A method for preparing multi-level micro / nano-structured composite materials for nuclear radiation detection

Abstract

This invention discloses a method for preparing a multi-level micro / nano-structured composite material for nuclear radiation detection, relating to the field of nuclear radiation detection technology. Specifically, it utilizes gold-sulfur self-assembly technology to modify the surface of a gold nanoparticle core with boron-containing molecules, obtaining a functionalized gold nanoparticle core. This core is then used as a seed, with chloroauric acid as the gold source, to grow a gold nanoshell. Finally, silver nitrate is used as the silver source to deposit a silver nanoshell in situ, resulting in a multi-level micro / nano-structured composite material. This multi-level micro / nano-structure uses gold nanoparticles as the core, boron-containing molecules as the neutron detection medium, the gold nanoshell as the surface-enhanced Raman scattering (SERS) carrier, and the silver nanoshell as the gamma-ray detection medium. This material possesses both neutron and gamma-ray detection capabilities, and the neutron response of the boron-containing molecules and the gamma-ray response of the silver nanoshell can be quantitatively measured using SERS and LSPR spectroscopy, respectively. This enables efficient discrimination of mixed radiation field doses and has broad application prospects in the field of nuclear radiation detection.

Description

Technical Field

[0001] This invention relates to the field of nuclear radiation detection technology, and specifically to a method for preparing a multi-level micro-nano structure composite material for nuclear radiation detection. Background Technology

[0002] With the rapid development of the nuclear energy and nuclear technology industries, there is an urgent need for nuclear radiation detection technology in multiple application fields. In practical applications such as radiotherapy, radiation processing, and radiation effect research, accurate radiation dose delivery is crucial for ensuring the reliability of radiation practice activities. In nuclear emergency situations, rapid and accurate dose measurement is not only a key basis for assessing the degree of radiation damage to exposed populations, but also an important reference for medical rescue and classification. Therefore, developing advanced nuclear radiation detection technologies and high-performance radiation detection materials to achieve rapid and accurate measurement of complex nuclear radiation fields has significant application value.

[0003] Thermoluminescent materials, optically stimulated luminescence materials, radiation-photoluminescent materials, radiochromic materials, and gel materials have played a crucial role in nuclear radiation detection. Due to their unique physicochemical properties, they can exhibit specific responses to nuclear radiation, thus being applied to radiation dose measurement. In recent years, to further improve the sensitivity of radiation detection, researchers have developed novel detection materials such as quantum dots, carbon nanomaterials, boron-based nanomaterials, perovskites, and metal-organic frameworks. Studies have shown that by controlling the composition and structure of detection materials, their radiation response characteristics (such as sensitivity, linearity, and response range) can be effectively adjusted, thereby meeting the diverse needs of radiation detection in different application scenarios. However, limited by the detection principle and signal readout method, existing detection materials face the challenge of mutual interference when applied to complex radiation field environments. Different types of radiation may have complex and combined effects on materials, making it difficult to accurately distinguish and measure various radiation doses in mixed radiation fields. Therefore, how to simultaneously and rapidly and accurately detect different types of nuclear radiation in a single type of material has become a pressing technical challenge in this field. Summary of the Invention

[0004] To address the aforementioned technical challenges, the present invention aims to provide a multi-level micro / nano-structured composite material for nuclear radiation detection and its preparation method. This composite material is prepared using gold-sulfur self-assembly technology and a seed growth method, exhibiting a multi-level micro / nano-structure with gold nanoparticles as the core, boron-containing molecules as the neutron detection medium, a gold nanoshell as the surface-enhanced Raman scattering (SERS) carrier, and a silver nanoshell as the gamma-ray detection medium. The neutron response of the boron-containing molecules originates from the nuclear reaction of boron-10 with neutrons, leading to changes in molecular structure, and is quantitatively and sensitively characterized by SERS spectroscopy. The gamma-ray response of the silver nanoshell originates from the free radical-mediated oxidation etching effect induced by gamma radiation, and is quantitatively and sensitively characterized by LSPR spectroscopy. Through SERS / LSPR dual-channel measurement, simultaneous, rapid, and accurate detection of the neutron-gamma mixed radiation field can be achieved.

[0005] Specifically, the above-mentioned objective is achieved through the following technical solutions:

[0006] First, this application provides a method for preparing a multi-level micro / nano-structured composite material for nuclear radiation detection, comprising the following steps:

[0007] 1) Preparation of boron-containing molecularly functionalized gold nanonuclei

[0008] The boron-containing molecular solution was added to the gold nanoparticle solution coated with surfactant I, and the reaction was carried out at room temperature under a nitrogen atmosphere for 4-8 hours with stirring. The solution was centrifuged after the reaction, and the supernatant was discarded to remove unreacted boron-containing molecules. The precipitate was redispersed in the surfactant II solution to obtain a boron-functionalized gold nanoparticle core solution for later use.

