Preparation method of rod-shaped and four-foot-shaped gold nanocapsules

Abstract

The invention provides a preparation method of rod-shaped and four-foot-shaped gold nanocapsules, and belongs to the field of interface modification. The method comprises the following steps: firstly, preparing CTAB (Cetyltrimethyl Ammonium Bromide) stable rod-shaped / four-foot-shaped gold nanoparticles, replacing by a sulfydryl polyethylene glycol amino ligand to obtain polyethylene glycol modified gold nanoparticles with amino groups at the tail ends, and then adding N-hydroxysuccinimide acrylate into a solution to react with the amino groups on the surfaces of the gold nanoparticles, so as to obtain the gold nanoparticles. And finally, adding a reaction monomer, a cross-linking agent and an initiator into the solution, and carrying out in-situ free radical polymerization, so as to prepare the gold nanocapsule with the core-shell structure. The surface of the rod-shaped and / or four-foot-shaped gold nanoparticle is modified with a cross-linked polymer shell layer, so that the rod-shaped and / or four-foot-shaped gold nanoparticle is endowed with higher stability, and the structural integrity can be kept 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] As a nanomaterial with unique physical and chemical properties, gold nanoparticles have shown great application potential in catalysis, biomedicine, electronics and other fields in recent years. With the continuous development of nanotechnology, people are paying more and more attention to the morphology control and performance research of gold nanoparticles. Among the many morphologies of gold nanoparticles, rod-shaped and tetrapod-shaped gold nanoparticles have attracted much attention due to their unique structural characteristics. Rod-shaped and tetrapod-shaped gold nanoparticles have broad application prospects in optoelectronics, biosensors, catalysis and biomedicine due to their unique geometric structure and excellent photophysical properties. However, if rod-shaped and tetrapod-shaped gold nanoparticles are to be applied in the biomedical field, they still face many challenges in their 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, thiol polyethylene glycol is commonly used as a ligand to modify rod-shaped / tetrapod gold nanoparticles, but it still faces the following problems: (1) thiol polyethylene 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 thiol polyethylene 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 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 solution:

[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 into a reaction container, mix well, add the rod-shaped / tetrapod-shaped gold nanoparticle solution obtained in step 1, react, and obtain a thiol polyethylene glycol amino-modified Au NR-PEG / NTPs-PEG solution;

[0009] Step 3: Add N-hydroxysuccinimide acrylate solution (NAS) to the Au NR-PEG / NTPs-PEG solution modified with thiol polyethylene glycol amino groups in step 2 to react, thereby obtaining an Au NR-PEG-NAS / NTPs-PEG-NAS solution modified with N-hydroxysuccinimide acrylate;

[0010] Step 4: Add an acryloyl polymer monomer containing a double bond, a crosslinker and a buffer solution into a reaction container to obtain a mixed solution, then add the Au NR-PEG-NAS / NTPs-PEG-NAS solution modified with N-hydroxysuccinimide acrylate in step 3 into 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.

[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 described 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 three 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, dimethyl acrylate or polyethylene glycol diacrylate.

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

[0019] Preferably, the concentration of the double bond-containing acryloyl polymer monomer described in step 4 is 200 mg / mL, the concentration of the Au NR-PEG-NAS / NTPs-PEG-NAS solution modified with N-hydroxysuccinimide acrylate 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 rod-shaped / tetrapod-shaped gold nanoparticles stabilized by CTAB, replacing thiol polyethylene glycol amino ligands 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 prior art, 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 (rod-shaped, tetrapod-shaped). After adding monomers and initiators, a TEMED / APS mild initiation system is used to crosslink a layer of polymer network on the surface of the nanoparticles. Compared with traditional grafted polymers, the 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 gold nanoparticles with special shapes to stably perform specific functions in the biomedical field. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 Transmission electron microscope 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 curve 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 rod-shaped gold nanoparticle (Au NR) solution or a tetrapod-shaped gold nanoparticle (NTPs) solution; the preparation of the rod-shaped / tetrapod-shaped gold nanoparticle solution is not particularly limited and can be prepared by a method 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, an ethanol solution and a thiol polyethylene glycol amino solution (SH-PEG-NH2, Mw=2000g / mol) are added to a reaction container, mixed evenly, and then the rod-shaped / tetrapod-shaped gold nanoparticle concentrate is added, first ultrasonicated, the ultrasonication time is preferably 5-10min, and then reacted, 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 Au NR-PEG / NTPs-PEG solution modified with thiol polyethylene glycol amino group in step 2 for reaction, the reaction temperature is preferably room temperature, the reaction time is preferably more than 4 hours, more preferably 4 hours, to obtain Au NR-PEG-NAS / NTPs-PEG-NAS solution modified with N-hydroxysuccinimide acrylate; 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 4: Add an acrylic polymer monomer containing a double bond, a cross-linking agent 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 and stir evenly, then add tetramethylethylenediamine solution and stir evenly, and finally add ammonium persulfate solution to react. 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, tetrapod-shaped gold nanocapsules n(Au NR) / n(NTPs).

