WO2017038712A1 - Fluorophore and method for producing same, and bioimaging method - Google Patents

Fluorophore and method for producing same, and bioimaging method Download PDF

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WO2017038712A1
WO2017038712A1 PCT/JP2016/075058 JP2016075058W WO2017038712A1 WO 2017038712 A1 WO2017038712 A1 WO 2017038712A1 JP 2016075058 W JP2016075058 W JP 2016075058W WO 2017038712 A1 WO2017038712 A1 WO 2017038712A1
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phosphor
manganese
earth metal
alkaline earth
metal phosphate
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PCT/JP2016/075058
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French (fr)
Japanese (ja)
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稲垣　徹
大観　光徳
雅 石垣
航 上原
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宇部興産株式会社
国立大学法人鳥取大学
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Priority to JP2017537860A priority Critical patent/JPWO2017038712A1/en
Publication of WO2017038712A1 publication Critical patent/WO2017038712A1/en

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    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K49/00—Preparations for testing in vivo
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
    • C09K11/00—Luminescent, e.g. electroluminescent, chemiluminescent materials
    • C09K11/08—Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials
    • C09K11/70—Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials containing phosphorus
    • C09K11/71—Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials containing phosphorus also containing alkaline earth metals

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  • the present invention relates to a phosphor suitable for a biological imaging method, a manufacturing method thereof, and a biological imaging method.
  • the light absorption rate of water and hemoglobin is shown in FIG.
  • the light absorptance 11 of water becomes smaller on the shorter wavelength side than 1200 nm.
  • the light absorption rate 12 of hemoglobin becomes smaller on the longer wavelength side than 700 nm. Therefore, since the living tissue containing these easily transmits near-infrared light having a wavelength of 700 to 1200 nm, this wavelength region is called a so-called “biological window”.
  • a phosphor that emits light in this wavelength region is injected into a living body and localized at a specific site, light emitted from the site can be observed from outside the living body through a window of the living body.
  • Such a method for observing a specific part is a so-called “biological imaging method”.
  • Non-Patent Document 1 describes a phosphor having a composition of Ba 3 (PO 4 ) 2 : Mn 5+ .
  • the peak wavelength of this phosphor is 1191 nm. Since 1191 nm is included in the window of the living body, this phosphor is suitable for the living body imaging method.
  • Non-Patent Document 1 if the particle size of the phosphor is too small, it is filtered by the kidney, and if the particle size of the phosphor is too large, it is filtered by the liver and discharged outside the body. Therefore, it is difficult to perform a stable biological imaging method. Therefore, in order to perform the biological imaging method stably, a more suitable phosphor is required.
  • Some aspects of the present invention have a low light absorption by water, have low toxicity to the living body, or are difficult to be discharged out of the body, and therefore are suitable for a stable in vivo imaging method and production of such a phosphor. It is an object to provide a method and a stable biological imaging method.
  • a first aspect of the present invention includes a manganese-activated alkaline earth metal phosphate, and each valence of phosphorus and manganese of the manganese-activated alkaline earth metal phosphate is pentavalent.
  • the phosphor is characterized in that the alkaline earth metal of the manganese-activated alkaline earth metal phosphate contains 80 mol% or more of Ca.
  • a phosphor containing manganese-activated alkaline earth metal phosphate, each of valences of phosphorus and manganese being pentavalent, and the alkaline earth metal containing 80 mol% or more of Ca is Ba 3 (PO 4 ) 2 :
  • the emission peak shifts to a shorter wavelength side than Mn 5+, light absorption by water is small, and toxicity to a living body is low, which is suitable for a stable living body imaging method.
  • the manganese-activated alkaline earth metal phosphate is M 10-X (HPO 4 ) 2X (PO 4 ) 6-2X (OH) 2 : Mn 5+ , M 10 -X (HPO 4 ) 2X (PO 4 ) 6-2X F 2 : Mn 5+ , M 10-X (HPO 4 ) 2X (PO 4 ) 6-2X Cl 2 : Mn 5+ , M 3 (PO 4 ) 2 : Mn 5+ , M 10 (PO 4 ) 6 O: Mn 5+ , M 4 (PO 4 ) 2 O: Mn 5+ , M (H 2 PO 4 ) 2 .H 2 O: Mn 5+ , M (PO 3 ) 2 : Mn 5+, MHPO 4 ⁇ 2H 2 O: Mn 5+, MHPO 4: Mn 5+, M 2 P 2 O 7: Mn 5+, M 4 P 2 O 9: Mn 5+ and M 8 H 2 (
  • the manganese-activated alkaline earth metal phosphate is M 10-X (HPO 4 ) 2X (PO 4 ) 6-2X (OH) 2 : Mn 5+ and M 3 It is more preferable to have one or more compositions selected from the group of (PO 4 ) 2 : Mn 5+ (provided that M is one or more selected from the group of Ca, Mg, Ba, Sr, and Ca is 80 Including at least mol%, and 0 ⁇ X ⁇ 2.) This is because the emission peak is shifted to the short wavelength side, the water absorption is further reduced, and the emission intensity is increased, so that the emission emitted from outside the living body is further increased.
  • the manganese-activated alkaline earth metal phosphate is Ca 10-X (HPO 4 ) 2X (PO 4 ) 6-2X (OH) 2 : Mn 5+ and Ca 3 It is particularly preferable to have one or more compositions selected from the group of (PO 4 ) 2 : Mn 5+ (provided that 0 ⁇ X ⁇ 2). This is because the emission peak is further shifted to the short wavelength side, water absorption is further reduced, and the emission intensity is further increased, so that the emission emitted from outside the living body is further increased.
  • Scherrer's formula represented by Formula 1 (where K is the Scherrer constant, ⁇ is the X-ray wavelength, ⁇ is the full width at half maximum of the peak (however, in radians), and ⁇ is
  • the crystallite size of the (002) plane is preferably 10 to 200 nm, which is determined using a Bragg angle (half the diffraction angle 2 ⁇ ) and ⁇ represents the average crystallite size. This is because a phosphor having a crystallite size of 10 to 200 nm is difficult to be filtered by the kidney and difficult to be filtered by the liver. Since such a phosphor is difficult to be discharged outside the body, it is suitable for a stable biological imaging method.
  • a second aspect of the present invention relates to a biological imaging method using the phosphor according to the first aspect of the present invention.
  • the phosphor according to the first aspect of the present invention By using the phosphor according to the first aspect of the present invention, light absorption by water is small, toxicity to the living body is weak, or it is difficult to be discharged outside the body, and thus a stable in vivo imaging method can be provided. .
  • a step for performing a phosphor, comprising a manganese-activated alkaline earth metal phosphate is suitable for a stable in vivo imaging method because the emission peak shifts to the short wavelength side, light absorption by water is small, toxicity to the living body is weak, or it is difficult to be discharged outside the body. Such a phosphor can be manufactured.
  • FIG. 2 shows an X-ray diffraction (XRD) pattern of the phosphor obtained in Example 1.
  • FIG. 2 shows a photoluminescence (PL) spectrum of the phosphor obtained in Example 1.
  • the XRD pattern of the fluorescent substance obtained in Example 2 is shown.
  • the comparison of the PL spectrum of the fluorescent substance obtained in Example 2 and Example 1 is shown.
  • the PL excitation spectrum of the fluorescent substance obtained in Example 2 is shown.
  • the XRD pattern of the fluorescent substance obtained in Example 3 is shown.
  • the scanning electron microscope (SEM) image of the fluorescent substance obtained in Example 3 is shown.
  • the PL spectrum of the fluorescent substance obtained in Example 3 is shown.
  • the diffuse reflection spectrum of the fluorescent substance obtained in Example 3 is shown.
  • the phosphor in the present embodiment contains a manganese-activated alkaline earth metal phosphate, each of valences of phosphorus and manganese is pentavalent, and the alkaline earth metal contains 80 mol% of Ca. Including above.
  • the manganese-activated alkaline earth metal phosphate is M 10-X (HPO 4 ) 2X (PO 4 ) 6-2X (OH) 2 : Mn 5+ , M 10-X (HPO 4 ) 2X (PO 4 ) 6-2X F 2 : Mn 5+ , M 10-X (HPO 4 ) 2X (PO 4 ) 6-2X Cl 2 : Mn 5+ , M 3 (PO 4 ) 2 : Mn 5+ , M 10 (PO 4 ) 6 O: Mn 5+ , M 4 (PO 4 ) 2 O: Mn 5+ , M (H 2 PO 4 ) 2 .H 2 O: Mn 5+ , M (PO 3 ) 2 : Mn 5+ , MHPO 4 2H 2 O: Mn 5+ , MHPO 4 : Mn 5+ , M 2 P 2 O 7 : Mn 5+ , M 4 P 2 O 9 : Mn 5+ and M 8
  • the manganese-activated alkaline earth metal phosphate is M 10-X (HPO 4 ) 2X (PO 4 ) 6-2X (OH) 2 : Mn 5+ and M 3 (PO 4 ) 2 : It is more preferable to have at least one composition selected from the group of Mn 5+ . This is because the emission peak shifts to the short wavelength side, the water absorption becomes smaller, and the emission intensity becomes larger.
  • M preferably contains 90 mol% or more of Ca, and most preferably contains 100 mol% of Ca. This is because the emission peak shifts to the short wavelength side, so that the water absorption is further reduced and the emission intensity is particularly increased, so that the emission emitted from outside the living body becomes stronger.
  • pentavalent Mn emits light as an activator.
  • the Mn content is preferably 0.01 to 50 mol%, more preferably 0.1 to 10 mol%, and even more preferably 1 to 8 mol%. If the Mn content is too small, the luminous efficiency is lowered. On the other hand, when the Mn content exceeds 50 mol%, the emission efficiency decreases because the emission centers come close to each other and cancel each other (concentration quenching).
  • the Scherrer equation represented by Equation 1 (where K is the Scherrer constant, ⁇ is the X-ray wavelength, ⁇ is the full width at half maximum of the peak (in radians)), and ⁇ is the Bragg angle (times
  • the crystallite size of the (002) plane is preferably in the range of 10 to 200 nm, which is obtained using (half the folding angle 2 ⁇ ) and ⁇ represents the average crystallite size).
  • the lower limit of the crystallite size is 1 nm or more, more preferably 10 nm or more. This is because the larger the crystallite size, the larger the particle size of the phosphor, and the more difficult the phosphor is filtered by the kidney.
  • the upper limit of the crystallite size is more preferably 100 nm or less, and still more preferably 80 nm or less. This is because the smaller the crystallite size, the smaller the particle size of the phosphor, and the more difficult the phosphor is to be filtered by the liver. Since the phosphor of the present embodiment is not easily discharged outside the body, it is suitable for a stable biological imaging method.
  • the particle size measured using a dynamic light scattering particle size distribution device is preferably in the range of 1 to 100 nm.
  • the lower limit of the particle size is more preferably 10 nm or more, and further preferably 20 nm or more. This is because the larger the particle size of the phosphor, the more difficult it is to be filtered by the kidney.
  • the upper limit of the particle size is more preferably 90 nm or less, still more preferably 80 nm or less. This is because the smaller the particle size of the phosphor, the more difficult it is to be filtered by the liver. Since the phosphor of the present embodiment is not easily discharged outside the body, it is suitable for a stable biological imaging method.
  • a suitable raw material is appropriately selected from each material of M compound, P compound and Mn compound, and weighed and mixed to prepare a mixture of raw materials.
  • M compound known materials such as oxides, carbonates, nitrates and sulfates can be used, but carbonates (including basic carbonates) are preferable.
  • M is at least one selected from the group consisting of Ca, Mg, Ba, and Sr, and contains 80 mol% or more of Ca.
  • Examples of the P compound include diammonium hydrogen phosphate ((NH 4 ) 2 HPO 4 ), ammonium dihydrogen phosphate ((NH 4 H 2 PO 4 )), ammonium phosphate ((NH 4 ) 3 PO 4 ), and the like.
  • Known materials can be used, but diammonium hydrogen phosphate ((NH 4 ) 2 HPO 4 ) is preferred.
  • Mn compound known materials such as oxides, carbonates, nitrates and sulfates can be used, but carbonates (including basic carbonates) are preferable.
  • the M compound, P compound and Mn compound may each be selected from one material as a raw material, or two or more materials may be used in combination as a raw material.
  • the purity of the raw material is preferably 99% by mass or more.
  • the selected raw material is weighed according to the target composition, and the mixing ratio is adjusted.
  • mixing method for example, a known method such as dry mixing using a mortar or wet mixing in which a solvent such as pure water is added can be used.
  • a known device such as a ball mill, a vibration mill, or a rocking mill can be used.
  • the preparation step further includes a drying step of drying the mixture.
  • a drying method for example, a known method such as a spray dryer, heat drying, freeze drying, or natural drying can be used.
  • the preparation step may further include a step of pulverizing the mixture of raw materials. By making the particle size of the mixture of raw materials fine and uniform, a solid phase reaction in the firing step is likely to occur, and a uniform phosphor can be obtained.
  • the target phosphor is produced by firing the mixture of raw materials obtained in the preparation step.
  • Firing conditions such as atmosphere, temperature, and time are appropriately determined according to the selected raw material, the target composition, and the like.
  • the firing atmosphere is preferably air.
  • the firing temperature is generally in the range of 300 ° C. to 1200 ° C.
  • the firing time is generally in the range of 0.5 to 6 hours. Firing may be performed in a plurality of times. In this case, the calcined body obtained by firing may be fired again after being ground and mixed using a mortar or the like.
  • the solid phase method may further include a grinding step for grinding the phosphor after the firing step.
  • a pulverization method for example, a known method such as a planetary ball mill or a jet mill can be used.
  • the pulverization step may further include a step of classifying the pulverized phosphor.
  • a phosphor having an average particle diameter of 100 nm or more and 200 nm or less can be obtained when the maximum distance between two opposing grain boundaries is defined as the particle diameter of the particle. .
  • By controlling the average particle size of the phosphor in this way for example, when the phosphor is injected into the living body as a dispersion, it can be made difficult to be discharged out of the body.
  • liquid phase method an aqueous solution is prepared by dissolving the M compound, P compound and Mn compound in water (preparation step), and the pH of the aqueous solution is adjusted to a range of 7.0 or higher.
  • hydrothermal synthesis step hydroothermal synthesis step.
  • the liquid phase method further includes a step (separation step) of separating the product from the hydrothermal synthesis step using centrifugation, lyophilization, or the like, if necessary.
  • a suitable raw material is appropriately selected from each material of M compound, P compound and Mn compound, weighed and dissolved in water.
  • M is at least one selected from the group consisting of Ca, Mg, Ba, and Sr, and contains 80 mol% or more of Ca.
  • M is most preferably Ca 100 mol% (Ca compound).
  • Ca compound calcium nitrate (Ca (NO 3 ) 2 ), calcium chloride (CaCl 2 ), calcium acetate ((CH 3 COO) 2 Ca) and hydrates thereof can be used. Hydrates are preferred.
  • P compounds include sodium dihydrogen phosphate (NaH 2 PO 4 ), trisodium phosphate (Na 3 PO 4 ), diammonium hydrogen phosphate ((NH 4 ) 2 PO 4 ), ammonium dihydrogen phosphate (NH 4 H 2 PO 4 ) can be used, but sodium dihydrogen phosphate is preferred.
  • Mn compound potassium permanganate (KMn 4 ), manganese nitrate (Mn (NO 3 ) 2 ), manganese chloride (MnCl 2 ), manganese acetate ((CH 3 COO) 2 Mn) and hydrates thereof are used. However, potassium permanganate is preferred.
  • M compound (Ca compound), P compound and Mn compound may each be selected from one material as a raw material, or two or more materials may be used in combination as a raw material.
  • the purity of the raw material is preferably 99% by mass or more.
  • the selected raw materials are weighed according to the target composition, the mixing ratio is adjusted, dissolved in water, and an aqueous solution is prepared.
  • (2-2-2) Hydrothermal synthesis step In the hydrothermal synthesis step, a basic substance is dropped into the aqueous solution prepared in the preparation step, and the pH is adjusted to 7.0 or higher to carry out hydrothermal synthesis.
  • a known material can be used as the basic substance. In this embodiment, sodium hydroxide was used.
  • the pH is preferably 8.0 or more, more preferably 9.5 or more, and particularly preferably 11.0 or more. By adjusting the pH to the above range, the emission intensity of the product (phosphor) obtained by hydrothermal synthesis can be increased.
  • the separation step the product (phosphor) obtained in the hydrothermal synthesis step is subjected to centrifugation, freeze-drying, or the like as necessary.
  • the phosphor can be separated by rotating at a rate of 5000 to 15000 times per minute for 0.5 to 2 hours. More preferably, the centrifugation is performed a plurality of times.
  • the separated material (phosphor) separated by centrifugation is frozen at ⁇ 10 to ⁇ 50 ° C., depressurized to 20 to 40 Pa, and then sublimated at ⁇ 50 to ⁇ 60 ° C. to remove water.
  • a phosphor can be obtained.
  • the phosphor in the present embodiment can be used in the following biological imaging method. That is, the phosphor of the present embodiment is combined with a substance that is selectively localized at a specific site to be observed in the living body and injected into the living body to thereby make the phosphor of the present embodiment a specific site in the living body. To localize. In this state, the phosphor is excited and light emitted from the phosphor is observed from outside the living body.
  • the surface of the phosphor is modified with saccharides or proteins. Glucose is particularly preferable as the saccharide. This is because cancer cells abnormally consume glucose for cell division, so that the phosphor can be localized in the cancer cells.
  • the cancer cells can be observed from outside the body.
  • a method of modifying the surface of the phosphor with a saccharide for example, an amphiphilic coating that coats the surface of the phosphor by adding glucose to the dispersion of the phosphor surface-treated with an amphiphilic polymer and stirring it.
  • a method of attaching glucose to a polymer can be mentioned.
  • a known material can be used as the amphiphilic polymer, and examples thereof include polyethylene glycol (PEG).
  • Example 1 The composition of the target phosphor is Ca 3 (P 0.975 Mn 0.025 O 4 ) 2, and calcium carbonate (CaCO 3 ), ammonium phosphate ((NH 4 ) 2 HPO 4 ) and manganese carbonate (MnCO) are used as raw materials. 3 ) was selected. These raw materials were weighed so that the molar ratio was 60: 39: 1 (mass ratio was 53.3: 45.7: 1) and mixed using a mortar to obtain a mixture of raw materials. The obtained mixture of raw materials was heated in the atmosphere at 400 ° C. for 4 hours, and then fired in the atmosphere at 800 ° C. for 3 hours to obtain a phosphor.
  • CaCO 3 calcium carbonate
  • ammonium phosphate (NH 4 ) 2 HPO 4 )
  • MnCO manganese carbonate
  • Example 2 The composition of the target phosphor is Ca 10 (P 0.985 Mn 0.015 O 4 ) 6 (OH) 2, and calcium carbonate (CaCO 3 ), ammonium phosphate ((NH 4 ) 2 HPO 4 ) and Manganese carbonate (MnCO 3 ) was selected. These raw materials were weighed so that the molar ratio was 57.4: 34.0: 8.6, and mixed using a mortar to obtain a mixture of raw materials. The obtained mixture of raw materials was heated in air at 400 ° C. for 4 hours and then calcined in air at 700 ° C. for 3 hours to obtain a calcined body. The calcined body was pulverized and mixed using a mortar, and then fired at 700 ° C. for 12 hours in the air to obtain a phosphor.
  • CaCO 3 calcium carbonate
  • Ammonium phosphate (NH 4 ) 2 HPO 4 )
  • MnCO 3 Manganese carbonate
  • Example 3 The composition of the target phosphor is Ca 10 (PO 4 ) 6 (OH) 2, and calcium nitrate tetrahydrate (Ca (NO 3 ) 2 .4H 2 O), sodium dihydrogen phosphate (NaH 2 PO) as raw materials 4 ), potassium permanganate (KMnO 4 ) was selected. These raw materials were weighed so that the molar ratio was 57.4: 34.0: 8.6, and dissolved in ion-exchanged water to prepare an aqueous solution. A sodium hydroxide aqueous solution was added dropwise to this aqueous solution to adjust the pH to 11.9, and then hydrothermal synthesis was carried out by holding at 150 ° C. for 6 hours while stirring 500 times per minute in an autoclave. Next, centrifugation was performed 3 times for 1 hour at 12,000 times per minute, and then freeze-dried to obtain a phosphor.
  • Ca 10 (PO 4 ) 6 (OH) 2 calcium nitrate tetrahydrate
  • Example 4 A phosphor was obtained in the same manner as in Example 3 except that the pH was adjusted to 11.1.
  • Example 5 A phosphor was obtained in the same manner as in Example 3 except that the pH was adjusted to 5.0.
  • FIG. 3 shows the PL spectrum of the phosphor obtained in Example 1.
  • the wavelength of the excitation light was 600 nm.
  • the peak wavelength is 1157 nm, which belongs to the 3d-3d core transition ( 1 E ⁇ 3 A 2 ) of Mn 5+ . Therefore, the valence of Mn contained in the phosphor is pentavalent. Since the peak wavelength of the phosphor having the composition of the conventional Ba 3 (PO 4 ) 2 : Mn 5+ is 1191 nm, the phosphor of the present embodiment has less light absorption of water than the conventional one, and FIG. It can be seen that it is suitable for the method.
  • FIG. 5 shows the PL spectrum 13 of the phosphor obtained in Example 2.
  • the wavelength of the excitation light was 600 nm.
  • the peak wavelength of the PL spectrum 13 of the phosphor obtained in Example 2 is also 1157 nm, which is attributed to the 3d-3d core transition ( 1 E ⁇ 3 A 2 ) of Mn 5+ as in Example 1. Therefore, the valence of Mn contained in the phosphor is pentavalent.
  • a PL spectrum 14 of the phosphor obtained in Example 1 is shown in FIG. Since the peak intensity of the PL spectrum 13 of the phosphor obtained in Example 2 is about 10 times the peak intensity of the PL spectrum 14 of the phosphor obtained in Example 1, it was obtained in Example 2. It can be seen that the phosphor is very suitable for biological imaging methods.
  • FIG. 6 shows a PL excitation spectrum of the phosphor obtained in Example 2.
  • the detection wavelength of the PL excitation spectrum was 1157 nm. From the PL excitation spectrum, 2 A 3 ⁇ 1 A 1 (690 nm) and 2 A 3 ⁇ 3 T 1 ( 3 F) (651 nm), which are transitions of Mn 5+ as the emission center, can be confirmed.
  • FIG. 7 show the XRD pattern of the phosphor obtained in Example 3 and the crystal data of Ca 10 (PO 4 ) 6 (OH) 2 of ICSD, respectively. Both agree well, and it can be seen that the obtained phosphor is an almost single phase of Ca 10 (PO 4 ) 6 (OH) 2 . From the above formula 3, the valence of P is pentavalent. From the results of energy dispersive X-ray analysis, it was confirmed that the ratio of Ca and P was 1.55, which was lower than the stoichiometric ratio of 1.67.
  • FIG. 8 shows an SEM image of the phosphor obtained in Example 3. It can be seen from the SEM image that the crystal grows in the c-axis direction.
  • FIG. 9 and 10 show the PL spectrum and diffuse reflection spectrum of the phosphor obtained in Example 3.
  • the wavelength of the excitation light in the PL spectrum was 600 nm.
  • the PL spectral peak wavelength is 1157 nm, which is attributed to the 3d-3d core transition ( 1 E ⁇ 3 A 2 ) of Mn 5+ . Therefore, the valence of Mn contained in the phosphor is pentavalent. According to existing reports, there are transitions of Mn 5+ from ground states 3 A 2 to 3 T 2 , 1 A 1 , 3 T 1 ( 3 F), etc., which are consistent with the diffuse reflectance spectrum results of FIG.
  • Table 1 shows the emission intensity of PL of the phosphors obtained in Example 3, Example 4, and Example 5.
  • the wavelength of the excitation light in the PL spectrum was 600 nm.
  • the emission intensity is the emission intensity at the peak of the PL spectrum, and is expressed as a relative value when the emission intensity of the phosphor obtained in Example 3 is set to 100. It can be seen that the higher the pH, the higher the emission intensity, which is suitable for the biological imaging method.

