WO2020218313A1

WO2020218313A1 - Separator and separation method of stationary phase member and nanostructure

Info

Publication number: WO2020218313A1
Application number: PCT/JP2020/017264
Authority: WO
Inventors: 鳥本　司; 達矢亀山; 奈緒子山口; 竹岡　敬和; 一孝秋吉; 結衣前田; 泰之坪井; 一石原
Original assignee: 国立大学法人東海国立大学機構; 公立大学法人大阪
Priority date: 2019-04-25
Filing date: 2020-04-21
Publication date: 2020-10-29
Also published as: JPWO2020218313A1; JP7431418B2

Abstract

[Problem] To provide a separator and a separation method of a stationary phase member and a nanostructure, which can separate a target nanostructure by reducing the moving speed of the nanostructure, which is a separation target and present in a mobile phase, by irradiation with light, or by fixing, in any region of the stationary phase, the nanostructure in the mobile phase. [Solution] This separator 1000 comprises: a substrate 110; a stationary phase member 100 having a stationary phase on the substrate 110; a developing tank 1200 capable of accommodating the stationary phase member 100; and a light irradiation unit 1100 for irradiating light to the stationary phase member 100. The stationary phase of the stationary phase member 100 has an adsorbent and a plasmon structure-containing layer 130 in which gold nanoparticles P1 are dispersed in the adsorbent. The stationary phase member 100 moves the mobile phase including inorganic nanoparticles N1 and liquid L1 along the stationary phase.

Description

Separation device and method for separating stationary phase members and nanostructures

The technical field of the present specification relates to a separation device for separating nanoparticles and the like, and a method for separating stationary phase members and nanostructures.

Liquid chromatography is a method for separating the target compound from the mixture. In liquid chromatography, an adsorbent such as silica gel is used as a stationary phase, and a mobile phase is passed through the stationary phase. This mobile phase is a liquid containing the compound of interest. The target compound passes through the inside of the stationary phase while repeatedly adsorbing and desorbing to the stationary phase. Here, the degree of adsorption / desorption and the adsorption force of the target compound are different from those of other impurities. Therefore, the target compound can be separated from the mixture.

Various separation devices using liquid chromatography have been developed. For example, Patent Document 1 discloses a technique for gradient elution using two or more types of mobile phase liquids. The value of the internal volume of the mobile phase liquid flow path from the confluence point where multiple mobile phase liquids merge to the sample injection point is stored, and the time from this value until the composition of the mobile phase liquid begins to change at the sample injection point is calculated. A technique for calculating is disclosed (paragraph [0005] of Patent Document 1).

Japanese Unexamined Patent Publication No. 2002-014084

As described above, in ordinary liquid chromatography, the interaction between the adsorbent in the stationary phase and the compound in the mobile phase in the ground state or in the non-photoexcited state is utilized. Then, in the analysis using a mobile phase having the same stationary phase and a constant composition and at a constant temperature, the compound to be separated is separated at a fixed position or eluted with a fixed retention time. Therefore, in ordinary liquid chromatography, it is difficult to keep the target substance to be separated in a region other than the fixed separation position.

The problem to be solved by the technique of the present specification is to reduce the moving speed of the nanostructures which are separation targets existing in the mobile phase by light irradiation, or to reduce the moving speed of the nanostructures in the mobile phase to the stationary phase. The purpose of the present invention is to provide a separation device capable of separating a target nanostructure by keeping it within a certain region, and a method for separating a stationary phase member and the nanostructure.

The separation device in the first aspect includes a stationary phase member having a stationary phase, a developing tank capable of accommodating the stationary phase member and the mobile phase, and a light irradiation unit that irradiates light toward the stationary phase member. The stationary phase has an adsorbent and a plasmon structure-containing layer in which a plasmon structure is arranged on the adsorbent. The stationary phase member can be supplied with a mobile phase containing nanostructures and can move the mobile phase along the stationary phase.

This separation device can excite surface plasmon resonance in the plasmon structure by irradiating it with light. As a result, an attractive force is generated between the plasmon structure and the nanostructure in the mobile phase. Therefore, the separator can capture and separate the nanostructures by slowing them down in the liquid of the mobile phase or by keeping them within a region. Therefore, this separation device can be used as a test device. In addition, this separation device can be used for manufacturing nanostructures.

