Preparation method of liquid metal nanoparticle photo-thermal material

Abstract

The invention belongs to the technical field of photo-thermal material preparation, and particularly relates to a preparation method of a liquid metal nanoparticle photo-thermal material, which comprises the following steps: step 1, preparing a sodium alginate aqueous solution; 2, gallium-based liquid metal is added into the sodium alginate aqueous solution, stirring and mixing are conducted firstly, and then ultrasonic treatment is conducted for sufficient mixing; and step 3, drying to obtain a product. The preparation process is carried out in a conventional environment, so that the requirement on the environment is low. In addition, the nanoparticles prepared by the method have the characteristics of good stability, excellent photo-thermal performance, simple preparation method, high formation rate and easiness in control, and can be used for preparing materials with efficient photo-thermal capacity. By integrating the beneficial effects, the method has a good application prospect in the technical field of photo-thermal material preparation.

Description

Technical Field

[0001] The present invention belongs to the technical field of photothermal material preparation, and in particular relates to a method for preparing a liquid metal nanoparticle photothermal material. Background Art

[0002] Cancer is a leading cause of death worldwide. Traditional cancer treatments include surgery, radiotherapy, and chemotherapy. Although these traditional treatments have improved the survival rate of patients, they have certain limitations, such as many contraindications and side effects, unbearable pain during surgery, and multiple post-treatment care challenges. Therefore, there is an urgent need to develop treatments with high efficacy and few side effects. At the same time, photothermal therapy has made great progress in the field of anti-tumor with its advantages of low adverse reactions, high specificity, and repeatable treatment.

[0003] The first generation of photothermal materials are precious metals (such as gold, silver, platinum, etc.), and the most widely studied are gold nanostructures, including gold nanospheres, gold nanorods, gold nanostars, etc. Gold nanostructures have good photothermal conversion efficiency, but the difficulty of precious metal metabolism in the body and the high cost limit their further application in clinical practice.

[0004] Liquid metal refers to metal or metal alloy with a melting point lower than or close to room temperature. It is liquid at room temperature and has metallic properties. Compared with solid metal materials, the good fluidity of liquid metal at room temperature does not change its inherent advantages as a metal, namely good electrical and thermal conductivity. Among the many types of liquid metals, cesium and rubidium are very active in the air, francium is radioactive, and mercury is a highly toxic material. Therefore, research on liquid metals is basically focused on gallium metal and gallium-based liquid metal alloys. Gallium-based liquid metal nanoparticles have good photothermal properties and show good advantages in photothermal therapy. At the same time, they have the advantages of good biocompatibility, low price, easy preparation, in vivo degradation and self-healing ability, which has attracted widespread attention in the biomedical field and has developed rapidly in the field of photothermal therapy, playing an important role in precise and non-invasive anti-tumor treatment.

[0005] Liquid metal nanoparticles have poor environmental stability. In air or water environments, their surfaces will be instantly oxidized to form oxides with a thickness of about 1-3 nm. The main component is Ga2O3. As time goes by, the Ga2O3 content will increase, greatly affecting its photothermal performance. Summary of the invention

[0006] In order to solve the above problems, the present invention provides a method for preparing a liquid metal nanoparticle photothermal material, comprising the following steps:

[0007] Step 1, preparing sodium alginate aqueous solution; Step 2, adding gallium-based liquid metal to the sodium alginate aqueous solution, first mixing by stirring, and then fully mixing by ultrasonic treatment; Step 3: After drying, a product is obtained.

[0008] The present invention is a method for synthesizing a composite material with a core-shell structure by stirring a block of liquid metal into a spherical liquid metal by stirring with a magnet (polytetrafluoroethylene) at room temperature, and then ultrasonically treating the solution so that the sodium alginate macromolecular coating uses liquid metal nanoparticles as nucleation sites and coats them. Gallium-based liquid metal has poor chemical stability in aqueous solution due to the high activity of gallium element. After preparing it into liquid metal nanoparticles, the larger specific surface area increases the possibility of its denaturation in water, and chemical reactions occur to become rod-shaped gallium hydroxide oxide. When liquid metal nanoparticles are used as photothermal agents in cancer treatment, the process of heating the liquid metal nanoparticles during photothermal treatment will also accelerate this change, affecting the treatment effect of cancer. Therefore, the present invention wraps a layer of sodium alginate with stable chemical properties and can effectively isolate the external water environment on the surface of the liquid metal nanoparticles, so as to effectively improve the chemical stability of the liquid metal nanoparticles.

