A copper-cobalt bimetallic nanoreactor for generating active nitrogen and a preparation method and application thereof

Abstract

The application discloses a copper-cobalt bimetallic nanoreactor for generating active nitrogen and a preparation method and application thereof, and relates to the technical field of nanomaterial synthesis. The application is characterized in that polyvinylpyrrolidone-coated CuO2 nanodots, hexadecyl trimethyl ammonium bromide, Co(NO3)2*6H2O and 2-methyl imidazole are reacted, and the active component CuO2 for self-supplying hydrogen peroxide is encapsulated in a metal-organic framework material ZIF-67 to obtain CuO2@ZIF-67; then the CuO2@ZIF-67 is mixed with an L-arginine solution to perform functional modification, and a Co(OH)2 dissociation layer is formed on the surface of the ZIF-67, so that the L-arginine is anchored on the surface of the ZIF-67, and finally, a copper-cobalt bimetallic nanoreactor for generating active nitrogen is prepared. The copper-cobalt bimetallic nanoreactor has the characteristics of self-supplying hydrogen peroxide, peroxidase and releasing nitric oxide, and can effectively realize efficient and controllable generation of active nitrogen species, i.e., peroxynitrite.

Description

Technical Field

[0001] This invention relates to the field of nanomaterial synthesis technology, and in particular to a copper-cobalt bimetallic nanoreactor for generating active nitrogen, its preparation method, and its application. Background Technology

[0002] Reactive nitrogen species (RNS), such as nitric oxide (NO·), nitrogen dioxide (NO2·), and nitrite peroxide (NO2·). - Nitrites, such as sodium peroxide (ONO), are a class of highly chemically reactive molecules that play important roles in many biological processes and environmental chemical reactions, particularly in cell signaling, immune responses, and environmental remediation. - Its oxidizing and nitrifying abilities are extremely strong, playing a dual role in physiological and pathological processes, making it a current research hotspot.

[0003] Nitrite peroxide (ONOO) - Nitrite peroxide has been confirmed to be generated by the reaction of nitric oxide and superoxide anion. Studies have shown that when nitric oxide and superoxide anion are spatially close, the rate at which they react to form nitrite peroxide even exceeds the ability of superoxide dismutase to decompose superoxide anion. Therefore, the key to the efficient synthesis of nitrite peroxide lies in the continuous supply of superoxide anion and the synergistic supply of nitric oxide and superoxide anion. Superoxide anion, as a key reactive oxygen species precursor, is chemically reactive and readily decomposes in physiological environments, especially under the action of natural superoxide dismutase, making it difficult to remain stable and accumulate to an effective concentration. Current technologies often utilize materials with oxidase-like properties to catalyze the generation of superoxide anion in situ from oxygen in the environment. However, the hypoxic environment of the tumor microenvironment severely limits the effectiveness of such materials. Therefore, how to prepare superoxide anion under hypoxic conditions is a prerequisite for ensuring the generation of nitrite peroxide.

[0004] In the prior art, CN115887750A discloses a polymer / CaO2@ZIF-67 scaffold. This material can decompose under weakly acidic conditions, releasing cobalt ions and exposing CaO2. The CaO2 then reacts with water under acidic conditions to generate hydrogen peroxide, thereby replenishing H2O2. Due to the Ca produced in the reaction... 2+ It lacks catalytic activity and cannot catalyze the generation of hydroxyl radicals from hydrogen peroxide. CN119385981A discloses a polydopamine-modified, copper peroxide-supported ZIF-8 nanomaterial. In a weakly acidic environment, the ZIF-8 nanomaterial degrades to release CuO2NPs. The CuO2NPs decompose in an acidic environment, producing H2O2 and Cu. 2+ Cu 2+It catalyzes the decomposition of H2O2, triggering a Fenton-like reaction and generating hydroxyl radicals. However, the combination of CuO2 and ZIF-8 can only prepare hydroxyl radicals, not superoxide anions.

[0005] Therefore, it is urgent to construct a material that simultaneously possesses high oxidase activity, sufficient hydrogen peroxide supply capacity, and nitric oxide supply capacity, so as to achieve the synchronous and continuous generation of nitric oxide and superoxide anions in an oxygen-deficient environment, thereby realizing the efficient synthesis of nitrite peroxide. Summary of the Invention