In the present specification, light irradiation slows down the moving speed of the nanostructures that are separation targets existing in the mobile phase, or keeps the nanostructures in the mobile phase within a region in the stationary phase. Separators capable of separating the nanostructures of interest and methods for separating stationary phase members and nanostructures are provided.

It is a figure which shows the schematic structure of the separation device of 1st Embodiment. It is a figure for demonstrating the structure of the stationary phase member of 1st Embodiment. It is a figure which conceptually shows the inside of the plasmon structure containing layer of 1st Embodiment. It is a figure which shows the flow of the mobile phase in the separation apparatus of 1st Embodiment. It is a figure explaining the conventional thin layer chromatography. It is a conceptual diagram for demonstrating the surface plasmon resonance of the first embodiment. It is a figure which shows the state that the gold nanoparticles of the plasmon structure-containing layer capture the inorganic nanoparticles in a mobile phase in the separation apparatus of 1st Embodiment. It is a diffuse reflection spectrum (vertical axis: Kubelker-Munk function) of the stationary phase member (silica gel particle layer carrying gold nanoparticles) of 1st Embodiment. It is a figure which shows the stationary phase member in the modification of 1st Embodiment. It is a figure for demonstrating the structure of the stationary phase member of the 2nd Embodiment. 9 is a TEM image showing rice-shaped ZAIS nanoparticles. It is a photograph of the stationary phase member after developing ZAIS nanoparticles while irradiating the stationary phase member having the gold nanoparticles-containing layer with light. It is a photograph of the stationary phase member after developing ZAIS nanoparticles without irradiating the stationary phase member having the gold nanoparticles-containing layer with light. It is a photograph of the stationary phase member after developing ZAIS nanoparticles while irradiating the stationary phase member having no gold nanoparticles-containing layer with light. It is a photograph of the stationary phase member after developing ZAIS nanoparticles without irradiating the stationary phase member having no gold nanoparticles-containing layer with light. It is a graph which shows the relationship between the particle diameter and the arrival position (Rf value) of a quantum dot. It is a photograph showing the case where monochromatic light having a wavelength of 610 nm is developed on a stationary phase member by changing the light intensity with respect to ZAIS nanoparticles having a particle diameter of 19 nm. It is a photograph showing the case where monochromatic light having a wavelength of 610 nm is developed on a stationary phase member by changing the light intensity with respect to ZAIS nanoparticles having a particle diameter of 12 nm. It is a graph which shows the relationship between the light intensity of monochromatic light (wavelength 610 nm) which irradiates a gold nanoparticle-containing layer, and the arrival position (Rf value) of ZAIS nanoparticles. It is a micrograph which shows the mixed state of elliptical spherical ZAIS nanoparticles and dumbbell-shaped ZAIS nanoparticles. It is a graph which shows the particle diameter distribution of elliptical spherical ZAIS nanoparticles and dumbbell-shaped ZAIS nanoparticles. (A) Photograph of the stationary phase member after developing ZAIS nanoparticles having a plurality of particle shapes while irradiating the stationary phase member having the gold nanoparticles-containing layer with monochromatic light (wavelength 610 nm), (b) gold nanoparticles. It is a graph of the particle size distribution of ZAIS nanoparticles not captured in the containing layer, and (c) is a graph of the particle size distribution of ZAIS nanoparticles captured in the gold nanoparticles-containing layer by light irradiation. The relationship between the diffuse reflection spectrum of gold nanoparticles (vertical axis: Kubelker-Munk function) and the wavelength distribution of red LED light (610 nm) and near-infrared light (820 nm) of Xe lamp light monochromaticized by a bandpass filter. It is a graph which shows. It is a graph which shows the spectrum of the near-infrared light (wavelength 820 nm) of the red LED light (wavelength 610 nm), and the Xe lamp light monochromatically lit by a bandpass filter. 