Preparation method and application of chiral manganese dioxide enantiomer nanozyme
Chiral manganese dioxide nanozymes were synthesized via a tartaric acid-induced hydrothermal reaction, solving the problems of uncontrollable optical activity of chiral nanozymes and insufficient stability of traditional enzymes, and achieving highly efficient catalytic activity in the visible and near-infrared light regions.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- DALIAN INSTITUTE OF CHEMICAL PHYSICS CHINESE ACADEMY OF SCIENCES
- Filing Date
- 2024-11-27
- Publication Date
- 2026-05-29
AI Technical Summary
In existing technologies, the optical activity of chiral nanozymes is difficult to control, and traditional natural enzymes are prone to inactivation or degradation under certain conditions.
Using tartaric acid as a chiral ligand, chiral manganese dioxide nanozymes were synthesized under alkaline conditions via a hydrothermal reaction. Using a cationic surfactant as a template agent, manganese dioxide nanozymes with a chiral configuration were prepared, exhibiting both peroxidase and oxidase activities.
The prepared chiral manganese dioxide nanozymes exhibit good chiral optical response in the visible and near-infrared light regions, demonstrating excellent peroxidase and oxidase activities, thus solving the stability and activity problems of chiral nanozymes.
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Figure CN122098545A_ABST
Abstract
Description
Technical Field
[0001] This application relates to a method for preparing chiral manganese dioxide enantiomeric nanozymes and their applications, belonging to the field of functional material synthesis technology. Background Technology
[0002] Chirality is widespread in nature; many biomolecules, such as amino acids and sugars, possess chirality. Studying chirality helps to deepen our understanding of the fundamental mechanisms of life processes. Chirality has a broad impact on many scientific fields, particularly in chemistry, life sciences, and pharmaceuticals. Because chiral molecules' two mirror-image isomers (enantiomers) can exhibit completely different physical, chemical, and biological activities, understanding chirality is crucial for understanding and controlling the selectivity of chemical reactions. In the pharmaceutical industry, chiral research is especially important because different chiral isomers of drugs can have drastically different effects on organisms: one enantiomer may be an effective therapeutic agent, while another may be ineffective or toxic.
[0003] Nanozymes are a class of nanomaterials that mimic the function of natural enzymes, exhibiting enzyme-like catalytic activity. First discovered in 2007, they have attracted widespread attention due to their high efficiency, stability, and tunability in catalytic reactions. Compared to natural enzymes, nanozymes possess higher stability and tolerance, are less affected by environmental factors (such as temperature and pH), and are relatively inexpensive, making them suitable for large-scale production. Common types of nanozymes include metal oxide nanoparticles, metal nanoparticles, and carbon-based nanomaterials.
[0004] Nanozymes are widely used in the biomedical field, including biosensors, antibacterial agents, and cancer treatment. Furthermore, they show great potential in environmental protection (such as pollutant degradation) and food safety testing. By controlling the size, shape, and surface function of nanozymes, their catalytic activity can be precisely controlled, allowing them to perform specific functions in different application scenarios.
[0005] Chiral nanozymes are nanozymes with chiral structures that can mimic the catalytic function of natural chiral enzymes. Chirality refers to the asymmetry in molecular structure; chiral molecules typically have two mirror-image isomers, similar to a human left and right hand. Compared to traditional chiral catalysts, chiral nanozymes exhibit higher stability, reusability, and environmental tolerance. By adjusting the surface structure, size, and composition of chiral nanozymes, their chiral selectivity and catalytic efficiency can be further improved, bringing new directions for development in the field of chiral catalysis.