[0009] Furthermore, in step 1, distilled water is used as a solvent to prepare a sodium alginate aqueous solution at room temperature.

[0010] Furthermore, in step 1, the molar concentration of the sodium alginate aqueous solution is 0.023 mol / L.

[0011] Furthermore, in step 2, the gallium-based liquid metal is a binary gallium-based alloy composed of Ga and In, wherein the mass of Ga accounts for 74.5% of the gallium-based liquid metal and the mass of metallic indium accounts for 25.5%.

[0012] Furthermore, the temperature of step 2 is 21° C. to 26° C., and the humidity is 40% to 60%.

[0013] Beneficial effects of the present invention: The present invention is prepared under conventional conditions and has low environmental requirements. In addition, the nanoparticles prepared by the present invention have the characteristics of good stability, good photothermal performance, fast formation rate, and easy control, and can prepare materials with high-efficiency photothermal capacity. Based on the above beneficial effects, the present invention has good application prospects in the field of photothermal material preparation technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 The SEM image and EDS of the liquid metal nanoparticles prepared in the present invention.

[0015] Figure 2 TEM image and EDS of the liquid metal nanoparticles prepared in the present invention.

[0016] Figure 3 This is a Fourier infrared spectrum of the liquid metal nanoparticles prepared in the present invention.

[0017] Figure 4 This is the ultraviolet absorption spectrum of the liquid metal nanoparticles prepared by the present invention.

[0018] Figure 5 This is a Raman spectrum of the liquid metal nanoparticles prepared in the present invention.

[0019] Figure 6 This is the XPS graph of the liquid metal nanoparticles prepared in the present invention.

[0020] Figure 7 a is the temperature change diagram of sodium alginate modified liquid metal nanoparticles, liquid metal, sodium alginate aqueous solution, and deionized water after irradiation with 808 nm near-infrared laser at a power density of 1.5 W / cm2 for 10 min.

[0021] Figure 7 b is the temperature change diagram of sodium alginate modified liquid metal nanoparticles after irradiation with 808 nm near-infrared laser for 10 min under different power conditions.

[0022] Figure 7 c Four photothermal cycle tests on sodium alginate modified liquid metal nanoparticles.

[0023] Figure 7 d is the photothermal conversion efficiency diagram of sodium alginate modified liquid metal nanoparticles.

[0024] Figure 8 This is a photothermal experiment diagram of liquid metal nanoparticles prepared by the present invention. DETAILED DESCRIPTION

[0025] In order to make the objectives, technical solutions and advantages of the present application more clearly understood, the present application is further described in detail below with reference to the accompanying drawings and examples.

[0026] Example 1 The present invention provides a method for preparing a liquid metal nanoparticle photothermal material, which is achieved by the following steps: Step 1. Prepare sodium alginate aqueous solution: select a 100 ml volumetric flask, use deionized water and ethanol for ultrasonic cleaning in turn, and the ultrasonic time is 10 min each time. After the ultrasonic is completed, put the cleaned volumetric flask into an electric blast drying oven, set the temperature to 60 ℃, and dry it. Weigh 0.5 g of sodium alginate powder with an electronic balance, add it to a 100 ml volumetric flask after weighing, and make up the volume with distilled water. At room temperature, use a clean Basque pipette to titrate until the sodium alginate powder is submerged, then shake the solution, and then continue to add distilled water, 1 to 2 cm away from the scale line, and finally use a Basque pipette to titrate the scale line to the same level as the liquid surface. The molar concentration of the obtained sodium alginate aqueous solution is 0.023 mol / L.

