JP4586191B2 - Use of radiation-sensitive dye composition containing silica particles for measurement of radiation at a low dose of 10 Gy or less - Google Patents

Description

The present invention relates to a radiation-sensitive dye composition containing a novel silica particle, and radiation that is discolored by radiation such as X-rays, β-rays, γ-rays, neutrons, etc., and particularly that is easily discolored even at a low dose of 10 Gy or less. The present invention relates to the use of colored materials (Enhanced Radiochromic Materials).

  2. Description of the Related Art Conventionally, various dosimeters are used for the purpose of preventing radiation damage by operators of nuclear radiation generators such as X-rays, operators of nuclear reactors, and researchers. One of the most easily handled is a black and white photographic film in a badge-shaped metal or plastic case that is placed on the chest of the operator and developed after a certain number of days. There is a film badge that calculates the photographic density of the obtained image and calculates the radiation dose received by the film. This system has the advantage that the badge itself can be made compact, easy to handle and the record can be stored permanently, but all the images are sent to the laboratory, where they are developed under certain conditions. However, it has to be dried, and the result of exposure cannot be immediately known on the spot.

  Therefore, when the instant photographic color film disclosed in Patent Document 1 is exposed to X-rays and developed, a special color image is generated, and the phenomenon that the color tone changes sequentially according to the exposure dose as described above. A method for measuring radiation exposure without defects has been invented. That is, at least one photosensitive color film and a processing liquid pot capable of developing a processing liquid on the film by pressing a roller or the like to develop the film are packed in a light-shielded state by light-shielding paper. After exposing a set of instant photographic color films to radiation, the processing solution is developed and developed on the photosensitive surface of the film, and the color tone of the resulting image is compared with the standard color tone of a pre-made instant photographic film image of the same type The radiation exposure dose measurement method is characterized in that the exposure dose is measured by:

In 2001, as a radiation measurement method for X-rays and the like, a sheet-like self-development type reflection film was released by ISP (International Specialty Products). GAFCHROMIC series. A dye having a peak at 680 nm is used. The composition is unknown. Especially for GAFCHROMIC XR Type R and Type T, Type R is the type that measures reflected light, Type T is the type that measures transmitted light, and the sensitivity is Type R and the intensity of the densitometer is 0.26 at 0.75 Gy, In 0.58 at 2Gy, 1.27 at 6Gy, 1.58 at 10Gy, and Type T, it is 0.40 at 1Gy, 0.80 at 2Gy, 1.75 at 5Gy, 3.00 at 10Gy. For example, in the case of Type R, with X-ray irradiation, a color change is caused to an absorbed dose of about 0 to 10 Gy and the dose can be visually confirmed. However, in a low dose part, that is, a dose of 1 Gy or less, a densitometer There are disadvantages such as need to measure by. Therefore, this product is optimal for use at around 10 Gy, which is different from what is clearly visible even at doses of 1 Gy or less.
7-104412

An object of the present invention is to provide a use of a novel dye composition.
The present invention relates to a radiation-sensitive dye composition containing silica particles that are discolored by radiation such as X-rays, β-rays, γ-rays, neutrons, etc., and particularly, silica particles that are easily discolored even at a low dose of 10 Gy or less. It is an object of the present invention to provide use of a radiochromic material (Enhanced Radiochromic Materials) for measurement of radiation at a low dose of 10 Gy or less .