Abstract

Provided is a fluorophore suitable for a stable bioimaging method because of low light absorption by water and weak toxicity to the body. The fluorophore includes a manganese-activated alkaline earth metal phosphate; the valence of each of the phosphorus and manganese in the manganese-activated alkaline earth metal phosphate is five, and the alkaline earth metal of the manganese-activated alkaline earth metal phosphate includes 80 mol% or more of Ca.

Description

蛍光体及びその製造方法並びに生体イメージング方法Phosphor, production method thereof, and biological imaging method
　本発明は、生体イメージング方法に好適な蛍光体及びその製造方法並びに生体イメージング方法に関する。 The present invention relates to a phosphor suitable for a biological imaging method, a manufacturing method thereof, and a biological imaging method.
　水及びヘモグロビンの光吸収率を図１に示す。水の光吸収率１１は１２００ｎｍより短波長側で小さくなる。また、ヘモグロビンの光吸収率１２は７００ｎｍより長波長側で小さくなる。したがって、これらを含む生体組織は波長７００～１２００ｎｍの近赤外光を透過しやすいため、この波長域はいわゆる「生体の窓」と呼ばれる。この波長域で発光する蛍光体を生体内に注入して特定部位に局在させると、その部位からの発光を生体の窓を通して生体外から観察することができる。このような特定部位の観察方法がいわゆる「生体イメージング方法」である。非特許文献１には、Ｂａ３（ＰＯ４）２：Ｍｎ５＋の組成を有する蛍光体が記載されている。この蛍光体のピーク波長は１１９１ｎｍである。１１９１ｎｍは生体の窓に含まれるため、この蛍光体は生体イメージング方法に好適である。 The light absorption rate of water and hemoglobin is shown in FIG. The light absorptance 11 of water becomes smaller on the shorter wavelength side than 1200 nm. Moreover, the light absorption rate 12 of hemoglobin becomes smaller on the longer wavelength side than 700 nm. Therefore, since the living tissue containing these easily transmits near-infrared light having a wavelength of 700 to 1200 nm, this wavelength region is called a so-called “biological window”. When a phosphor that emits light in this wavelength region is injected into a living body and localized at a specific site, light emitted from the site can be observed from outside the living body through a window of the living body. Such a method for observing a specific part is a so-called “biological imaging method”. Non-Patent Document 1 describes a phosphor having a composition of Ba 3 (PO 4 ) 2 : Mn 5+ . The peak wavelength of this phosphor is 1191 nm. Since 1191 nm is included in the window of the living body, this phosphor is suitable for the living body imaging method.
　しかし、この蛍光体の発光は、ピーク波長が１１９１ｎｍであるから、図１からわかるように、水に吸収される割合が比較的大きい。さらに、この蛍光体から溶出するバリウムは生体への毒性を有する。したがって、この蛍光体は安定した生体イメージング方法を行うことが難しい。また、非特許文献１に蛍光体の粒径に関する記載はないが、蛍光体の粒径が小さすぎると腎臓でろ過され、蛍光体の粒径が大きすぎると肝臓でろ別されて、体外に排出されるため、安定した生体イメージング方法を行うことが難しい。したがって、生体イメージング方法を安定して行うために、さらに好適な蛍光体が求められている。 However, since the emission of this phosphor has a peak wavelength of 1191 nm, as can be seen from FIG. 1, the proportion absorbed by water is relatively large. Furthermore, barium eluted from this phosphor has toxicity to living bodies. Therefore, it is difficult to perform a stable biological imaging method with this phosphor. Further, although there is no description regarding the particle size of the phosphor in Non-Patent Document 1, if the particle size of the phosphor is too small, it is filtered by the kidney, and if the particle size of the phosphor is too large, it is filtered by the liver and discharged outside the body. Therefore, it is difficult to perform a stable biological imaging method. Therefore, in order to perform the biological imaging method stably, a more suitable phosphor is required.
　本発明の幾つかの態様は、水による光吸収が小さく、生体への毒性が弱く、又は、体外に排出されにくいため、安定した生体イメージング方法に好適な蛍光体及びそのような蛍光体の製造方法並びに安定した生体イメージング方法を提供することを目的とする。 Some aspects of the present invention have a low light absorption by water, have low toxicity to the living body, or are difficult to be discharged out of the body, and therefore are suitable for a stable in vivo imaging method and production of such a phosphor. It is an object to provide a method and a stable biological imaging method.
（１）本発明の第１の態様は、マンガン付活アルカリ土類金属リン酸塩を含み、前記マンガン付活アルカリ土類金属リン酸塩のリン及びマンガンの各々の原子価が５価であり、前記マンガン付活アルカリ土類金属リン酸塩のアルカリ土類金属がＣａを８０モル％以上含むことを特徴とする蛍光体に関する。マンガン付活アルカリ土類金属リン酸塩を含み、リン及びマンガンの各々の原子価が５価であり、アルカリ土類金属が、Ｃａを８０モル％以上含むことを特徴とする蛍光体は、Ｂａ３（ＰＯ４）２：Ｍｎ５＋よりも発光ピークが短波長側にシフトして水による光吸収が小さく、かつ、生体への毒性が弱いことから、安定した生体イメージング方法に好適である。 (1) A first aspect of the present invention includes a manganese-activated alkaline earth metal phosphate, and each valence of phosphorus and manganese of the manganese-activated alkaline earth metal phosphate is pentavalent. The phosphor is characterized in that the alkaline earth metal of the manganese-activated alkaline earth metal phosphate contains 80 mol% or more of Ca. A phosphor containing manganese-activated alkaline earth metal phosphate, each of valences of phosphorus and manganese being pentavalent, and the alkaline earth metal containing 80 mol% or more of Ca is Ba 3 (PO 4 ) 2 : The emission peak shifts to a shorter wavelength side than Mn 5+, light absorption by water is small, and toxicity to a living body is low, which is suitable for a stable living body imaging method.
（２）本発明の第１の態様では、前記マンガン付活アルカリ土類金属リン酸塩がＭ１０－Ｘ（ＨＰＯ４）２Ｘ（ＰＯ４）６－２Ｘ（ＯＨ）２：Ｍｎ５＋、Ｍ１０－Ｘ（ＨＰＯ４）２Ｘ（ＰＯ４）６－２ＸＦ２：Ｍｎ５＋、Ｍ１０－Ｘ（ＨＰＯ４）２Ｘ（ＰＯ４）６－２ＸＣｌ２：Ｍｎ５＋、Ｍ３（ＰＯ４）２：Ｍｎ５＋、Ｍ１０（ＰＯ４）６Ｏ：Ｍｎ５＋、Ｍ４（ＰＯ４）２Ｏ：Ｍｎ５＋、Ｍ（Ｈ２ＰＯ４）２・Ｈ２Ｏ：Ｍｎ５＋、Ｍ（ＰＯ３）２：Ｍｎ５＋、ＭＨＰＯ４・２Ｈ２Ｏ：Ｍｎ５＋、ＭＨＰＯ４：Ｍｎ５＋、Ｍ２Ｐ２Ｏ７：Ｍｎ５＋、Ｍ４Ｐ２Ｏ９：Ｍｎ５＋及びＭ８Ｈ２（ＰＯ４）６・５Ｈ２Ｏ：Ｍｎ５＋の群から選ばれる１種以上の組成を有することがより好ましい（但し、ＭはＣａ、Ｍｇ、Ｂａ、Ｓｒの群から選ばれる１種以上であり、Ｃａを８０モル％以上含み、０≦Ｘ＜２である）。発光強度が大きくなるため、生体外から観察される発光がより強くなるからである。 (2) In the first aspect of the present invention, the manganese-activated alkaline earth metal phosphate is M 10-X (HPO 4 ) 2X (PO 4 ) 6-2X (OH) 2 : Mn 5+ , M 10 -X (HPO 4 ) 2X (PO 4 ) 6-2X F 2 : Mn 5+ , M 10-X (HPO 4 ) 2X (PO 4 ) 6-2X Cl 2 : Mn 5+ , M 3 (PO 4 ) 2 : Mn 5+ , M 10 (PO 4 ) 6 O: Mn 5+ , M 4 (PO 4 ) 2 O: Mn 5+ , M (H 2 PO 4 ) 2 .H 2 O: Mn 5+ , M (PO 3 ) 2 : Mn 5+, MHPO 4 · 2H 2 O: Mn 5+, MHPO 4: Mn 5+, M 2 P 2 O 7: Mn 5+, M 4 P 2 O 9: Mn 5+ and M 8 H 2 (PO 4) 6 · 5H One or more compositions selected from the group of 2 O: Mn 5+ More preferably, M is one or more selected from the group consisting of Ca, Mg, Ba and Sr, contains 80 mol% or more of Ca, and 0 ≦ X <2. This is because the emitted light intensity increases, and thus the emitted light observed from outside the living body becomes stronger.
（３）本発明の第１の態様では、前記マンガン付活アルカリ土類金属リン酸塩がＭ１０－Ｘ（ＨＰＯ４）２Ｘ（ＰＯ４）６－２Ｘ（ＯＨ）２：Ｍｎ５＋及びＭ３（ＰＯ４）２：Ｍｎ５＋の群から選ばれる１種以上の組成を有することがさらに好ましい（但し、ＭはＣａ、Ｍｇ、Ｂａ、Ｓｒの群から選ばれる１種以上であり、Ｃａを８０モル％以上含み、０≦Ｘ＜２である）。発光ピークが短波長側によりにシフトして水の吸収がよりに小さくなり、かつ、発光強度がより大きくなるため、生体外から観察される発光がさらに強くなるからである。 (3) In the first aspect of the present invention, the manganese-activated alkaline earth metal phosphate is M 10-X (HPO 4 ) 2X (PO 4 ) 6-2X (OH) 2 : Mn 5+ and M 3 It is more preferable to have one or more compositions selected from the group of (PO 4 ) 2 : Mn 5+ (provided that M is one or more selected from the group of Ca, Mg, Ba, Sr, and Ca is 80 Including at least mol%, and 0 ≦ X <2.) This is because the emission peak is shifted to the short wavelength side, the water absorption is further reduced, and the emission intensity is increased, so that the emission emitted from outside the living body is further increased.
（４）本発明の第１の態様では、前記マンガン付活アルカリ土類金属リン酸塩がＣａ１０－Ｘ（ＨＰＯ４）２Ｘ（ＰＯ４）６－２Ｘ（ＯＨ）２：Ｍｎ５＋及びＣａ３（ＰＯ４）２：Ｍｎ５＋の群から選ばれる１種以上の組成を有することが特に好ましい（但し、０≦Ｘ＜２である）。発光ピークが短波長側にさらにシフトして水の吸収がさらに小さくなり、かつ、発光強度がさらに大きくなるため、生体外から観察される発光がさらに強くなるからである。 (4) In the first aspect of the present invention, the manganese-activated alkaline earth metal phosphate is Ca 10-X (HPO 4 ) 2X (PO 4 ) 6-2X (OH) 2 : Mn 5+ and Ca 3 It is particularly preferable to have one or more compositions selected from the group of (PO 4 ) 2 : Mn 5+ (provided that 0 ≦ X <2). This is because the emission peak is further shifted to the short wavelength side, water absorption is further reduced, and the emission intensity is further increased, so that the emission emitted from outside the living body is further increased.
（５）本発明の第１の態様では、式１で表されるシェラーの式（ここで、Ｋはシェラー定数、λはＸ線波長、βはピーク半値全幅（但し、ラジアン単位）、θはブラッグ角（回折角２θの半分）、τは結晶子の平均サイズを表す）を用いて求められる（００２）面の結晶子サイズが１０～２００ｎｍであることが好ましい。結晶子サイズが１０～２００ｎｍの蛍光体は、腎臓でろ過されにくく、かつ、肝臓でろ別されにくいからである。このような蛍光体は体外に排出されにくいため、安定した生体イメージング方法に好適である。
Figure JPOXMLDOC01-appb-M000002
 (5) In the first aspect of the present invention, Scherrer's formula represented by Formula 1 (where K is the Scherrer constant, λ is the X-ray wavelength, β is the full width at half maximum of the peak (however, in radians), and θ is The crystallite size of the (002) plane is preferably 10 to 200 nm, which is determined using a Bragg angle (half the diffraction angle 2θ) and τ represents the average crystallite size. This is because a phosphor having a crystallite size of 10 to 200 nm is difficult to be filtered by the kidney and difficult to be filtered by the liver. Since such a phosphor is difficult to be discharged outside the body, it is suitable for a stable biological imaging method.