[0027] Step 2: Add gallium-based liquid metal to the sodium alginate aqueous solution, first mix by stirring, and then mix thoroughly by ultrasonic treatment. Specifically, select a clean mobile phase bottle to weigh the liquid metal, place the mobile phase bottle on an electronic balance, peel it, use a rubber-tipped dropper to absorb the gallium-based liquid metal and add it to the mobile phase bottle, and add 20 g of gallium-based liquid metal. Gallium-based liquid metal is a binary gallium-based alloy composed of Ga and In, in which the mass of Ga accounts for 74.5% of the gallium-based liquid metal. Then add the fixed volume of sodium alginate aqueous solution to the mobile phase bottle, then add a magnet to the bottle, tighten the bottle cap, put the bottle on the magnetic stirrer, turn on the switch to adjust the speed for stirring. After stirring for one day, the liquid metal at the bottom of the bottle was observed to be in the form of small spheres. Then, the probe was ultrasonicated for 60 minutes using a power ratio (99%, 148.5W), working for 90 seconds and stopping for 10 seconds. After the ultrasonication, it was placed on a magnetic stirrer for stirring. This process was repeated until there were no liquid metal spheres at the bottom of the bottle when it was shaken, and a gray suspension was present with a small amount of liquid metal precipitated at the bottom. The temperature of step 2 was 21°C~26°C, and the humidity was 40%~60%.

[0028] Step 3, drying to obtain a product. Specifically, the prepared sodium alginate liquid metal mixture is allowed to stand for 24 hours, and then the suspension is sucked with a Bassett pipette and added into a screw-mouth bottle to prepare a sample, and finally the sample is dried to prepare a solid powder.

[0029] Example 2 On the basis of Example 1, in step 1, 0.1 g of sodium alginate powder was weighed, and the other steps were the same as in Example 1, and the molar concentration of the obtained sodium alginate aqueous solution was 0.005 mol / L.

[0030] Example 3 On the basis of Example 1, in step 1, 0.3 g of sodium alginate powder was weighed, and the other steps were the same as in Example 1, and the molar concentration of the obtained sodium alginate aqueous solution was 0.014 mol / L.

[0031] Example 4 On the basis of Example 1, in step 1, 0.7 g of sodium alginate powder was weighed, and the other steps were the same as in Example 1, and the molar concentration of the obtained sodium alginate aqueous solution was 0.032 mol / L.

[0032] Example 5 On the basis of Example 1, in step 1, 0.9 g of sodium alginate powder was weighed, and the other steps were the same as in Example 1, and the molar concentration of the obtained sodium alginate aqueous solution was 0.042 mol / L.

[0033] Examples 1-5 form sodium alginate-encapsulated liquid metal photothermal materials with different molar concentrations. Five groups of materials were prepared for comparison to explore the optimal concentration of sodium alginate-encapsulated liquid metal photothermal materials. The conclusion was that the sodium alginate-encapsulated liquid metal with a concentration of 0.023 mol / L was the optimal concentration and was suitable for preparation into photothermal materials. Figure 1-8 Both correspond to 0.023 mol / L sodium alginate.

[0034] Figure 1 The SEM image shows spherical nanoparticles at the 200 nm scale. At the scales of approximately 600 nm, 400 nm, and 1 μm in diameter, it can be clearly seen that the sodium alginate coating tightly wraps the liquid metal nanoparticles. The EDS image clearly shows the distribution of the four elements Ga, In, O, and C.

[0035] Figure 2 The TEM images show spherical nanoparticles with core-shell structures at the scales of 20, 50, and 100 nm. The core-shell structure is obvious and the diameter is about 100 nm. At the size of 10 nm, it can be clearly seen that the sodium alginate coating is tightly wrapped on the surface of the liquid metal nanoparticles. The EDS image can clearly show the distribution of the four elements Ga, In, O, and C.

[0036] Figure 3 The infrared spectrum shows that 3221 cm -1 The absorption peak at 1026 cm -1 The absorption peaks at 1601 and 1412 cm correspond to the bending vibration of the COC functional group in sodium alginate. -1 The peaks at represent the asymmetric and symmetric stretching vibrations of the COOH functional group, which means that sodium alginate is successfully wrapped on the liquid metal.

