A preparation method for constructing gold-silver heterogeneous nanoclusters
By mixing gold and silver nanoclusters and adding polymers under high-frequency ultrasound, a gold-silver heterogeneous nanocluster structure with high biocompatibility was prepared, which solved the problem of harsh preparation conditions in the existing technology and achieved morphology control and wide application.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- RONGHAI SUPERSONIC MEDICINE EN
- Filing Date
- 2022-07-26
- Publication Date
- 2026-05-26
Smart Images
Figure CN117505839B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of alloy nanoparticle technology, specifically to a method for constructing gold-silver heterogeneous nanocluster structures. Background Technology
[0002] Metal nanoparticles possess unique optical, electrical, and catalytic properties, as well as good stability, with particle sizes ranging from 10 to 100 nm. Metal nanoclusters, composed of anywhere from a few to hundreds of atoms with particle sizes less than 3 nm, represent a highly promising new type of functional material. Fundamental research on metal nanoclusters began in the 1960s. By controlling the number of atoms in metal nanoclusters, various materials with different physicochemical properties can be created using a single metal element. Using multiple elements may further increase the diversity of functions.
[0003] In recent decades, noble metal nanoclusters, composed of several to hundreds of noble metal atoms such as gold, silver, and copper, have attracted widespread attention due to their unique physicochemical properties (such as magnetic, optical, thermal, and electrical properties), ultra-small size, controllable emission range, strong stability, good water solubility, and good biocompatibility.
[0004] Copper nanoclusters synthesized using DNA as a template formed DNA-Cu NCs / CDs self-assembled complexes through electrostatic interactions with carbon quantum dots. This demonstrates that constructing heterostructures through assembly not only provides a feasible approach to the application of nanomaterials but also generates new physical or chemical functions, extending the functionality of individual building blocks through collective behavior. Traditionally, these assembly processes presuppose that the shape and structure of the assembled structure should be exceptionally stable when exposed to different media. This requirement severely limits the application range of controllably assembled nanoparticles, as the synthesis of metallic or non-metallic multiphase nanoparticles is both time-consuming and expensive, requiring precise control during nucleation and growth, resulting in demanding preparation conditions for heterostructures. Other currently employed methods also encounter the problem of demanding preparation conditions.
[0005] Preparation under high temperature, high pressure, vacuum, or organic solvent conditions is often difficult to achieve under normal conditions. Existing research on the preparation of cluster assembly structures has employed too many modifying materials, such as liposomes and chitosan, through surface chemical modifications (esterification, coupling agents, and surface grafting). Furthermore, the assembly structures prepared by existing techniques do not exhibit properties that are different from or more prominent than their individual components, especially in heterogeneous assembly structures, where the advantages of ordered assembly and the necessity of assembly fabrication are not highlighted. Summary of the Invention
[0006] I. Technical problems to be solved
[0007] To address the shortcomings of existing technologies, this invention provides a method for constructing gold-silver heterogeneous nanocluster structures.
[0008] The preparation method can obtain spherical particles with a particle size of 100~200nm and porous spherical structures with a particle size of 50nm or larger.
[0009] The gold-silver heterogeneous assembly structure has high biocompatibility and good surface modifiability.
[0010] II. Technical Solution
[0011] To achieve the above objectives, the present invention provides the following technical solution:
[0012] A method for constructing gold-silver heterogeneous nanoclusters involves mixing gold and silver nanoclusters, adding polyvinylpyrrolidone or polyethylene glycol, reacting under high-frequency ultrasound in the dark, and then dialysis to purify the mixture to obtain gold-silver heterogeneous nanoclusters.
[0013] Optionally, the frequency of the high-frequency ultrasound is 4~6MHz and the power is 8~18W.
[0014] Optionally, the concentration of the gold nanoclusters is 25-30 mg / ml, and / or the concentration of the silver nanoclusters is 18-20 mg / ml.
[0015] Optionally, the gold nanoclusters and silver nanoclusters are mixed in an equal volume ratio.
[0016] Optionally, the morphology of the gold and silver heterogeneous nanoclusters can be controlled by the amount of polyvinylpyrrolidone or polyethylene glycol added.
