JP2018203612A - Quantum dot composite and manufacturing method of quantum dot composite - Google Patents

Abstract

To provide a quantum dot composite capable of reducing risk to directly touch quantum dots, capable of effectively suppressing release of the quantum dots to outside of a skeleton, and small in harmful effect to human body and environment especially even when using the quantum dots containing a harmful material such as Cd by holding the quantum dots inside of the skeleton properly.SOLUTION: There is provided a quantum dot composite 1 having a skeleton 10 with a porous structure constituted by a zeolite type compound, and at least one quantum dot 20 included in the skeleton, in which the skeleton has passages 11 communicated each other, and the quantum dot exists at least in the passages of the skeleton.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a quantum dot composite including a skeleton having a porous structure and quantum dots, and a method for producing the quantum dot composite.

  In recent years, a method using a molecule-recognized luminescent marker substance has been frequently used as a highly sensitive method for measuring biologically-related substances such as proteins, viruses and nucleic acids contained in living bodies, and environment-related substances such as dioxins and metal ions. Yes.

  Among these, quantum dots are attracting attention as molecular recognition luminescent marker substances. A quantum dot is a nanoparticle made of an inorganic compound having a particle size of several nanometers to several tens of nanometers. When excitation light has the same wavelength, the wavelength of fluorescence is changed by changing the composition ratio of the compound material to be formed. Can be controlled. Furthermore, since the quantum dot has a three-dimensional well-type potential structure in which electrons are confined three-dimensionally, by changing the particle diameter of the quantum dot in the wavelength region where the compound material used has a light emission gain, There is a remarkable feature that the wavelength of the emitted fluorescence itself can be controlled by changing the band gap structure.

  For example, as quantum dots using a semiconductor material, those using CdSe, CdS, CdTe, etc. have been put into practical use (Patent Document 1). However, since cadmium (Cd) is a specific harmful substance, it is not preferable to use it as a medical drape used in surgery or the like that can confirm the presence or absence of radiation exposure by light emission. For such quantum dots used in vivo, a material that does not use harmful substances such as Cd is required.

In response to these needs, research on quantum dots that do not use Cd is also progressing recently. For example, there is a semiconductor nanoparticle having a composition of (AgIn) _X Zn _(1-2X) S (silver, indium, zinc, and sulfur) developed by a group of Osaka University, Nagoya University, and IDEC. Patent Document 2 proposes a technique for forming a medical drape using a compound material that does not contain such harmful substances as Cd as quantum dots.

  However, quantum dots that do not contain harmful substances such as Cd as described above are difficult to mass-produce and have not yet been put into practical use. For this reason, the use of quantum dots using materials such as Cd is still mainstream, and there are concerns about adverse effects on living bodies and the environment.

JP 2003-329686 A JP 2011-0561131 A

  The object of the present invention is to appropriately hold the quantum dots inside the skeleton body, so that the risk of direct contact with the quantum dots can be reduced even when a quantum dot containing a harmful substance such as Cd is used. Another object of the present invention is to provide a quantum dot composite and a method for producing the quantum dot composite that can effectively suppress the release of quantum dots to the outside of the skeleton body and have a small adverse effect on the living body and the environment.

  As a result of intensive studies, the inventors of the present invention have a porous structure made of a zeolite-type compound and at least one quantum dot inherent in the structure, and the structures are mutually connected. Even if a quantum dot containing a harmful substance such as Cd is used due to the presence of a passage that communicates and the quantum dot is present in at least the passage of the skeleton, there is a risk of direct contact with the quantum dot. It is found that a quantum dot composite can be obtained that can reduce the property of the quantum dot and can effectively suppress the release of the quantum dot to the outside of the skeleton body, and particularly has a small adverse effect on the living body and the environment, and the present invention is completed based on such knowledge It came to.

That is, the gist configuration of the present invention is as follows.
[1] A skeleton having a porous structure composed of a zeolite-type compound, and at least one quantum dot inherent in the skeleton, wherein the skeleton has a channel communicating with each other, The quantum dot composite is held in at least the passage of the skeleton.
[2] The quantum dot composite according to [1], wherein the passage has an enlarged diameter portion, and the quantum dots are included in at least the enlarged diameter portion.
[3] The quantum dot composite according to [2], wherein the enlarged diameter portion communicates a plurality of holes constituting any one of the one-dimensional hole, the two-dimensional hole, and the three-dimensional hole. body.
[4] The quantum dot composite according to [2] or [3], wherein an average particle diameter of the quantum dots is larger than an average inner diameter of the passage and is equal to or smaller than an inner diameter of the expanded portion. body.
[5] The quantum dot composite according to any one of [1] to [4], wherein an average particle diameter of the quantum dots is 0.1 nm to 50 nm.
[6] The quantum dot composite according to [5], wherein the metal oxide fine particles have an average particle diameter of 1 nm to 15.0 nm.
[7] The quantum dot according to any one of [1] to [6], wherein a ratio of an average particle diameter of the quantum dots to an average inner diameter of the passage is 0.06 to 500. Complex.
[8] The quantum dot composite according to [7], wherein a ratio of an average particle diameter of the quantum dots to an average inner diameter of the passage is 1.1 to 4.5.
[9] The metal element (M) of the quantum dot is contained in an amount of 0.5 to 2.5% by mass with respect to the quantum dot composite, according to [1] to [8] The quantum dot composite according to any one of the above.
[10] The passage includes any one of a one-dimensional hole, a two-dimensional hole, and a three-dimensional hole defined by a skeleton structure of the zeolite-type compound, and the one-dimensional hole, the two-dimensional hole, and the three-dimensional hole. Having an enlarged diameter part different from any one of them, an average inner diameter of the passage is 0.1 nm to 1.5 nm, and an inner diameter of the enlarged diameter part is 0.5 nm to 50 nm, [1] The quantum dot composite according to any one of [9].
[11] The quantum dot composite according to any one of [1] to [10], wherein the zeolite-type compound is a silicate compound.
[12] The quantum dot composite according to any one of [1] to [11], wherein the quantum dots contain at least one of cadmium (Cd) and arsenic (As).
[13] A calcining step of calcining a precursor material (B) obtained by impregnating a precursor material (A) with a metal-containing solution into a porous structure skeleton composed of a zeolite type compound, and the precursor A hydrothermal treatment step of hydrothermally treating the precursor material (C) obtained by firing the material (B), and a method for producing a quantum dot composite.
[14] The quantum dot composite according to [13], wherein a nonionic surfactant is added in an amount of 50 to 500% by mass with respect to the precursor material (A) before the firing step. Body manufacturing method.
[15] Before the firing step, the precursor material (A) is impregnated with the metal-containing solution by adding the metal-containing solution to the precursor material (A) in a plurality of times. The method for producing a quantum dot composite according to [13] or [14], which is characterized.
[16] When the precursor material (A) is impregnated with the metal-containing solution before the firing step, the amount of the metal-containing solution added to the precursor material (A) is changed to the precursor material. In terms of the ratio of silicon (Si) constituting the precursor material (A) to the metal element (M) contained in the metal-containing solution added to (A) (atomic ratio Si / M), It adjusts so that it may become 10-1000, The manufacturing method of the quantum dot composite_body | complex as described in any one of [13]-[15] characterized by the above-mentioned.
[17] The method for producing a quantum dot composite according to [13], wherein in the hydrothermal treatment step, the precursor material (C) and a structure directing agent are mixed.
[18] The method for producing a quantum dot composite according to [13], wherein the hydrothermal treatment step is performed in a basic atmosphere.

