Nanogold as well as normal-temperature rapid preparation method and application thereof

Abstract

The invention discloses nanogold and a normal-temperature rapid preparation method and application thereof. The preparation process comprises the steps that a chloroauric acid solution and a reducing agent are evenly mixed to form a mixed solution, then a stabilizing agent is added to form a mixed reaction system, the mixed reaction system is placed in the environment with the temperature being 15-35 DEG C to react, and after the reaction is finished, centrifugal cleaning is conducted to obtain nanogold uniform in size. The method has the advantages that raw materials are cheap and easy to obtain, process conditions are mild, the method is suitable for large-scale use, and wide application of the gold nanoparticles is facilitated. The defects that existing gold nanoparticle synthesis steps are tedious, synthesis time is long and cost is high are effectively overcome.

Description

Technical Field

[0001] The invention relates to the technical field of nano material preparation, in particular to a nano gold synthesis technology. Background Art

[0002] Nanogold refers to tiny gold particles with a diameter of 1 to 100 nm, and its color varies depending on the diameter. Nanogold plays an important role in modern science and technology. It has high electron density, dielectric properties and catalytic effects. Its unique physical and chemical properties make it have a wide range of application potentials in many fields. It can combine with a variety of biological macromolecules without affecting their biological activity. Nanogold can be used as an efficient biomedical marker and drug delivery carrier to improve diagnostic accuracy and treatment effects; at the same time, its application in sensor technology makes monitoring and detection more sensitive and reliable, which is of great significance to environmental monitoring and food safety.

[0003] In order to meet different needs, a variety of synthesis methods have been developed in recent years, such as chemical reduction, photochemical synthesis, solvothermal, plant extract and microemulsion. Although these methods can be effectively prepared, each method has its own unique disadvantages and challenges. The equipment cost of photochemical synthesis and solvothermal method is relatively high; the preparation process of plant extract method and microemulsion method is complicated. Adding a strong reducing agent, sodium borohydride, to the classic sodium citrate reduction method can reduce the heating process and simplify the synthesis process. However, the sodium borohydride solution needs to be prepared and used immediately, and often needs to be used at low temperature, which requires high preparation conditions. Summary of the invention

[0004] The purpose of the present invention is to provide a method and application of rapid preparation of nano-gold at room temperature, so as to solve the problem of high requirements on preparation conditions of nano-gold in the prior art.

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

[0006] A method for rapidly preparing nano-gold at room temperature comprises: uniformly mixing a chloroauric acid solution and a reducing agent to form a mixed solution, then adding a stabilizer solution to form a mixed reaction system, placing the system in an environment with a temperature of 15 to 35°C to react, and obtaining nano-gold of uniform size.

[0007] Furthermore, the reducing agent is tripropylamine buffer.

[0008] Furthermore, the process includes: uniformly mixing 15-50 μl of 1-4% chloroauric acid solution and 100-450 μl of 50-500 mmol / L tripropylamine buffer to form a mixed solution, then adding 10-40 μl of stabilizer solution to form a mixed reaction system, placing the system in an environment with a temperature of 15 to 35° C. for reaction, and centrifuging and washing the system after the reaction to obtain nano-gold of uniform size.

[0009] Furthermore, the stabilizer is selected from polyvinyl pyrrolidone, sodium citrate, thiol compounds, polyethylene glycol, dendrimers, bovine serum albumin, dextran, chitosan, and ionic liquids.

[0010] Furthermore, the stabilizer solution is a polyvinyl pyrrolidone solution with a mass fraction of 2%-30%.

[0011] Furthermore, the particle size of the nano-gold is 10-60nm.

[0012] Further, the chloroauric acid solution and the reducing agent are mixed for 1-3 minutes to form a mixed solution;

[0013] The mixed reaction system is placed in an environment with a temperature of 15 to 35° C. for reaction for 2 to 10 minutes.

[0014] Furthermore, the chloroauric acid solution and the reducing agent are mixed to form a mixed solution and the mixed solution is allowed to stand until the solution state is stable before adding a stabilizer solution.

[0015] The invention provides nano gold prepared by the method described above.

[0016] The invention provides an application of the nano gold in preparing biomedical markers, drug delivery carriers, environmental detection and food safety detection sensors.