[0017] Optionally, the volume ratio of the gold nanoclusters to the added weight of polyvinylpyrrolidone is 3.5~50 ml / g.
[0018] Optionally, the volume ratio of the gold nanoclusters to the polyethylene glycol is 0.7 to 2.
[0019] Optionally, the preparation process of the gold nanoclusters is as follows: after mixing the gold precursor with the reducing agent, a solvent is added, and ultrasonic treatment is performed to promote dissolution. When the mixed solution is milky white, the mixture is stirred until it turns bright yellow, thus obtaining the gold nanoclusters.
[0020] Optionally, the preparation process of the silver nanoclusters is as follows: after mixing the silver precursor and stabilizer, a solvent is added, and ultrasonic treatment is performed to promote dissolution until the mixed solution is milky white. Then, the mixture is stirred in an ice bath to react. Finally, a reducing agent is added to the mixed solution, and the mixture is stirred in an ice bath to react fully to obtain the silver nanoclusters.
[0021] A gold-silver heterogeneous nanocluster prepared using any of the above examples is also provided.
[0022] III. Beneficial Effects
[0023] 1. By adding polymer materials of different masses or volumes and combining them with ultrasonic induction, spherical or porous gold-silver heterogeneous nanocluster structures are obtained, thereby achieving directional control of the morphology and diversified preparation of gold-silver heterogeneous nanoclusters.
[0024] 2. The gold-silver heterogeneous nanocluster structure also exhibits significant high loading capacity and high biocompatibility, and can be used for drug delivery, imaging examination, etc.
[0025] 3. The synthesis method is simple, low-cost, and can be synthesized in large quantities. It has a wide range of applications and can be used for the large-scale preparation of various hollow micro and nano materials. Attached Figure Description
[0026] Figure 1 shows the synthesis mechanism of gold-silver heterogeneous nanoclusters induced by ultrasound.
[0027] Figure 2 shows a lens image of gold-silver heterogeneous nanoclusters at 0.2g PVP.
[0028] Figure 3 shows a lens image of gold-silver heterogeneous nanoclusters at 1g PVP;
[0029] Figure 4 shows a lens image of gold-silver heterogeneous nanoclusters at 2g PVP;
[0030] Figure 5 shows a lens image of gold-silver heterogeneous nanoclusters in 5 ml PEG400.
[0031] Figure 6 shows a lens image of gold-silver heterogeneous nanoclusters in 10 ml PEG400;
[0032] Figure 7 shows the morphology of gold-silver heterogeneous nanoclusters under different ultrasonic powers (where a is the lens image of gold-silver heterogeneous nanoclusters under PVP 18W ultrasonic power, b is the lens image of gold-silver heterogeneous nanoclusters under PVP 13W ultrasonic power, c is the lens image of gold-silver heterogeneous nanoclusters under PVP 8W ultrasonic power, d is the lens image of gold-silver heterogeneous nanoclusters under PEG400 18W ultrasonic power, e is the lens image of gold-silver heterogeneous nanoclusters under PEG400 13W ultrasonic power, and f is the lens image of gold-silver heterogeneous nanoclusters under PEG400 8W ultrasonic power).
[0033] Figure 8 shows the porosity image of the gold-silver heterogeneous nanoclusters;
[0034] Figure 9 shows the fluorescence of gold-silver heterogeneous nanoclusters acting on 293T cells, HACAT cells, and IMEF cells.
[0035] Figure 10 shows the cell viability histogram of 293T cells when gold and silver heterogeneous nanoclusters of different concentrations were applied.
[0036] Figure 11 shows the cell activity bar graphs of HACAT cells when different concentrations of gold and silver heterogeneous nanoclusters were applied.
[0037] Figure 12 shows the cell activity bar graphs of IMEF cells when gold and silver heterogeneous nanoclusters of different concentrations were applied.
[0038] Figure 13 is a bar chart showing the drug loading of gold-silver heterogeneous nanoclusters used for loading doxorubicin. Detailed Implementation
[0039] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0040] Unless otherwise specified, all raw materials used in this invention can be obtained commercially, and the equipment used in this invention can be conventional equipment in the relevant field or refer to existing technology in the relevant field.