6 is a graph showing the relationship between the irradiation light intensity and the Rf value when ZAIS nanoparticles having a particle diameter of 19 nm are developed while irradiating the gold nanoparticles-containing layer with monochromatic light having a wavelength of 820 nm. The relationship between the diffuse reflection spectrum (vertical axis: Kubelker-Munk function) of the plasmon structure-containing layer carrying gold nanoparticles at different densities and the particle number density (numerical values in the figure) of the supported gold nanoparticles is shown. It is a graph. It is a graph which shows the relationship between the Rf value and the irradiation light intensity when rice-shaped ZAIS nanoparticles (19 nm) are developed by irradiating LED light with a wavelength of 610 nm, and the dependence of the particle number density of gold nanoparticles. The particle number density of gold nanoparticles in the gold nanoparticles-containing layer, which is a plasmon structure-containing layer, and the minimum irradiation light intensity (wavelength) capable of capturing rice-shaped ZAIS nanoparticles (particle size 19 nm) in the gold nanoparticles-containing layer. It is a graph which shows the relationship with 610 nm). It is an electron micrograph of gold nanoparticles used as a plasmon structure. It is a table summarizing the number of gold atoms contained in the plasmon structure-containing layer and the particle density when gold nanoparticles having different sizes and shapes are supported. Rf value and irradiation light intensity when rice-shaped ZAIS nanoparticles (19 nm) are developed by irradiating LED light having a wavelength of 610 nm using a plasmon structure-containing layer carrying gold nanoparticles of various shapes shown in FIG. It is a graph which shows the relationship with. It is a graph which shows the diffuse reflection spectrum (vertical axis: Kubelka-Munk function) of the plasmon structure-containing layer carrying silver nanoparticles. It is a photograph of a stationary phase supporting plate after developing rice-shaped ZAIS nanoparticles (19 nm) while irradiating a plasmon structure-containing layer carrying silver nanoparticles with blue LED light having a wavelength of 460 nm at various light intensities. FIG. 33 is a graph showing the relationship between the monochromatic light intensity at a wavelength of 460 nm and the Rf value of rice-shaped ZAIS nanoparticles (19 nm) in FIG. 33. A graph showing the relationship between the monochromatic light intensity of irradiating the silver nanoparticles-containing layer, which is a plasmon structure-containing layer, and the minimum irradiation light intensity required for capturing rice-shaped ZAIS nanoparticles (19 nm) in the silver nanoparticles-containing layer. Is. It is a graph which shows the relationship between the particle diameter of a quantum dot, and the Rf value at the time of developing the quantum dot of various particle diameters while irradiating monochromatic light with a wavelength of 460 nm using silver nanoparticles as a plasmon structure. It is a graph which shows the diffuse reflection spectrum (vertical axis: Kubelka-munch) of the stationary phase-supported plate which supported ITO particles. It is a photograph of a stationary phase supporting plate when rice-shaped ZAIS nanoparticles (19 nm) are developed while irradiating a plasmon structure-containing layer carrying ITO particles with monochromatic light having a wavelength of 820 nm. It is a graph which shows the relationship between the irradiation light intensity and the Rf value when rice-shaped ZAIS nanoparticles (19 nm) are developed while irradiating the plasmon structure-containing layer carrying ITO particles with monochromatic light having a wavelength of 820 nm. It is a photograph of a stationary phase-supported plate after developing polystyrene beads as nanostructures while irradiating a gold nanoparticle-containing layer with monochromatic light having a wavelength of 610 nm. It is a graph which shows the relationship between the moving distance (cm) from the origin of polystyrene beads in FIG. 40, and irradiation light intensity.