[0006] Nanozymes possess catalytic activity, promoting specific biochemical reactions that enhance the targeting and killing effect on tumor cells. By designing nanomaterials with enzymatic activity, researchers can implement various therapeutic strategies, including photothermal therapy, chemotherapy, and biotherapy. Nanozymes can generate reactive oxygen species or other cytotoxic substances through specific reactions, thereby directly inhibiting the growth and proliferation of tumor cells. Furthermore, they can be used in combination with other treatment methods to improve efficacy and reduce side effects. Summary of the Invention
[0007] To address the challenges of controlling chiral optical activity and the susceptibility of traditional natural enzymes to inactivation or degradation under certain conditions in existing chiral nanozyme preparation techniques, this application proposes a technical scheme for preparing chiral manganese dioxide nanozymes using tartaric acid induction. The prepared chiral manganese dioxide nanozymes possess a specific chiral configuration. The chiral nanozymes synthesized with tartaric acid as a ligand exhibit chiral optical responses in both the visible and near-infrared light regions. Furthermore, the prepared chiral manganese dioxide nanozymes simultaneously possess excellent peroxidase and oxidase activities.
[0008] The technical solution adopted in this application is as follows:
[0009] According to a first aspect of this application, a method for preparing chiral manganese dioxide enantiomeric nanozymes is provided, comprising the following steps:
[0010] An alkaline aqueous solution containing a mixture of manganese source, chiral ligand, template agent, and base is placed in a sealed container and reacted to obtain the chiral manganese dioxide enantiomer nanozyme.
[0011] The chiral ligand is selected from L-tartaric acid and / or D-tartaric acid;
[0012] The template agent is selected from cationic surfactants.
[0013] Optionally, the following steps are included:
[0014] A template agent aqueous solution, a chiral ligand aqueous solution, and an alkaline solution are mixed, and then a manganese source aqueous solution is added to obtain an alkaline aqueous solution of the mixture. The alkaline aqueous solution of the mixture is placed in a sealed container and reacted to obtain the chiral manganese dioxide enantiomer nanozyme.
[0015] The chiral ligand is selected from L-tartaric acid and / or D-tartaric acid;
[0016] The template agent is selected from cationic surfactants.
[0017] Optionally, the cationic surfactant is selected from at least one of hexadecyltrimethylammonium bromide, hexadecyltrimethylammonium chloride, and octadecyltrimethylammonium chloride.
[0018] Optionally, the manganese source is selected from at least one of potassium permanganate and potassium manganate.
[0019] Optionally, the alkali is selected from at least one of sodium hydroxide, potassium hydroxide, sodium bicarbonate, and sodium carbonate.
[0020] Optionally, the pH of the alkaline aqueous solution of the mixture is 8 to 10.
[0021] Optionally, the concentration of the template agent aqueous solution is 5-10 mg / mL.
[0022] Optionally, the concentration of the chiral ligand aqueous solution is 10–20 mg / mL.
[0023] Optionally, the concentration of the chiral ligand aqueous solution is selected from any value of 10 mg / mL, 12 mg / mL, 14 mg / mL, 16 mg / mL, 18 mg / mL, 20 mg / mL, or a range between any two of the above.
[0024] Optionally, the concentration of the template agent aqueous solution is selected from any value of 5 mg / mL, 6 mg / mL, 7 mg / mL, 8 mg / mL, 9 mg / mL, 10 mg / mL, or a range between any two of the above.
[0025] Optionally, the concentration of the manganese source aqueous solution is 2 to 10 mg / mL.
[0026] Optionally, the concentration of the manganese source aqueous solution is selected from any value of 2 mg / mL, 4 mg / mL, 6 mg / mL, 8 mg / mL, 10 mg / mL, or a range between any two of the above.
[0027] Optionally, the volume ratio of the template agent aqueous solution, the chiral ligand aqueous solution, the alkaline solution, and the manganese source aqueous solution is (5-10):1:(1-4):(10-15).
[0028] Optionally, the volume ratio of the manganese source aqueous solution to the amino acid solution is selected from any value of 15:1, 14:1, 13:1, 12:1, 11:1, 10:1 or a range between any two of the above.
[0029] Optionally, the reaction conditions include: a reaction temperature of 90–120°C and a reaction time of 4–8 h.
[0030] Optionally, the reaction time is selected from any value of 90°C, 100°C, 110°C, 120°C, or a range between any two of the above.
[0031] Optionally, the stirring reaction time is selected from any value of 4h, 5h, 6h, 7h, 8h or a range between any two of the above.