The gist of the present invention is the use of a radiation-sensitive dye composition containing silica particles that are discolored by the following radiations (1) to ( 10 ) for measurement of radiation at a low dose of 10 Gy or less .
(1) Use of a radiation-sensitive dye composition containing silica particles that are discolored by radiation selected from the group consisting of the following ( A ) to ( F ) for measurement of low-dose radiation.
( A ) Mixture of an aqueous solution of a substance in which xylenol orange molecules are encapsulated in silica particles, an ammonium iron (II) sulfate solution and gelatin ( B ) A mixed aqueous solution of silica particles and potassium chloroaurate ( C ) Silica particles and chloroauric acid Mixture of potassium, isopropanol, and gelatin ( D ) Mixture of aqueous solution of substance containing xylenol orange molecules in silica particles and ammonium iron (II) sulfate solution ( 2 ) Use for measurement of radiation is for medical exposure evaluation Use of (1) above, which is a use for.
( 3 ) Use of said (1) whose use for the measurement of said radiation is use for contamination detection of a management area laboratory level.
( 4 ) Use of said (1) whose use for the measurement of said radiation is use for the pollution control which concerns on a radioactive substance.
( 5 ) Use of said (1) whose use for measurement of said radiation is use for the measurement of the integrated dose which concerns on a radiation.
( 6 ) Use of said (1) whose use for the measurement of said radiation is use for the personal exposure management which concerns on radiation.
( 7 ) Use of said (1) whose use for the measurement of said radiation is use for nuclear disaster prevention.
( 8 ) Use of said (1) whose use for the measurement of said radiation is use for atomic energy public information (PA).
( 9 ) The use according to claim 1, wherein the use of the radiation for the measurement is a detection of about 0.1 Gy to 10 Gy when the radiation is X-ray and γ-ray.
( 10 ) Use of said (1) whose use for the measurement of said radiation is use for detection as a polyethylene filter paper, when a radiation is a beta ray and a gamma ray.

New “mixed dye” applications (use for measuring low doses of radiation) can be provided.
Radiation-sensitive dye composition containing silica particles that easily discolor due to exposure to radiation such as X-rays, β-rays, γ-rays, neutrons, etc., especially those that are easily discolored even at low doses, and radiation-colored substances (Enhanced) Radiochromic Materials (use for measurement of low dose radiation of 10 Gy or less ) can be provided.

  The target radiation in the present invention is 10 Gy as an air absorbed dose by a therapeutic 60-Co γ-ray irradiator as γ-ray, 1 Gy to 2 Gy as X-ray generated by an X-ray diagnostic device, low dose As the sealed radiation source, 60-Coγ ray 74 kBq, 137-Csγ ray 3.7 MBq, and β ray 90-Sr / 90-Yβ ray 74 kBq are exemplified.

The low-dose radiation color-changing substance containing silica particles is not particularly limited as long as it is a material containing a radiation-sensitive dye and silica particles in a form that causes a color change that can be visually recognized by low-dose radiation, and is a powder as a solid, Examples include a sample obtained by protecting a liquid sample contained in a filter paper with a transparent tape, a sample obtained by solidifying a plastic cell of 4 cm volume of 1 cm square using gelatin, and the same liquid sample.

In the present invention, as the radiation-sensitive dye containing silica particles, a color change which can be visually observed by irradiation with radiation, for example, the following 3) to 6) are adopted in the following examples .
1) Reagent using Prussian Blue The blue color of Prussian Blue is used as a β-ray and γ-ray photosensitive dye. Prussian Blue uses a general preparation method and mixes a 2,5-dihydroxy-para-benzoquinone (dhqH ₂ ) aqueous solution, which has a reducing action by irradiation, with a mixture of ferric chloride aqueous solution and potassium ferrocyanide aqueous solution in a certain ratio. To make a reagent. As a method of use, this reagent is applied to a filter paper in a state containing about 10% of water. For example, when covering with a commercially available mending tape so that moisture does not evaporate and irradiating with 60-Co as a sealed radiation source and 90-Sr as a β radiation source, In about an hour, the color of the source fades slightly. It is characterized in that it is possible to determine that radiation has been irradiated based on the color change. A reagent containing a radiation-sensitive dye is applied, and the dye causes a color change that can be visually observed by radiation irradiation.
This is for detecting β-rays and γ-rays and is applied to polyethylene filter paper and used to detect contamination at the laboratory level in the control area.