Hereinafter, a specific embodiment will be described with reference to the drawings, taking as an example a separation device, a stationary phase member, and a method for separating nanostructures. As used herein, the plasmon structure is a material capable of exciting surface plasmon resonance. The plasmon structure is a metal nanoparticle having a surface plasmon resonance peak such as gold (Au) nanoparticles or silver (Ag) nanoparticles, or a metal compound having a surface plasmon resonance peak such as indium tin oxide (ITO) or copper sulfide. It is a nanoparticle. As used herein, nanostructures are nanoparticles or molecules composed of inorganic or organic compounds. In addition, the size of the particles in the present specification shall be measured by observation with an electron microscope such as a scanning electron microscope or a transmission electron microscope. The particle size is the length of the longest line segment that virtually crosses the three-dimensional shape of the particle. However, for the size of octahedral particles, the length of one side of the octahedron is taken as the particle size.

(First Embodiment)
1. 1. Separation device FIG. 1 is a diagram showing a schematic configuration of the separation device 1000 of the first embodiment. As shown in FIG. 1, the separator 1000 separates nanoparticles using the stationary phase member 100. As shown in FIG. 1, the separation device 1000 includes a light irradiation unit 1100 and a development tank 1200.

The light irradiation unit 1100 is for irradiating light toward the stationary phase member 100 arranged inside the developing tank 1200. The light emitted by the light irradiation unit 1100 irradiates the fixed material (plasmon structure) in the stationary phase member 100 with light capable of exciting surface plasmon resonance. The energy required to excite surface plasmon resonance depends on the material and the surface plasmon resonance peak wavelength. The light emitted by the light irradiation unit 1100 may be monochromatic light as long as it can photoexcitate the surface plasmon resonance of the plasmon structure. The light irradiation unit 1100 is, for example, an Xe lamp light source that is monochromaticized through an LED light source or a bandpass filter. Of course, it may be another light source.

The developing tank 1200 can accommodate the stationary phase member 100 and the liquid L1 which is the mobile phase. The developing tank 1200 is preferably made of a transparent material. This is because the light from the light irradiation unit 1100 is transmitted and the stationary phase member 100 is irradiated with the light. The material of the developing tank 1200 is, for example, glass. Of course, other transparent materials may be used. The liquid L1 is a solvent that is a mobile phase. The liquid L1 may contain inorganic nanoparticles as the nanostructure that is the separation target.

2. Fixed phase member (fixed phase supporting plate)
FIG. 2 is a diagram for explaining the structure of the stationary phase member 100 of the first embodiment. The stationary phase member 100 is a member having a stationary phase of a liquid chromatograph. As shown in FIG. 2, the stationary phase member 100 has a base material 110, a carrier layer 120, a plasmon structure-containing layer 130, and a carrier layer 140. The stationary phase member 100 has a structure substantially similar to that of a thin layer plate (plate) of thin layer chromatography, except for the plasmon structure-containing layer 130. Therefore, both the carrier layers 120 and 140 and the plasmon structure-containing layer 130 act as stationary phases in the chromatograph on the base material 110. The stationary phase of the stationary phase member 100 can be supplied with a liquid containing inorganic nanoparticles, which is a separation target described later, and moves the mobile phase along the stationary phase.

The base material 110 is for supporting the carrier layers 120 and 140 and the plasmon structure-containing layer 130. The base material 110 does not absorb the liquid L1 and does not allow the liquid L1 to permeate. The base material 110 is, for example, a glass plate.

The carrier layer 120 is a layer capable of permeating the liquid L1 which is a mobile phase. The carrier layer 120 is a first carrier layer that does not contain a plasmon structure but contains an adsorbent. Examples of the material of the adsorbent include silica gel, alumina, activated carbon, diatomaceous earth, filter paper, cellulose, zeolite, and organic polymer. Alternatively, it may be another material having high adsorptivity. The carrier layer 120 is a solid.

The plasmon structure-containing layer 130 is a layer for capturing the target inorganic nanoparticles in the mixture. The plasmon structure-containing layer 130 is arranged between the carrier layer 120 and the carrier layer 140 at a position sandwiched between them. The plasmon structure-containing layer 130 is a solid. The plasmon structure-containing layer 130 can permeate the liquid L1 which is the mobile phase. The plasmon structure-containing layer 130 contains an adsorbent and a plasmon structure (metal nanoparticles).

In the plasmon structure-containing layer 130, metal nanoparticles are sufficiently discretely fixed and arranged on adsorbent particles such as silica gel. The metal nanoparticles may be separated one by one or may form aggregates to some extent. The metal nanoparticles used here may be any material as long as they exhibit a surface plasmon resonance peak, and are, for example, gold nanoparticles, silver nanoparticles, copper nanoparticles, or alloy nanoparticles containing them.

The metal nanoparticles are plasmon structures capable of exciting the surface plasmon resonance peak by being irradiated with light from the light irradiation unit 1100. The plasmon structure-containing layer 130 contains a plasmon structure.