[0032] According to another aspect of this application, a chiral manganese dioxide enantiomeric nanozyme prepared by the above preparation method is provided, wherein the chiral manganese dioxide nanozyme simultaneously possesses peroxidase activity and oxidase activity.
[0033] Optionally, the characteristic peaks of the circular dichroism spectral signal of the chiral manganese dioxide nanozyme are 200-250 nm, 280-320 nm and 380-420 nm.
[0034] Optionally, the asymmetry factor g value of the chiral manganese dioxide nanozyme is 0.008-0.012.
[0035] Optionally, the chiral manganese dioxide nanozyme has a particle size of approximately 120–200 nm.
[0036] According to another aspect of this application, a chiral manganese dioxide enantiomeric nanozyme prepared by the above preparation method or the above-mentioned chiral manganese dioxide enantiomeric nanozyme is provided for application in the fields of biomedicine and biosensing.
[0037] The beneficial effects of this application include:
[0038] The preparation methods of chiral manganese dioxide enantiomeric nanozymes provided in this application are all carried out in a hydrothermal reactor, which has the advantages of convenient operation and stable chiral optical signal of materials. The synthesized L and D configuration nanozymes have good chiral optical activity in the visible and near-infrared light regions, and the circular dichroism spectrum and g-factor spectrum have good symmetry. The prepared chiral manganese dioxide nanozymes have both peroxidase and oxidase activities, which is of great significance for the preparation of enantiomeric chiral nanomaterials and biocompatible chiral nanozymes. Attached Figure Description
[0039] Figure 1 The image shows a scanning electron microscope (SEM) image of the chiral manganese dioxide nanozyme induced by L-tartaric acid prepared in Example 2 of this application. The scale bar is 100 nm.
[0040] Figure 2 The image shows a scanning electron microscope (SEM) image of the chiral manganese dioxide nanozyme synthesized by D-tartaric acid in Example 2 of this application. The scale bar is 100 nm.
[0041] Figure 3 The circular dichroism and g-factor spectra of the chiral manganese dioxide nanozymes synthesized by L-tartaric acid and D-tartaric acid in Example 2 of this application are shown.
[0042] Figure 4The images show the absorption spectra of the chiral manganese dioxide nanozymes synthesized in Example 2 of this application, which were synthesized in accordance with L-tartaric acid and D-tartaric acid respectively.
[0043] Figure 5 The images show the infrared spectra of the chiral manganese dioxide nanozymes synthesized in Example 2 of this application, which were synthesized in accordance with L-tartaric acid and D-tartaric acid respectively.
[0044] Figure 6 The X-ray diffraction spectra of the chiral manganese dioxide nanozymes synthesized in Example 2 of this application, which were induced by L-tartaric acid and D-tartaric acid respectively.
[0045] Figure 7 The electron paramagnetic resonance spectra of hydroxyl radicals generated by the chiral manganese dioxide nanozymes synthesized in L-tartaric acid and D-tartaric acid in Example 2 of this application are shown.
[0046] Figure 8 The electron paramagnetic resonance spectra of the superoxide anion free radicals generated by the chiral manganese dioxide nanozymes synthesized in L-tartaric acid and D-tartaric acid in Example 2 of this application are shown. Detailed Implementation
[0047] The present application is described in detail below with reference to the embodiments, but the present application is not limited to these embodiments.
[0048] Unless otherwise specified, all raw materials used in the embodiments of this application were purchased through commercial channels.
[0049] Unless otherwise specified, all test methods are standard and all instrument settings are those recommended by the manufacturer.
[0050] Circular dichroism spectroscopy characterization: Circular dichroism spectroscopy was performed using a J1500 circular dichroism spectrometer from Japan Spectrophotometer Co., Ltd., with a detection wavelength range of 200-800 nm. Ultraviolet-visible absorption spectra were also collected simultaneously.
[0051] Scanning electron microscopy characterization: Scanning electron microscopy (SEM) images were taken using a JEOL JSM-7610Plus with an accelerating voltage of 5 kV.
[0052] Fourier transform infrared spectroscopy characterization: Fourier transform infrared spectra were measured using an INVENIO S infrared spectrometer from Bruker Instruments, Germany, with a detection wavelength range of 400-4000 nm.