[0009] The surfactant I in the above-mentioned solution of gold nanoparticles coated with surfactant I is the same as surfactant II.

[0010] 2) Preparation of functionalized gold nanocore-gold nanoshell

[0011] Chloroauric acid solution and ascorbic acid solution were added sequentially to surfactant III solution, and the mixture was vortexed for 3 min to quickly and evenly mix to obtain mixed solution A. The boron-containing functionalized gold nanoparticle core solution obtained in step 1) was added to mixed solution A, and the mixture was stirred at 40 °C for 1–3 h until the solution color no longer changed. Heating was stopped, and the solution was stirred for another 1 h after cooling to room temperature. The solution was centrifuged after reaction, and the supernatant was discarded to remove unreacted reagents. The precipitate was resuspended in ultrapure water to obtain functionalized gold nanoparticle core-gold nanoshell with a particle size of approximately 22–65 nm.

[0012] 3) Preparation of functionalized gold nanocore-gold nanoshell-silver nanoshell

[0013] Under stirring conditions, the functionalized gold nanocore-gold nanoshell solution obtained in step 2) was added to silver nitrate solution, and then ascorbic acid solution was added dropwise. The pH of the reaction system was adjusted to 7-9 using 0.1M sodium hydroxide solution to promote uniform deposition of the silver nanoshells. The reaction was stirred at 50°C for 1-3 hours until the solution color no longer changed. Heating was then stopped, and the solution was cooled to room temperature and stirred for another hour. The solution was centrifuged after the reaction, and the supernatant was discarded to remove unreacted reagents. The precipitate was resuspended in ultrapure water to obtain the functionalized gold nanocore-gold nanoshell-silver nanoshell, which is a multi-level micro-nano structure composite material for nuclear radiation detection, with a particle size range of 25-70 nm.

[0014] Preferably, in step 1) above, the boron-containing molecule contains a thiol group and a benzene ring, preferably 4-mercaptophenylboronic acid pinene ester, mercaptophenylboronic acid or its derivatives (complexes formed by mercaptophenylboronic acid and molecules containing cis-vicinal diol structures, such as mercaptophenylboronic acid-fructose complex, mercaptophenylboronic acid-glucose complex, mercaptophenylboronic acid-sialic acid complex, etc.), and the solution concentration of the boron-containing molecule is preferably 0.1-2 mM; gold nanoparticles and the thiol group of the boron-containing molecule form gold-sulfur bonds through self-assembly to achieve functionalization.

[0015] Preferably, surfactants I, II, and III are the same, and are one of cetyltrimethylammonium bromide, cetyltrimethylammonium chloride, or polyvinylpyrrolidone; the gold nanoparticles are spherical particles with a particle size of 20-60 nm, and the solution concentration is 0.1-1 μM; the ratio of the amount of boron-containing molecules added to the amount of gold nanoparticles is 200:1-500:1 based on molar mass.

[0016] Preferably, in step 2), the type of surfactant is the same as in step 1), and its concentration is 0.05-0.2M; the concentration of chloroauric acid in mixed solution A is 0.1-0.5mM; the concentration of ascorbic acid in mixed solution A is 0.6-3.0mM; and the molar mass ratio of ascorbic acid (C6H8O6): chloroauric acid: boron-containing molecularly functionalized gold nanonucleus is 12:2:1.

[0017] Preferably, in step 3), the concentration of silver nitrate solution is 10-20 mM; the concentration of ascorbic acid solution is 40-80 mM; and the ratio of added ascorbic acid: silver nitrate: functionalized gold nanonucleus-gold nanoshell is 8:2:1 by molar mass. In this step, the added ascorbic acid affects the deposition rate and uniformity of the silver nanoshell in the final product, the amount of silver nitrate affects the thickness of the silver nanoshell, and the amount of each component ultimately affects the radiation response sensitivity. The final particle size of the functionalized gold nanonucleus-gold nanoshell-silver nanoshell is 25-70 nm.