The carrier layer 140 is a layer capable of permeating the liquid L1 which is a mobile phase. The carrier layer 140 is a second carrier layer that does not contain a plasmon structure but contains an adsorbent. Examples of the material of the adsorbent include silica gel, alumina, activated carbon, diatomaceous earth, filter paper, cellulose, zeolite, and organic polymer. Alternatively, it may be another material having high adsorptivity. The carrier layer 140 is a solid.

The carrier layer 120, the plasmon structure-containing layer 130, and the carrier layer 140 are stationary phases capable of moving the liquid L1 which is the mobile phase into the carrier layer 120. That is, the liquid L1 which is the mobile phase can move inside the carrier layer 120, the plasmon structure-containing layer 130, and the carrier layer 140 along the stationary phase.

FIG. 3 is a diagram conceptually showing the inside of the plasmon structure-containing layer 130. Examples of the plasmon structure include metal nanoparticles P1 having a particle size of 1 nm or more and 500 nm or less. The metal nanoparticles P1 may be discretely arranged on the adsorbent while aggregating in the order of several to several hundreds. Alternatively, the metal nanoparticles P1 may be completely dispersed and uniformly dispersed and fixed on the adsorbent one by one. Metal nanoparticles P1 are sparsely arranged in the adsorbent at a level of several hundred μm or less.

3. 3. Liquid (mobile phase)
The liquid L1 is a mobile phase that moves relative to the stationary phase. The nanostructure to be separated moves in the stationary phase together with the mobile phase while repeating adsorption and desorption to the stationary phase between the mobile phase and the stationary phase. The nanostructure is, for example, inorganic nanoparticles. Therefore, the liquid L1 to be used may have even a slight ability to uniformly disperse or dissolve the inorganic nanoparticles to be separated. The mixture containing the target inorganic nanoparticles does not need to be dispersed in the liquid L1 from the beginning.

FIG. 4 is a diagram showing the flow of the mobile phase in the separation device 1000 of the first embodiment. As shown in FIG. 4, the liquid L1 penetrates into the stationary phase in the direction of arrow J1. The liquid L1 as the mobile phase moves inside the carrier layer 120, the plasmon structure-containing layer 130, and the carrier layer 140, which are the stationary phases, but cannot move inside the base material 110. This is similar to thin layer chromatography.

4. Inorganic nanoparticles (nanostructures)
Inorganic nanoparticles are nanostructures that are targets for the plasmon structure to capture or slow down its movement rate. The size of the inorganic nanoparticles is, for example, 0.5 nm or more and 100 nm or less. Similar to thin layer chromatography, the inorganic nanoparticles may be supported in advance in dots on a small part of the carrier layer 120. In this case, the inorganic nanoparticles are supplied to the mobile phase when the mobile phase (liquid L1) penetrates into the stationary phase in the direction of arrow J1. Alternatively, the liquid L1 in which the inorganic nanoparticles are dispersed may be supplied to the carrier layer 120 of the stationary phase member 100. Here, examples of the inorganic nanoparticles include nanoparticles such as metals, alloys, semiconductors, and metal oxides.

Elements that form inorganic nanoparticles include, for example, Mg, Zn, Cd, Hg, Al, Ga, In, Ti, Zr, Si, Ge, Sn, Pb, Fe, Ru, Co, Rh, Ir, Ni, Pd. , Pt, V, Ta, Nb, Cr, Mo, W, Mn, Re, Cu, Ag, Au, Sb, Bi, S, Se, Te, F, Cl, Br, I. Further, it may be an element other than the above.

5. Thin Layer Chromatography (TLC)
FIG. 5 is a diagram illustrating conventional thin layer chromatography. The separator 1000 of this embodiment is different from thin layer chromatography. However, the separator 1000 has some parts in common with thin layer chromatography. Therefore, thin layer chromatography will be briefly described.