[0053] X-ray diffraction spectroscopy characterization: X-ray diffraction spectra were measured using an Empyream X-ray diffraction spectrometer from Malvern Panaco Instruments Ltd., UK, with a detection angle of 5-90°.
[0054] Electron paramagnetic resonance spectroscopy characterization: Electron paramagnetic resonance spectra were measured using a Bruker E500 electron paramagnetic resonance spectrometer, with a magnetic field range of 0–1.45 T.
[0055] In one embodiment, the method for preparing chiral manganese dioxide nanozymes by chiral tartaric acid-induced reaction mediated by a cationic surfactant includes the following steps: using hexadecyltrimethylammonium bromide as a template agent, using L-tartaric acid and D-tartaric acid as chiral inducers, using potassium permanganate as a manganese source, and reacting under alkaline conditions at high temperature and high pressure to obtain chiral manganese dioxide nanozymes.
[0056] In one embodiment, the method for preparing chiral manganese dioxide nanozymes induced by chiral tartaric acid through cationic surfactant mediation specifically includes the following steps:
[0057] S1. Adjust the concentration of the surfactant cetyltrimethylammonium bromide in the solution, control the amount of L-tartaric acid or D-tartaric acid ligand added, adjust the pH value of the system with sodium hydroxide, add potassium permanganate solution, stir evenly in a hydrothermal reactor, place in a constant temperature drying oven, and react for 4-8 hours at a temperature of 90-120℃ to obtain the chiral manganese dioxide nanozyme reaction product.
[0058] S2. The obtained product is purified by centrifugation to obtain the chiral manganese dioxide nanozyme.
[0059] In one embodiment, in step S1, in the presence of the cationic surfactant hexadecyltrimethylammonium bromide, an L-tartaric acid or D-tartaric acid solution is added, the pH of the reaction system is adjusted to 8-10 using an alkaline solution, and then a potassium permanganate solution is added and stirred evenly. The alkaline solution is one of sodium hydroxide solution, potassium hydroxide solution, sodium carbonate solution, or sodium bicarbonate solution.
[0060] In the specific operation of the preparation method of this application, an aqueous solution of potassium permanganate is prepared at room temperature. Then, L-tartaric acid and D-tartaric acid solutions are prepared separately. A cetyltrimethylammonium bromide solution is prepared under ultrasonic conditions to promote the accelerated dissolution of the surfactant. The prepared cationic surfactant and L-tartaric acid or D-tartaric acid solution are added sequentially to a hydrothermal reactor. The pH value of the reaction system is adjusted to 8-10 by sodium hydroxide solution. Finally, potassium permanganate solution is added. The mixture is magnetically stirred at room temperature for 5-10 minutes and placed in a constant temperature drying oven. The reaction is carried out at 100°C for 4 hours. The final product is observed to be black.
[0061] Example 1: Preparation method of chiral manganese dioxide nanozyme induced by chiral tartaric acid ligand
[0062] (1) Weigh 3.6g of hexadecyltrimethylammonium bromide powder and dissolve it in 100mL of ultrapure water. Weigh 80mg of potassium permanganate solid powder and dissolve it in 50mL of ultrapure water. Then prepare 100mM L-tartaric acid and D-tartaric acid aqueous solutions respectively, i.e., weigh 150mg of each chiral ligand and dissolve it in 10mL of water respectively. Weigh 40mg of sodium hydroxide and dissolve it in 10mL of ultrapure water. Then add 1.5mL of the prepared hexadecyltrimethylammonium bromide solution and L- 0.25 mL of tartaric acid or D-tartaric acid solution and 0.5 mL of sodium hydroxide solution were added to a hydrothermal reactor containing 4.75 mL of ultrapure water. Then, 3 mL of potassium permanganate was added and stirred for 5 minutes. The reactor was placed in a constant temperature oven and reacted at 100°C for 4 hours. The resulting L-type chiral manganese dioxide nanozymes (labeled Mn-L-Tar) and D-type chiral manganese dioxide nanozymes (labeled Mn-D-Tar) showed that the final color of the reaction system was black.