Figure JPOXMLDOC01-appb-M000002
（６）本発明の第２の態様は、本発明の第１の態様の蛍光体を使用することを特徴とする生体イメージング方法に関する。本発明の第１の態様の蛍光体を使用することにより、水による光吸収が小さく、生体への毒性が弱く、又は、体外に排出されにくいため、安定した生体イメージング方法を提供することができる。 (6) A second aspect of the present invention relates to a biological imaging method using the phosphor according to the first aspect of the present invention. By using the phosphor according to the first aspect of the present invention, light absorption by water is small, toxicity to the living body is weak, or it is difficult to be discharged outside the body, and thus a stable in vivo imaging method can be provided. .
（７）本発明の第３の態様は、Ｃａ化合物、Ｐ化合物及びＭｎ化合物を水に溶解して水溶液を調製する工程と、前記水溶液のｐＨを７．０以上に調整して水熱合成を行う工程と、を有することを特徴とするマンガン付活アルカリ土類金属リン酸塩を含む蛍光体の製造方法に関する。この蛍光体は、発光ピークが短波長側にシフトして水による光吸収が小さく、生体への毒性が弱く、又は、体外に排出されにくいため、安定した生体イメージング方法に好適である。このような蛍光体を製造することができる。 (7) In the third aspect of the present invention, a step of preparing an aqueous solution by dissolving a Ca compound, a P compound and a Mn compound in water, and adjusting the pH of the aqueous solution to 7.0 or higher for hydrothermal synthesis And a step for performing a phosphor, comprising a manganese-activated alkaline earth metal phosphate. This phosphor is suitable for a stable in vivo imaging method because the emission peak shifts to the short wavelength side, light absorption by water is small, toxicity to the living body is weak, or it is difficult to be discharged outside the body. Such a phosphor can be manufactured.
水及びヘモグロビンの光吸収率を示す。The light absorption rate of water and hemoglobin is shown. 実施例１で得られた蛍光体のＸ線回折（ＸＲＤ）パターンを示す。2 shows an X-ray diffraction (XRD) pattern of the phosphor obtained in Example 1. FIG. 実施例１で得られた蛍光体のフォトルミネッセンス（ＰＬ）スペクトルを示す。2 shows a photoluminescence (PL) spectrum of the phosphor obtained in Example 1. 実施例２で得られた蛍光体のＸＲＤパターンを示す。The XRD pattern of the fluorescent substance obtained in Example 2 is shown. 実施例２及び実施例１で得られた蛍光体のＰＬスペクトルの比較を示す。The comparison of the PL spectrum of the fluorescent substance obtained in Example 2 and Example 1 is shown. 実施例２で得られた蛍光体のＰＬ励起スペクトルを示す。The PL excitation spectrum of the fluorescent substance obtained in Example 2 is shown. 実施例３で得られた蛍光体のＸＲＤパターンを示す。The XRD pattern of the fluorescent substance obtained in Example 3 is shown. 実施例３で得られた蛍光体の走査型電子顕微鏡（ＳＥＭ）画像を示す。The scanning electron microscope (SEM) image of the fluorescent substance obtained in Example 3 is shown. 実施例３で得られた蛍光体のＰＬスペクトルを示す。The PL spectrum of the fluorescent substance obtained in Example 3 is shown. 実施例３で得られた蛍光体の拡散反射スペクトルを示す。The diffuse reflection spectrum of the fluorescent substance obtained in Example 3 is shown.
　以下、本発明の好適な実施形態について詳細に説明する。なお、以下に説明する本実施形態は、請求の範囲に記載された本発明の内容を不当に限定するものではなく、本実施形態で説明される構成の全てが本発明の解決手段として必須であるとは限らない。 Hereinafter, preferred embodiments of the present invention will be described in detail. The present embodiment described below does not unduly limit the contents of the present invention described in the claims, and all the configurations described in the present embodiment are indispensable as means for solving the present invention. Not always.
（１）蛍光体
　本実施形態における蛍光体は、マンガン付活アルカリ土類金属リン酸塩を含み、リン及びマンガンの各々の原子価が５価であり、アルカリ土類金属がＣａを８０モル％以上含む。 (1) Phosphor The phosphor in the present embodiment contains a manganese-activated alkaline earth metal phosphate, each of valences of phosphorus and manganese is pentavalent, and the alkaline earth metal contains 80 mol% of Ca. Including above.
　本実施形態における蛍光体は、マンガン付活アルカリ土類金属リン酸塩がＭ１０－Ｘ（ＨＰＯ４）２Ｘ（ＰＯ４）６－２Ｘ（ＯＨ）２：Ｍｎ５＋、Ｍ１０－Ｘ（ＨＰＯ４）２Ｘ（ＰＯ４）６－２ＸＦ２：Ｍｎ５＋、Ｍ１０－Ｘ（ＨＰＯ４）２Ｘ（ＰＯ４）６－２ＸＣｌ２：Ｍｎ５＋、Ｍ３（ＰＯ４）２：Ｍｎ５＋、Ｍ１０（ＰＯ４）６Ｏ：Ｍｎ５＋、Ｍ４（ＰＯ４）２Ｏ：Ｍｎ５＋、Ｍ（Ｈ２ＰＯ４）２・Ｈ２Ｏ：Ｍｎ５＋、Ｍ（ＰＯ３）２：Ｍｎ５＋、ＭＨＰＯ４・２Ｈ２Ｏ：Ｍｎ５＋、ＭＨＰＯ４：Ｍｎ５＋、Ｍ２Ｐ２Ｏ７：Ｍｎ５＋、Ｍ４Ｐ２Ｏ９：Ｍｎ５＋及びＭ８Ｈ２（ＰＯ４）６・５Ｈ２Ｏ：Ｍｎ５＋の群から選ばれる１種以上の組成を有することが好ましい。発光強度が大きくなるからである。但し、ＭはＣａ、Ｍｇ、Ｂａ、Ｓｒの群から選ばれる１種以上であり、Ｃａを８０モル％以上含み、０≦Ｘ＜２である。より好ましくは、０≦Ｘ≦１である。 In the phosphor of the present embodiment, the manganese-activated alkaline earth metal phosphate is M 10-X (HPO 4 ) 2X (PO 4 ) 6-2X (OH) 2 : Mn 5+ , M 10-X (HPO 4 ) 2X (PO 4 ) 6-2X F 2 : Mn 5+ , M 10-X (HPO 4 ) 2X (PO 4 ) 6-2X Cl 2 : Mn 5+ , M 3 (PO 4 ) 2 : Mn 5+ , M 10 (PO 4 ) 6 O: Mn 5+ , M 4 (PO 4 ) 2 O: Mn 5+ , M (H 2 PO 4 ) 2 .H 2 O: Mn 5+ , M (PO 3 ) 2 : Mn 5+ , MHPO 4 2H 2 O: Mn 5+ , MHPO 4 : Mn 5+ , M 2 P 2 O 7 : Mn 5+ , M 4 P 2 O 9 : Mn 5+ and M 8 H 2 (PO 4 ) 6 · 5H 2 O: Mn 5+ Having at least one composition selected from the group of It is preferable. This is because the emission intensity increases. However, M is 1 or more types chosen from the group of Ca, Mg, Ba, and Sr, contains 80 mol% or more of Ca, and is 0 <= X <2. More preferably, 0 ≦ X ≦ 1.
　本実施形態における蛍光体は、マンガン付活アルカリ土類金属リン酸塩がＭ１０－Ｘ（ＨＰＯ４）２Ｘ（ＰＯ４）６－２Ｘ（ＯＨ）２：Ｍｎ５＋及びＭ３（ＰＯ４）２：Ｍｎ５＋の群から選ばれる１種以上の組成を有することがさらに好ましい。発光ピークが短波長側によりにシフトして水の吸収がよりに小さくなり、かつ、発光強度がより大きくなるからである。但し、ＭはＣａ、Ｍｇ、Ｂａ、Ｓｒの群から選ばれる１種以上であり、Ｃａを８０モル％以上含み、０≦Ｘ＜２である。より好ましくは、０≦Ｘ≦１である。 In the phosphor in this embodiment, the manganese-activated alkaline earth metal phosphate is M 10-X (HPO 4 ) 2X (PO 4 ) 6-2X (OH) 2 : Mn 5+ and M 3 (PO 4 ) 2 : It is more preferable to have at least one composition selected from the group of Mn 5+ . This is because the emission peak shifts to the short wavelength side, the water absorption becomes smaller, and the emission intensity becomes larger. However, M is 1 or more types chosen from the group of Ca, Mg, Ba, and Sr, contains 80 mol% or more of Ca, and is 0 <= X <2. More preferably, 0 ≦ X ≦ 1.
　ＭはＣａを９０モル％以上含むことがより好ましく、Ｃａを１００モル％含むことが最も好ましい。発光ピークが短波長側にシフトするため、水の吸収がさらに小さくなり、かつ、発光強度が特に大きくなるため、生体外から観察される発光が強くなるからである。 M preferably contains 90 mol% or more of Ca, and most preferably contains 100 mol% of Ca. This is because the emission peak shifts to the short wavelength side, so that the water absorption is further reduced and the emission intensity is particularly increased, so that the emission emitted from outside the living body becomes stronger.
　本実施形態における蛍光体において、５価のＭｎが付活剤として発光する。Ｍｎの含有量は０．０１～５０モル％が好ましく、０．１～１０モル％がより好ましく、１～８モル％がさらに好ましい。Ｍｎの含有量が小さすぎると発光効率は低下する。一方、Ｍｎの含有量が５０モル％を超えると発光中心が近接して互いに発光を打ち消し合う（濃度消光）ため発光効率は低下する。 In the phosphor in the present embodiment, pentavalent Mn emits light as an activator. The Mn content is preferably 0.01 to 50 mol%, more preferably 0.1 to 10 mol%, and even more preferably 1 to 8 mol%. If the Mn content is too small, the luminous efficiency is lowered. On the other hand, when the Mn content exceeds 50 mol%, the emission efficiency decreases because the emission centers come close to each other and cancel each other (concentration quenching).
　本実施形態における蛍光体において、式１で表されるシェラーの式（ここで、Ｋはシェラー定数、λはＸ線波長、βはピーク半値全幅（但し、ラジアン単位）、θはブラッグ角（回折角２θの半分）、τは結晶子の平均サイズを表す）を用いて求められる（００２）面の結晶子サイズは、好ましくは１０～２００ｎｍの範囲である。結晶子サイズの下限は１ｎｍ以上であり、より好ましくは１０ｎｍ以上である。結晶子サイズが大きいほど蛍光体の粒径が大きくなり、蛍光体は腎臓でろ過されにくくなるからである。一方、結晶子サイズの上限は、より好ましくは１００ｎｍ以下であり、さらに好ましくは８０ｎｍ以下である。結晶子サイズが小さいほど蛍光体の粒径が小さくなり、蛍光体は肝臓でろ別されにくくなるからである。本実施形態の蛍光体は体外に排出されにくいことから、安定した生体イメージング方法に好適である。
Figure JPOXMLDOC01-appb-M000003
 In the phosphor according to the present embodiment, the Scherrer equation represented by Equation 1 (where K is the Scherrer constant, λ is the X-ray wavelength, β is the full width at half maximum of the peak (in radians)), and θ is the Bragg angle (times The crystallite size of the (002) plane is preferably in the range of 10 to 200 nm, which is obtained using (half the folding angle 2θ) and τ represents the average crystallite size). The lower limit of the crystallite size is 1 nm or more, more preferably 10 nm or more. This is because the larger the crystallite size, the larger the particle size of the phosphor, and the more difficult the phosphor is filtered by the kidney. On the other hand, the upper limit of the crystallite size is more preferably 100 nm or less, and still more preferably 80 nm or less. This is because the smaller the crystallite size, the smaller the particle size of the phosphor, and the more difficult the phosphor is to be filtered by the liver. Since the phosphor of the present embodiment is not easily discharged outside the body, it is suitable for a stable biological imaging method.
Figure JPOXMLDOC01-appb-M000003