The TLC plate C1 is, for example, supported on the surface of glass with silica gel particles as a stationary phase and having a thickness of several hundred μm. Sample S1 is dropped in dots at the position of the origin (K1) of the TLC plate C1, dried and supported. Then, when the lower part (K1 side) of the TLC plate C1 is immersed in the developing solvent, the developing solvent moves in a direction parallel to the arrow J2 due to the capillary phenomenon. Here, the silica gel of the TLC plate C1 is a stationary phase, and the developing solvent is a mobile phase.

Sample S1 moves in the direction of arrow J2. However, the sample S1 actually rises in the direction of the arrow J2 while repeating adsorption and desorption to the silica gel which is the carrier. Therefore, for example, when the developing solvent reaches the position K1 to the position K3, the sample S1 reaches the position K1 to the position K2. In this way, there is a difference between the arrival position of the developing solvent and the arrival position of the sample S1. There is a difference between the moving distance of the mobile phase itself and the moving distance of the target compound in the mobile phase.

Here, the Rf value can be defined as follows.
Rf = W2 / W1
The distance W1 is the moving distance of the developing solvent. The distance W2 is the moving distance of the sample S1. If the composition, temperature, carrier, and spot amount of the developing solvent are controlled, the Rf value has reproducibility. Therefore, thin layer chromatography can be used for the separation and identification of sample S1.

Using thin layer chromatography in this way, it is also possible to separate the target compound from the mixture sample using a developing solvent. However, when the nanoparticles are used as sample S1 and separation and identification are attempted by this method, the arrival position K2 at which the target nanoparticles stop is not always sufficiently separated from the arrival position of the contaminants. .. Also, the nanoparticles to be separated do not always have color.

6. Principle of Separation of Particles In the first embodiment, a mixture of inorganic nanoparticles containing an object is developed by a liquid L1 and the surface plasmon resonance of the metal nanoparticles of the plasmon structure-containing layer 130 is photoexcited. As a result, the target inorganic nanoparticles are selectively captured by utilizing the force that selectively acts on the inorganic nanoparticles. Alternatively, the moving speed of the target inorganic nanoparticles is selectively reduced. As a result, the desired nanoparticles are separated from the contaminants present in the mixture used as the sample.

6-1. Surface plasmon resonance FIG. 6 is a conceptual diagram for explaining the local surface plasmon resonance of the first embodiment. The horizontal axis of FIG. 6 represents the traveling direction of the light wave. The vertical axis of FIG. 6 represents the electric field intensity of light. In FIG. 6, metal nanoparticles exhibiting surface plasmon resonance, for example, gold nanoparticles P1a, P1b, P1c are drawn. The gold nanoparticles P1a, P1b, and P1c may be regarded as three particles at different positions. Further, the gold nanoparticles P1a, P1b, and P1c may be considered to indicate the appearance of one gold nanoparticle P1 at different times.

Light propagates while forming a vibrating electric and magnetic fields. An object that is large enough to be perceived by the naked eye is sufficiently large compared to the wavelength of light. Therefore, the influence of the electric field of light rarely appears as a phenomenon. However, nanoparticles with a size smaller than the wavelength of light are affected by the local electric field formed by light.

The gold nanoparticles P1a are receiving an upward electric field formed by light. Therefore, the electrons of the gold nanoparticles P1a gather at the lower side in the figure. The gold nanoparticles P1b are subjected to a downward electric field formed by light. Therefore, the electrons of the gold nanoparticles P1b are concentrated on the upper side in the figure. The gold nanoparticles P1c are subject to an upward electric field formed by light. Therefore, the electrons of the gold nanoparticles P1c are collected at the lower side in the figure.

Therefore, the electrons of the gold nanoparticles P1 vibrate in response to the electric field of light. That is, a collective vibration phenomenon of electrons occurs. In this way, surface plasmon resonance is photoexcited. As will be described later, this surface plasmon resonance forms a strong local electric field in the vicinity of the metal nanoparticles, and the local electric field plays an important role in capturing the nanoparticles.

6-2. Force acting on the inorganic nanoparticles in the mobile phase A local electric field is generated around the plasmon-excited gold nanoparticles P1 as described above according to the electric field intensity of light. The gold nanoparticles P1 are fixed in the stationary phase. Then, the nanoparticles in the mobile phase move in the electric field of light and the electric field formed by the gold nanoparticles P1 in the stationary phase. However, the electric field of light felt by the target inorganic nanoparticles is very weak, and the electric field felt by the nanoparticles in the mobile phase may be approximated by the localized electric field formed by the stronger gold nanoparticles P1.