[0018] Secondly, this application provides a multi-level micro / nanostructured composite material for nuclear radiation detection prepared according to the above method. From the inside out, this composite material consists of a multi-level micro / nanostructure including a gold nanocore, boron-containing molecules, a gold nanoshell, and a silver nanoshell. The boron-containing molecules located between the gold nanocore and the gold nanoshell are used to detect neutrons. The enhanced electromagnetic field in the gap between the gold nanocore and the gold nanoshell can excite the surface-enhanced Raman scattering (SERS) effect, and the response of the boron-containing molecules to neutrons is quantitatively measured using SERS spectroscopy. The silver nanoshell, exhibiting localized plasmon resonance (LSPR) effect, is used to detect gamma radiation, and the response of the silver nanoshell to gamma radiation is quantitatively measured using LSPR spectroscopy.

[0019] Compared with existing technologies, the method for preparing multi-level micro / nano-structured composite materials and the materials provided in this application have the following advantages:

[0020] (1) The preparation method is simple and does not involve the harsh conditions required for solid-phase synthesis, hydrothermal synthesis, etc., making it easy to implement;

[0021] (2) The neutron detection material (boron-containing molecules) and gamma ray detection material (silver nanoshell) prepared by this method are integrated in a multi-level micro-nano structure, which can realize the simultaneous detection of neutrons and gamma rays;

[0022] (3) The neutron detection material prepared by this method is located in the gap between the nano gold core and the nano gold shell, and is physically isolated from the gamma ray detection material, which is beneficial to improving the uniformity and stability of radiation response.

[0023] (4) The neutron detection material prepared by this method has a simple readout method. The neutron response signal is measured by SERS spectroscopy, and the gamma ray response signal is measured by LSPR spectroscopy. Direct readout is achieved and there is no crosstalk between the two. It can achieve efficient discrimination of mixed radiation field dose and solve the problem that the signal readout of existing scintillator materials and other materials requires scintillation detectors and matching spectrometers, which is highly dependent on equipment. Attached Figure Description

[0024] Figure 1 This is a flowchart illustrating the preparation method of a multi-level micro / nano-structured composite material for nuclear radiation detection, as an example.

[0025] Figure 2 The image shows a TEM image of the boron-containing molecularly functionalized gold nanonuclei prepared in the example.

[0026] Figure 3 TEM image of the functionalized gold nanocore-gold nanoshell prepared in the example.

[0027] Figure 4 A schematic diagram of a multi-level micro / nano-structured composite material used for nuclear radiation detection;

[0028] Among them, 1-nano gold core, 2-boron-containing molecule, 3-nano gold shell, 4-nano silver shell.

[0029] Figure 5 TEM image of the functionalized gold nanocore-gold nanoshell-silver nanoshell prepared for the example.

[0030] Figure 6 The SERS spectrum of the multi-level micro / nano structure composite material prepared in the example is shown. Detailed Implementation

[0031] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings and embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0032] Unless otherwise specified, all instruments and reagents used in the following examples were purchased through commercial channels.

[0033] The solution of hexadecyltrimethylammonium bromide-coated spherical gold nanoparticles was purchased from Suzhou Beike Nanotechnology Co., Ltd.

[0034] Example 1

[0035] In this embodiment, the flowchart of the preparation method for a multi-level micro / nano-structured composite material for nuclear radiation detection is as follows: Figure 1 As shown, the specific steps are as follows:

[0036] 1) Preparation of boron-containing molecularly functionalized gold nanonuclei

[0037] A 1 mM solution of 4-mercaptophenylboronic acid pineneol ester was added to a solution of spherical gold nanoparticles coated with hexadecyltrimethylammonium bromide (nanoparticle size 30 nm, 0.5 μM). The molar ratio of the added 4-mercaptophenylboronic acid pineneol ester to the gold nanoparticles was 200:1.

[0038] The reaction was carried out under a nitrogen atmosphere and stirred at room temperature for 8 hours. The resulting solution was centrifuged (10000 rpm, 20 min), and the supernatant was discarded to remove unreacted 4-mercaptophenylboronic acid pineneol ester. The precipitate was redispersed in cetyltrimethylammonium bromide solution (0.1 M) to obtain a 2 μM solution of 4-mercaptophenylboronic acid pineneol ester-functionalized gold nanoparticles, which is the boron-containing molecularly functionalized gold nanoparticle, for later use. TEM images of the boron-containing molecularly functionalized gold nanoparticles prepared in this step are shown below. Figure 2 As shown.

[0039] 2) Preparation of functionalized gold nanocore-gold nanoshell

[0040] Chloroauric acid solution (5 mM) and ascorbic acid solution (30 mM) were added sequentially to a hexadecyltrimethylammonium bromide solution (0.1 M), and the mixture was vortexed for 3 min to quickly and evenly mix it, resulting in mixed solution A (the final concentration of chloroauric acid in mixed solution A was 0.5 mM; the final concentration of ascorbic acid in mixed solution A was 3.0 mM).