  According to the present invention, a skeleton body having a porous structure composed of a zeolite-type compound and at least one quantum dot inherent in the skeleton body, the skeleton body having a passage communicating with each other, Since the quantum dots are present in at least the passage of the skeleton, in particular, even if quantum dots containing harmful substances such as Cd are used, the risk of direct contact with the quantum dots can be reduced, In addition, a quantum dot composite that can effectively suppress the release of the quantum dots to the outside of the skeleton and has little adverse effect on the living body and the environment can be obtained.

FIG. 1 schematically shows the internal structure of a quantum dot composite according to an embodiment of the present invention, and FIG. 1A is a perspective view (a part thereof is shown in cross section). FIG. 1B is a partially enlarged sectional view. FIG. 2 is a partial enlarged cross-sectional view for explaining an example of the function of the quantum dot composite of FIG. FIG. 3 is a schematic diagram showing a modification of the quantum dot composite of FIG. FIG. 4 is a flowchart showing an example of a method for producing the quantum dot composite of FIG.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[Configuration of quantum dot composite]
1A and 1B are diagrams schematically showing a configuration of a quantum dot composite according to an embodiment of the present invention, in which FIG. 1A is a perspective view (a part is shown in cross section), and FIG. 1B is a partially enlarged cross section. FIG. Note that the quantum dot composite in FIG. 1 shows an example, and the shape, dimensions, and the like of each component according to the present invention are not limited to those in FIG.

  As shown in FIG. 1 (a), the quantum dot composite 1 includes a skeleton body 10 having a porous structure composed of a zeolite-type compound and at least one quantum dot 20 present in the skeleton body 10. Prepare.

  The skeleton body 10 has a porous structure and, as shown in FIG. 1B, preferably has a plurality of holes 11a, 11a,. Here, the quantum dots 20 exist in at least the passage 11 of the skeleton body 10, and are preferably held in at least the passage 11 of the skeleton body 10.

  According to the above configuration, even when a substance containing a regulated metal such as Cd is used as the quantum dot 20, it can be contained in the inside of the skeleton body 10 so as to be harmful substances such as Cd harmful to the human body. The risk of direct contact with the user can be greatly reduced. Therefore, when the quantum dot composite 1 is used, the adverse effects on the living body and the environment can be reduced as compared with the case where the conventional quantum dots containing a harmful substance such as Cd are used alone.

  In addition, since movement of the quantum dots 20 is restricted in the skeleton body 10, it is possible to effectively suppress aggregation of the quantum dots 20 and 20 and release of the quantum dots 20 to the outside of the skeleton body 10. . In addition, when the quantum dot composite is used in an environment that receives external force from a fluid, if the quantum dot is only held in an attached state on the outer surface of the skeleton body 10, the skeleton is affected by the external force from the fluid. There is a problem that it is easily detached from the outer surface of the body 10. In contrast, in the quantum dot composite 1, the quantum dots 20 exist in at least the passage 11 of the skeleton body 10, so that the quantum dots 20 are detached from the skeleton body 10 even when affected by an external force due to fluid. Hateful. That is, when the quantum dot composite 1 is in the fluid, the fluid flows into the passage 11 from the hole 11a of the skeleton body 10, and the speed of the fluid flowing in the passage 11 is determined by the flow resistance (friction force). This is considered to be slower than the speed of the fluid flowing on the outer surface of the skeleton body 10. Due to the influence of the channel resistance, the pressure that the quantum dots 20 existing in the passage 11 receive from the fluid is lower than the pressure that the quantum dots receive from the fluid outside (outer surface) of the skeleton 10. . Therefore, it is possible to effectively suppress the separation of the quantum dots 20 existing in the skeleton body 11, and it is possible to stably maintain the functions of the quantum dots 20 for a long period of time. The flow path resistance as described above increases as the passage 11 of the skeleton body 10 has a plurality of bends and branches, and the inside of the skeleton body 10 has a more complicated and three-dimensional structure. Conceivable.

