2O (0.05mmol), Co(NO3)2·6H2O (0.95mmol) and (NH4)6Mo7O 244H₂O (0.714 mmol) was dissolved in deionized water (70 mL) as solution A. Under a nitrogen atmosphere, NaOH solution (40 mg mL⁻¹) was added to solution A until the pH reached 9.8. The mixture was then stirred at room temperature for 0.5 h before being transferred to a reactor and crystallized at 100°C for 12 h. Finally, CoFeMo-LDH nanosheets were obtained after washing with deionized water and anhydrous ethanol.

[0032] Example 4

[0033] Combine Fe(NO3)3·9H2O (0.05mmol), Co(NO3)2·6H2O (0.95mmol) and (NH4)6Mo7O 24 4H2O (1.428 mmol) was dissolved in deionized water (70 mL) as solution A. NaOH solution (40 mg mL⁻¹) was added to solution A under a nitrogen atmosphere until the pH reached 9.8. The mixture was then stirred at room temperature for 0.5 h before being transferred to a reactor and crystallized at 80°C for 24 h. Finally, CoFeMo-LDH nanosheets were obtained after washing with deionized water and anhydrous ethanol.

[0034] Example 5

[0035] The method of this embodiment is different from that of embodiment 1 in that: Fe(NO3)3·9H2O, Co(NO3)2·6H2O, (NH4)6Mo7O 24 The molar ratio of 4H2O was 1:20:100, the crystallization reaction temperature was 100°C, and the crystallization reaction time was 8 h.

[0036] Example 6

[0037] The method of this embodiment is different from that of embodiment 1 in that: Fe(NO3)3·9H2O, Co(NO3)2·6H2O, (NH4)6Mo7O 24 The molar ratio of 4H2O was 1:50:200, the crystallization reaction temperature was 60°C, and the crystallization reaction time was 36 h.

[0038] Example 7

[0039] The method of this embodiment is different from that of embodiment 1 in that: Fe(NO3)3·9H2O, Co(NO3)2·6H2O, (NH4)6Mo7O 24 The molar ratio of 4H2O was 1:4:35, the crystallization reaction temperature was 60°C, and the crystallization reaction time was 36 h.

[0040] Comparative Example 1

[0041] (CoFe-LDH)

[0042] Fe(NO3)3·9H2O (0.05 mmol) and Co(NO3)2·6H2O (0.95 mmol) were dissolved in deionized water (70 mL) as solution A. NaOH solution (40 mg mL -1 ) was added to Solution A until the pH reached 9.8. The mixture was then stirred at room temperature for 0.5 h and transferred to a reactor for crystallization at 80°C for 24 h. Finally, the CoFe-LDH nanosheets were washed with deionized water and anhydrous ethanol.

[0043] Comparative Example 2

[0044] (CoMo-LDH)

[0045] Co(NO3)2·6H2O (0.95mmol), (NH4)6Mo7O 24 4H2O (0.714 mmol) was dissolved in deionized water (70 mL) as solution A. Under N2 atmosphere, NaOH solution (40 mg mL -1 ) was added to Solution A until the pH reached 9.8. The mixture was then stirred at room temperature for 0.5 h and transferred to a reactor for crystallization at 80°C for 24 h. Finally, the CoMo-LDH nanosheets were obtained after washing with deionized water and anhydrous ethanol.

[0046] Comparative Example 3

[0047] (FeMo-LDH)

[0048] Fe(NO3)3·9H2O (0.05mmol), (NH4)6Mo7O 24 4H2O (0.714 mmol) was dissolved in deionized water (70 mL) as solution A. Under N2 atmosphere, NaOH solution (40 mg mL -1 ) was added to Solution A until the pH reached 9.8. The mixture was then stirred at room temperature for 0.5 h and transferred to a reactor for crystallization at 80°C for 24 h. Finally, FeMo-LDH nanosheets were obtained after washing with deionized water and anhydrous ethanol.

[0049] Comparative Example 4

[0050] CoFeMo-LDH (calcined layered bimetallic oxide)

[0051] First, CoFeMo-LDH nanosheets were synthesized according to the method of Example 1. The dried sample was placed in a muffle furnace and calcined at 450° C. for 4 h in air atmosphere to obtain a structurally disintegrated layered bimetallic oxide CoFeMo-LDH material, which was labeled as Comparative Example 4.

[0052] Performance Testing

[0053] 1. Take the CoFeMo ternary hydrotalcite nanomaterial prepared in Example 1 and perform powder X-ray diffraction (XRD) detection. The detection results are as follows: Figure 1 As shown in the figure, it can be seen that its crystal structure is CoFeMo hydrotalcite.

[0054] 2. The CoFeMo ternary hydrotalcite nanomaterial prepared in Example 1 was tested by transmission electron microscopy (TEM). The test results are as follows: Figure 2 As shown in the figure, it can be seen that it is a flake structure with a size ranging from 30nm to 100nm.