[0006] To address the aforementioned limitations of existing technologies, the present invention aims to provide a copper-cobalt bimetallic nanoreactor for generating active nitrogen. This invention involves reacting polyvinylpyrrolidone-coated CuO2 nanodots, hexadecyltrimethylammonium bromide, Co(NO3)2•6H2O, and 2-methylimidazole to encapsulate the self-supplying hydrogen peroxide active component CuO2 within a metal-organic framework material ZIF-67, yielding CuO2@ZIF-67. This CuO2 is then functionalized by mixing it with an L-arginine solution, forming a Co(OH)2 dissociation layer on the ZIF-67 surface, allowing L-arginine to anchor onto the ZIF-67 surface. This ultimately yields the copper-cobalt bimetallic nanoreactor CuO2@ZIF-67@L-Arg, which generates active nitrogen. The copper-cobalt bimetallic nanoreactor prepared by this invention simultaneously possesses the characteristics of self-supplying hydrogen peroxide, peroxidase-like properties, and nitric oxide release, effectively achieving the efficient and controllable generation of the active nitrogen species—nitrite peroxide.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] In a first aspect, the present invention provides a method for preparing a copper-cobalt bimetallic nanoreactor that generates active nitrogen, comprising the following steps:

[0009] (1) Polyvinylpyrrolidone was added to CuCl2•2H2O solution, and then sodium hydroxide solution and hydrogen peroxide solution were added to react. After the reaction, the mixture was centrifuged, washed and dried to obtain CuO2 nanodots coated with polyvinylpyrrolidone.

[0010] The ratio of polyvinylpyrrolidone, CuCl2•2H2O solution, sodium hydroxide solution and hydrogen peroxide solution is 1g:(8-12)mL:(8-12)mL:(150-250)μL;

[0011] (2) Add the polyvinylpyrrolidone-coated CuO2 nanodots to methanol to obtain a polyvinylpyrrolidone-coated CuO2 solution; add hexadecyltrimethylammonium bromide and Co(NO3)2•6H2O to the polyvinylpyrrolidone-coated CuO2 solution, and then add a methanol solution containing 2-methylimidazole to react. After the reaction is completed, filter and collect the solid, wash and dry it to obtain CuO2@ZIF-67.

[0012] The amounts of polyvinylpyrrolidone-coated CuO2 nanodots, hexadecyltrimethylammonium bromide, Co(NO3)2•6H2O, and methanol solution containing 2-methylimidazole were (15-25) mg: (8-12) mg: (115-120) mg: (25-30) mL.

[0013] (3) Disperse CuO2@ZIF-67 in ethanol to obtain CuO2@ZIF-67 solution; mix CuO2@ZIF-67 solution and L-arginine solution and react them. After the reaction, centrifuge to obtain copper-cobalt bimetallic nanoreactor that generates active nitrogen, denoted as CuO2@ZIF-67@L-Arg.

[0014] Preferably, in step (1), the concentration of CuCl2•2H2O solution is 0.005-0.015 mol / L, the concentration of sodium hydroxide solution is 0.015-0.025 mol / L, and the mass percentage of hydrogen peroxide solution is 25%-35%.

[0015] Preferably, in step (1), the reaction time is 25-35 min.

[0016] Preferably, in step (2), the ratio of CuO2 nanodots coated with polyvinylpyrrolidone to methanol is (15-25) mg: 4 mL.

[0017] Preferably, in step (2), the methanol solution containing 2-methylimidazole is prepared by mixing 2-methylimidazole and methanol at a ratio of (1.8-1.9) g: (25-30) mL.

[0018] Preferably, in step (2), the reaction time is 25-35 min.

[0019] As a preferred option, in step (2), the specific washing operation is as follows: wash the filtered solid with methanol 3-5 times.

[0020] Preferably, in step (3), the ratio of CuO2@ZIF-67 to ethanol is (45-55) mg: 10 mL.

[0021] Preferably, in step (3), the L-arginine solution is prepared by mixing L-arginine and deionized water at a ratio of (450-550) mg: 10 mL.

[0022] Preferably, in step (3), the mass ratio of CuO2@ZIF-67 to L-arginine in the L-arginine solution is 1:(8-12).

[0023] Preferably, in step (3), the reaction time is 20-30 h.

[0024] In a second aspect, the present invention provides a copper-cobalt bimetallic nanoreactor that generates active nitrogen, prepared by the above-described preparation method.

[0025] A third aspect of the present invention provides the application of the above-described copper-cobalt bimetallic nanoreactor for generating active nitrogen in the production of nitrite peroxide.

[0026] The beneficial effects of this invention are:

[0027] 1. This invention involves reacting polyvinylpyrrolidone-coated CuO2 nanodots, hexadecyltrimethylammonium bromide, Co(NO3)2•6H2O, and 2-methylimidazole to encapsulate the self-supplying hydrogen peroxide active component CuO2 inside a metal-organic framework material ZIF-67, resulting in CuO2@ZIF-67. Then, it is mixed with an L-arginine solution for functionalization, forming a Co(OH)2 dissociation layer on the ZIF-67 surface, allowing L-arginine to be anchored there. Finally, a copper-cobalt bimetallic nanoreactor, CuO2@ZIF-67@L-Arg, is obtained that generates active nitrogen.