[0041] Examples 1-11
[0042] This invention discloses a method for preparing gold-silver heterogeneous nanocluster structures:
[0043] I. Preparation of Gold Nanoclusters
[0044] Mix 0.1–0.2 g of the gold precursor tetrachloroauric acid trihydrate (HAuCl4·3H2O) and 0.046–0.05 g of the reducing agent reduced glutathione (L-GSH), add 50 ml of deionized water, and dissolve in a round-bottom flask to maintain a molar ratio of 1:1.5. Sonicate for 5 minutes to promote dissolution. When the mixed solution turns milky white, transfer the entire reaction system to a magnetic stirrer and stir continuously for 5 hours at 80°C and 500 rpm. Observe the color change of the solution; if it changes from milky white to bright yellow, it indicates successful synthesis of gold nanoclusters. After the solution temperature drops to room temperature, collect the sample and store it at 4°C.
[0045] II. Preparation of Silver Nanoclusters
[0046] Mix 0.0425 g to 0.045 g of silver nitrate (the silver precursor) and 0.30 to 0.31 g of glutathione (the stabilizer), add 50 ml of deionized water, and dissolve in a round-bottom flask. Sonicate for 5 minutes to promote dissolution; the resulting solution is milky white. Place the solution in a magnetic stirrer containing crushed ice and stir for 30 minutes in an ice bath. Then, add NaBH4 at a rate of 0.0075 to 0.0076 g / ml. The entire reaction system is stirred continuously in an ice bath for 3 hours to complete the preparation of silver nanoclusters. Because silver is easily oxidized, the sample should be wrapped in aluminum foil and stored at 4°C to protect it from light.
[0047] III. Preparation of Gold-Silver Heterogeneous Nanocluster Structures
[0048] The purified gold nanoclusters (25–30 mg / ml) and silver nanoclusters (18–20 mg / ml) were prepared and purified, with 7–10 ml of each added to a small beaker. 0.2–2 g of polyvinylpyrrolidone or 5–10 ml of polyethylene glycol were added to the mixed solution, and the mixture was reacted under high-frequency ultrasound for 8 h at a frequency of 4–6 MHz and a power of 8–18 W. The entire experiment was conducted in the dark. Finally, the mixture was purified by dialyzing with Milli-Q water at room temperature, with a 1 kDa cutoff, to obtain the gold-silver heterogeneous nanocluster structure. The synthesis mechanism is shown in Figure 1.
[0049]
[0050] Example 2
[0051] Example 12: Effect of polyvinylpyrrolidone (PVP) on the morphology of gold-silver heterogeneous nanoclusters at different ratios. The gold-silver heterogeneous nanoclusters prepared in Examples 1, 2, and 3 were observed by transmission electron microscopy. The results are shown in Figures 2, 3, and 4. Figure 2 is a lens image of the gold-silver heterogeneous nanoclusters with 0.2 g PVP.
[0052] Figure 3 shows the lens image of the gold-silver heterogeneous nanoclusters at 1g PVP; Figure 4 shows the lens image of the gold-silver heterogeneous nanoclusters at 2g PVP.
[0053] Results explanation:
[0054] 1. The gold-silver heterogeneous nanoclusters prepared with 0.2g and 1g PVP exhibit spherical morphology with particle sizes ranging from 100 to 200 nm; the gold-silver heterogeneous nanoclusters prepared with 2g PVP exhibit porous spherical morphology with particle sizes exceeding 50 nm. In contrast, the particle sizes of single-component gold and silver nanoclusters are significantly smaller than 50 nm, thus increasing the particle size of the gold-silver heterogeneous nanoclusters.
[0055] 2. Different morphologies of products can be obtained by adding different masses of PVP. When too little PVP is added, the attachment points of gold and silver nanoclusters decrease, coupling becomes less, and the final sample has irregular and uniform morphology, with fewer formations. When too much PVP is added, due to the influence of chemical bonds and intermolecular forces, gold and silver nanoclusters in the entire solution are difficult to aggregate and form assembled structures.
[0056] Example 13: Effect of polyethylene glycol (PEG400) on the structural morphology of gold-silver heterogeneous nanoclusters at different ratios. The gold-silver heterogeneous nanoclusters prepared in Examples 7 and 8 were observed by transmission electron microscopy. The results are shown in Figures 5 and 6. Figure 5 is a lens image of the gold-silver heterogeneous nanoclusters with 5 ml of PEG400.