Therefore, the nanoparticles in the mobile phase receive the attractive force F represented by the following equation.
F = (1/2) ・ α ・ ∇E ²
F: Attractive force acting on nanoparticles in mobile phase α: Polarizability of nanoparticles in mobile phase E: Local electric field formed by gold nanoparticles

FIG. 7 is a diagram showing how the gold nanoparticles P1 of the plasmon structure-containing layer 130 capture the inorganic nanoparticles N1 in the mobile phase in the separation device 1000 of the first embodiment. In this way, while the light irradiation unit 1100 continues to irradiate the stationary phase member 100 with light, the photoexcited gold nanoparticles P1 continue to form a local electric field E. The inorganic nanoparticles N1 in the mobile phase are decelerated by the attractive force of the local electric field E. When the local electric field E is strong, the inorganic nanoparticles N1 in the mobile phase are captured by the gold nanoparticles P1. That is, while the light irradiation unit 1100 continues to irradiate the stationary phase member 100 with light, the gold nanoparticles P1 in the stationary phase selectively reduce the moving speed of the inorganic nanoparticles N1 in the mobile phase. Or continue to capture the inorganic nanoparticles N1 completely.

The inorganic nanoparticles N1 have different sizes. Each inorganic nanoparticle N1 having a different size has a different polarizability. That is, different forces act on the inorganic nanoparticles N1 having different particle diameters.

As described above, the plasmon structure (metal nanoparticles) of the plasmon structure-containing layer 130 exerts an attractive force on the inorganic nanoparticles N1 in the mobile phase by exciting the surface plasmon. Therefore, the plasmon structure-containing layer 130 captures the inorganic nanoparticles N1 in the mobile phase during the period of being irradiated with light, or slows down the moving speed of the inorganic nanoparticles N1 in the mobile phase.

6-3. The larger the output of the light emitted by the light irradiation unit 1100 of the wavelength separator 1000 of the light irradiation unit, the larger the electric field formed tends to be. In addition, there is a suitable wavelength region of light for plasmon-exciting the plasmon structure (gold nanoparticles P1).

FIG. 8 is a diffuse reflection spectrum of the stationary phase member 100 of the first embodiment in which gold nanoparticles P1 are used as the plasmon structure and silica gel particles are used as the stationary phase. The horizontal axis of FIG. 8 is the wavelength of light. The vertical axis of FIG. 8 is the Kubelker-Munch function. Here, the plasmon structure-containing layer 130 of the stationary phase member 100 has gold nanoparticles (particle diameter: 12 nm). As shown in FIG. 8, a broad surface plasmon resonance peak is observed in a wavelength region of 500 nm or more with respect to the stationary phase member 100 having the plasmon structure-containing layer 130. In particular, the Kubelker-Munch function is large in the wavelength region of 600 nm or more and 900 nm or less. That is, it shows that the light absorption and scattering of the stationary phase member 100 is large in this wavelength region.

Therefore, for the gold nanoparticles, the light emitted by the light irradiation unit 1100 is preferably light in this wavelength region. When the light irradiation unit 1100 irradiates the stationary phase member 100 with light in this wavelength region, the energy of the irradiated light is used for surface plasmon excitation of the plasmon structure-containing layer 130 of the stationary phase member 100.

In the first embodiment, the light irradiation unit 1100 irradiates, for example, red light having a wavelength of 610 nm toward the stationary phase member 100. Therefore, in the plasmon structure-containing layer 130, the gold nanoparticles P1 cause relatively strong plasmon excitation.

7. Separation method of nanoparticles in mobile phase 7-1. Development tank accommodating step First, in the lower part of the stationary phase member 100, a sample solution containing the target inorganic nanoparticles is applied in the same manner as in the case of the thin layer plate (plate) of thin layer chromatography (position of K1 in FIG. 5). A small amount is dropped, dried and supported. At this time, the fixed position of the sample is the region of the carrier layer 120 outside the plasmon structure-containing layer 130. The stationary phase member 100 is housed inside the developing tank 1200. As a result, the stationary phase having the plasmon structure-containing layer 130 is housed inside the developing tank 1200. Further, the liquid L1 is housed inside the developing tank 1200. At this time, the amount of the liquid L1 is adjusted so that the position of the sample supported on the stationary phase member 100 is higher than the liquid level of the liquid L1.