[0017] The advantages of the invention include: simplified synthesis steps, easy operation, using tripropylamine as a reducing agent, and only needing to simply mix the reagents required for the reaction at room temperature of 15 to 35°C. The entire reaction can be completed in a very short time, and the time can be as low as 3 minutes to synthesize nano-gold particles. The repetition rate is high, and a large number of nano-gold particles with good morphology and continuously adjustable size can be effectively obtained. The reducing agent tripropylamine solution used is chemically stable at room temperature and is easy to transport and store. The raw materials are cheap and easy to obtain, and the process conditions are mild, which is suitable for large-scale use and is conducive to the wide application of nano-gold particles. The disadvantages of the existing nano-gold particle synthesis steps being complicated, the synthesis time being long, and the cost being high are effectively solved. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The drawings described herein are used to provide a further understanding of the present invention, constitute a part of the present application, and do not constitute an improper limitation of the present invention. In the drawings:

[0019] Figure 1 It is a process flow chart of preparing nano-gold particles of the present invention;

[0020] Figure 2 is the ultraviolet-visible absorption spectrum of the gold nanoparticles in Example 1 of the present invention;

[0021] Figure 3is the potential diagram of the gold nanoparticles in Example 1 of the present invention;

[0022] Figure 4 is a transmission electron microscope image of the gold nanoparticles in Example 1 of the present invention;

[0023] Figure 5 is the potential diagram of the gold nanoparticles in Example 2 of the present invention;

[0024] Figure 6 is a transmission electron microscope image of the gold nanoparticles in Example 2 of the present invention;

[0025] Figure 7 These are photos of the appearance of the nano-gold particle solutions of Examples 1 and 2 of the present invention. DETAILED DESCRIPTION

[0026] The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments. The exemplary embodiments and descriptions of the present invention are used to explain the present invention, but are not intended to limit the present invention.

[0027] Example 1

[0028] This embodiment provides a method for rapidly preparing nano-gold at room temperature, such as Figure 1 As shown, the steps include:

[0029] (1) Add 25 μl of 2.5% chloroauric acid solution and 200 μl of 200-500 mmol / L tripropylamine buffer to 2000 μl of water and mix for 3 min. The color of the solution quickly turns purple-red. Let it stand for a while to stabilize the solution.

[0030] (2) Add 20 μl of 20% polyvinyl pyrrolidone solution to the solution obtained in step (1), and then place the mixture at room temperature (25°C) to react until completion. After the reaction is completed, centrifuge and wash to obtain gold nanoparticles of uniform size.

[0031] The UV-visible absorption spectrum of the nano-gold particle solution obtained by the process of this embodiment is as follows: Figure 2 As shown, it can be seen that its ultraviolet absorption spectrum absorption peak is around 545nm. Figure 3 The figure shows the potential diagram of the gold nanoparticles obtained in this example after three measurements. It can be seen that the potential of these gold nanoparticles is about -28.9 mV. Figure 4 , which is a transmission electron microscope photo of the gold nanoparticles obtained in this example, the particle size of these gold nanoparticles is about 10-30 nm.

[0032] like Figure 7 As shown, sample 1 is a photograph of the appearance of the nano-gold particle solution of this embodiment.

[0033] Example 2

[0034] This embodiment provides a method for rapidly preparing nano-gold at room temperature, the steps comprising:

[0035] (1) Add 35 μl of 1.5% chloroauric acid solution and 400 μl of 50-200 mmol / L tripropylamine buffer to 1800 μl of water and mix for 3 min. The color of the solution quickly changes to purple-black. Let it stand for a while to stabilize the solution.

[0036] (2) Add 20 μl of 20% polyvinyl pyrrolidone solution to the solution obtained in step (1), and then place the mixture at room temperature (25°C) to react until completion. After the reaction is completed, centrifuge and wash to obtain gold nanoparticles of uniform size.

[0037] The ultraviolet absorption peak of the nano-gold particle solution obtained by the process of this embodiment is equivalent to that of Example 1.

