Hollow polydopamine nanomaterial coordinated with multiple metal ions, synthesis method and application

Abstract

The application belongs to the field of nanometer material preparation, and particularly relates to a hollow polydopamine nanometer material coordinated with multiple metal ions, a synthesis method and application. The application is Co / Fe / Ni-Zn polydopamine coordinated with multiple metal ions, has a hollow structure, the particle size of Fe-Zn polydopamine coordinated with multiple metal ions is 238-272nm, the particle size of Co-Zn polydopamine coordinated with multiple metal ions is 45-56nm, and the particle size of Ni-Zn polydopamine coordinated with multiple metal ions is 58-70nm. The application forms the hollow polydopamine nanometer material coordinated with multiple metal ions with controllable size through an etching template method, which is different from a single polydopamine structure, the prepared composite material has good crystallinity, is uniformly and stably dispersed, has higher nanometer enzyme catalytic activity, and has a good application prospect in solar cells, biological photothermal imaging and treatment, and drug loading.

Description

Technical Field

[0001] This invention belongs to the field of nanomaterial preparation, and more specifically, relates to hollow polydopamine nanomaterials with multi-metal ion coordination, their synthesis methods, and applications. Background Technology

[0002] Polydopamine (PDA) is a polymer synthesized from dopamine molecules through oxidative polymerization. It possesses chemical stability and abundant functional groups, such as hydroxyl, phenolic, and aldehyde groups. Nanozymes are a class of enzyme-mimicking materials that combine the unique properties of nanomaterials with catalytic functions. They are characterized by high catalytic efficiency, stability, economy, and large-scale preparation, and are widely used in medicine, chemical engineering, food, agriculture, and environmental fields. Despite numerous methods for synthesizing PDA nanozymes, the synthesized PDA nanozymes generally exhibit low catalytic activity, making practical applications relatively difficult. Summary of the Invention

[0003] In view of the above-mentioned defects or improvement needs of the prior art, the purpose of this invention is to provide hollow polydopamine nanomaterials with multi-metal ion coordination, synthesis methods and applications.

[0004] To achieve the above-mentioned objectives, the technical solution adopted by this invention is as follows:

[0005] This invention provides hollow polydopamine nanomaterials coordinated by multiple metal ions, which are Co / Fe / Ni-Zn polydopamines with a hollow structure. The particle size of Fe-Zn polydopamine is 238-272 nm; the particle size of Co-Zn polydopamine is 45-56 nm; and the particle size of Ni-Zn polydopamine is 58-70 nm.

[0006] This invention also provides a method for synthesizing hollow polydopamine nanomaterials with multi-metal ion coordination, comprising the following steps:

[0007] (1) Dissolve zinc nitrate and nickel nitrate / cobalt nitrate / ferric chloride in methanol to obtain solution A;

[0008] (2) Dissolve dimethylimidazole in methanol solution to obtain solution B;

[0009] (3) At room temperature, solution A is quickly poured into solution B which is being stirred rapidly, and stirred to form a Co / Fe / Ni-Zn multi-metal ion doped ZIF-8 structure;

[0010] (4) Dissolve dopamine in methanol, add ZIF-8 doped with multi-metal ions to the dopamine methanol solution, stir, heat and reflux to form hollow polydopamine nanomaterials coordinated with multi-metal ions.

[0011] In the above scheme, the molar ratio of nickel nitrate / cobalt nitrate / ferric chloride:zinc nitrate is 1:5 to 30.

[0012] In the above scheme, the concentration of zinc nitrate in solution A is 10mM to 50mM.

[0013] In the above scheme, the concentration of dimethylimidazole in solution B is 240mM to 360mM.

[0014] In the above scheme, the concentration of dopamine is 20mM to 60mM.

[0015] In the above scheme, the stirring time in step (2) is 0.5 to 3 hours.

[0016] In the above scheme, the stirring reaction time in step (4) is 10-15 hours.

[0017] In the above scheme, the heating condensation reflux temperature is 50-70℃.

[0018] The present invention also provides the application of hollow polydopamine nanomaterials coordinated with multi-metal ions as SOD and / or CAT enzymes.

[0019] This invention also provides the application of hollow polydopamine nanomaterials coordinated with multi-metal ions in SOD and / or CAT enzyme catalytic reactions.

[0020] This invention utilizes an etching template method to first prepare a Co / Fe / Ni-Zn multi-metal ion-doped ZIF-8 structure, which is then added to a dopamine methanol solution. The mixture is stirred, heated, and refluxed to ultimately form a hollow polydopamine structure coordinated with zinc and iron / cobalt / nickel multi-metal ions. The synthesized multi-metal ion-coordinated polydopamine nanoparticles are stably soluble in methanol and aqueous solutions and exhibit lower toxicity. The size of the polydopamine can be precisely controlled by adjusting the size of the ZIF-8 template. Coordination of different multi-metal ions with polydopamine can enhance the activity of the nanozymes, including SOD and / or CAT enzyme activities. The method described in this invention is simple to operate, has a mild reaction, and is low in cost, showing promising applications in solar cells, catalysis, photothermal imaging and therapy in organisms, and drug loading.

