Preparation method of rod-shaped, tetrapod-shaped gold nanocapsules

Abstract

The application provides a preparation method of rod-shaped and four-foot-shaped gold nanocapsules, and belongs to the field of interface modification. The method first prepares CTAB-stabilized rod-shaped / four-foot-shaped gold nanoparticles, replaces the CTAB with a mercapto-polyethylene glycol amino ligand to obtain polyethylene glycol modified gold nanoparticles with amino groups at the ends, then adds N-hydroxysuccinimide acrylate into the solution to react with the amino groups on the surface of the gold nanoparticles to obtain polyethylene glycol modified gold nanoparticles with double bonds at the ends, and finally adds a reaction monomer, a crosslinking agent and an initiator into the solution to perform in-situ radical polymerization to prepare the gold nanocapsules with a core-shell structure. The application modifies a crosslinked polymer shell layer on the surface of the rod-shaped and / or four-foot-shaped gold nanoparticles, so that the gold nanoparticles have high stability and can maintain the structural integrity in a physiological environment.

Description

Technical Field

[0001] The invention belongs to the field of interface modification, and in particular relates to a method for preparing rod-shaped and tetrapod-shaped gold nanocapsules. Background Art

[0002] Gold nanoparticles, as nanomaterials with unique physical and chemical properties, have recently demonstrated tremendous potential for application in fields such as catalysis, biomedicine, and electronics. With the continuous advancement of nanotechnology, research into the morphology control and performance of gold nanoparticles has attracted increasing attention. Among the various morphologies of gold nanoparticles, rod-shaped and tetrapod-shaped gold nanoparticles have attracted considerable attention due to their unique structural characteristics. Their unique geometric structures and excellent photophysical properties hold great promise for applications in optoelectronics, biosensing, catalysis, and biomedicine. However, their biomedical applications still face numerous challenges in surface modification.

[0003] The synthetic ligand of rod-shaped / tetrapod gold nanoparticles is CTAB, which has strong biological toxicity and requires surface ligand replacement. Currently, mercaptopolyethylene glycol is often used as a ligand to modify rod-shaped / tetrapod gold nanoparticles, but it still faces the following problems: (1) mercaptopolyethylene glycol is easily detached in complex physiological environments (LU J, XUE Y, SHI R, et al. A non-sacrificial method for the quantification of poly(ethylene glycol)grafting density on gold nanoparticles for applications in nanomedicine[J]. ChemSci, 2019, 10(7): 2067-74.); (2) there are still certain limitations in grafting mercaptopolyethylene glycol onto the surface of gold nanoparticles with special shapes to maintain their morphology. Summary of the Invention

[0004] The purpose of the present invention is to provide a method for preparing rod-shaped and tetrapod-shaped gold nanocapsules. The modification method realizes the successful encapsulation of the surface of gold nanoparticles of different shapes.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] The present invention provides a method for preparing rod-shaped and tetrapod-shaped gold nanocapsules, comprising:

[0007] Step 1: Prepare rod-shaped / tetrapod-shaped gold nanoparticle solution;

[0008] Step 2: Add ethanol solution and thiol polyethylene glycol amino solution to a reaction container, mix well, add the rod-shaped / tetrapod-shaped gold nanoparticle solution obtained in step 1, and react to obtain thiol polyethylene glycol amino-modified Au NR-PEG / NTPs-PEG solution;

[0009] Step 3: Add N-hydroxysuccinimide acrylate solution (NAS) to the thiol-polyethylene glycol amino-modified Au NR-PEG / NTPs-PEG solution of step 2 to react to obtain N-hydroxysuccinimide acrylate-modified Au NR-PEG-NAS / NTPs-PEG-NAS solution;

[0010] Step 4: Add an acrylic polymer monomer containing a double bond, a crosslinker, and a buffer solution into a reaction vessel to obtain a mixed solution, then add the N-hydroxysuccinimide acrylate-modified Au NR-PEG-NAS / NTPs-PEG-NAS solution from step 3 to the above mixed solution, then add tetramethylethylenediamine solution and stir evenly, and finally add ammonium persulfate solution to react to obtain rod-shaped and tetrapod-shaped gold nanocapsules.