[0055] 3. Take 20 μg of the materials prepared in Examples 1 to 4 and Comparative Examples 1 to 4, respectively, take 8 parts of 20 μL 40 mM 3,3',5,5'-tetramethylbenzidine (TMB), and add them sequentially to 1 mL of acetic acid-sodium acetate buffer with a pH of 3.6, add 10 μL of 1 M H2O2 solution to obtain 8 groups of systems with different nanomaterials added. After shaking for 1 minute, place them in a UV-visible spectrophotometer and detect their absorbance at a wavelength of 652 nm. The absorbance intensity reflects the peroxidase-like activity of the nanoenzyme material. This is because the peroxidase-like activity can decompose H2O2 to produce hydroxyl radicals, and the hydroxyl radicals react with TMB to produce a blue product with an absorption peak at 652 nm. Therefore, the enzyme activity can be indicated by observing the absorption peak intensity at 652 nm. The absorbances of the systems with the addition of the ternary metal hydrotalcite nanomaterials of Examples 1 to 4 were 1.31, 1.26, 1.20, and 1.22, respectively. The absorbances of the systems with the addition of the materials of Comparative Examples 1 to 4 were 0.34, 0.38, 0.32, and 0.14, respectively. The specific results are shown in FIG. Figure 3 As shown, from Figure 3 It can be seen that, compared with the comparative example, the examples of the present invention have better peroxidase-like activity.

[0056] 4. The antibacterial effect of ternary metal hydrotalcite nanomaterials was determined by plate count method. The specific method was as follows: 1.0 mL of pH buffer solution containing Gram-negative bacteria Escherichia coli was prepared with a pH value of 5.4, and the bacterial concentration was 10 6 8 portions of the above bacterial solution were taken, and 100 μg of the nanomaterials of Examples 1 to 4 and Comparative Examples 1 to 4 and 50 μL of H2O2 (concentration 1 mM) were added to the 8 portions of bacterial solution to prepare different bacterial solution samples. After shaking and standing for 30 minutes, the different bacterial solution samples were plated and counted in turn to obtain the bacterial concentration C after sterilization. Material sterilization efficiency = (1-C / 10 6)×100%. After calculation, the sterilization efficiencies of Examples 1 to 4 were 97%, 96%, 94%, and 92%, respectively, and the sterilization efficiencies of Comparative Examples 1 to 4 were 16%, 19%, 14%, and 7%, respectively. Figure 4 As shown, Figure 4 The statistical results of the sterilization efficiency of different materials are shown in FIG. 1 , which shows that the sterilization efficiency of Examples 1 to 4 is above 90%, while the sterilization efficiency of the comparative examples is below 10%.

[0057] In summary, it can be seen that the CoFeMo ternary hydrotalcite nanozyme of the present invention has peroxidase activity, can catalyze low concentrations of hydrogen peroxide to produce hydroxyl radicals, and has excellent bactericidal performance, with a bactericidal effect of more than 90%.

[0058] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Anyone skilled in the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by one of ordinary skill in the art without departing from the spirit and technical principles disclosed herein are intended to be covered by the claims of the present invention.

Claims

1. A method for preparing a ternary metal hydrotalcite nanomaterial, characterized in that: The following steps are involved: (1) Using Fe(NO3)3·9H2O, Co(NO3)2·6H2O and (NH4)6Mo7O 24 4H2O was used as a metal source, deionized water was added as a solvent, and the pH was adjusted to 9.0-10.5 under a nitrogen atmosphere to obtain a reaction solution; (2) After stirring the reaction solution, a crystallization reaction is carried out, and after the reaction is completed, the ternary metal hydrotalcite nanomaterial is obtained by washing and drying.

2. The preparation method according to claim 1, wherein Fe(NO3)3·9H2O, Co(NO3)2·6H2O, (NH4)6Mo7O 24 The molar ratio of 4H2O is based on the molar ratio of metal ions: Fe 3+ 、Co 2+ 、Mo 6+ The molar ratio is (0.6~1.4):(5~30):(50~150).

3. The preparation method according to claim 1, wherein In step (1), a precipitant NaOH solution is added to adjust the pH.

4. The preparation method according to claim 1, wherein The stirring time in step (2) is 0.2h to 2h, and the stirring temperature is 15°C to 30°C.

5. The preparation method according to claim 1, wherein In step (2), the crystallization reaction temperature is 60° C. to 100° C., and the crystallization reaction time is 8 h to 36 h.

6. Ternary metal hydrotalcite nanomaterial prepared by the preparation method according to any one of claims 1 to 5.

7. Use of the ternary metal hydrotalcite nanomaterial prepared by the preparation method according to any one of claims 1 to 5, or the ternary metal hydrotalcite nanomaterial according to claim 6 in the antibacterial field.

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