　本実施形態における蛍光体において、動的光散乱式粒度分布装置を用いて測定した粒径は、好ましくは１～１００ｎｍの範囲である。粒径の下限は、より好ましくは１０ｎｍ以上であり、さらに好ましくは２０ｎｍ以上である。蛍光体の粒径が大きいほど蛍光体は腎臓でろ過されにくいからである。一方、粒径の上限は、より好ましくは９０ｎｍ以下であり、さらに好ましくは８０ｎｍ以下である。蛍光体の粒径が小さいほど蛍光体は肝臓でろ別されにくくなるからである。本実施形態の蛍光体は体外に排出されにくいことから、安定した生体イメージング方法に好適である。 In the phosphor of the present embodiment, the particle size measured using a dynamic light scattering particle size distribution device is preferably in the range of 1 to 100 nm. The lower limit of the particle size is more preferably 10 nm or more, and further preferably 20 nm or more. This is because the larger the particle size of the phosphor, the more difficult it is to be filtered by the kidney. On the other hand, the upper limit of the particle size is more preferably 90 nm or less, still more preferably 80 nm or less. This is because the smaller the particle size of the phosphor, the more difficult it is to be filtered by the liver. Since the phosphor of the present embodiment is not easily discharged outside the body, it is suitable for a stable biological imaging method.
（２）蛍光体の製造方法
　本実施形態における蛍光体の製造方法は、固相法や液相法を用いることができる。 (2) Method for Producing Phosphor As the method for producing the phosphor in the present embodiment, a solid phase method or a liquid phase method can be used.
（２－１）固相法
　固相法は、好適な原料を適宜選択、秤量、混合して、原料の混合物を調製する工程（調製工程）と、原料の混合物を大気雰囲気の中で焼成する工程（焼成工程）と、必要に応じて、粉砕、分級する工程（粉砕工程）とを有する。 (2-1) Solid phase method In the solid phase method, suitable raw materials are appropriately selected, weighed, and mixed to prepare a raw material mixture (preparation step), and the raw material mixture is baked in an air atmosphere. A step (firing step) and, if necessary, a step of crushing and classification (crushing step).
（２－１－１）調製工程
　調製工程では、Ｍ化合物、Ｐ化合物及びＭｎ化合物の各材料から好適な原料を適宜選択し、秤量、混合して、原料の混合物を調製する。Ｍ化合物としては、酸化物、炭酸塩、硝酸塩、硫酸塩等、公知の材料を用いることができるが、炭酸塩（塩基性炭酸塩を含む）が好ましい。ＭはＣａ、Ｍｇ、Ｂａ、Ｓｒの群から選ばれる１種以上であり、Ｃａを８０モル％以上含む。Ｐ化合物としては、リン酸水素二アンモニウム（（ＮＨ４）２ＨＰＯ４）、リン酸二水素アンモニウム（（ＮＨ４Ｈ２ＰＯ４））、リン酸アンモニウム（（ＮＨ４）３ＰＯ４）等、公知の材料を用いることができるが、リン酸水素二アンモニウム（（ＮＨ４）２ＨＰＯ４）が好ましい。Ｍｎ化合物としては、酸化物、炭酸塩、硝酸塩、硫酸塩等、公知の材料を用いることができるが、炭酸塩（塩基性炭酸塩を含む）が好ましい。 (2-1-1) Preparation Step In the preparation step, a suitable raw material is appropriately selected from each material of M compound, P compound and Mn compound, and weighed and mixed to prepare a mixture of raw materials. As the M compound, known materials such as oxides, carbonates, nitrates and sulfates can be used, but carbonates (including basic carbonates) are preferable. M is at least one selected from the group consisting of Ca, Mg, Ba, and Sr, and contains 80 mol% or more of Ca. Examples of the P compound include diammonium hydrogen phosphate ((NH 4 ) 2 HPO 4 ), ammonium dihydrogen phosphate ((NH 4 H 2 PO 4 )), ammonium phosphate ((NH 4 ) 3 PO 4 ), and the like. Known materials can be used, but diammonium hydrogen phosphate ((NH 4 ) 2 HPO 4 ) is preferred. As the Mn compound, known materials such as oxides, carbonates, nitrates and sulfates can be used, but carbonates (including basic carbonates) are preferable.
　Ｍ化合物、Ｐ化合物及びＭｎ化合物は、それぞれ１種の材料を原料として選択してもよいし、２種以上の材料を原料として併用してもよい。原料の純度は、９９質量％以上が好ましい。選択された原料は、目的の組成に合わせて秤量されて、混合比が調整される。 The M compound, P compound and Mn compound may each be selected from one material as a raw material, or two or more materials may be used in combination as a raw material. The purity of the raw material is preferably 99% by mass or more. The selected raw material is weighed according to the target composition, and the mixing ratio is adjusted.
　混合方法としては、例えば、乳鉢を用いる乾式混合や、純水等の溶媒を加える湿式混合等、公知の方法を用いることができる。混合装置としては、ボールミル、振動ミル、ロッキングミル等、公知の装置を用いることができる。 As the mixing method, for example, a known method such as dry mixing using a mortar or wet mixing in which a solvent such as pure water is added can be used. As the mixing device, a known device such as a ball mill, a vibration mill, or a rocking mill can be used.
　純水等の溶媒を加えて混合する場合、調製工程は、混合物を乾燥する乾燥工程をさらに含む。乾燥方法としては、例えば、スプレードライヤー、加熱乾燥、凍結乾燥、自然乾燥等、公知の方法を用いることができる。調製工程は、原料の混合物を粉砕する工程をさらに含んでもよい。原料の混合物の粒度を微細かつ均一にすることにより、焼成工程の固相反応が生じやすくなり、均一な蛍光体を得ることができる。 When adding and mixing a solvent such as pure water, the preparation step further includes a drying step of drying the mixture. As a drying method, for example, a known method such as a spray dryer, heat drying, freeze drying, or natural drying can be used. The preparation step may further include a step of pulverizing the mixture of raw materials. By making the particle size of the mixture of raw materials fine and uniform, a solid phase reaction in the firing step is likely to occur, and a uniform phosphor can be obtained.
（２－１－２）焼成工程
　焼成工程では、調製工程で得られた原料の混合物を焼成することにより目的の蛍光体を生成する。雰囲気、温度及び時間等の焼成条件は、選択された原料や目的の組成等に応じて適宜決定される。焼成雰囲気は大気が好ましい。焼成温度は一般に３００℃～１２００℃の範囲であり、焼成時間は一般に０．５～６時間の範囲である。焼成は複数回に分けて行ってもよい。この場合、焼成して得た仮焼体を、乳鉢等を用いて粉砕、混合した後、再度焼成してもよい。 (2-1-2) Firing Step In the firing step, the target phosphor is produced by firing the mixture of raw materials obtained in the preparation step. Firing conditions such as atmosphere, temperature, and time are appropriately determined according to the selected raw material, the target composition, and the like. The firing atmosphere is preferably air. The firing temperature is generally in the range of 300 ° C. to 1200 ° C., and the firing time is generally in the range of 0.5 to 6 hours. Firing may be performed in a plurality of times. In this case, the calcined body obtained by firing may be fired again after being ground and mixed using a mortar or the like.
（２－１－３）粉砕工程
　固相法は、蛍光体を粉砕する粉砕工程を焼成工程の後にさらに含んでもよい。粉砕方法としては、例えば、遊星ボールミル、ジェットミル等、公知の方法を用いることができる。また、粉砕工程は、粉砕された蛍光体を分級する工程をさらに含んでもよい。粉砕、分級条件を適宜選択することにより、粒界の対向する２点間の最大距離をその粒子の粒径としたとき、例えば、平均粒径が１００ｎｍ以上２００ｎｍ以下の蛍光体を得ることができる。このように蛍光体の平均粒径を制御することにより、例えば、蛍光体を分散液として生体内に注入したとき体外に排出されにくくすることができる。 (2-1-3) Grinding Step The solid phase method may further include a grinding step for grinding the phosphor after the firing step. As a pulverization method, for example, a known method such as a planetary ball mill or a jet mill can be used. Further, the pulverization step may further include a step of classifying the pulverized phosphor. By appropriately selecting the pulverization and classification conditions, for example, a phosphor having an average particle diameter of 100 nm or more and 200 nm or less can be obtained when the maximum distance between two opposing grain boundaries is defined as the particle diameter of the particle. . By controlling the average particle size of the phosphor in this way, for example, when the phosphor is injected into the living body as a dispersion, it can be made difficult to be discharged out of the body.
（２－２）液相法
　液相法は、Ｍ化合物、Ｐ化合物及びＭｎ化合物を水に溶解して水溶液を調製する工程（調製工程）と、水溶液のｐＨを７．０以上の範囲に調整して水熱合成を行う工程（水熱合成工程）と、を有する。液相法は、必要に応じて、水熱合成工程による生成物を遠心分離、凍結乾燥等を用いて分離する工程（分離工程）をさらに有する。 (2-2) Liquid Phase Method In the liquid phase method, an aqueous solution is prepared by dissolving the M compound, P compound and Mn compound in water (preparation step), and the pH of the aqueous solution is adjusted to a range of 7.0 or higher. And hydrothermal synthesis step (hydrothermal synthesis step). The liquid phase method further includes a step (separation step) of separating the product from the hydrothermal synthesis step using centrifugation, lyophilization, or the like, if necessary.
（２－２－１）調製工程
　調製工程では、Ｍ化合物、Ｐ化合物及びＭｎ化合物の各材料から好適な原料を適宜選択、秤量し、水に溶解する。ＭはＣａ、Ｍｇ、Ｂａ、Ｓｒの群から選ばれる１種以上であり、Ｃａを８０モル％以上含む。ＭはＣａ１００モル％（Ｃａ化合物）が最も好ましい。Ｃａ化合物としては、硝酸カルシウム（Ｃａ（ＮＯ３）２）、塩化カルシウム（ＣａＣｌ２）、酢酸カルシウム（（ＣＨ３ＣＯＯ）２Ｃａ）及びこれらの水和物を用いることができるが、硝酸カルシウムの水和物が好ましい。Ｐ化合物は、リン酸二水素ナトリウム（ＮａＨ２ＰＯ４）、リン酸三ナトリウム（Ｎａ３ＰＯ４）、リン酸水素二アンモニウム（（ＮＨ４）２ＰＯ４）、リン酸二水素アンモニウム（ＮＨ４Ｈ２ＰＯ４）を用いることができるが、リン酸二水素ナトリウムが好ましい。Ｍｎ化合物は、過マンガン酸カリウム（ＫＭｎ４）、硝酸マンガン（Ｍｎ（ＮＯ３）２）、塩化マンガン（ＭｎＣｌ２）、酢酸マンガン（（ＣＨ３ＣＯＯ）２Ｍｎ）及びこれらの水和物を用いることができるが、過マンガン酸カリウムが好ましい。 (2-2-1) Preparation Step In the preparation step, a suitable raw material is appropriately selected from each material of M compound, P compound and Mn compound, weighed and dissolved in water. M is at least one selected from the group consisting of Ca, Mg, Ba, and Sr, and contains 80 mol% or more of Ca. M is most preferably Ca 100 mol% (Ca compound). As the Ca compound, calcium nitrate (Ca (NO 3 ) 2 ), calcium chloride (CaCl 2 ), calcium acetate ((CH 3 COO) 2 Ca) and hydrates thereof can be used. Hydrates are preferred. P compounds include sodium dihydrogen phosphate (NaH 2 PO 4 ), trisodium phosphate (Na 3 PO 4 ), diammonium hydrogen phosphate ((NH 4 ) 2 PO 4 ), ammonium dihydrogen phosphate (NH 4 H 2 PO 4 ) can be used, but sodium dihydrogen phosphate is preferred. As the Mn compound, potassium permanganate (KMn 4 ), manganese nitrate (Mn (NO 3 ) 2 ), manganese chloride (MnCl 2 ), manganese acetate ((CH 3 COO) 2 Mn) and hydrates thereof are used. However, potassium permanganate is preferred.