[0038] Figure 5 The figure shows the potential diagram of the gold nanoparticles obtained in this example after three measurements. It can be seen that the potential of these gold nanoparticles is about -36.3 mV. Figure 6 , which is a scanning electron microscope photograph of the nano-gold particles obtained in this example, the particle size of these nano-gold particles is about 20-50nm.

[0039] like Figure 7 As shown, sample 2 is a photograph of the appearance of the nano-gold particle solution of this embodiment.

[0040] Example 3

[0041] In this embodiment, the mass fraction of the chloroauric acid solution is 3%, the concentration of the polyvinyl pyrrolidone solution is 15%, and the rest is the same as in Example 1, to obtain nano-gold particles of uniform size. The absorption peak of the ultraviolet absorption spectrum, the potential diagram, and the particle size results are equivalent to those in Example 1.

[0042] Example 4

[0043] In this embodiment, the mass fraction of the chloroauric acid solution is 3%, the concentration of the polyvinyl pyrrolidone solution is 15%, and the rest is the same as in Example 2, to obtain nano-gold particles of uniform size. The absorption peak of the ultraviolet absorption spectrum, the potential diagram, and the particle size results are equivalent to those in Example 2.

[0044] It can be seen from the above examples that the particle size of nanogold is related to the concentration of the added tripropylamine buffer. Compared with the reaction with a high concentration tripropylamine buffer, the nanogold particle size obtained by the reaction system using a low concentration tripropylamine reaction solution is larger. The size of the nanogold particles can be continuously adjusted by adjusting the reaction concentration of the tripropylamine buffer.

[0045] The technical solutions provided by the embodiments of the present invention are introduced in detail above. Specific examples are used herein to illustrate the principles and implementation methods of the embodiments of the present invention. The description of the above embodiments is only applicable to help understand the principles of the embodiments of the present invention. At the same time, for those skilled in the art, according to the embodiments of the present invention, there will be changes in the specific implementation methods and application scopes. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A method for rapidly preparing nano-gold at room temperature, characterized in that: The process includes: uniformly mixing chloroauric acid solution and a reducing agent to form a mixed solution, then adding a stabilizer solution to form a mixed reaction system, placing the system in an environment with a temperature of 15 to 35°C to react, and obtaining nano-gold with uniform size.

2. A method for rapidly preparing nano-gold at room temperature according to claim 1, characterized in that: The reducing agent is tripropylamine buffer.

3. A method for rapidly preparing nano-gold at room temperature according to claim 1 or 2, characterized in that: The process includes: uniformly mixing 15-50 μl of 1-4% chloroauric acid solution and 100-450 μl of 50-500 mmol / L tripropylamine buffer to form a mixed solution, then adding 10-40 μl of a stabilizer solution to form a mixed reaction system, placing the system in an environment with a temperature of 15 to 35° C. for reaction, and centrifuging and washing the system after the reaction to obtain nano-gold with uniform size.

4. A method for rapidly preparing nano-gold at room temperature according to claim 3, characterized in that: The stabilizer is selected from polyvinyl pyrrolidone, sodium citrate, thiol compounds, polyethylene glycol, dendrimers, bovine serum albumin, dextran, chitosan, and ionic liquids.

5. A method for rapidly preparing nano-gold at room temperature according to claim 3 or 4, characterized in that: The stabilizer solution is a polyvinyl pyrrolidone solution with a mass fraction of 2%-30%.

6. A method for rapidly preparing nano-gold at room temperature according to any one of claims 1 to 5, characterized in that: The particle size of the nano gold is 10-60 nm.

7. A method for rapidly preparing nano-gold at room temperature according to claim 1, characterized in that: The chloroauric acid solution and the reducing agent are mixed for 1-3 minutes to form a mixed solution; The mixed reaction system is placed in an environment with a temperature of 15 to 35° C. for reaction for 2 to 10 minutes.

8. A method for rapidly preparing nano-gold at room temperature according to claim 1 or 7, characterized in that: The chloroauric acid solution and the reducing agent are mixed to form a mixed solution, and the mixed solution is allowed to stand until the solution is stable before adding the stabilizer solution.

9. A gold nanoparticle prepared by the method according to any one of claims 1 to 8.

10. Use of the nano-gold as claimed in claim 9 in the preparation of biomedical markers, drug delivery carriers, environmental detection and food safety detection sensors.

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