2) White powder based on X-ray-induced phosphor X-ray-induced phosphor When white powder based on CaWO ₄ is prepared, a certain ratio of iodine (from Na ₂ WO ₄ , CaCl ₂ and KI is 1: 2: 2) White precipitate CaWO ₄ : I obtained by mixing in (Preparation).
The method of use is either using the powder sample sandwiched between two transparent double-sided tapes, or molding it into a pellet. The irradiated back surface is colored yellow after X-ray irradiation. It is possible to determine that X-rays have been irradiated by this color change. This is a material for medical exposure evaluation that can be used for detection of about 0.1 Gy to 10 Gy for X-ray detection, and for medical exposure evaluation with an X-ray-induced phosphor that generates a color change by X-ray irradiation. These materials are integrally attached to constitute a medical instrument, and the X-ray irradiated display is discriminated by the color change of the X-ray induced phosphor.

3) Fe ²⁺ / xylenol orange / SiO ₂ reagent The Fe ²⁺ / xylenol orange / gelatin reagent reported in the literature (Radiation Physics and Chemistry, 61 (2001) 433-435) has been improved. SiO ₂ ) Nano (particle diameter of about 30 nm) contained in the particles is used. As a result, it is expected to increase the sensitivity by concentrating xylenol orange at a high concentration in the silica nanoparticles. A mixture of a compound containing Fe ²⁺ in a xylenol orange / SiO ₂ aqueous solution is irradiated with γ-rays, and Fe ³⁺ produced by oxidation of Fe ²⁺ is coordinated to xylenol orange to change from yellow to purple. Change occurs. As the compound having Fe ²⁺ , known compounds that do not affect the reaction can be widely used, but ammonium iron sulfate (II) is preferable.
It is possible to determine that γ rays have been irradiated by this color change.

4 ) Fe ²⁺ / xylenol orange / SiO ₂ / gelatin reagent The Fe ²⁺ / xylenol orange / gelatin reagent reported in the literature (Radiation Physics and Chemistry, 61 (2001) 433-435) has been improved. Silica (SiO ₂ ) nano (particle size: about 30 nm) contained in particles. As a result, it is expected to increase the sensitivity by concentrating xylenol orange at a high concentration in the silica nanoparticles. From yellow to purple by the coordination of Fe ³⁺ produced by oxidation of Fe ²⁺ by γ-ray irradiation to a mixed solution of a compound containing Fe ²⁺ in an aqueous solution of xylenol orange / SiO ₂ / gelatin Color change occurs. As the compound having Fe ²⁺ , known compounds that do not affect the reaction can be widely used, but ammonium iron sulfate (II) is preferable.
It is possible to determine that γ rays have been irradiated by this color change.

5 ) Coloring reagent for producing fine gold particles from dispersed potassium chloroaurate solution in high-density silica nanoparticles Add KAuCl ₄ to commercially available high-density silica nanoparticles and mix to make a sample. When this is irradiated with gamma rays (10 Gy), it appears red, which is thought to be the formation of Au fine particles. It is possible to determine that γ rays have been irradiated by this color change.

6 ) High-sensitivity coloring reagent (by producing fine gold particles from a silica nanoparticle-dispersed potassium chloroaurate solution containing a sensitizer)
Further, KauCl ₄ and isopropanol and gelatin as sensitizers are added to and mixed with commercially available high-density silica nanoparticles to prepare a sample. When this is irradiated with γ-rays, it appears red, which seems to be the formation of Au fine particles. It is possible to determine that γ rays have been irradiated by this color change.

  In the application method, a predetermined amount of sample solution to be applied is collected, applied with a pipette, etc., and then naturally dried.

  In the method of applying to filter paper, a predetermined amount of sample solution to be applied is collected and applied with a pipette or the like, and then naturally dried leaving about 10% of water.

  For use, for example, it can be used as a roll paper for detecting contamination with radioactive isotopes in a laboratory using radioactive isotopes.