[0041] The 4-mercaptophenylboronic acid pineneol ester functionalized gold nanoparticle core solution obtained in step 1) was added to mixed solution A (molar mass: ascorbic acid: chloroauric acid: boron-containing functionalized gold nanoparticle core = 12:2:1), and stirred at 40℃ for 2 h until the solution color no longer changed. Heating was then stopped, and stirring was continued for 1 h after the solution cooled to room temperature. The reaction solution was centrifuged (10000 rpm, 20 min), and the supernatant was discarded to remove unreacted reagents. The precipitate was resuspended in ultrapure water to obtain the functionalized gold nanoparticle core-gold nanoshell (final concentration 2 μM), which was set aside for later use. The TEM image of the functionalized gold nanoparticle core-gold nanoshell prepared in this step is shown below. Figure 3 As shown.

[0042] 3) Preparation of functionalized gold nanocore-gold nanoshell-silver nanoshell

[0043] Under stirring conditions, the functionalized gold nanocore-gold nanoshell solution obtained in step 2) was added to silver nitrate solution (10 mM), and then ascorbic acid solution (40 mM) was added dropwise. The pH of the system was adjusted to 7-9 using 0.1 M sodium hydroxide solution to promote uniform deposition of the silver nanoshell (molar mass: ascorbic acid: silver nitrate: functionalized gold nanocore-gold nanoshell = 8:2:1). The reaction was stirred at 50 °C for 2 h until the solution color no longer changed. Heating was stopped, and the solution was stirred for another 1 h after cooling to room temperature. The reaction solution was centrifuged (10000 rpm, 20 min), and the supernatant was discarded to remove unreacted reagents. The precipitate was resuspended in ultrapure water to obtain the functionalized gold nanocore-gold nanoshell-silver nanoshell composite material.

[0044] A schematic diagram of the composite material is shown below. Figure 4 As shown, from the inside out, the composite material is composed of a multi-level micro-nano structure, including a gold nano core 1, boron-containing molecules 2, a gold nano shell 3, and a silver nano shell 4.

[0045] The TEM image of the composite material is as follows. Figure 5 As shown. Figure 2 , Figure 3 , Figure 5TEM images show boron-containing molecularly functionalized gold nanonuclei, functionalized gold nanonuclei-gold nanoshells, and functionalized gold nanonuclei-gold nanoshells-silver nanoshells, respectively. The microstructure of all of them is spherical, indicating that the gold nanonuclei were not affected during the stepwise preparation process. The particle size of the gold nanonuclei-gold nanoshells is slightly larger than that of the boron-containing molecularly functionalized gold nanonuclei. A thin layer of silver shell is clearly visible in the functionalized gold nanonuclei-gold nanoshells-silver nanoshells, indicating that the composite material has been successfully prepared.

[0046] According to GB / T 40219-2021 standard, the SERS spectrum of the obtained composite material was tested using a Raman spectrometer (InVia, Renishaw), as follows: Figure 6 As shown, the SERS spectrum has sharp peaks and high intensity, at 1580 and 1570 cm⁻¹. -1 The characteristic peaks of nearby boron-related functional groups are clearly distinguishable, indicating that the SERS effect is effectively excited by the gap between the gold nanocore and the gold nanoshell, and that the gold nanocore is effectively functionalized by boron-containing molecules. According to GB / T26810-2011 standard, the LSPR spectrum of the obtained composite material was measured using a UV-Vis spectrophotometer (UV-2550, Shimadzu). It showed absorption peaks near 550 nm and 400 nm, originating from the extinction properties of the gold nanostructure and the silver nanoshell, respectively.

[0047] Using the Am-Be neutron source (moderated) and 60 The nuclear radiation detection performance of the composite material obtained by testing with a Co gamma-ray source is as follows:

[0048] 1) The obtained composite material was irradiated with an Am-Be neutron source (moderated) at a neutron dose of 1–50 mGy, and its SERS spectrum was tested to evaluate its neutron response performance;

[0049] 2) Use 60 The obtained composite material was irradiated with a Co gamma ray source at a gamma dose of 4 Gy, and its SERS spectrum was tested to evaluate its resistance to gamma ray interference.

[0050] 3) Use 60 The obtained composite material was irradiated with a Co gamma ray source with a gamma dose of 1–10 Gy, and its LSPR spectrum was measured to evaluate its gamma ray response performance.

[0051] 4) The obtained composite material was irradiated with an Am-Be neutron source (moderated) at a neutron dose of 200 mGy, and its LSPR spectrum was tested to evaluate its anti-neutron interference performance.

