Preparation method of chiral enantiomeric manganese-based nanoflower
Chiral manganese-based nanoflowers were synthesized using a cysteine-induced self-assembly method, solving the challenges of morphology and optical signal modulation in chiral nanomaterials. This method achieves stable chiral response in the visible light region and is easy to prepare, making it suitable for the preparation of functional materials.
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 morphology construction and optical signal modulation of chiral nanomaterials are quite difficult, making it hard to achieve efficient preparation and stable chiral optical response.
Chiral manganese-based nanoflowers were synthesized by self-assembly using a cysteine-induced method. L-cysteine and D-cysteine were used as chiral ligands to react with manganese source and alkaline reducing agent in water-soluble alcohol solvent to prepare manganese-based nanoflowers with chiral configuration. The characteristic peaks of the circular dichroism spectroscopy signal were 250-300 nm and 450-500 nm.
The prepared manganese-based nanoflowers exhibit good chiral optical activity and stable optical signals in the visible light region, simplifying the preparation process and making them suitable for large-scale production. The circular dichroism spectrum and g-factor pattern show good symmetry, guiding the preparation of enantiomeric chiral nanomaterials.
Smart Images
Figure CN122099348A_ABST
Abstract
Description
Technical Field
[0001] This application relates to a method for preparing chiral enantiomeric manganese-based nanoflowers, belonging to the field of functional material synthesis technology. Background Technology
[0002] Chiral nanomaterials, due to their unique chiral structure, can selectively promote specific reaction pathways in catalytic reactions, thereby improving reaction efficiency and selectivity. Furthermore, in drug delivery systems, they can improve drug bioavailability and targeting by modulating molecular structure. In the field of sensors, chiral nanomaterials can enhance detection sensitivity and selectivity through interaction with target molecules. Common chiral nanomaterials include chiral metal nanoparticles, chiral polymers, and chiral nanotubes. The development of these materials not only advances basic scientific research but also holds broad application prospects in materials science and biomedicine.
[0003] The synthesis of chiral materials employs a variety of methods, each with its own characteristics and applications. Asymmetric synthesis, a common method, utilizes chiral catalysts to guide reactions and generate specific chiral isomers, and is widely used in drug synthesis. Self-assembly utilizes intermolecular interactions to spontaneously aggregate molecules into chiral structures, suitable for the preparation of chiral polymers and nanomaterials. Chiral template methods use chiral templates to promote material deposition, followed by template removal to obtain the chiral structure, thus achieving precise morphological control. Biosynthesis relies on the metabolic processes of natural organisms, utilizing bacteria or plants to synthesize chiral materials, offering advantages such as environmental friendliness and high selectivity. Finally, chemical modification involves modifying achiral materials with chiral reagents to obtain the desired chiral characteristics.
[0004] Chiral self-assembly synthesis is a method that utilizes non-covalent intermolecular interactions (such as hydrogen bonds, ionic bonds, π-π stacking, and hydrophobic interactions) to spontaneously aggregate chiral molecules into ordered supramolecular structures. The key lies in the design and selection of molecules; the spatial arrangement and interactions of chiral molecules determine the final self-assembly result. This method is widely used in drug delivery, improving drug release characteristics by enhancing bioavailability and targeting. In materials science, it is used to manufacture novel functional materials, such as chiral optoelectronic materials and sensors, enhancing optical properties and reactivity. Simultaneously, chiral self-assembly also demonstrates excellent performance in catalysis; chiral supramolecular catalysts can selectively promote certain reactions, improving efficiency and selectivity. Summary of the Invention
[0005] To address the challenges of constructing chiral morphologies and controlling chiral optical signals in existing chiral nanomaterial technologies, this application proposes a technique for preparing chiral manganese-based nanoflowers using cysteine-induced synthesis. The prepared chiral manganese-based nanoflowers possess a specific chiral configuration, and the chiral nanoflowers synthesized using cysteine as a ligand exhibit chiral optical responses in the visible light region.
[0006] The technical solution adopted in this application is as follows:
[0007] According to a first aspect of this application, a method for preparing chiral enantiomeric manganese-based nanoflowers is provided, characterized by comprising the following steps:
[0008] A mixed aqueous solution containing an assembly solvent, a manganese source, a chiral ligand, and a basic reducing agent is reacted to obtain the chiral enantiomer manganese-based nanoflowers.
[0009] The chiral ligand is selected from L-cysteine and / or D-cysteine;
[0010] The assembly solvent is selected from water-soluble alcohols.