The radiation-sensitive dye composition and low-dose radiation-colorable substance of the present invention can be used for the following applications.
(a) For pollution control related to radioactive materials For example, for valves, pumps, piping, etc. installed in nuclear power plants, maintenance, inspection, repair, or decontamination work is performed regularly or temporarily. ing. Contamination management at the work site is important so that work can be performed safely, accurately and efficiently, and the radiation-sensitive dye composition of the present invention and the low-dose radiation-colorable substance are used for contamination management related to such radioactive materials. be able to.
(b) For integrated dose measurement related to radiation In and around the surrounding monitoring areas such as fuel manufacturing and processing facilities and nuclear power generation related facilities, measuring instruments and monitor indicators for measuring the air dose rate of radiation in the concerned areas Facilities for transmitting data such as moving average values, integrated values, and instantaneous values obtained from measuring instruments to management offices are installed as appropriate. The low dose radiation colorable material of the present invention can be used to monitor doses at low dose levels.
(c) For personal exposure management related to radiation Workers who work in a management area such as a nuclear power plant are required to manage radiation exposure dose values and work hours in the management area. For personal exposure management related to radiation, there is equipment that monitors the environmental dose rate at the work site that changes from moment to moment in real time, but as a supplement to these, the radiation sensitivity of the present invention that allows visual attention to the presence of radiation A dye composition or a low-dose radiation-coloring substance can be used.
(d) For nuclear disaster prevention systems Although nuclear power plants and fuel manufacturing and processing facilities have systems that do not cause accidents, in the unlikely event that nuclear accidents occurred at JCO on September 30, 1999, such as nuclear accidents. In the event of a disaster, the radiation-sensitive dye composition of the present invention or a low-dose radiation-coloring substance according to the present invention, which visually notices the presence of radiation, can be used as one of the materials for determining the exposure dose of the surrounding residents.
(e) For Nuclear Public Relations (PA) The safe use of nuclear power needs to be understood from the world, including local residents, from children to adults. With the radiation-sensitive dye composition of the present invention and a low-dose radiation-coloring substance that makes visual observation of radiation present, it is a matter of course that the dose management of workers in radiation-controlled areas does not exceed the allowable dose. , Familiar materials and materials that allow people to know that nuclear energy is being used safely by keeping each worker's exposure dose as low as possible and notifying them that unnecessary exposure is managed Become.

The details of the present invention will be described in Examples. The present invention is not limited to these examples. Examples 1 and 2 are reference examples.

Prussian blue is a mixture of 1 mM ferric chloride aqueous solution and 1 mM potassium ferrocyanide aqueous solution. Next, 1 mM of a 2,5-dihydroxy-para-benzoquinone (dhqH ₂ ) aqueous solution having a reducing action by irradiation is mixed with a mixture of 1 mM of ferric chloride aqueous solution and 1 mM of potassium ferrocyanide in a ratio of 1: 1: 0.3. The reagent is applied to the filter paper in a state in which about 10% of water is contained. Cover with commercial mending tape so that moisture does not evaporate, and then irradiate with 60-Co as the sealed radiation source (74kBq) γ-ray source and 90-Sr as the β-ray source. In about an hour, the color of the source fades slightly (Figure 1). The reproducibility under the same conditions has been confirmed.

Dissolve 0.5 g of CaCl ₂ · 2H ₂ O and 1.13 g of KI in 3 ml of distilled water, mix with 0.51 g of Na ₂ WO ₄ dissolved in ₂ ml of distilled water, and add white precipitate CaWO ₄ : I. obtain. Then, it is washed several times with distilled water, dried and used. The powder sample was sandwiched between two transparent double-sided tapes, and the irradiated back surface was colored yellow after about 2 Gy of X-ray irradiation (tube voltage 80 kV, tube current 200 mA, irradiation time 2 sec 10 times) (Figure 2) .