[0028] This invention utilizes ZIF-67 encapsulation of CuO2 and L-arginine surface modification to prepare a copper-cobalt bimetallic nanoreactor that simultaneously possesses the characteristics of self-supplying hydrogen peroxide, peroxidase-like enzymes, and releasing nitric oxide. This effectively realizes the production of the active nitrogen species—nitrite peroxide (ONOO). - The efficient and controllable generation of ZIF-67-encapsulated CuO2 and L-arginine surface modification can be carried out at room temperature. The synthesis process is simple and the conditions are mild, which is conducive to large-scale preparation.

[0029] 2. Due to the drawback of slow decomposition of CuO2 in water, this invention encapsulates CuO2 nanodots coated with polyvinylpyrrolidone (PVP) as a hydrogen peroxide donor within ZIF-67. This avoids the slow decomposition of CuO2 during synthesis, ensuring the stability of the precursor. Simultaneously, the Co in the ZIF-67 framework... 2+ It has peroxidase-like activity and can promote the generation of reactive oxygen species—hydroxyl radicals. Attached Figure Description

[0030] Figure 1 Transmission electron microscope (TEM) images of the products obtained in steps (1)-(3) of Example 1, wherein a is a TEM image of CuO2 nanodots coated with polyvinylpyrrolidone; b is a TEM image of CuO2@ZIF-67; c is a TEM image of CuO2@ZIF-67@L-Arg copper-cobalt bimetallic nanoreactor that generates active nitrogen.

[0031] Figure 2 Line scan data of CuO2@ZIF-67@L-Arg prepared in Example 1 using transmission electron microscopy;

[0032] Figure 3 XRD patterns of polyvinylpyrrolidone-coated CuO2 nanodots, CuO2@ZIF-67, and CuO2@ZIF-67@L-Arg prepared in Example 1;

[0033] Figure 4 Thermogravimetric curves of CuO2@ZIF-67 and CuO2@ZIF-67@L-Arg obtained in Example 1;

[0034] Figure 5 UV-Vis absorption spectra of CuO2@ZIF-67 prepared in Example 1 with and without hydrogen peroxide and TMB colorimetric solution;

[0035] Figure 6 Example 1 shows the ESR spectrum of CuO2@ZIF-67 capturing reactive oxygen species; where a is the ESR spectrum of CuO2@ZIF-67 capturing hydroxyl radicals; b is the ESR spectrum of CuO2@ZIF-67 capturing superoxide anions.

[0036] Figure 7 ESR spectrum of CuO2@ZIF-67@L-Arg obtained in Example 1;

[0037] Figure 8 Fluorescence spectra of active nitrogen species detected in CuO2@ZIF-67 and CuO2@ZIF-67@L-Arg, ZIF-67 prepared in Example 1 and materials prepared in Comparative Examples 1-2. Detailed Implementation

[0038] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0039] Existing technologies disclose the combination of peroxides (such as CaO2, CuO2, ZnO2, etc.) with other supports to supplement hydrogen peroxide. However, these studies only focus on generating hydroxyl radicals from hydrogen peroxide by reacting metal ions capable of undergoing Fenton / Fenton-like reactions. Hydroxyl radicals, however, cannot satisfy the reactive nitrogen—peroxynitroso (ONOO) group. - The synthesis requirements of ).

[0040] Based on this, the present invention provides a copper-cobalt bimetallic nanoreactor, which is prepared by reacting polyvinylpyrrolidone-coated CuO2 nanodots, 2-methylimidazole and cobalt nitrate as raw materials to obtain CuO2@ZIF-67, thereby encapsulating the polyvinylpyrrolidone-coated CuO2 inside the ZIF-67 carrier; then, CuO2@ZIF-67 is mixed with L-arginine and reacted to anchor L-arginine on the surface of ZIF-67, thus obtaining the copper-cobalt bimetallic nanoreactor.

[0041] The copper-cobalt bimetallic nanoreactor prepared in this invention rapidly dissociates ZIF-67 to release Co in a slightly acidic environment. 2+ And CuO2, then CuO2 decomposes into Cu 2+ and H2O2, metal ions (Co) 2+ and Cu 2+ ) Catalyzes the generation of hydroxyl radicals from H2O2, in Co 2+ and Cu 2+ Under the dual catalytic action, sufficient hydroxyl radicals are generated. This invention utilizes sufficient hydroxyl radicals and hydrogen peroxide to disrupt the dynamic equilibrium between hydroxyl radicals and superoxide anions, and then generates superoxide anions via the Haber-Weiss reaction. Simultaneously, L-arginine can decompose to produce nitric oxide under reactive oxygen species conditions; the specific reaction process is: L-Arg + H₂O₂ + H₂O + →L-Citrulline + NO + H2O, where the final nitrogen oxide and superoxide anion rapidly combine to produce nitrite peroxide.