[0011] Preferably, the reaction temperature in step 2 is room temperature, and the reaction time is 12-24 hours.

[0012] Preferably, the volume ratio of the ethanol solution, the thiol polyethylene glycol amino solution and the rod-shaped / tetrapod-shaped gold nanoparticle solution in step 2 is 90:4:5.

[0013] Preferably, the concentration of the thiol polyethylene glycol amino solution in step 2 is 50 mg / mL.

[0014] Preferably, the reaction temperature in step 3 is room temperature, and the reaction time is more than 4 hours.

[0015] Preferably, the concentration of the N-hydroxysuccinimide acrylate solution in step 3 is 10 mg / mL.

[0016] Preferably, the double bond-containing acrylic polymer monomer in step 4 is 2-methacryloyloxyethyl phosphorylcholine, acrylamide (AAM), N-(3-aminopropyl) methacrylamide (APM) or 2-acrylamido-2-methylpropanesulfonic acid (AMPS).

[0017] Preferably, the cross-linking agent in step 4 is N,N'-methylenebisacrylamide, glycerol 1,3-dimethacrylate, dimethacrylic anhydride oil or polyethylene glycol diacrylate.

[0018] Preferably, the volume ratio of the double bond-containing acrylic polymer monomer, crosslinker, N-hydroxysuccinimide acrylate-modified Au NR-PEG-NAS / NTPs-PEG-NAS solution, tetramethylethylenediamine solution and ammonium persulfate solution in step 4 is 53.3:23.1:300:8.85:34.2.

[0019] Preferably, the concentration of the double bond-containing acrylic polymer monomer in step 4 is 200 mg / mL, the concentration of the N-hydroxysuccinimide acrylate-modified Au NR-PEG-NAS / NTPs-PEG-NAS solution is 1 mg / mL, the concentration of the tetramethylethylenediamine solution is 775 mg / mL, and the concentration of the ammonium persulfate solution is 100 mg / mL.

[0020] Preferably, the reaction temperature in step 4 is room temperature, and the reaction time is more than 2 hours.

[0021] Beneficial effects of the present invention

[0022] The invention provides a method for preparing rod-shaped and tetrapod-shaped gold nanocapsules. The method comprises the following steps: firstly preparing CTAB-stabilized rod-shaped / tetrapod-shaped gold nanoparticles, performing thiol-polyethylene glycol amino ligand replacement to obtain polyethylene glycol-modified gold nanoparticles with amino groups at the ends; then adding N-hydroxysuccinimide acrylate to a solution to react with amino groups on the surfaces of the gold nanoparticles to obtain polyethylene glycol-modified gold nanoparticles with double bonds at the ends; and finally adding a reaction monomer, a crosslinking agent and an initiator to the solution to perform in-situ free radical polymerization to prepare gold nanocapsules with a core-shell structure. Compared with the existing technology, the present invention uses an in situ free radical polymerization method to introduce double bond polymerization sites on the surface of thiol-polyethylene glycol-modified gold nanoparticles with special shapes (rods, tetrapods). After adding monomers and initiators, a mild TEMED / APS initiation system is used to crosslink a layer of polymer network on the surface of the nanoparticles. Compared with traditional grafted polymers, this network polymer can effectively improve the stability of gold nanoparticles and effectively maintain the morphology and photophysical properties of the nanoparticles, providing a guarantee for the special-shaped gold nanoparticles to stably perform specific functions in the biomedical field. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 Transmission electron microscopy images of Au NR-PEG, n(Au NR), NTPs-PEG, and n(NTPs) prepared in Examples 1 and 2 of the present invention;

[0024] Figure 2 The stability test curves of the gold nanocapsules prepared in Example 1 of the present invention under different conditions;

[0025] Figure 3 Surface potential diagram of rod-shaped gold nanocapsules wrapped with different monomers prepared by changing the monomer type in Example 3;

[0026] Figure 4 Surface potential diagram of rod-shaped gold nanocapsules wrapped with different monomers prepared by changing the monomer type in Example 4. DETAILED DESCRIPTION

[0027] The present invention provides a method for preparing rod-shaped and tetrapod-shaped gold nanocapsules, comprising:

[0028] Step 1: preparing a solution of rod-shaped gold nanoparticles (Au NR) or a solution of tetrapod-shaped gold nanoparticles (NTPs); the preparation of the rod-shaped / tetrapod-shaped gold nanoparticle solution is not particularly limited and can be prepared using methods well known in the art;

[0029] Step 2: The rod-shaped / tetrapod-shaped gold nanoparticle solution obtained in step 1 is preferably centrifuged at 12000rpm for 15min to obtain a rod-shaped / tetrapod-shaped gold nanoparticle concentrate, and an ethanol solution and a thiol polyethylene glycol amino solution (SH-PEG-NH2, Mw=2000g / mol) are added to the reaction container. After mixing evenly, the above-mentioned rod-shaped / tetrapod-shaped gold nanoparticle concentrate is added, and ultrasonication is first performed, and the ultrasonication time is preferably 5-10min, and then the reaction is carried out. The reaction temperature is preferably room temperature, and the reaction time is preferably 12-24h to obtain a thiol polyethylene glycol amino-modified Au NR-PEG / NTPs-PEG solution; the volume ratio of the ethanol solution, the thiol polyethylene glycol amino solution and the rod-shaped / tetrapod-shaped gold nanoparticle solution is preferably 90:4:5, and the concentration of the thiol polyethylene glycol amino solution is preferably 50mg / mL.

[0030] Step 3: Adding N-hydroxysuccinimide acrylate solution (NAS) to the thiol polyethylene glycol amino-modified Au NR-PEG / NTPs-PEG solution of step 2 for reaction, wherein the reaction temperature is preferably room temperature, and the reaction time is preferably more than 4 h, more preferably 4 h, to obtain N-hydroxysuccinimide acrylate-modified Au NR-PEG-NAS / NTPs-PEG-NAS solution; the volume ratio of the thiol polyethylene glycol amino solution to the N-hydroxysuccinimide acrylate solution is preferably 40:3, and the concentration of the N-hydroxysuccinimide acrylate solution is preferably 10 mg / mL;

[0031] Step four: adding the acryl polymer monomer containing double bond, crosslinking agent and buffer solution into a reaction container to obtain a mixed solution, then adding the N-hydroxysuccinimide acrylate modified Au NR-PEG-NAS / NTPs-PEG-NAS solution of step three into the mixed solution and stirring uniformly, then adding tetramethyl ethylenediamine solution and stirring uniformly, and finally adding ammonium persulfate solution for reaction, wherein the reaction temperature is preferably room temperature, and the reaction time is preferably more than 2 hours, more preferably 2 hours, to obtain rod-shaped, four-legged gold nanocapsules n(Au NR) / n(NTPs).

[0032] According to the present application, the acryl polymer monomer containing double bond is preferably 2-methacryloyloxyethyl phosphorylcholine (MPC), acrylamide (AAM), N-(3-aminopropyl) methacrylamide (APM) or 2-acrylamido-2-methylpropanesulfonic acid (AMPS). The crosslinking agent is preferably N,N'-methylene bisacrylamide (BIS), glycerol 1,3-di-methacrylate, dimethyl acrylate anhydride oil or polyethylene glycol diacrylate, and the buffer solution is preferably a phosphate buffer solution.

[0033] According to the present application, the volume ratio of the acryl polymer monomer containing double bond, crosslinking agent, N-hydroxysuccinimide acrylate modified Au NR-PEG-NAS / NTPs-PEG-NAS, tetramethyl ethylenediamine solution and ammonium persulfate solution is preferably 53.3:23.1:300:8.85:34.2.

[0034] According to the present application, the concentration of the acryl polymer monomer containing double bond is preferably 200 mg / mL, the concentration of the N-hydroxysuccinimide acrylate modified Au NR-PEG-NAS / NTPs-PEG-NAS is preferably 1 mg / mL, the concentration of the tetramethyl ethylenediamine solution is preferably 775 mg / mL, the concentration of the ammonium persulfate solution is preferably 100 mg / mL, and the concentration of the phosphate buffer solution is preferably 0.1 mol / L.

[0035] The present application will be further described in detail below with reference to specific examples. The raw materials involved in the examples are commercially available.