　Ｍ化合物（Ｃａ化合物）、Ｐ化合物及びＭｎ化合物は、それぞれ１種の材料を原料として選択してもよいし、２種以上の材料を原料として併用してもよい。原料の純度は、９９質量％以上が好ましい。選択された原料は、目的の組成に合わせて秤量されて混合比が調整され、水に溶解され、水溶液が調製される。 M compound (Ca compound), P compound and Mn compound may each be selected from one material as a raw material, or two or more materials may be used in combination as a raw material. The purity of the raw material is preferably 99% by mass or more. The selected raw materials are weighed according to the target composition, the mixing ratio is adjusted, dissolved in water, and an aqueous solution is prepared.
（２－２－２）水熱合成工程
　水熱合成工程では、調製工程で調製された水溶液に塩基性物質を滴下し、ｐＨを７．０以上に調整して水熱合成を行う。塩基性物質としては公知の材料を用いることができる。本実施形態では、水酸化ナトリウムを用いた。ｐＨは、好ましくは８．０以上であり、より好ましくは９．５以上であり、特に好ましくは１１．０以上である。ｐＨを上記範囲に調整することにより、水熱合成で得られた生成物（蛍光体）の発光強度を高くすることができる。 (2-2-2) Hydrothermal synthesis step In the hydrothermal synthesis step, a basic substance is dropped into the aqueous solution prepared in the preparation step, and the pH is adjusted to 7.0 or higher to carry out hydrothermal synthesis. A known material can be used as the basic substance. In this embodiment, sodium hydroxide was used. The pH is preferably 8.0 or more, more preferably 9.5 or more, and particularly preferably 11.0 or more. By adjusting the pH to the above range, the emission intensity of the product (phosphor) obtained by hydrothermal synthesis can be increased.
（２－２－３）分離工程
　分離工程では、水熱合成工程で得られた生成物（蛍光体）に対して必要に応じて遠心分離や凍結乾燥等を行う。遠心分離では、５０００～１５０００回毎分の回転を０．５～２時間行うことによって蛍光体を分取することができる。遠心分離は複数回行うことがさらに好ましい。凍結乾燥では、遠心分離で分取された分離体（蛍光体）を－１０～－５０℃で凍結し、２０～４０Ｐａに減圧した後、－５０～－６０℃で水分を昇華して除去することによって蛍光体を得ることができる。 (2-2-3) Separation step In the separation step, the product (phosphor) obtained in the hydrothermal synthesis step is subjected to centrifugation, freeze-drying, or the like as necessary. In the centrifugal separation, the phosphor can be separated by rotating at a rate of 5000 to 15000 times per minute for 0.5 to 2 hours. More preferably, the centrifugation is performed a plurality of times. In lyophilization, the separated material (phosphor) separated by centrifugation is frozen at −10 to −50 ° C., depressurized to 20 to 40 Pa, and then sublimated at −50 to −60 ° C. to remove water. Thus, a phosphor can be obtained.
（３）生体イメージング方法
　本実施形態における蛍光体は、以下のような生体イメージング方法に使用することができる。即ち、本実施形態の蛍光体と、生体内の観察したい特定部位に選択的に局在する物質とを結合させて生体内に注入することにより、本実施形態の蛍光体を生体内の特定部位に局在させる。この状態で蛍光体を励起し、蛍光体からの発光を生体外から観察するというものである。例えば、がん細胞の生体イメージング方法では、蛍光体の表面を糖類又はタンパク質で修飾する。糖類としては、ブドウ糖が特に好ましい。がん細胞は細胞***のためにブドウ糖を異常に消費するため、蛍光体をがん細胞に局在させることができるからである。この蛍光体からの発光を生体外から観察することにより、がん細胞を生体外から観察することができる。蛍光体の表面を糖類で修飾する方法としては、例えば、両親媒性高分子によって表面処理された蛍光体の分散液にブドウ糖を添加、撹拌することで、蛍光体の表面を被覆する両親媒性高分子にブドウ糖を付着させる方法が挙げられる。両親媒性高分子としては、公知の材料を用いることができるが、例えば、ポリエチレングリコール（ＰＥＧ）が挙げられる。 (3) Biological Imaging Method The phosphor in the present embodiment can be used in the following biological imaging method. That is, the phosphor of the present embodiment is combined with a substance that is selectively localized at a specific site to be observed in the living body and injected into the living body to thereby make the phosphor of the present embodiment a specific site in the living body. To localize. In this state, the phosphor is excited and light emitted from the phosphor is observed from outside the living body. For example, in the in vivo imaging method for cancer cells, the surface of the phosphor is modified with saccharides or proteins. Glucose is particularly preferable as the saccharide. This is because cancer cells abnormally consume glucose for cell division, so that the phosphor can be localized in the cancer cells. By observing the light emitted from the phosphor from outside the body, the cancer cells can be observed from outside the body. As a method of modifying the surface of the phosphor with a saccharide, for example, an amphiphilic coating that coats the surface of the phosphor by adding glucose to the dispersion of the phosphor surface-treated with an amphiphilic polymer and stirring it. A method of attaching glucose to a polymer can be mentioned. A known material can be used as the amphiphilic polymer, and examples thereof include polyethylene glycol (PEG).
　以下、本発明の実施例について詳細に説明する。 Hereinafter, embodiments of the present invention will be described in detail.
（１）実施例１
　目的の蛍光体の組成をＣａ３（Ｐ０．９７５Ｍｎ０．０２５Ｏ４）２とし、原料として炭酸カルシウム（ＣａＣＯ３）、リン酸アンモニウム（（ＮＨ４）２ＨＰＯ４）及び炭酸マンガン（ＭｎＣＯ３）を選択した。これらの原料のモル比が６０：３９：１（質量比は５３．３：４５．７：１）となるように秤量し、乳鉢を用いて混合して原料の混合物を得た。得られた原料の混合物を、大気中４００℃で４時間加熱した後、大気中８００℃で３時間焼成して蛍光体を得た。 (1) Example 1
The composition of the target phosphor is Ca 3 (P 0.975 Mn 0.025 O 4 ) 2, and calcium carbonate (CaCO 3 ), ammonium phosphate ((NH 4 ) 2 HPO 4 ) and manganese carbonate (MnCO) are used as raw materials. 3 ) was selected. These raw materials were weighed so that the molar ratio was 60: 39: 1 (mass ratio was 53.3: 45.7: 1) and mixed using a mortar to obtain a mixture of raw materials. The obtained mixture of raw materials was heated in the atmosphere at 400 ° C. for 4 hours, and then fired in the atmosphere at 800 ° C. for 3 hours to obtain a phosphor.
（２）実施例２
　目的の蛍光体の組成をＣａ１０（Ｐ０．９８５Ｍｎ０．０１５Ｏ４）６（ＯＨ）２とし、原料として炭酸カルシウム（ＣａＣＯ３）、リン酸アンモニウム（（ＮＨ４）２ＨＰＯ４）及び炭酸マンガン（ＭｎＣＯ３）を選択した。これらの原料のモル比が５７．４：３４．０：８．６となるように秤量し、乳鉢を用いて混合して原料の混合物を得た。得られた原料の混合物を、大気中４００℃で４時間加熱した後、大気中７００℃で３時間焼成して仮焼体を得た。乳鉢を用いて仮焼体を粉砕、混合した後、さらに大気中７００℃で１２時間焼成して蛍光体を得た。 (2) Example 2
The composition of the target phosphor is Ca 10 (P 0.985 Mn 0.015 O 4 ) 6 (OH) 2, and calcium carbonate (CaCO 3 ), ammonium phosphate ((NH 4 ) 2 HPO 4 ) and Manganese carbonate (MnCO 3 ) was selected. These raw materials were weighed so that the molar ratio was 57.4: 34.0: 8.6, and mixed using a mortar to obtain a mixture of raw materials. The obtained mixture of raw materials was heated in air at 400 ° C. for 4 hours and then calcined in air at 700 ° C. for 3 hours to obtain a calcined body. The calcined body was pulverized and mixed using a mortar, and then fired at 700 ° C. for 12 hours in the air to obtain a phosphor.
（３）実施例３
　目的の蛍光体の組成をＣａ１０（ＰＯ４）６（ＯＨ）２とし、原料として硝酸カルシウム四水和物（Ｃａ（ＮＯ３）２・４Ｈ２Ｏ）、リン酸二水素ナトリウム（ＮａＨ２ＰＯ４），過マンガン酸カリウム（ＫＭｎＯ４）を選択した。これらの原料を、モル比が５７．４：３４．０：８．６となるように秤量し、イオン交換水に溶解して水溶液を調製した。この水溶液に水酸化ナトリウム水溶液を滴下してｐＨを１１．９に調整した後、オートクレーブ内において５００回毎分で撹拌しながら１５０℃で６時間保持して水熱合成を行った。次に、１２０００回毎分で１時間の遠心分離を３回行った後、凍結乾燥して蛍光体を得た。 (3) Example 3
The composition of the target phosphor is Ca 10 (PO 4 ) 6 (OH) 2, and calcium nitrate tetrahydrate (Ca (NO 3 ) 2 .4H 2 O), sodium dihydrogen phosphate (NaH 2 PO) as raw materials 4 ), potassium permanganate (KMnO 4 ) was selected. These raw materials were weighed so that the molar ratio was 57.4: 34.0: 8.6, and dissolved in ion-exchanged water to prepare an aqueous solution. A sodium hydroxide aqueous solution was added dropwise to this aqueous solution to adjust the pH to 11.9, and then hydrothermal synthesis was carried out by holding at 150 ° C. for 6 hours while stirring 500 times per minute in an autoclave. Next, centrifugation was performed 3 times for 1 hour at 12,000 times per minute, and then freeze-dried to obtain a phosphor.
（４）実施例４
　ｐＨを１１．１に調整した以外は実施例３と同様にして、蛍光体を得た。 (4) Example 4
A phosphor was obtained in the same manner as in Example 3 except that the pH was adjusted to 11.1.
（５）実施例５
　ｐＨを５．０に調整した以外は実施例３と同様にして、蛍光体を得た。 (5) Example 5
A phosphor was obtained in the same manner as in Example 3 except that the pH was adjusted to 5.0.
（６）蛍光体の評価方法
　実施例１～５で得られた蛍光体に対して、Ｘ線回折（ＸＲＤ）測定、フォトルミネッセンス（ＰＬ）スペクトル測定、フォトルミネッセンス（ＰＬ）励起スペクトル測定、走査型電子顕微鏡（ＳＥＭ）測定又は拡散反射測定を行い、蛍光体の物性を評価した。ＰＬ測定に用いた励起光の波長は６００ｎｍとした。それぞれの測定に用いた装置は以下のとおりである。
＜ＸＲＤ測定＞
　リガク製試料水平型強力Ｘ線回折装置ＲＩＮＴ－ＴＴＲ　ＩＩＩ
＜ＰＬスペクトル測定、ＰＬ励起スペクトル測定＞
　日本分光製分光蛍光光度計ＦＰ－８７００
＜ＳＥＭ測定＞
　日立ハイテクノロジーズ製電界放出形走査電子顕微鏡Ｓ４８００
＜拡散反射測定＞
　日本分光製紫外可視近赤外分光光度計Ｖ－６７０ (6) Method for evaluating phosphors For the phosphors obtained in Examples 1 to 5, X-ray diffraction (XRD) measurement, photoluminescence (PL) spectrum measurement, photoluminescence (PL) excitation spectrum measurement, scanning type Electron microscope (SEM) measurement or diffuse reflection measurement was performed to evaluate the physical properties of the phosphor. The wavelength of the excitation light used for the PL measurement was 600 nm. The apparatus used for each measurement is as follows.
<XRD measurement>
Rigaku sample horizontal X-ray diffractometer RINT-TTR III
<PL spectrum measurement, PL excitation spectrum measurement>
Spectroscopic spectrophotometer FP-8700 manufactured by JASCO
<SEM measurement>
Hitachi High-Technologies Field Emission Scanning Electron Microscope S4800
<Diffusion reflection measurement>