Add about 7 mg of xylenol orange and 260 μl of isocyanate propyl silicate in 2 ml DMSO and stir for 1 hour. Thereafter, 6 ml of ethanol, 6 mg xylenol orange, 0.3 ml of tetraethylorthosilicate and 2 ml of concentrated aqueous ammonia are added to the solution and stirred at room temperature for 1 day. Thereafter, ultrafiltration is performed using an Amicon YM-100 filter and washing is performed to obtain about 2 ml of a xylenol orange / SiO ₂ aqueous solution.
0.4 ml of this xylenol orange / silica particle aqueous solution is mixed with 0.1 ml of 10 mM ammonium iron (II) sulfate (1N) aqueous solution and 0.1 ml of 1N sulfuric acid to obtain Fe ²⁺ / xylenol orange / SiO ₂ reagent. The Fe ²⁺ / xylenol orange / SiO ₂ reagent, xylenol although orange is fixed to a high concentration in the silica particles, the color is changed by the pH of the solution as well as xylenol orange solution, the Fe ³⁺ in xylenol orange solution When an aqueous solution was added, a color change from yellow to purple due to coordination of Fe ³⁺ to xylenol orange was also confirmed.
This Fe ²⁺ / xylenol orange / SiO ₂ reagent solution was irradiated with about 10 Gy of γ-rays at room temperature (irradiated with a 60-Co γ-ray irradiator for 30 minutes) to produce Fe ³ produced by oxidation of Fe ²⁺ in the aqueous solution. A color change from yellow to purple, which seems to have coordinated ⁺ to xylenol orange, was observed (FIG. 3). This color change was found to increase by about 0.15 upon γ-ray irradiation of the reagent at 600 nm (FIG. 4). From this, xylenol orange was fixed to silica nanoparticles, and the absorbance change accompanying γ-ray irradiation was first observed.

Fe ²⁺ / xylenol orange / SiO by mixing 0.4 ml or 0.2 ml of xylenol orange / silica particle aqueous solution with 10 mM ammonium sulfate, 0.1 ml of iron (II) (1N) aqueous solution, 0.1 ml of 1N sulfuric acid, and 0.6-2.4 ml of distilled water After preparing the _two reagents, the gelatin amount was decreased from 3 ml to 1 ml from 0.2 g / ml, and these aqueous solutions were irradiated with about 10 Gy of γ rays. (30-minute irradiation with 60-Co γ-ray irradiation device) As a result, the color change from yellow to purple caused by the coordination of Fe ³⁺ produced by oxidation of Fe ²⁺ by γ-ray irradiation with xylenol orange Could be observed. From these absorbance measurement results, it was confirmed that the purple absorbance changed to the maximum when the amount of gelatin was 1 ml. When the amount of gelatin was 1 ml, an absorbance of 1.329 was obtained at 586 nm. From this value, it was found that the sensitivity was about 1.2 times that of the literature (Radiation Physics and Chemistry, 61 (2001) 433-435). (Fig. 5)

Of the commercially available high-density silica nanoparticles, those having a particle size of 12 nm are set to about 36 wt%, and 0.4 ml of 0.5 mM KAuCl ₄ is added thereto and mixed to prepare a sample. When this is irradiated with γ-rays (10 Gy), it appears red, which seems to be the formation of Au fine particles (FIGS. 6 and 7). It was found that about 10 Gy of gamma ray irradiation on the silica nanoparticles / KAuCl ₄ system colored the solution red. This phenomenon was the maximum when the particle size was 12 nm (12 nm> 7 nm> 22 nm), and it was confirmed that the absorbance of the solution changed depending on the concentration of KauCl ₄ added. It was also found that the coloring speed varies depending on the pH of the solution. Furthermore, the sensitivity was remarkably increased by adding isopropanol. It was also found that the size of the gold fine particles produced by adding a small amount of gelatin can be adjusted. In other words, when gelatin was not added, a purple color in which the particle size was increased by aggregation was shown, and when a small amount of gelatin was added, red gold fine particles without aggregation were generated.