[0042] Since a sufficient supply of hydroxyl radicals is crucial for the generation of superoxide anions, the applicant conducted extensive research and screening on the selection of peroxides and zeolite imidazole frameworks, ultimately choosing ZIF-67 and CuO2. CuO2@ZIF-67 was prepared using these two components to ensure a continuous supply of superoxide anions, thus generating ONOO. - The generation provides sufficient reaction substrates.

[0043] Regarding the selection of peroxides, existing technologies disclose the use of peroxides such as CaO2, CuO2, and ZnO2. While CaO2 and ZnO2 also possess the ability to self-supply hydrogen peroxide, the metal ions generated from their decomposition cannot catalyze the production of hydroxyl radicals from hydrogen peroxide. Regarding the selection of the zeolite imidazole framework, existing technologies disclose the preparation of composite materials by combining ZIF-8 with CuO2. Since the metal nodes of ZIF-8 are Zn... 2+ The ZIF-67 metal node used in this application is Co. 2 + Co 2+ It can undergo a Fenton-like reaction with hydrogen peroxide to produce hydroxyl radicals, while Zn 2+ It does not possess this effect. Furthermore, this invention uses ZIF-67 as a carrier, utilizing its metal nodes Co... 2+ The catalytic effect of Cu 2+ The catalysis ensures the generation of sufficient hydroxyl radicals, thereby breaking the dynamic balance between the conversion of hydroxyl radicals and superoxide anions to generate superoxide anions.

[0044] To enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention will be described in detail below with reference to specific embodiments.

[0045] The experimental materials used in the embodiments of this invention are all conventional experimental materials in the art and can be purchased through commercial channels.

[0046] Example 1: Preparation of a copper-cobalt bimetallic nanoreactor for generating active nitrogen

[0047] (1) Add 1g of polyvinylpyrrolidone to 10mL of CuCl2•2H2O solution with a concentration of 0.01mol / L and mix well. Then add 10mL of sodium hydroxide solution with a concentration of 0.02mol / L and 200μL of hydrogen peroxide solution with a mass fraction of 30%. Stir for 30min to carry out the reaction. After the reaction, centrifuge and collect the solid after centrifugation. Wash with deionized water 3 times and freeze dry to obtain CuO2 nanodots coated with polyvinylpyrrolidone.

[0048] (2) After mixing 1.816g of 2-methylimidazole with methanol, 28mL of methanol solution containing 2-methylimidazole was obtained;

[0049] 20 mg of polyvinylpyrrolidone-coated CuO2 nanodots were added to 4 mL of methanol and mixed well to obtain a polyvinylpyrrolidone-coated CuO2 solution. 10 mg of hexadecyltrimethylammonium bromide and 116 mg of Co(NO3)2•6H2O were added to the polyvinylpyrrolidone-coated CuO2 solution, followed by 28 mL of methanol solution containing 2-methylimidazole. The mixture was stirred at room temperature for 30 min to carry out the reaction. After the reaction was completed, the purplish-black solid was collected by centrifugation, washed three times with methanol, and then freeze-dried to obtain CuO2@ZIF-67, denoted as CZ.

[0050] (3) Dissolve 50 mg CuO2@ZIF-67 in 10 mL of ethanol to obtain CuO2@ZIF-67 solution; mix 500 mg L-arginine and 10 mL of deionized water to obtain L-arginine solution; mix CuO2@ZIF-67 solution and L-arginine solution and stir for 24 h to react. After reaction, centrifuge to obtain CuO2@ZIF-67@L-Arg copper-cobalt bimetallic nanoreactor that generates active nitrogen, denoted as CZA.

[0051] Example 2: Preparation of a copper-cobalt bimetallic nanoreactor for generating active nitrogen

[0052] (1) Add 1g of polyvinylpyrrolidone to 8mL of CuCl2•2H2O solution with a concentration of 0.005mol / L and mix well. Then add 8mL of sodium hydroxide solution with a concentration of 0.015mol / L and 150μL of hydrogen peroxide solution with a mass fraction of 25%. Stir for 25min to carry out the reaction. After the reaction, centrifuge and collect the solid after centrifugation. Wash with deionized water 3 times and freeze dry to obtain CuO2 nanodots coated with polyvinylpyrrolidone.

[0053] (2) After mixing 1.8g of 2-methylimidazole with methanol, 25mL of methanol solution containing 2-methylimidazole was obtained;

[0054] 15 mg of polyvinylpyrrolidone-coated CuO2 nanodots were added to 4 mL of methanol and mixed to obtain a polyvinylpyrrolidone-coated CuO2 solution. 8 mg of hexadecyltrimethylammonium bromide and 115 mg of Co(NO3)2•6H2O were added to the polyvinylpyrrolidone-coated CuO2 solution, followed by 25 mL of methanol solution containing 2-methylimidazole. The mixture was stirred at room temperature for 25 min to carry out the reaction. After the reaction was completed, the purplish-black solid was collected by centrifugation, washed four times with methanol, and then freeze-dried to obtain CuO2@ZIF-67.