[0011] Optionally, the following steps are included:
[0012] An aqueous solution of a manganese source, an aqueous solution of a chiral ligand, and an aqueous solution of an alkaline reducing agent were added to a solution containing an assembly solvent, and the reaction was carried out to obtain the chiral enantiomer manganese-based nanoflowers.
[0013] The chiral ligand is selected from L-cysteine and / or D-cysteine;
[0014] The assembly solvent is selected from water-soluble alcohols.
[0015] Optionally, the water-soluble alcohol is selected from at least one of methanol, ethanol, and isopropanol.
[0016] Optionally, the manganese source in the manganese source solution is selected from at least one of manganese chloride, manganese sulfate, manganese carbonate, and manganese acetate.
[0017] Optionally, the alkaline reducing agent is selected from at least one of sodium borohydride, hydrazine hydrate, hydroxylamine hydrochloride, and sodium hypochlorite.
[0018] Optionally, the reaction conditions include: standing, reaction temperature of 20-40°C, and reaction time of 4-8 hours.
[0019] Optionally, the reaction time is selected from any value of 4h, 5h, 6h, 7h, 8h or a range between any two of the above.
[0020] Optionally, the concentration of the manganese source aqueous solution is 10–30 mg / mL.
[0021] Optionally, the concentration of the manganese source aqueous solution is selected from any value of 10 mg / mL, 15 mg / mL, 20 mg / mL, 25 mg / mL, 30 mg / mL, or a range between any two of the above.
[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 alkaline reducing agent aqueous solution is 2 to 6 mg / mL.
[0025] Optionally, the concentration of the alkaline reducing agent aqueous solution is selected from any value of 2 mg / mL, 3 mg / mL, 4 mg / mL, 5 mg / mL, 6 mg / mL, or a range between any two of the above.
[0026] Optionally, the volume ratio of the manganese source aqueous solution to the chiral ligand aqueous solution, the alkaline reducing agent aqueous solution, and the assembly solvent is (1-4):1:(1-4)(5-10).
[0027] Optionally, the volume ratio of the manganese source solution to the amino acid solution is selected from any value of 4:1, 3:1, 2:1, 1:1 or a range between any two of the above.
[0028] According to another aspect of this application, a chiral enantiomeric manganese-based nanoflower obtained by the above preparation method is provided, wherein the characteristic peaks of the circular dichroism spectral signal of the chiral manganese-based nanoflower are 250-300 nm and 450-500 nm.
[0029] Optionally, the asymmetry factor g of the chiral manganese-based nanoflower is 0.0006-0.001.
[0030] The beneficial effects of this application include:
[0031] The method for preparing chiral enantiomeric manganese-based nanoflowers provided in this application involves self-assembly synthesis. The synthesized chiral materials exhibit stable optical signals, and the preparation method is simple and easy to scale up. The synthesized L and D configuration nanoflowers both exhibit good chiral optical activity in the visible light region, and their circular dichroism and g-factor spectra show good symmetry. This method has important guiding significance for the preparation of enantiomeric chiral nanomaterials through self-assembly. Attached Figure Description
[0032] Figure 1This is a scanning electron microscope (SEM) image of the chiral manganese-based nanoflowers synthesized by L-cysteine induced in Example 2 of this application. The scale bar is 3 μm.
[0033] Figure 2 This is a scanning electron microscope (SEM) image of the chiral manganese-based nanoflowers synthesized by D-cysteine induced synthesis prepared in Example 2 of this application. The scale bar is 3 μm.
[0034] Figure 3 The circular dichroism spectra of the chiral manganese-based nanoflowers synthesized by L-cysteine and D-cysteine in Example 2 of this application are shown.
[0035] Figure 4 The images show the absorption spectra of the chiral manganese nanoflowers synthesized in Example 2 of this application, which were synthesized in accordance with L-cysteine and D-cysteine.
[0036] Figure 5 The images show the g-factor spectra of the chiral manganese-based nanoflowers synthesized in Example 2 of this application, which were synthesized in accordance with L-cysteine and D-cysteine.
[0037] Figure 6 The infrared spectra of the chiral manganese-based nanoflowers synthesized by L-cysteine and D-cysteine in Example 2 of this application are shown.
[0038] Figure 7 The X-ray diffraction spectra of the chiral manganese-based nanoflowers synthesized by L-cysteine and D-cysteine in Example 2 of this application are shown. Detailed Implementation
[0039] The present application is described in detail below with reference to the embodiments, but the present application is not limited to these embodiments.