UV-Vis Near-Infrared Spectrophotometer V-670 manufactured by JASCO
（７）蛍光体の評価結果
　図２の上段及び下段は、それぞれ実施例１で得られた蛍光体のＸＲＤパターン及びＩＣＳＤのＣａ３（ＰＯ４）２の結晶データを示す。両者はよく一致しており、得られた蛍光体はＣａ３（ＰＯ４）２のほぼ単一相であることがわかる。下記式２よりＰの価数は５価である。
　Ｐの価数＝（２（Ｏの価数）×４×２－２（Ｃａの価数）×３）÷２＝５価　（式２） (7) Evaluation Results of Phosphor The upper and lower parts of FIG. 2 show the XRD pattern of the phosphor obtained in Example 1 and the crystal data of Ca 3 (PO 4 ) 2 of ICSD, respectively. Both agree well, and it can be seen that the obtained phosphor is an almost single phase of Ca 3 (PO 4 ) 2 . From the following formula 2, the valence of P is pentavalent.
P valence = (2 (O valence) × 4 × 2-2 (Ca valence) × 3) ÷ 2 = 5 valence (Formula 2)
　図３は実施例１で得られた蛍光体のＰＬスペクトルを示す。励起光の波長は６００ｎｍとした。ピーク波長は１１５７ｎｍであり、Ｍｎ５＋の３ｄ－３ｄ内殻遷移（１Ｅ→３Ａ２）に帰属する。したがって、蛍光体に含まれるＭｎの価数は５価である。従来のＢａ３（ＰＯ４）２：Ｍｎ５＋の組成を有する蛍光体のピーク波長は１１９１ｎｍであるから、図１より、本実施形態の蛍光体は従来よりも水の光吸収が少なく、生体イメージング方法に好適であることがわかる。 FIG. 3 shows the PL spectrum of the phosphor obtained in Example 1. The wavelength of the excitation light was 600 nm. The peak wavelength is 1157 nm, which belongs to the 3d-3d core transition ( 1 E → 3 A 2 ) of Mn 5+ . Therefore, the valence of Mn contained in the phosphor is pentavalent. Since the peak wavelength of the phosphor having the composition of the conventional Ba 3 (PO 4 ) 2 : Mn 5+ is 1191 nm, the phosphor of the present embodiment has less light absorption of water than the conventional one, and FIG. It can be seen that it is suitable for the method.
　図４の上段、中段及び下段は、それぞれ実施例２で得られた蛍光体のＸＲＤパターン、ＩＣＳＤのＣａ１０（ＰＯ４）６（ＯＨ）２の結晶データ及びＩＣＳＤのＣａ３（ＰＯ４）２の結晶データを示す。得られた蛍光体のＸＲＤパターンのピークは、目的のＣａ１０（ＰＯ４）６（ＯＨ）２と不純物相のＣａ３（ＰＯ４）２のＸＲＤパターンのピークによく一致していることから、蛍光体は両者の混合物であり、混合割合はおよそ６：４と見積もられることがわかった。下記式３及び式４よりＰの価数は５価である。
　Ｃａ１０（ＰＯ４）６（ＯＨ）２のＰの価数＝（２（Ｏの価数）×（４×６＋２）－２（Ｃａの価数）×１０－１（Ｈの価数）×２）÷６＝５価　（式３）
　Ｃａ３（ＰＯ４）２のＰの価数＝（２（Ｏの価数）×４×２－２（Ｃａの価数）×３）÷２＝５価　（式４） 4, the XRD pattern of the phosphor obtained in Example 2, the crystal data of Ca 10 (PO 4 ) 6 (OH) 2 of ICSD, and the Ca 3 (PO 4 ) 2 of ICSD, respectively. The crystal data of is shown. Since the peak of the XRD pattern of the obtained phosphor is in good agreement with the peak of the XRD pattern of the target Ca 10 (PO 4 ) 6 (OH) 2 and the impurity phase Ca 3 (PO 4 ) 2 , The phosphor was a mixture of both, and the mixing ratio was estimated to be approximately 6: 4. From the following formulas 3 and 4, the valence of P is pentavalent.
Ca 10 (PO 4 ) 6 (OH) 2 P valence = (2 (O valence) × (4 × 6 + 2) −2 (Ca valence) × 10 −1 (H valence) × 2) ÷ 6 = 5 values (Formula 3)
Ca 3 (PO 4 ) 2 valence of P = (2 (valence of O) × 4 × 2-2 (valence of Ca) × 3) / 2 = 5 valence (formula 4)
　図５は、実施例２で得られた蛍光体のＰＬスペクトル１３を示す。励起光の波長は６００ｎｍとした。実施例２で得られた蛍光体のＰＬスペクトル１３のピーク波長も１１５７ｎｍであり、実施例１と同様にＭｎ５＋の３ｄ－３ｄ内殻遷移（１Ｅ→３Ａ２）に帰属する。したがって、蛍光体に含まれるＭｎの価数は５価である。比較のため、実施例１で得られた蛍光体のＰＬスペクトル１４を図５に示す。実施例２で得られた蛍光体のＰＬスペクトル１３のピーク強度は、実施例１で得られた蛍光体のＰＬスペクトル１４のピーク強度の約１０倍であることから、実施例２で得られた蛍光体が生体イメージング方法に非常に好適であることがわかる。 FIG. 5 shows the PL spectrum 13 of the phosphor obtained in Example 2. The wavelength of the excitation light was 600 nm. The peak wavelength of the PL spectrum 13 of the phosphor obtained in Example 2 is also 1157 nm, which is attributed to the 3d-3d core transition ( 1 E → 3 A 2 ) of Mn 5+ as in Example 1. Therefore, the valence of Mn contained in the phosphor is pentavalent. For comparison, a PL spectrum 14 of the phosphor obtained in Example 1 is shown in FIG. Since the peak intensity of the PL spectrum 13 of the phosphor obtained in Example 2 is about 10 times the peak intensity of the PL spectrum 14 of the phosphor obtained in Example 1, it was obtained in Example 2. It can be seen that the phosphor is very suitable for biological imaging methods.
　図６は、実施例２で得られた蛍光体のＰＬ励起スペクトルを示す。ＰＬ励起スペクトルの検出波長は１１５７ｎｍとした。ＰＬ励起スペクトルより、発光中心であるＭｎ５＋の遷移である２Ａ３→１Ａ１（６９０ｎｍ）、２Ａ３→３Ｔ１（３Ｆ）（６５１ｎｍ）が確認できる。 FIG. 6 shows a PL excitation spectrum of the phosphor obtained in Example 2. The detection wavelength of the PL excitation spectrum was 1157 nm. From the PL excitation spectrum, 2 A 3 → 1 A 1 (690 nm) and 2 A 3 → 3 T 1 ( 3 F) (651 nm), which are transitions of Mn 5+ as the emission center, can be confirmed.
　図７の上段及び下段は、それぞれ実施例３で得られた蛍光体のＸＲＤパターン及びＩＣＳＤのＣａ１０（ＰＯ４）６（ＯＨ）２の結晶データを示す。両者はよく一致しており、得られた蛍光体はＣａ１０（ＰＯ４）６（ＯＨ）２のほぼ単一相であることがわかる。上記式３よりＰの価数は５価である。なお、エネルギー分散型Ｘ線分析の結果から、ＣａとＰの比率は１．５５であり、量論比の１．６７より低いことが確認された。また、ＸＲＤパターンの（１００）面及び（００２）面の回折強度を比較すると、（００２）面の回折強度の方が大きいことから、ｃ軸方向の結晶成長に方向性が確認された。式１で表されるシェラーの式（ここで、Ｋはシェラー定数、λはＸ線波長、βはピーク半値全幅（但し、ラジアン単位）、θはブラッグ角（回折角２θの半分）、τは結晶子の平均サイズを表す）を用いて求められた結晶子サイズは、（１００）面が１８ｎｍ、（００２）面が４３ｎｍであった。
Figure JPOXMLDOC01-appb-M000004
 The upper and lower parts of FIG. 7 show the XRD pattern of the phosphor obtained in Example 3 and the crystal data of Ca 10 (PO 4 ) 6 (OH) 2 of ICSD, respectively. Both agree well, and it can be seen that the obtained phosphor is an almost single phase of Ca 10 (PO 4 ) 6 (OH) 2 . From the above formula 3, the valence of P is pentavalent. From the results of energy dispersive X-ray analysis, it was confirmed that the ratio of Ca and P was 1.55, which was lower than the stoichiometric ratio of 1.67. Further, when the diffraction intensities of the (100) plane and the (002) plane of the XRD pattern were compared, the diffraction intensity of the (002) plane was larger, and thus directionality was confirmed in the crystal growth in the c-axis direction. Scherrer's formula expressed by Formula 1 (where K is the Scherrer constant, λ is the X-ray wavelength, β is the full width at half maximum of the peak (in radians), θ is the Bragg angle (half the diffraction angle 2θ), and τ is The crystallite size obtained by using (representing the average size of crystallites) was 18 nm for the (100) plane and 43 nm for the (002) plane.
Figure JPOXMLDOC01-appb-M000004
　図８は実施例３で得られた蛍光体のＳＥＭ画像を示す。ＳＥＭ画像からも結晶がｃ軸方向に成長していることがわかる。 FIG. 8 shows an SEM image of the phosphor obtained in Example 3. It can be seen from the SEM image that the crystal grows in the c-axis direction.
　図９及び図１０は、実施例３で得られた蛍光体のＰＬスペクトル及び拡散反射スペクトルを示す。ＰＬスペクトルの励起光の波長は６００ｎｍとした。ＰＬスペクトルピーク波長は１１５７ｎｍであり、Ｍｎ５＋の３ｄ－３ｄ内殻遷移（１Ｅ→３Ａ２）に帰属する。したがって、蛍光体に含まれるＭｎの価数は５価である。既存の報告によれば、Ｍｎ５＋の遷移は基底状態３Ａ２から３Ｔ２、１Ａ１、３Ｔ１（３Ｆ）などがあり、図１０の拡散反射スペクトルの結果と一致する。 9 and 10 show the PL spectrum and diffuse reflection spectrum of the phosphor obtained in Example 3. FIG. The wavelength of the excitation light in the PL spectrum was 600 nm. The PL spectral peak wavelength is 1157 nm, which is attributed to the 3d-3d core transition ( 1 E → 3 A 2 ) of Mn 5+ . Therefore, the valence of Mn contained in the phosphor is pentavalent. According to existing reports, there are transitions of Mn 5+ from ground states 3 A 2 to 3 T 2 , 1 A 1 , 3 T 1 ( 3 F), etc., which are consistent with the diffuse reflectance spectrum results of FIG.
　表１は、実施例３、実施例４及び実施例５で得られた蛍光体のＰＬの発光強度を示す。ＰＬスペクトルの励起光の波長は６００ｎｍとした。発光強度は、ＰＬスペクトルのピークの発光強度であり、実施例３で得られた蛍光体の発光強度を１００とした場合の相対値で表される。ｐＨが大きいほど発光強度が大きく、生体イメージング方法に好適であることがわかる。
Figure JPOXMLDOC01-appb-T000005
     　　　　　　　　　　　　　　　　　  Table 1 shows the emission intensity of PL of the phosphors obtained in Example 3, Example 4, and Example 5. The wavelength of the excitation light in the PL spectrum was 600 nm. The emission intensity is the emission intensity at the peak of the PL spectrum, and is expressed as a relative value when the emission intensity of the phosphor obtained in Example 3 is set to 100. It can be seen that the higher the pH, the higher the emission intensity, which is suitable for the biological imaging method.
Figure JPOXMLDOC01-appb-T000005
　なお、上記のように本実施形態について詳細に説明したが、本発明の新規事項及び効果から実体的に逸脱しない多くの変形が可能であることは当業者には容易に理解できるであろう。したがって、このような変形例はすべて本発明の範囲に含まれる。例えば、明細書において、少なくとも一度、より広義又は同義の異なる用語とともに記載された用語は、明細書のいかなる箇所においても、その異なる用語に置き換えることができる。 Although the present embodiment has been described in detail as described above, it will be easily understood by those skilled in the art that many modifications can be made without departing from the novel matters and effects of the present invention. Therefore, all such modifications are included in the scope of the present invention. For example, in the specification, a term described at least once together with a different term having a broader meaning or the same meaning can be replaced with the different term anywhere in the specification.
　１１　水の光吸収率、１２　ヘモグロビンの光吸収率、１３　実施例２で得られた蛍光体のＰＬスペクトル、１４　実施例１で得られた蛍光体のＰＬスペクトル 11 Light absorption rate of water, 12 Light absorption rate of hemoglobin, 13 PL spectrum of the phosphor obtained in Example 2, 14 PL spectrum of the phosphor obtained in Example 1