Further, the passage 11 includes any one of a one-dimensional hole, a two-dimensional hole, and a three-dimensional hole defined by a skeleton structure of the zeolite type compound, and the one-dimensional hole, the two-dimensional hole, and the three-dimensional hole. Preferably, the quantum dots 20 are present at least in the enlarged diameter portion 12, and are at least included in the enlarged diameter portion 12. It is more preferable. As used herein, a one-dimensional hole means a tunnel-type or cage-type hole forming a one-dimensional channel, or a plurality of tunnel-type or cage-type holes forming a plurality of one-dimensional channels (a plurality of one-dimensional holes). Channel). A two-dimensional hole refers to a two-dimensional channel in which a plurality of one-dimensional channels are two-dimensionally connected. A three-dimensional hole refers to a three-dimensional channel in which a plurality of one-dimensional channels are three-dimensionally connected. Point to.
Thereby, the movement of the quantum dots 20 in the skeleton body 10 is further restricted, and the separation of the quantum dots 20 and the aggregation of the quantum dots 20 and 20 can be more effectively prevented. Here, the inclusion means a state in which the quantum dots 20 are included in the skeleton body 10. At this time, the quantum dot 20 and the skeleton body 10 do not necessarily need to be in direct contact with each other, and another substance (for example, a surfactant or the like) is interposed between the quantum dot 20 and the skeleton body 10. In this state, the quantum dots 20 may be indirectly present in the skeleton body 10.
Moreover, it is preferable that the enlarged diameter part 12 is connecting the some hole 11a and 11a which comprise either of the said one-dimensional hole, the said two-dimensional hole, and the said three-dimensional hole. Thereby, since the separate channel | path different from a one-dimensional hole, a two-dimensional hole, or a three-dimensional hole is provided in the inside of the frame | skeleton body 10, the function of the quantum dot 20 can be exhibited more.

  Although FIG. 1B shows a case where the quantum dots 20 are enclosed by the enlarged diameter portion 12, the configuration is not limited to this configuration, and the quantum dots 20 are partially formed of the enlarged diameter portion 12. You may hold | maintain at the channel | path 11 in the state which protruded outside. The quantum dots 20 may be partially embedded in a portion of the passage 11 other than the enlarged diameter portion 12 (for example, an inner wall portion of the passage 11), or may be held by fixing or the like.

  The passage 11 is three-dimensionally formed inside the skeleton body 10 including a branching part or a joining part, and the enlarged diameter part 12 is provided in the branching part or the joining part of the passage 11. preferable.

The average inner diameter _DF of the passage 11 formed in the skeleton 10 is calculated from the average value of the short diameter and the long diameter of the hole 11a constituting any one of the one-dimensional hole, the two-dimensional hole, and the three-dimensional hole, For example, it is 0.1-1.5 nm, Preferably it is 0.5-0.8 nm.
Moreover, the internal diameter _DE of the diameter expansion part 12 is 0.5-50 nm, for example, Preferably it is 1.1-40 nm, More preferably, it is 1.1-3.3 nm. Naikei D _E of the enlarged diameter section 12 depends on for example the pore size of which will be described later precursor material (A), and the average particle diameter D _C of the quantum dots 20 to be inclusion. The inner diameter _DE of the enlarged diameter portion 12 is a size that can enclose the quantum dots 20.

  The skeleton body 10 is composed of a zeolite-type compound. Zeolite type compounds include, for example, zeolites (aluminosilicates), cation exchange zeolites, silicate compounds such as silicalite, zeolite related compounds such as aluminoborate, aluminoarsenate, germanate, molybdenum phosphate, etc. And phosphate-based zeolite-like substances. Among these, the zeolite type compound is preferably a silicate compound.

  The framework structure of zeolite type compounds is FAU type (Y type or X type), MTW type, MFI type (ZSM-5), FER type (ferrierite), LTA type (A type), MWW type (MCM-22) , MOR type (mordenite), LTL type (L type), BEA type (beta type), etc., preferably MFI type, more preferably ZSM-5. In the zeolite type compound, a plurality of pores having a pore size corresponding to each skeleton structure are formed. For example, the maximum pore size of the MFI type is 0.636 nm (6.36 mm), and the average pore size is 0.560 nm (5.60 mm). is there.

  The quantum dots 20 are not particularly limited, and known ones can be used. For example, InAs quantum dots, CdE (E = S, Se, Te) quantum dots, and CdE quantum dots can be used. A core / shell type quantum dot whose core yield is improved by coating with a semiconductor having a large band gap (ZeS) as a core is exemplified. In the quantum dot composite 1, the quantum dots 20 exist mainly inside the skeleton 10 having a porous structure. Therefore, even when the quantum dots contain harmful substances such as cadmium and arsenic, as long as they are used as the quantum dot composite 1, the amount and concentration of direct contact with harmful substances such as cadmium and arsenic can be greatly reduced. . That is, the quantum dot composite 1 is particularly suitable when it is desired to use a quantum dot containing at least one of a regulated metal, particularly cadmium (Cd) and arsenic (As). In addition, as a regulation object metal, heavy metals, such as cadmium (Cd), mercury (Hg), and lead (Pb) prescribed | regulated by the RoHS regulation etc., are mentioned, for example.

Quantum dots 20, and if the primary particle, there are the cases are secondary particles in which primary particles are formed by aggregation, the average particle diameter D _C is preferably 0.1 to 50 nm, more Preferably it is 0.1-20 nm, More preferably, it is 1-15.0 nm, Most preferably, it is 1-10 nm. When the quantum dot 20 is included in the skeleton 10 by setting the above range, it is easy to ensure sufficient light emission intensity. Since the quantum dot 20 can adjust the band gap depending on the particle diameter, the quantum dot 20 has characteristic light emission characteristics depending on the particle diameter.

Further, from the viewpoint of the good retention of quantum dots 20 within the passage 11, the average particle diameter D _C of the quantum dots 20, in either case of the primary particles and secondary particles, than the average inner diameter D _F of the passage 11 And larger than the inner diameter D _E of the enlarged diameter portion 12 (D _F <D _C ≦ D _E ). According to such a configuration, the quantum dots 20 are configured to be included in the passage 11, particularly the enlarged diameter portion 12, and even when the quantum dots 20 receive external force from the fluid, The movement of the quantum dots 20 is effectively suppressed. Further, it is possible to effectively prevent the quantum dots 20, 20,... Included in each of the enlarged diameter portions 12, 12,. .