[0063] (2) Centrifugal purification: The obtained L-type and D-type chiral manganese dioxide nanozymes were separated by centrifugation. The centrifugation speed was 8000 rpm for 5 minutes, the supernatant was removed, and the nanozymes were washed twice with distilled water and filtered to obtain L-type and D-type chiral manganese dioxide nanozyme precipitates (the precipitates can be resuspended in ultrapure water for circular dichroism spectroscopy and morphological characterization by scanning electron microscopy).
[0064] (3) Drying: The L-type and D-type chiral manganese dioxide nanozyme precipitates obtained after purification in step (2) are placed in a vacuum drying oven at 60°C to dry, and the resulting L-type and D-type chiral manganese dioxide nanozyme solid powders are obtained (the solid powders can be used for Fourier transform infrared spectroscopy, X-ray diffraction spectroscopy and electron paramagnetic resonance spectroscopy characterization).
[0065] Characterization method of chiral manganese dioxide nanozymes in Test Example 1
[0066] (1) Scanning electron microscopy characterization: The chiral manganese dioxide nanozyme precipitate obtained by centrifugation purification was resuspended in ultrapure water and diluted to a concentration of 0.2 mg / mL. 6 μL was dropped onto the surface of a silicon wafer and dried under an infrared lamp for 1 minute. Its morphology was observed under a scanning electron microscope at a voltage of 5 kV. Electron microscopy image of nanozyme synthesized with the participation of L-tartaric acid ( Figure 1 Electron micrograph of nanozymes synthesized with the participation of D-tartaric acid ( Figure 2 ),from Figure 1 and Figure 2 It can be seen that L-tartaric acid and D-tartaric acid participate in the synthesis of nanozymes with similar particle sizes and exhibit certain helical configurations. Furthermore, the scanning electron microscopy results of L-type and D-type chiral manganese dioxide nanozymes show certain multi-level assembly structures.
[0067] (2) Circular dichroism spectroscopy characterization: The chiral manganese dioxide nanozyme obtained by centrifugation purification was resuspended in ultrapure water and diluted to 0.4 mg / mL. Using ultrapure water as the baseline background, the scanning wavelength range was 200 to 800 nm, and the scanning speed was 0.5 s / nm. The circular dichroism spectrum, g-factor spectrum, and UV-Vis absorption spectrum of the materials synthesized with L-tartaric acid and D-tartaric acid were obtained. Figure 3 and Figure 4 ),from Figure 3 It can be seen that the chiral optical signals generated by the nanozymes synthesized with the participation of L-tartaric acid and D-tartaric acid exhibit obvious symmetry, and the characteristic peaks appear at the same positions, showing obvious circular dichroism characteristic peaks at wavelengths of 220 nm, 300 nm, and 400 nm, respectively. Furthermore, the circular dichroism spectrum and g-factor spectrum of the chiral manganese dioxide nanozymes synthesized with the participation of L-tartaric acid and D-tartaric acid show symmetrical distribution. The asymmetry factor g value of the chiral manganese dioxide nanozymes is 0.01. Figure 4 It can be seen that the material has obvious absorption characteristic peaks in the 250-450nm range.
[0068] (3) Characterization by Fourier transform infrared spectroscopy and X-ray electron diffraction spectroscopy:
[0069] The powder obtained by vacuum drying the chiral manganese dioxide nanozyme obtained by centrifugation purification was used to determine the infrared spectrum. Figure 5 ) and X-ray electron diffraction spectroscopy ( Figure 6 ),from Figure 5 It can be seen that the characteristic peak of the hydroxyl group in tartaric acid (labeled L-Tar) is 3410 cm⁻¹ before and after the reaction. -1 and 3335cm -1 Significant changes occurred, and it participated in the synthesis of chiral manganese dioxide nanozymes. From Figure 6 X-ray electron diffraction spectroscopy revealed that the synthesized chiral nanomaterials have a crystalline structure similar to manganese dioxide.