Claims (7)

  1. 　マンガン付活アルカリ土類金属リン酸塩を含み、前記マンガン付活アルカリ土類金属リン酸塩のリン及びマンガンの各々の原子価が５価であり、前記マンガン付活アルカリ土類金属リン酸塩のアルカリ土類金属がＣａを８０モル％以上含むことを特徴とする蛍光体。 A manganese-activated alkaline earth metal phosphate, wherein the manganese-activated alkaline earth metal phosphate has a valence of 5 for phosphorus and manganese, and the manganese-activated alkaline earth metal phosphate The alkaline earth metal contains 80 mol% or more of Ca.
  2. 　請求項１に記載の蛍光体において、
    　前記マンガン付活アルカリ土類金属リン酸塩がＭ１０－Ｘ（ＨＰＯ４）２Ｘ（ＰＯ４）６－２Ｘ（ＯＨ）２：Ｍｎ５＋、Ｍ１０－Ｘ（ＨＰＯ４）２Ｘ（ＰＯ４）６－２ＸＦ２：Ｍｎ５＋、Ｍ１０－Ｘ（ＨＰＯ４）２Ｘ（ＰＯ４）６－２ＸＣｌ２：Ｍｎ５＋、Ｍ３（ＰＯ４）２：Ｍｎ５＋、Ｍ１０（ＰＯ４）６Ｏ：Ｍｎ５＋、Ｍ４（ＰＯ４）２Ｏ：Ｍｎ５＋、Ｍ（Ｈ２ＰＯ４）２・Ｈ２Ｏ：Ｍｎ５＋、Ｍ（ＰＯ３）２：Ｍｎ５＋、ＭＨＰＯ４・２Ｈ２Ｏ：Ｍｎ５＋、ＭＨＰＯ４：Ｍｎ５＋、Ｍ２Ｐ２Ｏ７：Ｍｎ５＋、Ｍ４Ｐ２Ｏ９：Ｍｎ５＋及びＭ８Ｈ２（ＰＯ４）６・５Ｈ２Ｏ：Ｍｎ５＋の群から選ばれる１種以上の組成を有することを特徴とする蛍光体（但し、ＭはＣａ、Ｍｇ、Ｂａ、Ｓｒの群からから選ばれる１種以上であり、Ｃａを８０モル％以上含み、０≦Ｘ＜２である）。     The phosphor according to claim 1,
    The manganese-activated alkaline earth metal phosphate is M 10-X (HPO 4 ) 2X (PO 4 ) 6-2X (OH) 2 : Mn 5+ , M 10-X (HPO 4 ) 2X (PO 4 ) 6 -2X F 2 : Mn 5+ , M 10-X (HPO 4 ) 2X (PO 4 ) 6-2X Cl 2 : Mn 5+ , M 3 (PO 4 ) 2 : Mn 5+ , M 10 (PO 4 ) 6 O: Mn 5+ , M 4 (PO 4 ) 2 O: Mn 5+ , M (H 2 PO 4 ) 2 .H 2 O: Mn 5+ , M (PO 3 ) 2 : Mn 5+ , MHPO 4 .2H 2 O: Mn 5+ , MHPO 4 : Mn 5+ , M 2 P 2 O 7 : Mn 5+ , M 4 P 2 O 9 : Mn 5+ and M 8 H 2 (PO 4 ) 6 · 5H 2 O: Mn 5+ A phosphor having the above composition ( However, M is 1 or more types chosen from the group of Ca, Mg, Ba, and Sr, contains 80 mol% or more of Ca, and is 0 <= X <2.
  3. 　請求項１に記載の蛍光体において、
    　前記マンガン付活アルカリ土類金属リン酸塩がＭ１０－Ｘ（ＨＰＯ４）２Ｘ（ＰＯ４）６－２Ｘ（ＯＨ）２：Ｍｎ５＋及びＭ３（ＰＯ４）２：Ｍｎ５＋の群から選ばれる１種以上の組成を有することを特徴とする蛍光体（但し、ＭはＣａ、Ｍｇ、Ｂａ、Ｓｒの群から選ばれる１種以上であり、Ｃａを８０モル％以上含み、０≦Ｘ＜２である）。     The phosphor according to claim 1,
    The manganese-activated alkaline earth metal phosphate is selected from the group of M 10-X (HPO 4 ) 2X (PO 4 ) 6-2X (OH) 2 : Mn 5+ and M 3 (PO 4 ) 2 : Mn 5+ A phosphor having at least one composition (provided that M is one or more selected from the group consisting of Ca, Mg, Ba, and Sr, contains 80 mol% or more of Ca, and 0 ≦ X < 2).
  4. 　請求項１に記載の蛍光体において、
    　前記マンガン付活アルカリ土類金属リン酸塩がＣａ１０－Ｘ（ＨＰＯ４）２Ｘ（ＰＯ４）６－２Ｘ（ＯＨ）２：Ｍｎ５＋及びＣａ３（ＰＯ４）２：Ｍｎ５＋の群から選ばれる１種以上の組成を有することを特徴とする蛍光体（但し、０≦Ｘ＜２である）。     The phosphor according to claim 1,
    The manganese-activated alkaline earth metal phosphate is selected from the group consisting of Ca 10-X (HPO 4 ) 2X (PO 4 ) 6-2X (OH) 2 : Mn 5+ and Ca 3 (PO 4 ) 2 : Mn 5+ A phosphor having one or more compositions (provided that 0 ≦ X <2).
  5. 　請求項１乃至４のいずれか１項に記載の蛍光体において、
    　式１で表されるシェラーの式（ここで、Ｋはシェラー定数、λはＸ線波長、βはピーク半値全幅（但し、ラジアン単位）、θはブラッグ角（回折角２θの半分）、τは結晶子の平均サイズを表す）を用いて求められる（００２）面の結晶子サイズが１０～２００ｎｍであることを特徴とする蛍光体。
    Figure JPOXMLDOC01-appb-M000001
         The phosphor according to any one of claims 1 to 4,
    Scherrer's formula expressed by Formula 1 (where K is the Scherrer constant, λ is the X-ray wavelength, β is the full width at half maximum of the peak (in radians), θ is the Bragg angle (half the diffraction angle 2θ), and τ is A phosphor having a (002) plane crystallite size of 10 to 200 nm, which is determined using a crystallite average size).
    Figure JPOXMLDOC01-appb-M000001
  6. 　請求項１乃至５のいずれか１項に記載の蛍光体を使用することを特徴とする生体イメージング方法。 A biological imaging method using the phosphor according to any one of claims 1 to 5.
  7. 　Ｃａ化合物、Ｐ化合物及びＭｎ化合物を水に溶解して水溶液を調製する工程と、
    　前記水溶液のｐＨを７．０以上に調整して水熱合成を行う工程と、
    　を有することを特徴とするマンガン付活アルカリ土類金属リン酸塩を含む蛍光体の製造方法。     A step of preparing an aqueous solution by dissolving a Ca compound, a P compound and a Mn compound in water;
    Adjusting the pH of the aqueous solution to 7.0 or higher and hydrothermal synthesis;
    A method for producing a phosphor containing manganese-activated alkaline earth metal phosphate, comprising:
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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2021527339A (en) * 2018-06-12 2021-10-11 フィジー グループ ビー．ブイ． Inorganic luminescent material for solar radiation conversion devices