The ratio of the average particle diameter _{D C} of the quantum dots 20 relative to the average inner diameter _{D F} of the passage 11 _(D C / D _F) is preferably from 0.06 to 500, more preferably from 1.1 to 4.5 It is.
When the quantum dots 20 are metal oxide fine particles, the metal element (M) of the metal oxide fine particles is contained in an amount of 0.5 to 2.5% by mass with respect to the quantum dot composite 1. Preferably, it is more preferably 0.5 to 1.5% by mass with respect to the quantum dot composite 1. For example, when the metal element (M) is Co, the content (mass%) of the Co element is represented by (mass of Co element) / (mass of all elements of the quantum dot composite 1) × 100.
When the quantum dot 20 is a metal fine particle, the metal element (M) of the metal fine particle is preferably contained in an amount of 0.5 to 2.5% by mass with respect to the quantum dot composite 1. It is more preferable that it is contained at 0.5 to 1.5% by mass relative to 1.
The ratio of the silicon (Si) constituting the skeleton 10 to the metal element (M) constituting the quantum dot 20 (atomic number ratio Si / M) is preferably 10 to 1000, and preferably 50 to 200. More preferably. If the ratio is greater than 1000, the activity as a quantum dot may not be sufficiently obtained, such as low activity. On the other hand, when the ratio is smaller than 10, the ratio of the quantum dots 20 becomes too large, and the strength of the skeleton 10 tends to decrease. The quantum dots 20 referred to here are fine particles held or carried inside the skeleton 10 and do not include fine particles attached to the outer surface of the skeleton 10.

[Functions of quantum dot composite]
FIG. 2 is a partially enlarged cross-sectional view for explaining an example of the quantum dot function of the quantum dot composite 1. As shown in FIG. 2, the quantum dots 20 are present in the passage 11 (particularly the enlarged diameter portion 12) of the carrier 10. Such a quantum dot composite 1 is used by being mixed with a body fluid, for example. Specifically, first, an antibody is adsorbed on the surface of the quantum dot complex 1, and then the antibody adsorbed on the surface of the quantum dot complex contacts an antigen in the body fluid. Thereby, the quantum dot 20 functions as a molecular recognition luminescent marker according to antigens, such as protein contained in a bodily fluid. As a result, the light emission of the quantum dots 20 can be visually recognized on the outer surface of the quantum dot composite 1.

  Further, in such a quantum dot composite 1, since the quantum dots 20 are contained inside the skeleton body 10, it is possible to greatly reduce the amount and density of the user directly contacting the quantum dots 20. Further, in the quantum dot composite 1, the quantum dots 20 are appropriately present inside the skeleton body 10, so that the quantum dots 20 can be effectively suppressed from being emitted to the outside of the skeleton body 10. Therefore, in the quantum dot composite 1, even when the quantum dot 20 contains a harmful substance such as Cd, compared to the conventional case where the quantum dot containing a harmful substance such as Cd is used alone, And adverse effects on the environment can be reduced.

  Further, conventional quantum dots are generally used in a fine particle shape, and recovery after use is complicated. On the other hand, since the quantum dot composite 1 of the present embodiment includes a plurality of quantum dots 20, 20,... Inside the skeleton body 10, collection after use is easy.

  Further, since the quantum dots 20 are present in the passage 11, movement in the passage 11 is suppressed, and aggregation of the quantum dots 20 can be prevented. Accordingly, it is possible to prevent the function of the quantum dot composite 1 from being deteriorated and to prevent the functional modification, thereby extending the function life. By prolonging the life of the quantum dot composite 1, the frequency of replacement of the quantum dot composite 1 can be reduced, the amount of used quantum dot composite 1 discarded can be greatly reduced, and resource saving can be achieved. it can.

  In addition, although the quantum dot composite body 1 of FIG. 1 has shown the case where the skeleton body 10 and the quantum dot 20 inherent in the skeleton body 10 are provided, it is not limited only to this structure, For example, FIG. As shown, the quantum dot composite 2 may further include at least one other quantum dot 30 held on the outer surface 10a of the skeleton body 10 as long as the effects of the present invention are not hindered.

  The quantum dot 30 is a substance that exhibits a quantum dot function, and may be the same as or different from the material of the quantum dot 20. According to this configuration, the content of the quantum dots held in the skeleton body 10 can be increased, the modification amount of the quantum dot complex 1 and the antibody can be adjusted, and the function of the quantum dots can be further increased. Can be promoted.

  On the other hand, since the other quantum dots 30 are configured to be held on the outer surface 10a of the skeleton body 10, when the quantum dot composite 2 is used, the amount that the user directly touches harmful substances such as Cd Concentration may be high. Therefore, the content of at least one other quantum dot 30 held on the outer surface 10a of the skeleton body 10 is preferably less than the content of the quantum dots 20 inherent in the skeleton body 10.

[Method for producing quantum dot composite]
FIG. 4 is a flowchart showing an example of a method for manufacturing the quantum dot composite 1 of FIG. Hereinafter, an example of a method for producing a quantum dot composite will be described.

(Step S1: Preparation process)
As shown in FIG. 4, first, a precursor material (A) for obtaining a porous skeleton composed of a zeolite-type compound is prepared. The precursor material (A) is preferably a regular mesoporous material, and can be appropriately selected according to the type (composition) of the zeolite-type compound constituting the skeleton of the quantum dot composite.

  Here, when the zeolitic compound constituting the skeleton of the quantum dot composite is a silicate compound, the regular mesoporous material has pores having a pore diameter of 1 to 50 nm in one dimension, two dimensions or It is preferably a compound composed of a Si—O skeleton having a uniform size in three dimensions and regularly developed. Such regular mesoporous materials can be obtained as various composites depending on the synthesis conditions. Specific examples of the composites include, for example, SBA-1, SBA-15, SBA-16, KIT-6, FSM- 16, MCM-41, etc., among which MCM-41 is preferable. The pore diameter of SBA-1 is 10 to 30 nm, the pore diameter of SBA-15 is 6 to 10 nm, the pore diameter of SBA-16 is 6 nm, the pore diameter of KIT-6 is 9 nm, and the pore diameter of FSM-16 is 3 -5 nm, MCM-41 has a pore diameter of 1-10 nm. Examples of such regular mesoporous materials include mesoporous silica, mesoporous aluminosilicate, and mesoporous metallosilicate.