[0036] Example 1

[0037] (1) Synthesis of rod-shaped gold nanoparticles (Au NR)

[0038] CTAB solution was prepared by adding 0.3645 g of cetyltrimethylammonium bromide (CTAB) into 3.5 g of deionized water. To the solution, 125 μL of 15 mM chloroauric acid solution was added, and 500 μL of 0.01 M sodium borohydride solution was quickly added under stirring at 25 °C. After stirring for 2 min, the solution was placed in a 25 °C water bath for 30 min to obtain a seed solution. 0.3645 g of CTAB was dissolved in 8.84 g of deionized water, and 400 μL of 4 mM silver nitrate solution, 520 μL of 15 mM chloroauric acid solution, and 124 μL of 0.08 M ascorbic acid solution were sequentially added. After shaking, the solution was controlled at a temperature of 24-26 °C, and 100 μL of the seed solution was quickly added. After shaking, the solution was placed in a 27.5 °C water bath for reaction for 12 h to obtain a solution of rod-shaped gold nanoparticles protected by a CTAB ligand.

[0039] (2) Au NR-PEG modified by thiol polyethylene glycol amino

[0040] The prepared solution of rod-shaped gold nanoparticles was centrifuged at 12000 rpm for 15 min to obtain 500 μL of concentrated solution of rod-shaped gold nanoparticles. A 20 mL glass bottle was taken, and 9 mL of ethanol solution and 400 μL of 50 mg / mL thiol polyethylene glycol amino solution (SH-PEG-NH2, Mw = 2000 g / mol) were added to the bottle, and the mixture was shaken. Under ultrasonic condition, 500 μL of the concentrated solution of rod-shaped gold nanoparticles was added, and after ultrasonic treatment for 5 min, the mixture was placed in a shaking bed for reaction at room temperature for 12 h to obtain a solution of Au NR-PEG modified by thiol polyethylene glycol amino.

[0041] (3) Au NR-PEG-NAS modified by N-hydroxysuccinimidyl acrylate

[0042] To the solution of Au NR-PEG, 30 μL of 10 mg / mL N-hydroxysuccinimidyl acrylate solution (NAS) was added, and the mixture was reacted at room temperature for 4 h.

[0043] (4) n(Au NR)

[0044] To a 1.5 mL centrifuge tube, add 53.3 μL of 200 mg / mL 2-methacryloyloxyethyl phosphorylcholine solution (MPC) as a monomer, 23.1 μL of 100 mg / mL N,N'-methylenebisacrylamide solution (BIS) as a crosslinker, 100 μL of 0.1 mol / L phosphate buffer, and 480 μL of deionized water, stirring uniformly. Add 300 μL of 1 mg / mL Au NR-PEG-NAS solution and stir uniformly. Add 8.85 μL of 775 mg / mL tetramethylethylenediamine solution (TEMED) and stir uniformly. Finally, add 34.2 μL of 100 mg / mL ammonium persulfate solution (APS) and stir uniformly. Allow to react at room temperature for 2 h to obtain a 0.3 mg / mL n(Au NR) solution.