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH09511520A (en) * 1994-04-11 1997-11-18 マリンクロッド・メディカル・インコーポレイテッド Microfluidization of particles containing calcium / oxyanions
JP2005307035A (en) * 2004-04-22 2005-11-04 Toshiba Corp Halophosphate salt fluorophor, and light-emitting device
CN104449713A (en) * 2014-11-03 2015-03-25 天津理工大学 Non-rare-earth doped yellow fluorophor as well as preparation method and application thereof

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH09511520A (en) * 1994-04-11 1997-11-18 マリンクロッド・メディカル・インコーポレイテッド Microfluidization of particles containing calcium / oxyanions
JP2005307035A (en) * 2004-04-22 2005-11-04 Toshiba Corp Halophosphate salt fluorophor, and light-emitting device
CN104449713A (en) * 2014-11-03 2015-03-25 天津理工大学 Non-rare-earth doped yellow fluorophor as well as preparation method and application thereof

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
BASSIERE,AURELIE. ET AL.: "How to induce red persistent luminescence in biocompatible Ca3(P04)2", JOURNAL OF MATERIALS CHEMISTRY C, vol. 1, no. 6, 2013, pages 1252 - 1259, XP055374073 *
WU,HAO. ET AL.: "Fabrication and Properties of Rare Earth Phosphors and Their Applications in White-light LED", CHINESE JOURNAL OF LUMINESCENCE, vol. 27, no. 2, 2006, pages 201 - 205 *

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2021527339A (en) * 2018-06-12 2021-10-11 フィジー グループ ビー．ブイ． Inorganic luminescent material for solar radiation conversion devices

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