[0055] (3) Dissolve 45mg CuO2@ZIF-67 in 10mL of ethanol to obtain CuO2@ZIF-67 solution; mix 450mg L-arginine with 10mL of deionized water to obtain L-arginine solution; mix CuO2@ZIF-67 solution and L-arginine solution and stir for 20h to react. After reaction, centrifuge to obtain copper-cobalt bimetallic nanoreactor that generates active nitrogen, denoted as CuO2@ZIF-67@L-Arg.

[0056] Example 3: Preparation of a copper-cobalt bimetallic nanoreactor for generating active nitrogen

[0057] (1) Add 1g of polyvinylpyrrolidone to 12mL of CuCl2•2H2O solution with a concentration of 0.015mol / L and mix well. Then add 12mL of sodium hydroxide solution with a concentration of 0.025mol / L and 250μL of hydrogen peroxide solution with a mass fraction of 35%. Stir for 35min to carry out the reaction. After the reaction, centrifuge and collect the solid after centrifugation. Wash with deionized water 3 times and freeze dry to obtain CuO2 nanodots coated with polyvinylpyrrolidone.

[0058] (2) After mixing 1.9g of 2-methylimidazole with methanol, 30mL of methanol solution containing 2-methylimidazole was obtained;

[0059] 25 mg of polyvinylpyrrolidone-coated CuO2 nanodots were added to 4 mL of methanol and mixed to obtain a polyvinylpyrrolidone-coated CuO2 solution. 12 mg of hexadecyltrimethylammonium bromide and 120 mg of Co(NO3)2•6H2O were added to the polyvinylpyrrolidone-coated CuO2 solution, followed by 30 mL of a methanol solution containing 2-methylimidazole. The mixture was stirred at room temperature for 35 min to carry out the reaction. After the reaction was completed, the purplish-black solid was collected by centrifugation, washed five times with methanol, and then freeze-dried to obtain CuO2@ZIF-67.

[0060] (3) Dissolve 55mg CuO2@ZIF-67 in 10mL of ethanol to obtain CuO2@ZIF-67 solution; mix 550mg L-arginine with 10mL of deionized water to obtain L-arginine solution; mix CuO2@ZIF-67 solution and L-arginine solution and stir for 30h to react. After reaction, centrifuge to obtain copper-cobalt bimetallic nanoreactor that generates active nitrogen, denoted as CuO2@ZIF-67@L-Arg.

[0061] Comparative Example 1:

[0062] The difference between this comparative example and Example 1 is that the metal-organic framework material is ZIF-8. The specific steps are as follows:

[0063] Polyvinylpyrrolidone-coated CuO2 nanodots were prepared according to the method in Example 1. 20 mg of polyvinylpyrrolidone-coated CuO2 nanodots were added to 4 mL of methanol and mixed well to obtain a polyvinylpyrrolidone-coated CuO2 solution. 116 mg of Zn(NO3)2•6H2O was added to the polyvinylpyrrolidone-coated CuO2 solution, followed by 28 mL of methanol solution containing 2-methylimidazole. The mixture was stirred at room temperature for 30 min to carry out the reaction. After the reaction was completed, the solid was collected by centrifugation, washed three times with methanol, and then freeze-dried to obtain CuO2@ZIF-8.

[0064] (3) Dissolve 50 mg CuO2@ZIF-8 in 10 mL of ethanol to obtain CuO2@ZIF-8 solution; mix 500 mg L-arginine with 10 mL of deionized water to obtain L-arginine solution; mix CuO2@ZIF-8 solution and L-arginine solution and stir for 24 h to react. After reaction, centrifuge to obtain copper-zinc bimetallic nanoreactor that generates active nitrogen, denoted as CuO2@ZIF-8@L-Arg.

[0065] Comparative Example 2:

[0066] The difference between this comparative example and Example 1 is that the ZIF-67 and CuO2 nanodots are physically mixed. The specific preparation method is as follows:

[0067] Polyvinylpyrrolidone-coated CuO2 nanodots, a 2-methylimidazolium solution, and an L-arginine solution were prepared according to the method in Example 1.

[0068] 20 mg of polyvinylpyrrolidone-coated CuO2 nanodots were added to 4 mL of methanol and mixed well to obtain a polyvinylpyrrolidone-coated CuO2 solution. 10 mg of hexadecyltrimethylammonium bromide and 116 mg of Co(NO3)2•6H2O were added, followed by 28 mL of methanol solution containing 2-methylimidazole. The mixture was stirred at room temperature for 30 min to carry out the reaction. After the reaction was completed, the solid was collected by centrifugation, washed three times with methanol, and then freeze-dried to obtain ZIF-67.