[0057] Figure 6 shows a lens image of gold-silver heterogeneous nanoclusters in 10 ml PEG400.
[0058] Results explanation:
[0059] The gold-silver heterogeneous nanoclusters prepared with 1.5 ml PEG400 had a spherical morphology; the gold-silver heterogeneous nanoclusters prepared with 10 ml PEG400 had a porous spherical morphology.
[0060] 2. Different morphologies of products can be obtained by adding different volumes of PEG400. When too little PEG400 is added, the attachment points of gold and silver nanoclusters decrease, coupling becomes less, and the final sample has irregular and uniform morphology, with fewer formations. When too much PEG400 is added, due to the influence of chemical bonds and intermolecular forces, gold and silver nanoclusters in the entire solution are difficult to aggregate and form assembled structures.
[0061] Example 14: Effect of different ultrasonic powers on the morphology of gold-silver heterogeneous nanoclusters
[0062] The gold-silver heterogeneous nanoclusters prepared in Examples 4, 5, 6, 9, 10, and 11 were observed using transmission electron microscopy. The results are shown in Figures 7a, b, and c. a is a lens image of the gold-silver heterogeneous nanoclusters under a PVP ultrasonic power of 18W, b is a lens image of the gold-silver heterogeneous nanoclusters under a PVP ultrasonic power of 13W, c is a lens image of the gold-silver heterogeneous nanoclusters under a PVP ultrasonic power of 8W, d is a lens image of the gold-silver heterogeneous nanoclusters under a PEG400 ultrasonic power of 18W, e is a lens image of the gold-silver heterogeneous nanoclusters under a PEG400 ultrasonic power of 13W, and f is a lens image of the gold-silver heterogeneous nanoclusters under a PEG400 ultrasonic power of 8W.
[0063] Results explanation:
[0064] 1. As can be seen from Figures 7a, b, and c, as the ultrasonic power increases, the particle size of the gold-silver heterogeneous nanoclusters decreases, the shape becomes more regular and controllable, and the number of assembled heterogeneous Au-Ag structures formed by small particles bonded together gradually increases. Increased ultrasonic power enhances cavitation, increases solution supersaturation, and consequently increases assembly rate and particle size. Therefore, the particle size of the 18W assembled heterogeneous Au-Ag structure is smaller than that of the 13W and 8W structures, and more of these structures are generated. Furthermore, PVP, with its C=O structure, is less prone to breakage under ultrasonication. As a high-performance nonionic polymer, PVP is chemically stable and possesses excellent emulsifying, dispersing, and solubilizing properties. During the reaction, it acts as a stabilizer, effectively preventing the aggregation of the assembled heterogeneous Au-Ag structure during preparation. It also strengthens the bonding strength between gold and silver nanoclusters and effectively guides the surface growth of the assembled heterogeneous Au-Ag structure, forming regularly shaped spherical aggregates.
[0065] 2. As can be seen from Figures 7d, e, and f, the regular shape of the assembled structure is difficult to form as the ultrasonic power increases. This is because PEG400 has hydroxyl groups (-OH), which have a certain reducing property, and PEG400 is easily activated. With the increase of ultrasonic power, the cavitation effect increases—the instantaneous energy release causes the breakage of the CO and COH functional groups. Therefore, the assembled structure of PEG400 is not easy to form at high power. PEG400 can also be used as a stabilizer to control the growth of nanoparticles. The lower the power, the less energy is released by the ultrasonic cavitation effect, and the lower the activation of PEG400. PEG400 acts as a stabilizer and dispersant to control the growth of assembled heterogeneous Au-Ag structures, resulting in more assembled heterogeneous Au-Ag structures with controllable shapes.
[0066] In general, different ultrasonic powers can control the morphology and structure of gold-silver heterogeneous nanoclusters.
[0067] Example 15: Porosity Detection
[0068] The porosity of the gold-silver heterogeneous nanoclusters in Example 3 was measured, and the results are shown in Figure 8 (porosity image).
[0069] Results show that the porosity image represents a porous structure, and the peaks represent the pore sizes with different particle sizes in the 0-10 nm range, with the 1.358 nm pore size being the most common.