[0052] Test results show that the SERS spectrum of the obtained composite material has a good response to neutron dose, with values ​​at 1570 and 1580 cm⁻¹. -1The relative intensities of the two characteristic peaks were fitted to the neutron dose, and the equation was y = 8.126x + 0.141(R0). 2 =0.972), and the signal drift caused by gamma irradiation is about 1.6%, indicating that it has good resistance to gamma irradiation interference; the LSPR spectrum has a good response to gamma irradiation dose, and the gamma irradiation dose is fitted by the relative intensity of the absorption peaks at 550 and 400 nm, and the equation is y = 0.218x + 0.512(R 2 =0.983), and the signal drift caused by neutron irradiation is approximately 0.9%. In summary, the obtained multi-level micro-nano structure composite material can be used for nuclear radiation detection and can distinguish the dose of mixed radiation fields.

Claims

1. A method for preparing a multi-level micro / nano-structured composite material for nuclear radiation detection, characterized in that, The specific steps are as follows: 1) Add the boron-containing molecular solution to the gold nanoparticle solution coated with surfactant I and stir the reaction under a nitrogen atmosphere; then centrifuge, take the precipitate and disperse it in surfactant II to obtain a boron-containing molecular functionalized gold nanoparticle core solution for later use. The boron-containing molecule is at least one of 4-mercaptophenylboronic acid pinene ester, mercaptophenylboronic acid, or a mercaptophenylboronic acid derivative; the mercaptophenylboronic acid derivative is a complex formed by mercaptophenylboronic acid and a molecule containing a cis-ortho-diol structure. 2) Add chloroauric acid and ascorbic acid solution I to surfactant III in sequence to obtain a mixed solution for later use; Add the boron-containing functionalized gold nanoparticle core solution obtained in step 1) to the mixed solution, stir the reaction until the solution color no longer changes, and after the solution is cooled to room temperature, centrifuge, take the precipitate and resuspend it in ultrapure water to obtain the functionalized gold nanoparticle core-gold nanoparticle shell solution. 3) Under stirring conditions, add the functionalized gold nano core-gold nano shell solution obtained in step 2) to silver nitrate solution, then add ascorbic acid II dropwise, adjust the pH to 7-9, stir the reaction until the solution color no longer changes, and centrifuge after the solution cools to room temperature. The precipitate is the multi-level micro-nano structure composite material used for nuclear radiation detection. Surfactant I, Surfactant II, and Surfactant III are of the same type, namely, one of hexadecyltrimethylammonium bromide, hexadecyltrimethylammonium chloride, or polyvinylpyrrolidone.

2. The method for preparing the multi-level micro / nano structure composite material for nuclear radiation detection according to claim 1, characterized in that, Step 1) The concentration of the boron-containing molecular solution is 0.1~2 mM.

3. The method for preparing the multi-level micro / nano structure composite material for nuclear radiation detection according to claim 1, characterized in that, In step 1), the gold nanoparticles coated with surfactant I have a particle size of 20-60 nm and a solution concentration of 0.1-1 μM.

4. The method for preparing the multi-level micro / nano-structured composite material for nuclear radiation detection according to claim 1, characterized in that, In step 1), the molar mass ratio of the added boron-containing molecules to the gold nanoparticles coated with surfactant I is 200:1 to 500:

1.

5. The method for preparing the multi-level micro / nano structure composite material for nuclear radiation detection according to claim 1, characterized in that, The concentrations of surfactant I, surfactant II, and surfactant III are all 0.05~0.2 M.

6. The method for preparing the multi-level micro / nano structure composite material for nuclear radiation detection according to claim 1, characterized in that, In step 2), the molar concentration of chloroauric acid in the mixed solution is 0.1~0.5 mM, and the molar concentration of ascorbic acid I is 0.6~3.0 mM.

7. The method for preparing the multi-level micro / nano structure composite material for nuclear radiation detection according to claim 1, characterized in that, In step 2), the molar ratio of ascorbic acid I, chloroauric acid, and boron-containing molecularly functionalized gold nanonuclei is 12:2:

1.

8. The method for preparing the multi-level micro / nano structure composite material for nuclear radiation detection according to claim 1, characterized in that, In step 3), the molar concentration of the silver nitrate solution is 10-20 mM; the molar concentration of ascorbic acid II is 40-80 mM.

9. The method for preparing the multi-level micro / nano structure composite material for nuclear radiation detection according to claim 1, characterized in that, In step 3), the molar mass ratio of ascorbic acid II, silver nitrate, and functionalized gold nanocore-gold nanoshell is 8:2:

1.

10. A multi-level micro / nano structure composite material for nuclear radiation detection prepared by any of the methods described in claims 1-9.

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