[0069] The ZIF-67 was added to the polyvinylpyrrolidone-coated CuO2 nanodot solution and mixed evenly to obtain a CuO2 / ZIF-67 composite solution. The CuO2 / ZIF-67 solution and L-arginine solution were mixed and stirred for 24 hours to react. After the reaction, the mixture was centrifuged to obtain a copper-cobalt bimetallic nanoreactor, denoted as CuO2 / ZIF-67@L-Arg.

[0070] Experimental Example 1: Structural Characterization

[0071] 1. Transmission electron microscopy analysis was performed on the polyvinylpyrrolidone-coated CuO2 nanodots, CuO2@ZIF-67, and the copper-cobalt bimetallic nanoreactor CuO2@ZIF-67@L-Arg that generates active nitrogen prepared in Example 1. The results are as follows: Figure 1 As shown.

[0072] Depend on Figure 1 As can be seen from 'a', the obtained polyvinylpyrrolidone-coated CuO2 nanodots exhibit a nanodot size of 2-10 nm. Figure 1 As can be seen from b, the prepared CuO2@ZIF-67 exhibits the dodecahedral morphology of ZIF-67, with a size of approximately 200 nm. Figure 1 As can be seen from c, the copper-cobalt bimetallic nanoreactor CuO2@ZIF-67@L-Arg that generates active nitrogen has a layer of flocculent material wrapped on its surface compared to CuO2@ZIF-67. This is because the rich amino and guanidine groups in L-Arg cause the surface of ZIF-67 to dissociate, forming a Co(OH)2 dissociation layer, which anchors L-Arg to its surface.

[0073] 2. Transmission electron microscopy analysis was performed on the copper-cobalt bimetallic nanoreactor CuO2@ZIF-67@L-Arg prepared in Example 1, which generates active nitrogen. The results are as follows: Figure 2 As shown.

[0074] Depend on Figure 2 It can be seen that the product contains Cu, Co, C, N and O elements, indicating that the copper-cobalt bimetallic nanoreactor includes two components: CuO2 and ZIF-67.

[0075] 3. XRD analysis was performed on the polyvinylpyrrolidone-coated CuO2 nanodots, CuO2@ZIF-67, and the copper-cobalt bimetallic nanoreactor CuO2@ZIF-67@L-Arg that generates active nitrogen prepared in Example 1. The results are as follows: Figure 3 As shown.

[0076] Due to the amorphous structure of CuO2 nanodots, no obvious diffraction peaks were observed in the spectrum, while CuO2@ZIF-67 exhibited the standard curve of ZIF-67, indicating the presence of the ZIF-67 framework within CuO2@ZIF-67. Finally, the diffraction peaks of CuO2@ZIF-67@L-Arg in the spectrum show that its main structure is still ZIF-67. However, diffraction peaks not belonging to ZIF-67 were found at 19.1°, 32.5°, 37.9°, and 38.7°, which are attributed to Co(OH)2. This demonstrates that a Co(OH)2 dissociation layer appeared on the ZIF-67 surface due to the effect of L-arginine, providing strong evidence for the successful loading of L-arginine.

[0077] 4. Thermogravimetric analysis was performed on the CuO2@ZIF-67 nanoreactor prepared in Example 1 and the CuO2@ZIF-67@L-Arg nanoreactor that generates active nitrogen. The results are as follows: Figure 4 As shown.

[0078] Depend on Figure 4 It can be seen that CuO2@ZIF-67@L-Arg has a significant weight loss compared to CuO2@ZIF-67, which is due to the decomposition of L-Arg, indicating that L-Arg was successfully added to the surface of CuO2@ZIF-67.

[0079] Experimental Example 2:

[0080] 1. The CuO2@ZIF-67 prepared in Example 1 was mixed with TMB colorimetric solution under conditions with and without hydrogen peroxide, and ultraviolet spectral analysis was performed. The results are as follows: Figure 5 As shown. The specific steps are as follows:

[0081] The CuO2@ZIF-67 obtained in step (2) of Example 1 was mixed with water to prepare CuO2@ZIF-67 solutions with concentrations of 50 μg / mL, 10 μg / mL, 150 μg / mL, 200 μg / mL, 400 μg / mL, 500 μg / mL and 1000 μg / mL respectively.

[0082] Under hydrogen peroxide conditions: 3 mL of CuO2@ZIF-67 solutions of different concentrations, 200 μL of 10% hydrogen peroxide solution, and 200 μL of 6 mg / mL TMB colorimetric solution were mixed and reacted for 5 min. After the reaction, the mixture was centrifuged, and the supernatant was collected for UV spectroscopy analysis. Under hydrogen peroxide-free conditions: 3 mL of CuO2@ZIF-67 solutions of different concentrations and 200 μL of 6 mg / mL TMB colorimetric solution were mixed and reacted for 5 min. After the reaction, the mixture was centrifuged, and the supernatant was collected for UV spectroscopy analysis.