[0045] Figure 2 The stability test curves of the gold nanocapsules prepared in Example 1 of the present invention under different conditions are shown in FIG. Figure 2 Figure A is a comparison of the relative absorbance (A / A0) of the absorption peaks of Au NR, Au NR-PEG, and n(Au NR) stored in aqueous solution for 0-30 days. It can be observed from the figure that the relative absorbance of n(Au NR) decreases the least compared with Au NR and Au NR-PEG, indicating that n(Au NR) has better storage stability. Figure 2 B is a comparison of the relative absorbance (A / A0) of the absorption peaks of Au NR, Au NR-PEG, and n(Au NR) after being stored in phosphate buffer solution (PBS) for 12 h and Au NR, Au NR-PEG, and n(Au NR) aqueous solutions frozen in a -20°C refrigerator for 12 h. It can be observed from the figure that the relative absorbance of n(Au NR) decreases the least compared with Au NR and Au NR-PEG, indicating that n(Au NR) has better salt solution stability. Figure 2 C is a comparison of the relative absorbance (A / A0) of the absorption peaks of Au NR, Au NR-PEG, and n(AuNR) after storage in different pH environments for 12 h. It can be observed from the figure that the relative absorbance of n(AuNR) decreases the least compared with Au NR and Au NR-PEG, indicating that n(Au NR) has better pH stability. Figure 2 D is a comparison of the relative absorbance (A / A0) of the absorption peaks of NTPs, NTPs-PEG, and n(NTPs) stored in aqueous solution for 0-30 days. It can be seen from the figure that the relative absorbance of n(NTPs) decreases the least compared with NTPs and NTPs-PEG, indicating that n(NTPs) has better storage stability; Figure 2E is a comparison of the relative absorbance (A / A0) of the absorption peaks of NTPs, NTPs-PEG, and n(NTPs) after being stored in phosphate buffer solution (PBS) for 12 h and NTPs, NTPs-PEG, and n(NTPs) aqueous solutions frozen in a -20°C refrigerator for 12 h. It can be observed from the figure that the relative absorbance of n(NTPs) decreases the least compared with NTPs and NTPs-PEG, indicating that n(NTPs) has better salt solution stability; Figure 2 Figure F compares the relative absorbance (A / A0) of NTPs, NTPs-PEG, and n(NTPs) after 12 hours of storage at different pH levels. The figure shows that n(NTPs) exhibits the smallest decrease in relative absorbance compared to NTPs and NTPs-PEG, indicating that n(NTPs) possesses superior pH stability. Overall, the high stability of gold nanocapsules under long-term storage, saline solutions, low temperatures, and varying pH levels demonstrates the effective protection of gold nanoparticles by this modification method.

[0046] Example 2

[0047] (1) Synthesis of tetrapod-shaped gold nanoparticles (NTPs)

[0048] Add 0.1823g of CTAB to 3.5g of deionized water to create a CTAB solution. Add 125μL of 15mM chloroauric acid solution to the solution. Rapidly add 500μL of 0.01M sodium borohydride solution while stirring at 25.5°C. Stir vigorously for 2 minutes and place in a 25.5°C water bath for 30 minutes to create a seed solution. Designate two glass bottles, designated bottles A and B. To bottle A, add 620μL of deionized water, 3ml of 0.1M CTAB solution, 380μL of 15mM chloroauric acid solution, 3ml of 0.1M hexamethylenetetramine (HMT) solution, and 1ml of 0.01M ascorbic acid solution. To bottle B, add 6ml of deionized water, 60μL of 1M sodium hydroxide solution, and 5μL of the seed solution. Within 45 seconds of preparing the solution in bottle A, prepare solution B and add it to the solution in bottle A, shake well, and place in a 25°C water bath for 5 minutes to obtain a CTAB ligand-protected tetrapod gold nanoparticle solution.

[0049] (2) NTPs-PEG modified with thiol polyethylene glycol amino groups

[0050] The prepared tetrapod gold nanoparticle solution was centrifuged at 12,000 rpm for 15 minutes to obtain 500 μL of tetrapod gold nanoparticle concentrate. In a 20 mL glass bottle, 9 mL of ethanol and 400 μL of a 50 mg / mL thiol-polyethylene glycol amino solution (SH-PEG-NH2, Mw = 2000 g / mol) were added and shaken thoroughly. While sonicating the solution, 500 μL of the tetrapod gold nanoparticle concentrate was added. After sonication for 5 minutes, the solution was placed on a shaker at room temperature for 12 hours to obtain a thiol-polyethylene glycol amino-modified NTPs-PEG solution.

[0051] (3) N-hydroxysuccinimide acrylate modified NTPs-PEG-NAS

[0052] 30 μL of 10 mg / mL N-hydroxysuccinimide acrylate solution (NAS) was added to the NTPs-PEG solution and reacted at room temperature for 4 h.

[0053] (4) Tetrapod-shaped gold nanocapsules (n(NTPs))

[0054] To a 1.5 mL centrifuge tube, add 53.3 μL of 200 mg / mL 2-methacryloyloxyethyl phosphorylcholine solution (MPC) as a monomer, 23.1 μL of 100 mg / mL N,N'-methylenebisacrylamide solution (BIS) as a crosslinker, 100 μL of 0.1 mol / L phosphate buffer, and 480 μL of deionized water, stirring thoroughly. Add 300 μL of 1 mg / mL NTPs-PEG-NAS solution and stir thoroughly. Add 8.85 μL of 775 mg / mL tetramethylethylenediamine solution (TEMED) and stir thoroughly. Finally, add 34.2 μL of 100 mg / mL ammonium persulfate solution (APS) and stir thoroughly. Allow to react at room temperature for 2 hours to obtain a 0.3 mg / mL n(NTPs) solution.