[0070] Example 16: Biocompatibility Testing
[0071] The gold-silver heterogeneous nanoclusters prepared in Example 3 were used to conduct biocompatibility tests on 293T cells, HACAT cells, and IMEF cells, respectively. At the same time, the gold-silver heterogeneous nanoclusters prepared in Example 11 were used to conduct biocompatibility tests on 293T cells, HACAT cells, and IMEF cells, respectively. The 293T cells, HACAT cells, and IMEF cells were stained with a live-dead cell staining agent. The live cells showed green fluorescence, and the dead cells showed red fluorescence. The results are shown in the fluorescence diagram in Figure 9 and the bar charts in Figures 10, 11, and 12.
[0072] Results show that, as can be seen from Figure 9, under the action of gold-silver heterogeneous nanoclusters, 293T cells, HACAT cells, and IMEF cells are basically green fluorescent live cells, indicating that it has no effect on cells and has high biocompatibility.
[0073] As shown in Figure 10, the activity of gold-silver heterogeneous nanoclusters at different concentrations fluctuated in 293T cells, HACAT cells, and IMEF cells, but the cell activity remained above 90%, which also indicates that they have high biocompatibility.
[0074] Example 17: Drug Loading Detection
[0075] The gold-silver heterogeneous nanoclusters prepared in Examples 3 and 11 were used for doxorubicin drug loading detection, and the drug loading was determined by ultraviolet spectroscopy as shown in Figure 13.
[0076] Results show that, as can be seen from Figure 13, gold and silver heterogeneous nanoclusters with different morphologies can all achieve drug loading, but their drug loading amounts are different.
[0077] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.
[0078] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.
Claims
1. A method for constructing gold-silver heterogeneous nanoclusters, characterized in that: Gold and silver nanoclusters were mixed, and then polyvinylpyrrolidone or polyethylene glycol was added. The mixture was subjected to a light-protected reaction under high-frequency ultrasound and purified by dialysis to obtain gold-silver heterogeneous nanoclusters. The frequency of the high-frequency ultrasound was 4-6 MHz and the power was 8-18 W.
2. The preparation method for constructing gold-silver heterogeneous nanoclusters according to claim 1, characterized in that: The concentration of the gold nanoclusters is 25–30 mg / ml, and / or the concentration of the silver nanoclusters is 18–20 mg / ml.
3. The preparation method for constructing gold-silver heterogeneous nanoclusters according to claim 2, characterized in that: The gold nanoclusters and the silver nanoclusters are mixed in equal volume ratios.
4. The preparation method for constructing gold-silver heterogeneous nanoclusters according to claim 2, characterized in that: The morphology of the gold-silver heterogeneous nanoclusters is controlled by the amount of polyvinylpyrrolidone or polyethylene glycol added.
5. The preparation method for constructing gold-silver heterogeneous nanoclusters according to claim 4, characterized in that: The volume ratio of the gold nanoclusters to the added weight of the polyvinylpyrrolidone is 3.5–50 ml / g.
6. The preparation method for constructing gold-silver heterogeneous nanoclusters according to claim 4, characterized in that: The volume ratio of the gold nanoclusters to the polyethylene glycol is 0.7 to 2.
7. The preparation method for constructing gold-silver heterogeneous nanoclusters according to claim 1, characterized in that... The preparation process of the gold nanoclusters is as follows: after mixing the gold precursor with the reducing agent, a solvent is added, and ultrasonic treatment is performed to promote dissolution. When the mixed solution is milky white, the mixture is stirred until it turns bright yellow, thus obtaining the gold nanoclusters.
8. The preparation method for constructing gold-silver heterogeneous nanoclusters according to claim 1, characterized in that... The preparation process of the silver nanoclusters is as follows: after mixing the silver precursor and stabilizer, a solvent is added, and ultrasonic treatment is performed to promote dissolution until the mixed solution is milky white. Then, the mixture is stirred in an ice bath to react. Finally, a reducing agent is added to the mixed solution, and the mixture is stirred in an ice bath to react fully to obtain the silver nanoclusters.
9. A gold-silver heterogeneous nanocluster prepared by the preparation method according to any one of claims 1 to 8.