Commercially available colloidal silica nanoparticles (LUDOX (R) HS-40 colloidal silica, weight% 40wt%, particle size 12nm) 2ml, H ₂ O 1ml, 10mM KAuCl ₄ 1ml, isopropanol 0.2ml in 1cm square type disposable cell And then heated in a hot water bath at about 100 degrees for 1 minute. Thereafter, 10 μl of gelatin (0.2 g / 1 ml) already heated to a solution was mixed in a square-shaped disposable cell to uniformly dissolve the gelatin. Gamma rays (0.002849Gy / h, 137-Cs irradiation dose rate 0.0770μGym ² MBq ^-1 h ^-1 emitted from 137-Cs (3.7MBq) were used for the sample thus prepared, and 3.7MBq , Calculated as a distance of 0.01 m) for 60.5 hours, the absorbed dose was about 0.17 Gy. At this time, Au ions were reduced, and the solution turned red due to the generated Au fine particles.
In order to examine the above optimum conditions, the absorbance (520 nm) was measured by changing gelatin, isopropanol, silica particle diameter, and silica particle content. Absorbance was measured with UV-1700 manufactured by Shimadzu Corporation using a square type disposable cell as it was. Table 1 shows the results of measuring the absorbance (520 nm) by changing the gelatin content, Table 2 shows the results of measuring the absorbance (520 nm) by changing the isopropanol content, and measuring the absorbance (520 nm) by changing the silica particle size. The results are shown in Table 3, and the absorbance (520 nm) was measured while changing the silica particle content. The results are shown in Table 4, respectively.

FIG. 8 shows the amount of gelatin added vs. the size diameter of gold particles or the color of gold particles.
As for the amount of gelatin added, only the most sensitive HS-40 was used.
Therefore, the conditions are 2 ml of commercially available colloidal silica particles (LUDOX (R) HS-40 colloidal silica, weight% 40 wt%, particle size 12 nm), 1 ml of H ₂ O, 1 ml of 10 mM KAuCl ₄ and 0.2 ml of isopropanol 1 cm square. It is mixed in a disposable cell, heated in a hot water bath at about 100 ° C. for 1 minute, and mixed with 2 μl of gelatin (0.2 g / 1 ml) heated to a solution to uniformly dissolve the gelatin.
Under these conditions, the solution was thinly applied to a glass plate, and the change in absorbance with the time of irradiation was measured. The results are shown in Table 5 and FIG.

Silica particles, HS-30 of LUDOX (SiO ₂ 30wt% aqueous solution of the particle diameter 7nm), HS-40 a (SiO ₂ 40 wt% aqueous solution of the particle diameter _{12nm) TM-50 (SiO 2} 50wt% aqueous solution of the particle size 22 nm) It was used as it was and diluted with distilled water. The network structure was prepared by using three solutions of silica nanoparticles with different sizes using tetraethyl orthosilicate (TEOS), 3-aminopropylsilicate (APS), and isothiocyano-propylsilicate (CNS) solutions from Aldrich as silane coupling reagents. And allowed to stand for 1 day with stirring.
Add 0.5ml of 10mM KAuCl ₄ aqueous solution to 3.5ml of the sample aqueous solution prepared in this way, and add about 5% isopropanol to further increase the yield. Was irradiated at room temperature in an air or nitrogen atmosphere so that the absorbed dose of air was ˜1 kGy. In either case, the solution was red and no aggregation occurred. From the relationship between TEOS and APS-CNS concentration changes (to the concentration at which silica nanoparticles become white precipitates) and the amount of Au fine particles produced, networking with TEOS is more Au than networking with APS-CNS. It was found that the amount of fine particles produced was large. In APS-CNS, when [APS-CNS] / [SiO ₂ ] _p is greater than about 3.6, an about 1.14 nm chain having 9 atoms between each two silicate groups of APS-CNS It is thought that the portions were intertwined with each other, causing the silica nanoparticles to easily aggregate and forming a lump and changing the particle size itself. HS-40 (particle size: 12 nm) and HS-30 (particle size: 7 nm) were confirmed. Especially, HS-30 with a particle size of 7 nm was remarkable.