[0040] Unless otherwise specified, all raw materials used in the embodiments of this application were purchased through commercial channels.
[0041] Unless otherwise specified, all test methods are standard and all instrument settings are those recommended by the manufacturer.
[0042] 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.
[0043] Scanning electron microscopy characterization: Scanning electron microscopy (SEM) images were taken using a JEOL JSM-7610Plus with an accelerating voltage of 5 kV.
[0044] 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.
[0045] 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°.
[0046] As a specific implementation method, this application is achieved through the following technical solution:
[0047] The preparation method of chiral manganese-based nanoflowers induced by chiral cysteine includes the following steps: using L-cysteine and D-cysteine as chiral inducers, manganese chloride as manganese source, and sodium borohydride as reducing agent, the reaction precursor is added to an ethanol solution for assembly, and the chiral manganese-based nanoflowers are obtained by reacting under isothermal conditions.
[0048] Furthermore, the synthesis method specifically includes the following steps:
[0049] S1. Mix manganese chloride aqueous solution and L-cysteine or D-cysteine aqueous solution, add alkaline reducing agent as reducing agent, add the prepolymer obtained from the reaction to alcohol solvent, shake evenly, and let the reaction stand for 4-8 hours at room temperature to obtain chiral manganese-based nanoflower product.
[0050] S2. The obtained product was purified by centrifugation to obtain the chiral manganese-based nanoflowers.
[0051] Further, in step S1, manganese chloride tetrahydrate, L-cysteine or D-cysteine aqueous solution, and alkaline reducing agent are added sequentially to the aqueous solution, stirred evenly, and the obtained prepolymer is then transferred to an ethanol solvent and allowed to stand at room temperature for reaction. The alkaline solution is sodium borohydride, hydrazine hydrate, hydroxylamine hydrochloride, or sodium hypochlorite.
[0052] Example 1: Preparation of chiral manganese-based nanoflowers induced by chiral cysteine
[0053] (1) Weigh 200 mg of manganese chloride tetrahydrate solid powder and add it to 10 mL of ultrapure water to dissolve. Then, prepare 100 mM L-cysteine and D-cysteine aqueous solutions respectively. Weigh 120 mg of the two chiral ligands and dissolve them in 10 mL of water. Weigh 40 mg of sodium borohydride and dissolve it in 10 mL of ultrapure water. Then, add 1 mL of the prepared manganese chloride tetrahydrate solution, 1 mL of L-cysteine or D-cysteine solution, and 1 mL of sodium borohydride aqueous solution to a solution containing 7 mL of ethanol. Shake well and let it stand for 4 hours to obtain L-type chiral manganese-based nanoflowers (labeled as Mn-L-Cys) and D-type chiral manganese-based nanoflowers (labeled as Mn-D-Cys). It can be observed that the color of the final product is light pink.
[0054] (2) Centrifugal purification: The L-type and D-type chiral manganese-based nanoflowers were separated by centrifugation. The centrifugation speed was 5000 rpm for 10 minutes. The supernatant was removed and the nanoflowers were washed repeatedly with ultrapure water 2-3 times to obtain the chiral enantiomer manganese-based nanoflower precipitate (the precipitate was resuspended in ultrapure water and used for circular dichroism spectroscopy and scanning electron microscopy).
[0055] (3) Drying: The L-type and D-type chiral manganese-based nanoflower precipitates obtained by centrifugation purification in step (2) are placed in a vacuum drying oven at 60℃ and dried to obtain L-type chiral manganese-based nanoflower and D-type chiral manganese-based nanoflower solid powders respectively (the solid powders can be used for Fourier transform infrared spectroscopy and X-ray diffraction spectroscopy characterization).
[0056] Characterization method of chiral manganese-based nanoflowers in Test Example 1
[0057] Scanning electron microscopy characterization:
[0058] The chiral manganese-based nanoflowers obtained by centrifugation purification were resuspended in ultrapure water and diluted to a concentration of 1 mg / mL. 8 μL of each nanoflower was dropped onto a silicon wafer surface and dried in a constant temperature oven for 30 minutes. The morphology was observed under a scanning electron microscope at 5 kV. (Scanning electron microscope image of L-type chiral manganese-based nanoflowers synthesized using L-cysteine as a ligand). Figure 1 Scanning electron microscopy image of D-type chiral manganese-based nanoflowers synthesized using D-cysteine as a ligand. Figure 2 ),from Figure 1 and Figure 2 It can be seen that the nanoflowers prepared by L-cysteine and D-cysteine as ligands have similar particle sizes, and the scanning electron microscope images of L-type chiral manganese-based nanoflowers and D-type chiral manganese-based nanoflowers show certain multi-level structures.