  The precursor material (A) may be a commercially available product or a synthetic product. When the precursor material (A) is synthesized, it can be performed by a known method for synthesizing regular mesoporous materials. For example, a mixed solution containing a raw material containing the constituent elements of the precursor material (A) and a templating agent for defining the structure of the precursor material (A) is prepared, and the pH is adjusted as necessary. Hydrothermal treatment (hydrothermal synthesis) is performed. Thereafter, the precipitate (product) obtained by hydrothermal treatment is recovered (for example, filtered), washed and dried as necessary, and further calcined to form a regular mesoporous material in powder form. A precursor material (A) is obtained. Here, as a solvent of the mixed solution, for example, an organic solvent such as water or alcohol, or a mixed solvent thereof can be used. Moreover, although a raw material is selected according to the kind of frame | skeleton, for example, silica agents, such as tetraethoxysilane (TEOS), fumed silica, quartz sand, etc. are mentioned. Further, as the templating agent, various surfactants, block copolymers and the like can be used, and it is preferable to select according to the type of the synthesized compound of regular mesoporous materials. For example, when preparing MCM-41 A surfactant such as hexadecyltrimethylammonium bromide is preferred. The hydrothermal treatment can be performed, for example, in a sealed container at 80 to 800 ° C., 5 hours to 240 hours, and treatment conditions of 0 to 2000 kPa. The baking treatment can be performed, for example, in air at 350 to 850 ° C. for 2 to 30 hours.

(Step S2: impregnation step)
Next, the prepared precursor material (A) is impregnated with the metal-containing solution to obtain the precursor material (B).

  The metal-containing solution may be a solution containing a metal component (for example, metal ion) corresponding to the metal element (M) constituting the quantum dot, for example, a metal salt containing the metal element (M) in a solvent. Can be prepared by dissolving. Examples of such metal salts include chlorides, hydroxides, oxides, sulfates, nitrates, and the like, and nitrates are particularly preferable. As the solvent, for example, water, an organic solvent such as alcohol, or a mixed solvent thereof can be used.

  The method for impregnating the precursor material (A) with the metal-containing solution is not particularly limited. For example, a plurality of metal-containing solutions are mixed while stirring the powdery precursor material (A) before the firing step described later. It is preferable to add in small portions in portions. Further, from the viewpoint of facilitating the penetration of the metal-containing solution into the pores of the precursor material (A), a surfactant as an additive is added in advance to the precursor material (A) before adding the metal-containing solution. It is preferable to add it. Such an additive has a function of coating the outer surface of the precursor material (A), suppresses the metal-containing solution added thereafter from adhering to the outer surface of the precursor material (A), and the metal It is considered that the contained solution is more likely to enter the pores of the precursor material (A).

  Examples of such additives include nonionic surfactants such as polyoxyethylene alkyl ethers such as polyoxyethylene oleyl ether and polyoxyethylene alkylphenyl ethers. Since these surfactants have a large molecular size and cannot penetrate into the pores of the precursor material (A), they do not adhere to the inside of the pores, and the metal-containing solution penetrates into the pores. It is thought not to interfere. As a method for adding the nonionic surfactant, for example, it is preferable to add 50 to 500% by mass of the nonionic surfactant with respect to the precursor material (A) before the firing step described later. When the addition amount of the nonionic surfactant to the precursor material (A) is less than 50% by mass, the above-described inhibitory action is hardly exhibited, and the nonionic surfactant is added to the precursor material (A) at 500. Addition of more than% by mass is not preferable because the viscosity increases excessively. Therefore, the addition amount of the nonionic surfactant with respect to the precursor material (A) is set to a value within the above range.

  The amount of the metal-containing solution added to the precursor material (A) is the amount of the metal element (M) contained in the metal-containing solution impregnated in the precursor material (A) (that is, the precursor material (B It is preferable to adjust appropriately in consideration of the amount of the metal element (M) contained in (). For example, the amount of the metal-containing solution added to the precursor material (A) before the firing step described later is relative to the metal element (M) contained in the metal-containing solution added to the precursor material (A). In terms of the ratio of silicon (Si) constituting the precursor material (A) (atomic number ratio Si / M), it is preferably adjusted to be 10 to 1000, and adjusted to be 50 to 200. It is more preferable. For example, when a surfactant is added as an additive to the precursor material (A) before the metal-containing solution is added to the precursor material (A), the addition of the metal-containing solution to be added to the precursor material (A) By converting the amount to 50 to 200 in terms of the atomic ratio Si / M, the metal element (M) of the quantum dot is contained at 0.5 to 2.5 mass% with respect to the quantum dot composite. be able to. In the state of the precursor material (B), the amount of the metal element (M) present in the pores is the same as the metal concentration of the metal-containing solution, the presence or absence of the additive, and other conditions such as temperature and pressure. If so, it is roughly proportional to the amount of the metal-containing solution added to the precursor material (A). Further, the amount of the metal element (M) inherent in the precursor material (B) is proportional to the amount of the metal element constituting the quantum dots inherent in the skeleton of the quantum dot composite. Therefore, by controlling the amount of the metal-containing solution added to the precursor material (A) within the above range, the metal-containing solution can be sufficiently impregnated inside the pores of the precursor material (A), and thus The amount of quantum dots contained in the skeleton of the quantum dot composite can be adjusted.

  After impregnating the precursor material (A) with the metal-containing solution, a cleaning treatment may be performed as necessary. As the cleaning solution, for example, water, an organic solvent such as alcohol, or a mixed solution thereof can be used. In addition, it is preferable to impregnate the precursor material (A) with a metal-containing solution and perform a cleaning treatment as necessary, followed by a drying treatment. Examples of the drying treatment include natural drying overnight or high temperature drying at 150 ° C. or lower. In addition, the regular mesopores of the precursor material (A) are obtained by performing the baking treatment described later in a state where a large amount of moisture contained in the metal-containing solution and the moisture of the cleaning solution remain in the precursor material (A). Since the skeletal structure as a substance may be broken, it is preferable to dry it sufficiently.