(1) In Example 4 using gold ions, 197-Au has a large activation cross-section for neutron radiation, and ¹⁹⁷ Au (n, γ) ¹⁹⁸ Au emits 0.412 MeV γ-rays with a half-life of 2.695 days. 198-Au is expected to form. Neutron rays can also be detected by measuring gamma rays of 198-Au generated by these neutron rays with a Ge detector.
(2) Currently, in interventional radiology where the number of cases is increasing, it is possible to visually confirm the dose during the operation and to prevent the patient from being overexposed.
(3) By applying to the wall of a nuclear power plant room, the presence of radiation can be visually observed.
(4) Since the gold fine particles can be prepared at room temperature, the production method is simplified. Moreover, since it is dispersed in silica particles, it is easy to process.
As described above, it can be used for the following applications.
(a) For pollution control of radioactive materials
(b) For cumulative dose measurement related to radiation
(c) For personal exposure management related to radiation
(d) For nuclear disaster prevention
(e) For Nuclear Publicity (PA)

It is a photograph replacing a drawing showing the color change after irradiation with low-dose radiation to Prussian blue / dhqH ₂ reagent (the part where the color is missing in a round shape is irradiated). It is a photograph replacing a drawing showing that the CaWO ₄ / I white powder turned yellow after X-ray irradiation (about 1 Gy). Photo instead of drawing showing color change of gamma-ray irradiation (10Gy) to Fe ²⁺ / xylenol orange / SiO ₂ reagent (change from the second color from the left to the color at the left edge after irradiation. See absorption spectrum change.) It is. Absorption spectrum change before and after γ-ray 10Gy irradiation to Fe ²⁺ / xylenol orange / SiO ₂ reagent. a is after irradiation and b is before irradiation. Absorption spectrum change of Fe ²⁺ / xylenol orange / SiO ₂ / gelatin reagent. The solid line is after irradiation and the broken line is before irradiation. Approximately 10Gy irradiation. (Degree of coloration depending on the conditions are different) color change gamma irradiation to silica particles / KAuCl ₄ reagent (10 Gy) is a photograph as a drawing which shows the. Spectral change of gamma ray irradiation (10 Gy) to silica nanoparticles / KAuCl ₄ reagent. a is after irradiation and b is before irradiation. Absorption spectrum change before and after gamma ray irradiation (0.2 Gy) to silica nanoparticles / KAuCl ₄ reagent / gelatin / isopropanol sample. Absorption spectrum change before and after gamma ray irradiation (0.2 Gy) to silica nanoparticles / KAuCl ₄ reagent / gelatin / isopropanol sample.

Claims (10)

Measurement of a low-dose radiation of 10 Gy or less of a radiation-sensitive dye composition containing silica particles, which produces a color change visually recognized by radiation of 10 Gy or less, selected from the group consisting of the following (1) to ( 4 ) Use for.
( 1 ) Mixture of an aqueous solution of a substance encapsulating xylenol orange molecules in silica particles, an ammonium iron (II) sulfate solution and gelatin ( 2 ) A mixed aqueous solution of silica particles and potassium chloroaurate ( 3 ) Silica particles and chloroauric acid Mixture of potassium, isopropanol and gelatin ( 4 ) Mixture of an aqueous solution of a substance in which xylenol orange molecules are encapsulated in silica particles and an iron (II) sulfate solution 2. Use according to claim 1, wherein the use for measuring radiation is for medical exposure assessment. Use according to claim 1 or 2, wherein the use for the measurement of radiation is for the detection of contamination at the laboratory level in the controlled area. 2. Use according to claim 1, wherein the use for measuring radiation is for contamination control of radioactive material. The use according to claim 1, wherein the use of the radiation for measurement is use for measurement of cumulative dose related to radiation. 2. Use according to claim 1, wherein the use for measuring radiation is for personal exposure management related to radiation. 2. Use according to claim 1, wherein the use for measuring radiation is for nuclear disaster prevention. Use according to claim 1, wherein the use for measuring radiation is for nuclear public relations (PA). The use according to claim 1, wherein the use of the radiation for the measurement is a detection of about 0.1 Gy to 10 Gy when the radiation is X-ray and γ-ray. The use according to claim 1, wherein the use for the measurement of radiation is use as a polyethylene filter paper for detection when the radiation is β rays or γ rays.