[0037] Figure 4 The ultraviolet absorption spectrum shows that the absorbance of sodium alginate modified liquid metal nanoparticles reaches a maximum of 0.765 at 262 nm.

[0038] Figure 5 The Raman spectrum shows that sodium alginate modified liquid metal nanoparticles have two classic peaks, segment D and segment G.

[0039] Figure 6 a is the XPS distribution diagram of C1s in sodium alginate modified liquid metal nanoparticles. Figure 6 b is the XPS distribution diagram of O1s in sodium alginate modified liquid metal nanoparticles. Figure 6 c is the XPS distribution diagram of In3d in sodium alginate modified liquid metal nanoparticles. Figure 6 d is the XPS distribution diagram of Ga2p in sodium alginate modified liquid metal nanoparticles.

[0040] Figure 7 a is the sodium alginate modified liquid metal nanoparticles, liquid metal, sodium alginate aqueous solution, and deionized water at a power density of 1.5 W / cm 2 Temperature change diagram after irradiation with 808 nm near-infrared laser for 10 min. Figure 7 b is the temperature change diagram of sodium alginate modified liquid metal nanoparticles after irradiation with 808 nm near-infrared laser for 10 min under different power conditions. It can be seen from the figure that when other conditions remain unchanged, as the laser power density increases, the temperature that can be raised also increases. Figure 7 c Four photothermal cycles were performed on the sodium alginate modified liquid metal nanoparticles. The laser used was a near-infrared laser of 808 nm with a laser power density of 1.5 W / cm 2 , the irradiation time is 10 min. It can be seen that because sodium alginate tightly wraps the liquid metal nanoparticles, it effectively isolates water and oxygen and improves the photothermal stability of the material. It remains consistent in the four cycle experiments, and the temperature that can be increased after 10 min of laser irradiation is close. Figure 7 d is the photothermal conversion efficiency diagram of sodium alginate modified liquid metal nanoparticles. According to the photothermal conversion efficiency calculation formula, τ can be calculated. s =359.4, R 2 =0.9383, η = 41.9%. The photothermal conversion efficiency is 41.9%, which is relatively high, proving that its photothermal performance is very good. Figure 8 Liquid metal nanoparticles, liquid metal, and sodium alginate aqueous solution modified by sodium alginate at a power density of 1.5 W / cm 2Infrared thermal imaging photos of 808 nm near-infrared laser irradiation for 0 min, 1 min, 3 min, 5 min, and 7 min (these photos were taken with an infrared camera to record the temperature). It can be seen from the photos that as the near-infrared laser irradiation time increases, the temperature in the center of the sample rises significantly, and the highest temperature appears in red. It can be seen from the figure that sodium alginate modified liquid metal nanoparticles have the best temperature increase effect. Compared with liquid metal, it can increase the temperature higher, proving that sodium alginate can synergistically enhance the photothermal properties of liquid metal nanoparticles.

[0041] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

Claims

1. A method for preparing a liquid metal nanoparticle photothermal material, characterized in that: The steps include: Step 1, preparing sodium alginate aqueous solution; Step 2, adding gallium-based liquid metal to the sodium alginate aqueous solution, first mixing by stirring, and then fully mixing by ultrasonic treatment; Step 3: After drying, a product is obtained.

2. The method for preparing the liquid metal nanoparticle photothermal material according to claim 1, characterized in that: In step 1, a sodium alginate aqueous solution is prepared at room temperature using distilled water as a solvent.

3. The method for preparing the liquid metal nanoparticle photothermal material according to claim 2, characterized in that: In step 1, the molar concentration of the sodium alginate aqueous solution is 0.023 mol / L.

4. The method for preparing the liquid metal nanoparticle photothermal material according to claim 1, characterized in that: In step 2, the gallium-based liquid metal is a binary gallium-based alloy composed of Ga and In, wherein the mass of Ga accounts for 74.5% of the gallium-based liquid metal.

5. The method for preparing the liquid metal nanoparticle photothermal material according to claim 1, characterized in that: The temperature of step 2 is 21°C~26°C, and the humidity is 40%~60%.

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