(Step S3: Firing step)
Next, the precursor material (B) obtained by impregnating the precursor material (A) for obtaining a porous structure composed of a zeolite-type compound with the metal-containing solution is fired, and the precursor material (C )

  The firing treatment is preferably performed, for example, in the air at 350 to 850 ° C. for 2 to 30 hours. By such a baking treatment, the metal component impregnated in the pores of the regular mesoporous material grows, and quantum dots are formed in the pores.

(Step S4: Hydrothermal treatment process)
Next, a mixed solution in which the precursor material (C) and the structure directing agent are mixed is prepared, and the precursor material (C) obtained by firing the precursor material (B) is hydrothermally treated to produce quantum dots. A complex is obtained.

  The structure directing agent is a templating agent for defining the skeletal structure of the skeleton of the quantum dot complex. For example, a surfactant can be used. The structure directing agent is preferably selected according to the skeleton structure of the skeleton of the quantum dot complex. For example, an interface such as tetramethylammonium bromide (TMABr), tetraethylammonium bromide (TEABr), tetrapropylammonium bromide (TPABr), etc. An activator is preferred.

  Mixing of the precursor material (C) and the structure directing agent may be performed during the main hydrothermal treatment step, or may be performed before the hydrothermal treatment step. Moreover, the preparation method of the said mixed solution is not specifically limited, A precursor material (C), a structure directing agent, and a solvent may be mixed simultaneously, or precursor material (C) and structure prescription | regulation are carried out to a solvent. After each agent is dispersed in each solution, each dispersion solution may be mixed. As the solvent, for example, water, an organic solvent such as alcohol, or a mixed solvent thereof can be used. In addition, the pH of the mixed solution is preferably adjusted using an acid or a base before hydrothermal treatment.

Hydrothermal treatment can be performed by a well-known method, for example, it is preferable to perform in 80-800 degreeC, 5 hours-240 hours, and processing conditions of 0-2000 kPa in an airtight container. The hydrothermal treatment is preferably performed in a basic atmosphere. Although the reaction mechanism here is not necessarily clear, by performing hydrothermal treatment using the precursor material (C) as a raw material, the skeleton structure of the precursor material (C) as a regular mesoporous material gradually collapses. While the position of the quantum dots within the pores of the precursor material (C) is generally maintained, a new skeletal structure (porous structure) is formed as a skeleton of the quantum dot composite by the action of the structure directing agent. Is done. The quantum dot composite obtained in this way comprises a porous structure skeleton composed of a zeolite-type compound and quantum dots inherent in the skeleton, and the quantum dots are held at least inside the skeleton. Has been.
In this embodiment, in the hydrothermal treatment step, a mixed solution in which the precursor material (C) and the structure directing agent are mixed is prepared, and the precursor material (C) is hydrothermally treated. Not limited to this, the precursor material (C) may be hydrothermally treated without mixing the precursor material (C) and the structure directing agent.

  It is preferable that the precipitate (quantum dot composite) obtained after the hydrothermal treatment is washed, dried and fired as necessary after collection (for example, filtration). As the cleaning solution, for example, water, an organic solvent such as alcohol, or a mixed solution thereof can be used. Examples of the drying treatment include natural drying overnight or high temperature drying at 150 ° C. or lower. In addition, if the baking treatment is performed in a state where a large amount of moisture remains in the precipitate, the skeleton structure as the skeleton of the quantum dot composite may be broken. Moreover, a baking process can be performed on the process conditions of 350-850 degreeC and 2 to 30 hours, for example in the air. By such a baking treatment, the structure directing agent attached to the quantum dot composite is burned out. In addition, the quantum dot composite can be used as it is without subjecting the recovered precipitate to a firing treatment depending on the purpose of use. For example, if the environment in which the quantum dot composite is used is a high-temperature environment in an oxidizing atmosphere, the structure directing agent will be burned down by exposure to the environment for a certain period of time, and the same quantum dot composite as when fired Since the body is obtained, it can be used as it is.

  When the metal element (M) contained in the metal-containing solution impregnated in the precursor material (A) is a metal species that is easily oxidized (for example, Cd), a reduction treatment is further performed after the hydrothermal treatment. It is preferable. When the metal element (M) contained in the metal-containing solution is an easily oxidized metal species, the metal component may be oxidized by the heat treatment in the steps (steps S3 to S4) after the impregnation treatment (step S2). There is. Therefore, the metal oxide is inherent in the skeleton formed in the hydrothermal treatment step (step S4). Therefore, in the case where quantum dots that are not oxides are contained in the skeleton body, it is desirable that after the hydrothermal treatment, the collected precipitate is fired and further reduced in a reducing gas atmosphere such as hydrogen gas. By performing the reduction treatment, the metal oxide present in the skeleton is reduced, and quantum dots of metal species corresponding to the metal element (M) constituting the metal oxide are formed. As a result, a quantum dot composite in which quantum dots are present in a highly dispersed state inside the skeleton is obtained.

  As described above, as an example of a method for producing a quantum dot composite, a metal component contained in a metal-containing solution impregnated in a precursor material (A) is crystal-grown in the precursor material (A), thereby producing quantum dots. Although the case of forming is described as an example, it is not limited to this manufacturing method.

  For example, the quantum dots may be synthesized separately from the synthesis of the skeleton. In this case, quantum dots are prepared in advance and a quantum dot-containing solution is prepared. The quantum dots prepared here may be commercially available products, or may be synthesized by a known method (for example, the method described in JP2009-161372A).

  In this method, instead of the metal-containing solution impregnated in the precursor material (A) in the impregnation step (step S2), a solution containing quantum dots prepared in advance is used for the precursor material (A). The quantum dots may be held directly. In this case, since it is not necessary to grow the quantum dots in the holes of the precursor material (A), after the quantum dots are directly held on the precursor material (A), the hydrothermal treatment step (step S4) is subsequently performed. By performing, a skeleton body can be formed and a quantum dot composite can be obtained. In this method, the firing step (step S3) is not essential, but may be performed as needed for the purpose of burning out the surfactant used in the impregnation step (step S2).

  As mentioned above, although embodiment of this invention was described, this invention is not limited to the said embodiment, All the aspects included in the concept of this invention and a claim are included, and various within the scope of this invention. Can be modified.