[0055] Figure 1 Transmission electron microscopy images of Au NR-PEG, n(Au NR), NTPs-PEG, and n(NTPs) prepared in Examples 1 and 2 of the present invention. It can be seen from the figure that the lateral size of the Au NR is about 9 nm and the longitudinal size is about 33 nm. No polymer morphology is observed around the Au NR ( Figure 1 A), after in situ free radical polymerization to form n(Au NR), there is a white polymer shell around the AuNR. After measurement, the shell thickness is about 6.97nm ( Figure 1 B), this change proves the successful encapsulation of the polymer on the Au NR surface and the successful preparation of the rod-shaped gold nanocapsules; Figure 1As can be seen in C and 1D, the trunk diameter of NTPs is about 13 nm, the branch size is about 18 nm, and no polymer morphology is observed around NTPs ( Figure 1 C), after in situ free radical polymerization to form n(NTPs), a white polymer shell is formed around the Au NR. The shell thickness is measured to be about 3.42 nm ( Figure 1 D), this change proves the successful encapsulation of polymer on the surface of NTPs and the successful preparation of tetrapod-shaped gold nanocapsules.

[0056] Example 3

[0057] The preparation steps and conditions were the same as those in Example 1, except that BIS was used as the cross-linking agent and only the type of monomer was changed to prepare rod-shaped gold nanocapsules coated with different monomers.

[0058] Figure 3 Surface potential diagrams of rod-shaped gold nanocapsules coated with different monomers prepared by changing the monomer type in Example 3, wherein neutral AAM is used as the reaction monomer to prepare rod-shaped gold nanocapsules, which are labeled as n(Au NR) / AAM; AAM is used as the main reaction monomer and positively charged APM is used as the secondary reaction monomer (AAM:APM molar ratio = 10:1) to prepare rod-shaped gold nanocapsules, which are labeled as n(Au NR) / AAM+; AAM is used as the main reaction monomer and negatively charged AMPS is used as the secondary reaction monomer (AAM:AMPS molar ratio = 10:1) to prepare rod-shaped gold nanocapsules, which are labeled as n(Au NR) / AAM-; zwitterionic monomer MPC is used as the reaction monomer to prepare rod-shaped gold nanocapsules, which are labeled as n(Au NR) / MPC; MPC is used as the main reaction monomer and positively charged APM is used as the secondary reaction monomer (MPC:APM molar ratio = 10:1) to prepare rod-shaped gold nanocapsules, which are labeled as n(Au Rod-shaped gold nanocapsules, labeled n(Au NR) / MPC-, were prepared by mixing MPC as the primary monomer and negatively charged AMPS as the secondary monomer (MPC:AMPS molar ratio = 10:1). This demonstrates that the surface potential of gold nanocapsules can be manipulated by varying the monomer types and mixing ratios.

[0059] Example 4

[0060] The preparation steps and conditions were the same as those in Example 2, except that BIS was used as the cross-linking agent and only the type of monomer was changed to prepare tetrapod-shaped gold nanocapsules coated with different monomers.

[0061] Figure 4Surface potential diagrams of tetrapod-shaped gold nanocapsules wrapped with different monomers prepared by changing the monomer type in Example 4, wherein neutral AAM is used as the reaction monomer to prepare tetrapod-shaped gold nanocapsules, marked as n(NTPs) / AAM; AAM is used as the main reaction monomer and positively charged APM is used as the secondary reaction monomer (AAM:APM molar ratio = 10:1) to prepare tetrapod-shaped gold nanocapsules, marked as n(NTPs) / AAM+; AAM is used as the main reaction monomer and negatively charged AMPS is used as the secondary reaction monomer (AAM:AMPS molar ratio = 10:1) to prepare tetrapod-shaped gold nanocolloids The researchers used the zwitterionic monomer MPC as a reactive monomer to prepare rod-shaped gold nanocapsules, labeled n(NTPs) / MPC. They used MPC as the primary reactive monomer and the positively charged APM as a secondary reactive monomer (MPC:APM molar ratio = 10:1) to prepare tetrapod-shaped gold nanocapsules, labeled n(ANTPs) / MPC+. They also used MPC as the primary reactive monomer and the negatively charged AMPS as a secondary reactive monomer (MPC:AMPS molar ratio = 10:1) to prepare tetrapod-shaped gold nanocapsules, labeled n(NTPs) / MPC-. It can be seen that the surface potential of gold nanocapsules can be controlled by changing the type and mixing ratio of the monomers.