[0083] TMB chromogenic solution is an indicator for detecting reactive oxygen species. Oxidized TMB exhibits a characteristic UV absorption peak at 652 nm. Figure 5It can be seen that even without the introduction of exogenous hydrogen peroxide, a very obvious absorption peak appears at 652 nm. This indicates that CuO2@ZIF-67 can generate reactive oxygen species by virtue of its own hydrogen peroxide supply capacity and peroxidase-like properties, which provides a basis for the production of nitric oxide through the L-Arg reaction. Furthermore, the absorption peak at 652 nm is further enhanced after the introduction of exogenous hydrogen peroxide, indicating that CuO2@ZIF-67 has an excellent ability to generate reactive oxygen species in certain special environments, such as tumor microenvironments with overexpressed hydrogen peroxide and microenvironments of bacterially infected tissues. This also provides a valuable reference for the application of reactive nitrogen species in disease treatment.

[0084] 2. ESR analysis was performed on CuO2@ZIF-67 prepared in Example 1 and the copper-cobalt bimetallic nanoreactor CuO2@ZIF-67@L-Arg that generates active nitrogen.

[0085] Specifically, 5,5-dimethyl-1-pyrrolidone-N-oxide (DMPO) was used as a probe to detect the types of reactive oxygen species generated by CuO2@ZIF-67, and 3-oxo-2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxo (PTIO) was used as a probe to detect nitric oxide generated by CuO2@ZIF-67@L-Arg. The specific steps are as follows:

[0086] (1) Detection of reactive oxygen species:

[0087] CuO2@ZIF-67 was mixed with methanol to obtain a CuO2@ZIF-67 methanol solution with a concentration of 200 μg / mL, which was used for subsequent detection of superoxide anions; CuO2@ZIF-67 was mixed with water to obtain a CuO2@ZIF-67 aqueous solution with a concentration of 200 μg / mL, which was used for subsequent detection of hydroxyl radicals.

[0088] 3 mL of CuO2@ZIF-67 methanol solution and CuO2@ZIF-67 aqueous solution were placed in centrifuge tubes, respectively. 200 μL of 10% hydrogen peroxide and 50 μL of DMPO (10 mM) were added, and the mixture was shaken for 5 min to obtain a mixed solution. The ESR spectrum of the mixed solution was detected by an electron paramagnetic resonance (ESR) spectrometer (Bruker ESR 5000, Germany), and the results are shown in Figure 6.

[0089] (2) Detection of reactive nitrogen:

[0090] A CuO2@ZIF-67@L-Arg solution with a concentration of 200 μg / mL was prepared by mixing CuO2@ZIF-67@L-Arg with water. 3 mL of the CuO2@ZIF-67@L-Arg solution was placed in a centrifuge tube, and 200 μL of 10% hydrogen peroxide and 1 mL of PTIO (10 mM) were added. After shaking for five minutes, the ESR spectrum of the mixed solution was detected using an electron paramagnetic resonance (ESR) spectrometer (Bruker ESR 5000, Germany). The results are as follows: Figure 7 As shown.

[0091] Depend on Figure 6 As can be seen from Figure a, using deionized water as a solvent, a signal peak with a ratio of 1:2:2:1 was successfully detected under slightly acidic conditions. This signal belongs to hydroxyl radicals, confirming the self-supplying hydrogen peroxide and peroxidase-like properties of CuO2@ZIF-67. Furthermore, it was determined that CuO2@ZIF-67 can generate hydroxyl radicals under slightly acidic conditions. On the other hand, since CuO2@ZIF-67 can generate hydrogen peroxide and hydroxyl radicals, it can produce superoxide anions through the Haber-Weiss reaction. Figure 6 In step b, methanol was used as the solvent, and the signal peak was attributed to the superoxide anion, verifying the conclusion that CuO2@ZIF-67 can generate superoxide anions. This lays the foundation for the generation of peroxide nitrite—a product of the combination of nitric oxide and superoxide anions.

[0092] PTIO itself exhibits a signal peak ratio of 1:2:3:2:1 in the ESR spectrum. After capturing nitric oxide, the peak value decreases. Figure 7 In the study, it was observed that after the addition of CuO2@ZIF-67@L-Arg, the PTIO signal showed a significant downward trend, indicating that the reactive oxygen species generated by CuO2@ZIF-67 can catalyze the production of nitric oxide from L-arginine.