[0070] (4) Electron paramagnetic resonance (EPR) spectroscopy characterization: The chiral manganese-based nanowires obtained by centrifugation purification were resuspended in ultrapure water. A scavenging agent (such as 5,5-dimethyl-1-pirroline N-oxide, DMPO) was used to capture ·OH radicals, thereby forming stable free radical adducts. Subsequently, the reaction solution was transferred to EPR sample tubes and tested using a spectrometer. The results are shown below. Figure 7 As shown. Furthermore, a trapping agent (tetramethylpiperidine, TEMP) was used to stabilize the superoxide anion, thereby forming a detectable radical adduct. Subsequently, the reaction liquid was transferred to an EPR sample tube and placed in a spectrometer for testing. The results are shown below. Figure 8 As shown.
[0071] The above description is merely a few embodiments of this application and is not intended to limit this application in any way. Although this application discloses preferred embodiments as described above, it is not intended to limit this application. Any changes or modifications made by those skilled in the art without departing from the scope of the technical solution of this application using the disclosed technical content are equivalent to equivalent implementation cases and fall within the scope of the technical solution.
Claims
1. A method for preparing a chiral manganese dioxide enantiomeric nanozyme, characterized in that, Includes the following steps: An alkaline aqueous solution containing a mixture of manganese source, chiral ligand, template agent, and base is placed in a sealed container and reacted to obtain the chiral manganese dioxide enantiomer nanozyme. The chiral ligand is selected from L-tartaric acid and / or D-tartaric acid; The template agent is selected from cationic surfactants.
2. The preparation method according to claim 1, characterized in that, Includes the following steps: A template agent aqueous solution, a chiral ligand aqueous solution, and an alkaline solution are mixed, and then a manganese source aqueous solution is added to obtain an alkaline aqueous solution of the mixture. The alkaline aqueous solution of the mixture is placed in a sealed container and reacted to obtain the chiral manganese dioxide enantiomer nanozyme. The chiral ligand is selected from L-tartaric acid and / or D-tartaric acid; The template agent is selected from cationic surfactants.
3. The preparation method according to claim 2, characterized in that, The cationic surfactant is selected from at least one of hexadecyltrimethylammonium bromide, hexadecyltrimethylammonium chloride, and octadecyltrimethylammonium chloride.
4. The preparation method according to claim 2, characterized in that, The manganese source is selected from at least one of potassium permanganate and potassium manganate.
5. The preparation method according to claim 2, characterized in that, The alkali is selected from at least one of sodium hydroxide, potassium hydroxide, sodium bicarbonate, and sodium carbonate.
6. The preparation method according to claim 2, characterized in that, The pH of the alkaline aqueous solution of the mixture is 8–10; Preferably, the concentration of the template agent aqueous solution is 5-10 mg / mL; Preferably, the concentration of the chiral ligand aqueous solution is 10–20 mg / mL; Preferably, the concentration of the manganese source aqueous solution is 2–10 mg / mL; Preferably, the volume ratio of the template agent aqueous solution, the chiral ligand aqueous solution, the alkaline solution, and the manganese source aqueous solution is (5-10):1:(1-4):(10-15).
7. The preparation method according to claim 2, characterized in that, The reaction conditions include: a reaction temperature of 90–120°C and a reaction time of 4–8 hours.
8. The chiral manganese dioxide enantiomeric nanozyme prepared by the preparation method according to any one of claims 1 to 7, characterized in that, The chiral manganese dioxide nanozyme exhibits both peroxidase and oxidase activities.
9. The chiral manganese dioxide enantiomeric nanozyme according to claim 8, characterized in that, The characteristic peaks of the circular dichroism spectrum of the chiral manganese dioxide nanozyme are 200-250 nm, 280-320 nm and 380-420 nm. Preferably, the asymmetry factor g of the chiral manganese dioxide nanozyme is 0.008-0.012; Preferably, the chiral manganese dioxide nanozyme has a particle size of about 120-200 nm.
10. The application of the chiral manganese dioxide enantiomeric nanozyme prepared by the preparation method according to any one of claims 1 to 7, or the chiral manganese dioxide enantiomeric nanozyme according to claim 8 or 9, in the fields of biomedicine and biosensing.