[0032] According to the present invention, the acrylic polymer monomer containing double bonds is preferably 2-methacryloyloxyethyl phosphorylcholine (MPC), acrylamide (AAM), N-(3-aminopropyl) methacrylamide (APM) or 2-acrylamido-2-methylpropanesulfonic acid (AMPS). The cross-linking agent is preferably N,N'-methylenebisacrylamide (BIS), glycerol 1,3-diisopropylacrylate, dimethyl acrylate oil or polyethylene glycol diacrylate, and the buffer solution is preferably a phosphate buffer solution;

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

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

[0035] The present invention is further described in detail below with reference to specific examples, and the raw materials involved in the examples are all commercially available.

[0036] Example 1

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

[0038] Take 0.3645g of hexadecyltrimethylammonium bromide (CTAB) and add 3.5g of deionized water to obtain a CTAB solution. Add 125μL of 15 mM chloroauric acid solution to the solution, quickly add 500μL of 0.01M sodium borohydride solution while stirring at 25℃, stir vigorously for 2min, and place in a 25℃ water bath for 30min to obtain a seed solution. Take 0.3645g of CTAB and add 8.84g of deionized water to dissolve, add 400μL of 4mM silver nitrate solution, 520μL of 15mM chloroauric acid solution, and 124μL of 0.08M ascorbic acid solution in sequence, shake well, control the solution temperature at 24-26℃, then quickly add 100μL of seed solution, shake well, and place in a 27.5℃ water bath for reaction for 12h to obtain a CTAB ligand-protected rod-shaped gold nanoparticle solution.

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

[0040] The prepared rod-shaped gold nanoparticle solution was centrifuged at 12000rpm for 15min to obtain 500μL of rod-shaped gold nanoparticle concentrate. Take a 20mL glass bottle, add 9mL of ethanol solution and 400μL of 50mg / mL thiol polyethylene glycol amino solution (SH-PEG-NH2, Mw=2000g / mol) to it, and shake well. Add 500μL of rod-shaped gold nanoparticle concentrate under ultrasonic conditions, ultrasonicate for 5min, and place on a shaker to react at room temperature for 12h to obtain thiol polyethylene glycol amino-modified Au NR-PEG solution.

[0041] (3) Au NR-PEG-NAS modified with N-hydroxysuccinimide acrylate

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

[0043] (4) Rod-shaped gold nanocapsules (n(Au NR))

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

[0045] Figure 2 The stability test curve of the gold nanocapsules prepared in Example 1 of the present invention under different conditions; Figure 2 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 being stored 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 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 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 after being 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 that of NTPs and NTPs-PEG, indicating that n(NTPs) has better salt solution stability; Figure 2 F is a comparison of the relative absorbance (A / A0) of the absorption peaks of NTPs, NTPs-PEG and n(NTPs) after being stored in different pH environments for 12 hours. It can be observed from the figure that the relative absorbance of n(NTPs) is the smallest compared with that of NTPs and NTPs-PEG, indicating that n(NTPs) has better pH stability. In short, the high stability of gold nanocapsules under long-term storage, salt solution, low temperature and different pH environments proves the effective protection ability of this modification method on gold nanoparticles.

[0046] Example 2

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

[0048] Take 0.1823g CTAB and add 3.5g deionized water to obtain CTAB solution. Add 125μL 15 mM chloroauric acid solution to the solution, quickly add 500μL 0.01M sodium borohydride solution while stirring at 25.5℃, stir vigorously for 2min, and put it in a 25.5℃ water bath for 30min to obtain a seed solution. Take two glass bottles and set them as bottles A and B. Add 620μL deionized water, 3ml 0.1M CTAB solution, 380μL 15mM chloroauric acid solution, 3ml 0.1M hexamethylenetetramine (HMT) solution, and 1ml 0.01M ascorbic acid solution to bottle A in sequence, and add 6ml deionized water, 60μL 1M sodium hydroxide solution, and 5μL seed solution to bottle B in sequence. 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 12000rpm for 15min to obtain 500μL of tetrapod gold nanoparticle concentrate. Take a 20mL glass bottle, add 9mL of ethanol solution and 400μL of 50mg / mL thiol polyethylene glycol amino solution (SH-PEG-NH2, Mw=2000g / mol) to it, and shake well. Add 500μL of tetrapod gold nanoparticle concentrate under ultrasonic conditions, ultrasonicate for 5min, and place on a shaker to react at room temperature for 12h to obtain thiol polyethylene glycol amino-modified NTPs-PEG solution.