Claims

1. A method for preparing rod-shaped or tetrapod-shaped gold nanocapsules, characterized in that: include: Step 1: Prepare rod-shaped / tetrapod-shaped gold nanoparticle solution; Step 2: Add ethanol solution and thiol polyethylene glycol amino solution to a reaction vessel, mix well, then add the rod-shaped / tetrapod-shaped gold nanoparticle solution obtained in step 1, and react to obtain a thiol polyethylene glycol amino-modified Au NR-PEG / NTPs-PEG solution; Step 3: Add N-hydroxysuccinimide acrylate solution to the thiol-polyethylene glycol amino-modified Au NR-PEG / NTPs-PEG solution of step 2 to react and obtain N-hydroxysuccinimide acrylate-modified Au NR-PEG-NAS / NTPs-PEG-NAS solution; Step 4: Add an acrylic polymer monomer containing a double bond, a crosslinker, and a buffer solution to a reaction vessel to obtain a mixed solution, then add the N-hydroxysuccinimide acrylate-modified Au NR-PEG-NAS / NTPs-PEG-NAS solution of step 3 to the mixed solution, then add tetramethylethylenediamine solution and stir evenly, and finally add ammonium persulfate solution to react to obtain rod-shaped and tetrapod-shaped gold nanocapsules; The volume ratio of the ethanol solution, the thiol polyethylene glycol amino solution and the rod-shaped / tetrapod-shaped gold nanoparticle solution described in step 2 is 90:4:5; The double bond-containing acrylic polymer monomer in step 4 is 2-methacryloyloxyethyl phosphorylcholine, acrylamide, N-(3-aminopropyl)methacrylamide or 2-acrylamido-2-methylpropanesulfonic acid; The cross-linking agent in step 4 is N,N'-methylenebisacrylamide, glycerol 1,3-diisoacrylate, dimethacrylic anhydride oil or polyethylene glycol diacrylate; The volume ratio of the double-bond-containing acrylic polymer monomer, cross-linking agent, N-hydroxysuccinimide acrylate-modified Au NR-PEG-NAS / NTPs-PEG-NAS solution, tetramethylethylenediamine solution and ammonium persulfate solution described in step 4 is 53.3:23.1:300:8.85:34.

2.

2. The method for preparing rod-shaped or tetrapod-shaped gold nanocapsules according to claim 1, wherein: The concentration of the thiol polyethylene glycol amino solution described in step 2 is 50 mg / mL.

3. The method for preparing rod-shaped or tetrapod-shaped gold nanocapsules according to claim 1, wherein: The reaction temperature in step 3 is room temperature, and the reaction time is more than 4 hours.

4. The method for preparing rod-shaped or tetrapod-shaped gold nanocapsules according to claim 1, wherein: The concentration of the N-hydroxysuccinimide acrylate solution in step 3 is 10 mg / mL.

5. The method for preparing rod-shaped or tetrapod-shaped gold nanocapsules according to claim 1, wherein: The concentration of the double-bond acrylic polymer monomer described in step 4 is 200 mg / mL, the concentration of the N-hydroxysuccinimide acrylate-modified Au NR-PEG-NAS / NTPs-PEG-NAS solution is 1 mg / mL, the concentration of the tetramethylethylenediamine solution is 775 mg / mL, and the concentration of the ammonium persulfate solution is 100 mg / mL.

6. The method for preparing rod-shaped or tetrapod-shaped gold nanocapsules according to claim 1, characterized in that: The reaction temperature in step 4 is room temperature, and the reaction time is more than 2 hours.

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