[0021] The beneficial effects of this invention are:

[0022] The hollow polydopamine nanomaterials coordinated with zinc and iron / cobalt / nickel polymetallic ions provided in this application are different from single polydopamine structures. Different polymetallic ions coordinated with polydopamine can significantly improve the activity of their own nanozymes, including SOD and / or CAT enzyme activities.

[0023] The method described in this invention is simple to operate, has a mild reaction, and is low in cost. The resulting composite material has good crystallinity, uniform and stable dispersion, and higher nanozyme catalytic activity. It has good application prospects in solar cells, catalysis, photothermal imaging and treatment of organisms, and drug loading. Attached Figure Description

[0024] Figure 1 It is a Zn / Co metal-doped organic framework ZIF-8 structure.

[0025] Figure 2 The structure is a polydopamine structure coordinated with Zn / Co metal ions.

[0026] Figure 3 Comparison of polydopamine SOD enzyme activities coordinated with Zn / Co metal ions.

[0027] Figure 4 It is a Zn / Fe metal-doped organic framework ZIF-8 structure.

[0028] Figure 5 The structure is a polydopamine structure coordinated with Zn / Fe metal ions.

[0029] Figure 6 Comparison of polydopamine CAT enzyme activities coordinated with Zn / Fe metal ions.

[0030] Figure 7 It is a Zn / Ni metal-doped organic framework ZIF-8 structure.

[0031] Figure 8 The structure is a polydopamine structure coordinated with Zn / Ni metal ions.

[0032] Figure 9 Comparison of polydopamine SOD enzyme activities coordinated with Zn / Ni metal ions. Detailed Implementation

[0033] To better understand the present invention, the following embodiments further illustrate the content of the present invention, but the content of the present invention is not limited to the following embodiments.

[0034] Example 1

[0035] Preparation process of hollow polydopamine nanomaterials coordinated with zinc and cobalt ions: 12 mL of 300 mM dimethylimidazolium methanol solution was added to a 25 mL round-bottom flask. While rapidly stirring, 3 mL of a methanol solution containing 8 mM cobalt nitrate and 40 mM zinc nitrate was added. After stirring for 30 min, the mixture was centrifuged and resuspended, then added to 2.5 mL of 40 mM dopamine methanol solution and mixed thoroughly. The mixture was heated and refluxed in a 60 °C water bath for 12 h. The hollow zinc and cobalt ion-coordinated polydopamine nanozyme was collected by centrifugation. The transmission electron microscope (TEM) image of the zinc and cobalt ion-doped ZIF-8 structure prepared in this example is shown below. Figure 1 ,from Figure 1 It can be seen that the particle size of the nanomaterial is 52.2 nm; Figure 2 Polydopamine nanozymes coordinated with zinc and cobalt ions, from Figure 2 It can be seen that the nanomaterial has a hollow structure and a particle size of 80.6 nm;

[0036] Superoxide dismutase (SOD) activity was detected using a superoxide dismutase (SOD) assay kit. Specifically, the SOD activity of the nanozyme was determined by the removal of superoxide anions. The results are as follows: Figure 3 By comparing the SOD enzyme activity of polydopamine nanozymes coordinated with Zn / Co metal ions, it can be found that the addition of cobalt ions significantly enhances the SOD enzyme activity of polydopamine. Compared with polydopamine HPDA, the SOD enzyme activity is increased by about 6 times, and compared with Zn-HPDA, the SOD enzyme activity is increased by about 2 times.

[0037] Example 2

[0038] Preparation process of zinc and iron ion coordinated polydopamine nanomaterials: 120 mL of 300 mM dimethylimidazole methanol solution was added to a 250 mL round-bottom flask. While rapidly stirring, 30 mL of 6 mM ferric chloride and 40 mM zinc nitrate methanol solution was added. After stirring for 2 h, the mixture was centrifuged and resuspended, then added to 10 mL of 40 mM dopamine methanol solution and mixed thoroughly. The mixture was heated and refluxed in a 60 °C water bath for 12 h. The hollow zinc and iron ion coordinated polydopamine nanozyme was collected by centrifugation. The transmission electron microscope (TEM) image of the zinc and iron ion doped ZIF-8 structure prepared in this example is shown below. Figure 4 ,from Figure 4 It can be seen that the particle size of the nanomaterial is 258.1 nm; Figure 5 Polydopamine nanozymes coordinated with zinc and iron ions, from Figure 5 It can be seen that the nanomaterial has a hollow structure and a particle size of 478.3 nm;

[0039] CAT enzyme activity was detected using a peroxidase assay kit, and the results are as follows: Figure 6By comparing the CAT enzyme activity of polydopamine coordinated with Zn / Fe metal ions, it was found that the addition of iron ions significantly enhanced the CAT enzyme activity of polydopamine, with the CAT enzyme activity increasing by about 4 times compared with polydopamine HPDA and Zn-HPDA.