[0093] Experimental Example 3:

[0094] Since L-tyrosine probes react with ONOO− to form tyrosine in a weakly alkaline environment of carbon dioxide, L-tyrosine probes are used to detect nitrite peroxide (ONOO−). - The generation of.

[0095] The test samples were: ZIF-67, CuO2@ZIF-67 prepared in step (2) of Example 1, CuO2@ZIF-67@L-Arg prepared in Example 1, CuO2@ZIF-8@L-Arg prepared in Comparative Example 1, and CuO2 / ZIF-67@L-Arg prepared in Comparative Example 2. The above test samples were mixed with deionized water to prepare a test sample solution with a concentration of 200 μg / mL.

[0096] The specific steps are as follows: Mix 10 mL of PBS solution containing sodium bicarbonate (150 mM) and L-tyrosine (0.5 mM), then add 3 mL of the sample solution to each mixture. Measure the fluorescence emission using a fluorescence spectrometer (excitation wavelength: 313 nm, emission wavelength: 406 nm). The results are as follows: Figure 8 As shown. The release of nitrite peroxide was qualitatively analyzed by observing the emission intensity at 406 nm. Figure 8 As can be seen, no emission peaks were observed in ZIF-67, CuO2@ZIF-67, or CuO2@ZIF-8@L-Arg (Comparative Example 1). However, CuO2 / ZIF-67@L-Arg and CuO2@ZIF-67@L-Arg showed a distinct peak at 406 nm, confirming the presence of nitrite peroxide. However, the peak value of the former was significantly lower than that of the latter, indicating that ZIF-67 has a significant protective effect on CuO2 and can store more CuO2. As a type of reactive nitrogen species, nitrite peroxide possesses stronger activity than nitric oxide, which suggests that CuO2@ZIF-67@L-Arg has broad development prospects in the fields of environmental chemistry and biomedicine.

[0097] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. The application of a copper-cobalt bimetallic nanoreactor in the generation of nitrite peroxide, characterized in that, The copper-cobalt bimetallic nanoreactor was prepared by the following method: (1) Polyvinylpyrrolidone was added to CuCl2•2H2O solution, and then sodium hydroxide solution and hydrogen peroxide solution were added to react. After the reaction, the mixture was centrifuged, washed and dried to obtain CuO2 nanodots coated with polyvinylpyrrolidone. The ratio of polyvinylpyrrolidone, CuCl2•2H2O solution, sodium hydroxide solution and hydrogen peroxide solution is 1g:(8-12)mL:(8-12)mL:(150-250)μL; (2) Add the polyvinylpyrrolidone-coated CuO2 nanodots to methanol to obtain a polyvinylpyrrolidone-coated CuO2 solution; add hexadecyltrimethylammonium bromide and Co(NO3)2•6H2O to the polyvinylpyrrolidone-coated CuO2 solution, and then add a methanol solution containing 2-methylimidazole to react. After the reaction is completed, filter and collect the solid, wash and dry it to obtain CuO2@ZIF-67. The amounts of polyvinylpyrrolidone-coated CuO2 nanodots, hexadecyltrimethylammonium bromide, Co(NO3)2•6H2O, and methanol solution containing 2-methylimidazole were (15-25) mg: (8-12) mg: (115-120) mg: (25-30) mL. (3) Disperse CuO2@ZIF-67 in ethanol to obtain CuO2@ZIF-67 solution; mix CuO2@ZIF-67 solution and L-arginine solution and react them. After the reaction, centrifuge to obtain copper-cobalt bimetallic nanoreactor that generates active nitrogen.

2. The application as described in claim 1, characterized in that, In step (1), the concentration of CuCl2•2H2O solution is 0.005-0.015 mol / L, the concentration of sodium hydroxide solution is 0.015-0.025 mol / L, and the mass percentage of hydrogen peroxide solution is 25%-35%.

3. The application as described in claim 1, characterized in that, In step (1), the reaction time is 25-35 min.

4. The application as described in claim 1, characterized in that, In step (2), the ratio of CuO2 nanodots coated with polyvinylpyrrolidone to methanol is (15-25) mg: 4 mL.

5. The application as described in claim 1, characterized in that, In step (2), the methanol solution containing 2-methylimidazole is prepared by mixing 2-methylimidazole and methanol at a ratio of (1.8-1.9) g: (25-30) mL.

6. The application as described in claim 1, characterized in that, In step (2), the reaction time is 25-35 min.

7. The application as described in claim 1, characterized in that, In step (3), the ratio of CuO2@ZIF-67 to ethanol is (45-55) mg: 10 mL; L-arginine solution is prepared by mixing L-arginine and deionized water at a ratio of (450-550) mg: 10 mL; the mass ratio of CuO2@ZIF-67 and L-arginine in the L-arginine solution is 1: (8-12).

8. The application as described in claim 1, characterized in that, In step (3), the reaction time is 20-30 hours.

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