  Next, in order to further clarify the effects of the present invention, examples and comparative examples will be described, but the present invention is not limited to these examples.

Example 1
[Synthesis of Precursor Material (A)]
Silica agent (tetraethoxysilane (TEOS), manufactured by Wako Pure Chemical Industries, Ltd.) and hexadecyltrimethylammonium bromide (CTAB) (made by Wako Pure Chemical Industries, Ltd.) which is a surfactant as a templating agent were mixed. A mixed aqueous solution was prepared, pH was adjusted as appropriate, and hydrothermal treatment was performed in a sealed container. Thereafter, the produced precipitate was filtered off, washed with water and ethanol, and further calcined in air at 600 ° C. for 24 hours to obtain MCM-41 as a precursor material (A).

[Synthesis of quantum dot composite]
To 7.4 g of trioctylphosphine (TOP: Tri-n-octylphosphine) (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.7896 g of Se powder (manufactured by Junsei Chemical Co., Ltd.) was added and mixed, and the mixture was mixed. A Se precursor liquid was prepared by heating at 150 ° C. under nitrogen flow.
Subsequently, 0.450 g of cadmium oxide (CdO) powder (manufactured by Mitsuwa Chemicals) and 8 g of stearic acid (manufactured by Nacalai Tesque) were heated to 150 ° C. in a three-necked flask under an argon atmosphere. After dissolving CdO, the solution was cooled to room temperature. Further, 8 g of trioctylphosphine oxide (TOPO: Tri-n-octylphosphine Oxide) (manufactured by Nippon Chemical Industry Co., Ltd.) and 12 g of hexadecylamine (HDA: Hexadecylamine) (Junsei Chemical Co., Ltd.) are added to the Cd solution. And mixed to prepare a Cd precursor.
4 mL of Se precursor solution was added to the Cd precursor, and the precursor material (A) was quickly injected into the reaction chamber to obtain a precursor material in which CdSe quantum dots were included in the precursor material (A). .

  The precursor material obtained as described above and TEABr as a structure directing agent were mixed to prepare a mixed aqueous solution, and hydrothermal treatment was performed in a sealed container. Thereafter, the formed precipitate is filtered off, washed with water, dried at 100 ° C. for 12 hours or more, and further calcined in the air at 600 ° C. for 24 hours, so that the CdSe is put inside the FAU type silicalite skeleton. A quantum dot composite containing quantum dots was obtained.

(Comparative Example 1)
In Comparative Example 1, a Cd precursor and an Se precursor liquid were produced in the same manner as in Example 1. Furthermore, 4 mL of Se precursor liquid was added to the produced Cd precursor and injected into the reaction chamber to obtain CdSe quantum dots.

(Comparative Example 2)
In Comparative Example 2, a gold colloid having an average particle size of 10 nm (manufactured by Sigma Aldrich Japan GK, product number 741957) was prepared.

[Evaluation]
Using the quantum dot composite of Example 1, the quantum dot of Comparative Example 1, and the gold colloid of Comparative Example 2, the following characteristic evaluation was performed. The evaluation conditions for each characteristic are as follows. The results are shown in Table 1.

[A] Cross-sectional observation About the quantum dot composite of Example 1 provided with a skeleton and quantum dots, an observation sample was prepared by a pulverization method, and a transmission electron microscope (TEM) (TITAN G2, manufactured by FEI) was used. The cross-section was observed.
As a result, in the quantum dot composite of Example 1, it was confirmed that the quantum dots were contained and held inside the skeleton composed of silicalite.

[B] Average inner diameter of passage of skeleton body and average particle diameter of quantum dots In the TEM image taken by cross-sectional observation performed in the above evaluation [A], arbitrarily select 500 passages of the skeleton body, The major axis and the minor axis were measured, the inner diameters were calculated from the average values (N = 500), and the average inner diameter value was obtained as the average inner diameter _DF of the skeleton body passage. Similarly, for quantum dots, 500 quantum dots are arbitrarily selected from the TEM image, the particle diameters are measured (N = 500), the average value is obtained, and the average of the quantum dots is calculated. I was having a particle diameter _{D C.} The results are shown in Table 1.

[C] Relationship between the addition amount of the metal-containing solution and the amount of metal included in the skeleton body Addition of atomic ratio Si / M = 50, 100, 200, 1000 (M = Co, Ni, Fe, Cu) A quantum dot composite in which metal oxide fine particles are included in the skeleton body in an amount, and then the amount of metal (mass) included in the skeleton body of the quantum dot composite prepared in the above addition amount. %). In this measurement, quantum dot composites having an atomic ratio of Si / M = 100, 200, 1000 were prepared by adjusting the addition amount of the metal-containing solution in the same manner as the quantum dot composite of Example 1, respectively. The quantum dot composite having the atomic ratio Si / M = 50 is the same as the quantum dot composite having the atomic ratio Si / M = 100, 200, 1000 except that the addition amount of the metal-containing solution is changed. It was produced by the method.
The amount of metal was determined by using ICP (high frequency inductively coupled plasma) alone or a combination of ICP and XRF (fluorescence X-ray analysis). XRF (energy dispersive X-ray fluorescence analyzer “SEA1200VX”, manufactured by SSI Nanotechnology Co., Ltd.) was performed under the conditions of vacuum atmosphere, acceleration voltage 15 kV (using Cr filter) or acceleration voltage 50 kV (using Pb filter). .
XRF is a method of calculating the abundance of a metal by fluorescence intensity, and a quantitative value (mass% conversion) cannot be calculated with XRF alone. Therefore, the metal amount of the quantum dot composite added with metal at Si / M = 100 is quantified by ICP analysis, and the metal amount of the quantum dot composite added with metal at Si / M = 50 and less than 100 is XRF. It calculated based on the measurement result and the ICP measurement result.
As a result, it was confirmed that the amount of metal included in the quantum dot composite increased as the amount of the metal-containing solution added increased at least in the atomic ratio Si / M in the range of 50 to 1000. It was done.

  For the quantum dots of Comparative Example 1, the particle size of each particle was measured in the same manner as in Example 1.