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

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

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

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

[0055] Figure 1 The transmission electron microscope images of Au NR-PEG, n(Au NR), NTPs-PEG, and n(NTPs) prepared in Examples 1 and 2 of the present invention are shown in FIG. It can be seen from the figure that the lateral size of Au NR is about 9 nm, the longitudinal size is about 33 nm, and no polymer morphology is observed around Au NR ( Figure 1 A), after in situ free radical polymerization to form n(Au NR), there is a white polymer shell around AuNR. After measurement, the shell thickness is about 6.97nm ( Figure 1 B), this change proves the successful encapsulation of Au NR surface polymer and the successful preparation of 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), there is a white polymer shell around the Au NR. The shell thickness is measured to be about 3.42nm ( Figure 1 D), this change proves the successful encapsulation of NTPs surface polymer 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 a cross-linking agent and only the type of monomer was changed to prepare rod-shaped gold nanocapsules wrapped with different monomers.

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

[0059] Example 4

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

[0061] Figure 4Surface potential diagrams of tetrapod gold nanocapsules wrapped with different monomers prepared by changing the monomer type in Example 4, wherein the tetrapod gold nanocapsules were prepared with neutral AAM as the reaction monomer, marked as n(NTPs) / AAM; AAM was used as the main reaction monomer and positively charged APM was used as the secondary reaction monomer (AAM:APM molar ratio = 10:1) to prepare tetrapod gold nanocapsules, marked as n(NTPs) / AAM+; AAM was used as the main reaction monomer and negatively charged AMPS was used as the secondary reaction monomer (AAM:AMPS molar ratio = 10:1) to prepare tetrapod gold nanogels capsules, marked as n(NTPs) / AAM-; zwitterionic monomer MPC was used as a reaction monomer to prepare rod-shaped gold nanocapsules, marked as n(NTPs) / MPC; MPC was used as the main reaction monomer and positively charged APM was used as a secondary reaction monomer (MPC:APM molar ratio = 10:1) to prepare tetrapod-shaped gold nanocapsules, marked as n(ANTPs) / MPC+; MPC was used as the main reaction monomer and negatively charged AMPS was used as a secondary reaction monomer (MPC:AMPS molar ratio = 10:1) to prepare tetrapod-shaped gold nanocapsules, marked as n(NTPs) / MPC-. It can be seen that the surface potential of gold nanocapsules can be regulated by changing the type and mixing ratio of 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 into a reaction container, mix well, add the rod-shaped / tetrapod-shaped gold nanoparticle solution obtained in step 1, react, and obtain a thiol polyethylene glycol amino-modified Au NR-PEG / NTPs-PEG solution; Step 3: adding N-hydroxysuccinimide acrylate solution to the Au NR-PEG / NTPs-PEG solution modified with thiol polyethylene glycol amino group in step 2 to react, thereby obtaining Au NR-PEG-NAS / NTPs-PEG-NAS solution modified with N-hydroxysuccinimide acrylate; Step 4: Add an acryloyl polymer monomer containing a double bond, a crosslinker and a buffer solution into a reaction container to obtain a mixed solution, then add the Au NR-PEG-NAS / NTPs-PEG-NAS solution modified with N-hydroxysuccinimide acrylate in step 3 into 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.

2. The method for preparing rod-shaped or tetrapod-shaped gold nanocapsules according to claim 1, characterized in that: 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.

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

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

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

6. The method for preparing rod-shaped or tetrapod-shaped gold nanocapsules according to claim 1, characterized in that: The double-bond-containing acryl-based polymerizable monomer described in step 4 is 2-methacryloyloxyethyl phosphorylcholine, acrylamide, N-(3-aminopropyl)methacrylamide or 2-acrylamido-2-methylpropanesulfonic acid.

7. The method for preparing rod-shaped or tetrapod-shaped gold nanocapsules according to claim 1, characterized in that: The cross-linking agent described in step 4 is N,N'-methylenebisacrylamide, glycerol 1,3-diisomethacrylate, dimethyl acrylate or polyethylene glycol diacrylate.

8. The method for preparing rod-shaped or tetrapod-shaped gold nanocapsules according to claim 1, characterized in that: The volume ratio of the double-bond-containing acrylic polymer monomer, the cross-linking agent, the N-hydroxysuccinimide acrylate-modified AuNR-PEG-NAS / NTPs-PEG-NAS solution, the tetramethylethylenediamine solution and the ammonium persulfate solution described in step 4 is 53.3:23.1:300:8.85:34.

2.

9. The method for preparing rod-shaped or tetrapod-shaped gold nanocapsules according to claim 1, characterized in that: The concentration of the double bond-containing acryloyl polymer monomer described in step 4 is 200 mg / mL, the concentration of the Au NR-PEG-NAS / NTPs-PEG-NAS solution modified with N-hydroxysuccinimide acrylate 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.

10. 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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