[0059] Circular dichroism spectroscopy characterization: The chiral manganese-based nanozyme obtained by centrifugation purification was resuspended in ultrapure water and diluted to 0.5 mg / mL. Using ultrapure water as the baseline background, the scanning wavelength range was 250 to 800 nm, and the scanning speed was 1 s / nm. The circular dichroism spectrum, UV-Vis absorption spectrum, and g-factor spectrum of the chiral nanoflowers synthesized with L-cysteine and D-cysteine were obtained. Figure 3 , Figure 4 and Figure 5 ),from Figure 3 and Figure 5 The results show that the circular dichroism spectra of the nanoflowers induced by L-cysteine and D-cysteine exhibit good symmetry, with their characteristic peaks at the same positions, showing distinct circular dichroism peaks at wavelengths of 280 nm and 470 nm, respectively. Their highest g-factor value is 0.0008. Figure 4 It can be seen that the material has obvious absorption characteristic peaks in the range of 250-800nm;
[0060] Fourier transform infrared spectroscopy and X-ray electron diffraction spectroscopy characterization:
[0061] The powder obtained by vacuum drying of the chiral manganese-based nanowires purified by centrifugation was used to determine the infrared spectrum. Figure 6 ) and X-ray electron diffraction spectroscopy ( Figure 7 ),from Figure 6 It can be seen that the characteristic peak of thiol group in cysteine (labeled as L-Cys) before and after the reaction (2600 cm⁻¹) -1 The X-ray electron diffraction spectroscopy revealed that the synthesized chiral manganese-based nanowires possessed a specific crystal structure.
[0062] 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 chiral enantiomeric manganese-based nanoflowers, characterized in that, Includes the following steps: A mixed aqueous solution containing an assembly solvent, a manganese source, a chiral ligand, and a basic reducing agent is reacted to obtain the chiral enantiomer manganese-based nanoflowers. The chiral ligand is selected from L-cysteine and / or D-cysteine; The assembly solvent is selected from water-soluble alcohols.
2. The preparation method according to claim 1, characterized in that, Includes the following steps: An aqueous solution of a manganese source, an aqueous solution of a chiral ligand, and an aqueous solution of an alkaline reducing agent were added to a solution containing an assembly solvent, and the reaction was carried out to obtain the chiral enantiomer manganese-based nanoflowers. The chiral ligand is selected from L-cysteine and / or D-cysteine; The assembly solvent is selected from water-soluble alcohols.
3. The preparation method according to claim 2, characterized in that, The water-soluble alcohols are selected from at least one of methanol, ethanol, and isopropanol.
4. The preparation method according to claim 2, characterized in that, The manganese source in the manganese source solution is selected from at least one of manganese chloride, manganese sulfate, manganese carbonate, and manganese acetate.
5. The preparation method according to claim 2, characterized in that, The alkaline reducing agent is selected from at least one of sodium borohydride, hydrazine hydrate, hydroxylamine hydrochloride, and sodium hypochlorite.
6. The preparation method according to claim 2, characterized in that, The reaction conditions include: a reaction temperature of 20–40°C and a standing reaction time of 4–8 hours.
7. The preparation method according to claim 2, characterized in that, The concentration of the manganese source aqueous solution is 10–30 mg / mL; Preferably, the concentration of the chiral ligand aqueous solution is 10–20 mg / mL; Preferably, the concentration of the alkaline reducing agent aqueous solution is 2-6 mg / mL.
8. The preparation method according to claim 7, characterized in that, The volume ratio of the manganese source aqueous solution to the chiral ligand aqueous solution, the alkaline reducing agent aqueous solution, and the assembly solvent is (1-4):1:(1-4)(5-10).
9. The chiral enantiomeric manganese-based nanoflowers obtained by the preparation method according to any one of claims 1 to 8, characterized in that, The circular dichroism spectral characteristic peaks of the chiral manganese-based nanoflowers are 250-300 nm and 450-500 nm.
10. The chiral enantiomeric manganese-based nanoflower according to claim 9, characterized in that, The asymmetry factor g of the chiral manganese-based nanoflower is 0.0006-0.001.