[D] Performance Evaluation The quantum dot composite of Example 1, the quantum dot of Comparative Example 1, and the gold colloid of Comparative Example 2 were evaluated using the evaluation method described in JP-A-2008-304401. .
Specifically, in place of the rhodamine-containing silica nanoparticle dispersion liquid of Example 1 of JP 2008-304401 A, the quantum dot composite dispersion liquid of Example 1, the quantum dot dispersion liquid of Comparative Example 1, and Evaluation was carried out using any one of the metal colloid dispersions of Comparative Example 2. The solvent was a phosphate buffer.
In this evaluation, each of the above dispersions was reacted with three antigens of 0.1, 0.5, and 5 mIU, the state was observed, the reactivity was visually confirmed, and the determination was made as follows.
For Example 1 and Comparative Example 1, the presence or absence of fluorescence was determined, and when the fluorescence was sufficiently confirmed visually, it was determined that the sensitivity was excellent, and “◯”, the determination was difficult because the fluorescence was thin. If it is determined that the sensitivity is not good, it is judged as being “acceptable”, “△”, and if no fluorescence is confirmed, it is judged that the sensitivity is inferior (impossible) and “×”. It was.
In Comparative Example 2, the presence or absence of coloration was determined instead of fluorescence, and when the coloration could be sufficiently confirmed visually, it was determined that the sensitivity was excellent, and “○”, the coloration was thin and the determination was difficult. If it is judged that the sensitivity is not acceptable, it is judged as being “acceptable”, “△”, and if the coloring is not confirmed, it is judged that the sensitivity is inferior (impossible) and “×”. It was.

  As shown in Table 1, the quantum dot composite of Example 1 is slightly inferior in sensitivity to the quantum dot alone of Comparative Example 1, but the quantum dots are held inside the skeleton, It has been found that the level of structural exposure of harmful substances to the external environment is dramatically reduced. Moreover, since the specific gravity of the quantum dot composite of Example 1 was larger than that of the quantum dot carrier of Comparative Example 1, it was found that it was easy to settle and the handling process was improved.

  Further, it was found that the quantum dot composite of Example 1 can improve the sensitivity as compared with the gold colloid simple substance of Comparative Example 2.

1 quantum dot composite 10 skeleton body 10a outer surface 11 passages 11a hole 12 enlarged diameter portion 20 quantum dots 30 quantum dots D _C average particle diameter D _F average inner diameter D _E inner diameter

Claims (18)

A porous structure composed of a zeolite-type compound;
At least one quantum dot inherent in the skeleton;
With
The skeleton has passages communicating with each other;
The quantum dot composite, wherein the quantum dot is held in at least the passage of the skeleton. 2. The quantum dot composite according to claim 1, wherein the passage has an enlarged diameter portion, and the quantum dots are included in at least the enlarged diameter portion.   3. The quantum dot composite according to claim 2, wherein the enlarged diameter portion communicates a plurality of holes constituting any one of the one-dimensional hole, the two-dimensional hole, and the three-dimensional hole.   4. The quantum dot composite according to claim 2, wherein an average particle diameter of the quantum dots is larger than an average inner diameter of the passage and is equal to or smaller than an inner diameter of the expanded portion.   The quantum dot composite according to any one of claims 1 to 4, wherein an average particle diameter of the quantum dots is 0.1 nm to 50 nm.   The quantum dot composite according to claim 5, wherein an average particle diameter of the metal oxide fine particles is 1 nm to 15.0 nm.   The quantum dot composite according to any one of claims 1 to 6, wherein a ratio of an average particle diameter of the quantum dots to an average inner diameter of the passage is 0.06 to 500.   The quantum dot composite according to claim 7, wherein a ratio of an average particle diameter of the quantum dots to an average inner diameter of the passage is 1.1 to 4.5.   The metal element (M) of the quantum dot is contained in an amount of 0.5 to 2.5% by mass with respect to the quantum dot composite body, according to any one of claims 1 to 8, The quantum dot composite as described. The passage is any one of a one-dimensional hole, a two-dimensional hole, and a three-dimensional hole defined by a skeleton structure of the zeolite-type compound, and any one of the one-dimensional hole, the two-dimensional hole, and the three-dimensional hole. Have different diameter expansion parts,
An average inner diameter of the passage is 0.1 nm to 1.5 nm,
10. The quantum dot composite according to claim 1, wherein an inner diameter of the expanded portion is 0.5 nm to 50 nm.   The quantum dot composite according to claim 1, wherein the zeolite-type compound is a silicate compound.   The quantum dot composite according to claim 1, wherein the quantum dot contains at least one of cadmium (Cd) and arsenic (As). A firing step of firing the precursor material (B) obtained by impregnating the precursor material (A) with a metal-containing solution into a porous structure skeleton body composed of a zeolite-type compound;
A hydrothermal treatment step of hydrothermally treating the precursor material (C) obtained by firing the precursor material (B);
A method for producing a quantum dot composite comprising:   14. The manufacture of a quantum dot composite according to claim 13, wherein a nonionic surfactant is added in an amount of 50 to 500 mass% with respect to the precursor material (A) before the firing step. Method.   Before the firing step, the precursor material (A) is impregnated with the metal-containing solution by adding the metal-containing solution to the precursor material (A) in a plurality of times. The manufacturing method of the quantum dot composite_body | complex of Claim 13 or 14.   When the precursor material (A) is impregnated with the metal-containing solution before the firing step, the amount of the metal-containing solution added to the precursor material (A) is changed to the precursor material (A). 10 to 1000 in terms of the ratio of silicon (Si) constituting the precursor material (A) to the metal element (M) contained in the metal-containing solution added to (atom ratio Si / M) It adjusts so that it may become, The manufacturing method of the quantum dot composite_body | complex of any one of Claims 13-15 characterized by the above-mentioned.   The method for producing a quantum dot composite according to claim 13, wherein the precursor material (C) and a structure directing agent are mixed in the hydrothermal treatment step.   The method for producing a quantum dot composite according to claim 13, wherein the hydrothermal treatment step is performed in a basic atmosphere.

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