[0040] Example 3

[0041] Preparation process of zinc and nickel ion coordinated polydopamine nanomaterials: 12 mL of 300 mM dimethylimidazole methanol solution was added to a 25 mL round-bottom flask. While rapidly stirring, 3 mL of 8 mM nickel nitrate and 40 mM zinc nitrate methanol solution were added. After stirring for 0.5 h, the mixture was centrifuged and resuspended, then added to 10 mL of 40 mM dopamine methanol solution and mixed thoroughly. The mixture was heated and refluxed in a 60 °C water bath for 12 h. The zinc and nickel ion coordinated polydopamine nanozyme was collected by centrifugation. The transmission electron microscope (TEM) image of the zinc and nickel ion doped ZIF-8 structure prepared in this example is shown below. Figure 7 ,from Figure 7 It can be seen that the particle size of the nanomaterial is 63.5 nm; Figure 8 Polydopamine nanozymes coordinated with zinc and nickel ions, from Figure 8 It can be seen that the nanomaterial has a hollow structure and a particle size of 128.5 nm;

[0042] Superoxide dismutase (SOD) activity was detected using a superoxide dismutase (SOD) assay kit. Specifically, the SOD activity of the nanozyme was determined by the removal of superoxide anions. The results are as follows: Figure 9 By comparing the SOD enzyme activity of polydopamine coordinated with n / Ni metal ions, it can be found that the addition of iron ions significantly enhances the SOD enzyme activity of polydopamine. Compared with polydopamine HPDA, the SOD enzyme activity is increased by about 3 times, and compared with Zn-HPDA, the SOD enzyme activity is increased by 1 time.

[0043] Zn-HPDA: Add 40 mL of 25 mM dimethylimidazolium methanol solution to a 100 mL round-bottom flask, and add 40 mL of 25 mM zinc nitrate methanol solution while stirring rapidly. After stirring and reacting for 4 h, centrifuge and resuspend the solution, then add it to 10 mL of 5 mM dopamine methanol solution and mix well. Reflux the solution in a 60 °C water bath for 12 h, and collect the polydopamine containing zinc ions by centrifugation.

[0044] HPDA: 0.2 g of dopamine (PDA) was dissolved in 100 mL of Tris-HCl buffer (pH 8.5, 10 mM) to prepare a dopamine solution (2 mg / mL). 0.1 g of polystyrene powder (PS) was dispersed in the dopamine solution by ultrasonication and magnetically stirred at room temperature for 24 h. This formed a PS / PDA composite nanosphere core-shell structure. These nanospheres were centrifuged at 10,000 rpm for 15 min at room temperature, washed repeatedly with ethanol, and then dried in a vacuum oven at room temperature for 24 h. Finally, PS / PDA powder was added to chloroform and stirred for 6 h to remove the PS template, forming hollow PDA nanospheres (HPDA). These were then centrifuged at 10,000 rpm for 15 min at room temperature and washed repeatedly with ethanol to collect the HPDA.

Claims

1. The application of hollow polydopamine nanomaterials coordinated by multi-metal ions in SOD and / or CAT enzymes, wherein the hollow polydopamine nanomaterials coordinated by multi-metal ions are Co / Fe / Ni-Zn polydopamines with a hollow structure, wherein the particle size of Fe-Zn polydopamine is 238-272 nm; the particle size of Co-Zn polydopamine is 45-56 nm; and the particle size of Ni-Zn polydopamine is 58-70 nm.

2. Application of hollow polydopamine nanomaterials coordinated by multi-metal ions in SOD and / or CAT enzyme catalytic reactions, wherein the hollow polydopamine nanomaterials coordinated by multi-metal ions are Co / Fe / Ni-Zn polydopamines with a hollow structure, the particle size of Fe-Zn polydopamine is 238-272 nm; the particle size of Co-Zn polydopamine is 45-56 nm; and the particle size of Ni-Zn polydopamine is 58-70 nm.

3. The application according to claim 1 or 2, characterized in that: The method for synthesizing the hollow polydopamine nanomaterial with multi-metal ion coordination includes the following steps: (1) Dissolve zinc nitrate and nickel nitrate / cobalt nitrate / ferric chloride in methanol to obtain solution A; (2) Dissolve dimethylimidazole in methanol to obtain solution B; (3) At room temperature, solution A is quickly poured into solution B which is being stirred rapidly, and stirred to form a Co / Fe / Ni-Zn multimetal ion doped ZIF-8 structure; (4) Dissolve dopamine in methanol, add ZIF-8 doped with multiple metal ions to the dopamine methanol solution, stir, heat and reflux to form hollow polydopamine nanomaterials coordinated with multiple metal ions.

4. The application according to claim 3, characterized in that: The molar ratio of nickel nitrate / cobalt nitrate / ferric chloride:zinc nitrate is 1:5~30.

5. The application according to claim 3, characterized in that: The concentration of zinc nitrate in solution A is 10 mM to 50 mM; the concentration of dimethylimidazole in solution B is 240 mM to 360 mM.

6. The application according to claim 3, characterized in that: The concentration of dopamine is 20 mM to 60 mM.

7. The application according to claim 3, characterized in that: The rapid stirring time is 0.5~3h.

8. The application according to claim 3, characterized in that: The stirring reaction time in step (4) is 10~15h.

9. The application according to claim 3, characterized in that: The heating and condensation reflux temperature is 50-70℃.

Images