7-2. Light irradiation step As soon as the stationary phase member 100 and the liquid L1 (mobile phase) are housed inside the developing tank 1200, the mobile phase begins to rise along the stationary phase due to the capillary phenomenon. Immediately after this, the light irradiation unit 1100 irradiates the stationary phase member 100 of the developing tank 1200 with light. The light irradiation unit 1100 may particularly preferably irradiate the plasmon structure-containing layer 130 with light.

By irradiating the stationary phase member 100 with light in this way, surface plasmons are excited to the gold nanoparticles P1 in the plasmon structure-containing layer 130. The mobile phase of the liquid L1 moves from the carrier layer 120 of the stationary phase member 100 toward the plasmon structure-containing layer 130. In the plasmon structure-containing layer 130, gold nanoparticles P1 are discretely arranged, and a localized electric field is generated by exciting the surface plasmon resonance thereof. The target inorganic nanoparticles N1 ascend the stationary phase member 100 while repeating adsorption and desorption with the stationary phase together with the liquid L1 which is the mobile phase. At this time, when the mobile phase passes through the location of the gold nanoparticles P1, the localized electric field generated by the surface plasmon generated in the vicinity of the gold nanoparticles P1 causes the gold nanoparticles P1 which is a plasmon structure and the inorganic nanoparticles in the mobile phase. An attractive force acts with the particles N1 to reduce the moving speed of the inorganic nanoparticles N1 in the mobile phase. Alternatively, the inorganic nanoparticles N1 in the mobile phase are completely captured in the vicinity of the gold nanoparticles P1.

Then, the mobile phase of the liquid L1 reaches the carrier layer 140 above the plasmon structure-containing layer 130. On the other hand, however, during the period in which the light irradiation unit 1100 irradiates the stationary phase member 100 with light, an attractive force is applied between the gold nanoparticles P1 of the plasmon structure-containing layer 130 and the inorganic nanoparticles N1 in the mobile phase. Will continue to work. Therefore, the moving speed of the inorganic nanoparticles N1 in the plasmon structure-containing layer 130 slows down, or the inorganic nanoparticles N1 are completely captured in the vicinity of the gold nanoparticles P1 which is the plasmon structure and are contained in the sample. Separated from existing contaminants.

In this way, inside the carrier layers 120 and 140, the mobile phase and the inorganic nanoparticles N1 move at a normal moving speed. As described above, the moving speed of the inorganic nanoparticles N1 is slower than the moving speed of the mobile phase. On the other hand, inside the plasmon structure-containing layer 130 under light irradiation, the mobile phase moves at a normal moving speed, and the inorganic nanoparticles N1 are further decelerated or captured.

7-3. Other Steps After that, the stationary phase member 100 is dried so that the desired nanoparticles do not move, and the mobile phase is removed. Then, the plasmon structure-containing layer 130 can be peeled off from the base material 110, and the target inorganic nanoparticles N1 can be extracted with a solvent. When the plasmon structure-containing layer 130 is peeled off, it is not necessary to irradiate with light because there is no mobile phase. The target inorganic nanoparticles N1 are separated in this way. For example, the inorganic nanoparticles N1 thus collected may be sent for inspection.

As described above, the technique of the first embodiment can be said to be a kind of liquid chromatograph in which a liquid is used as the mobile phase and a solid is used as the stationary phase. Further, in the first embodiment, a stationary phase containing a plasmon structure capable of photoexciting surface plasmon resonance is used, and a liquid containing the nanostructure is used as the mobile phase. By irradiating the plasmon structure-containing layer 130 with light, surface plasmon resonance is excited in the plasmon structure, and the plasmon structure (gold nanoparticles P1) in the stationary phase and the nanostructure (inorganic nanoparticles) in the mobile phase are excited. An attractive force is generated between the N1) and the particle. This causes the plasmon structure to capture the nanostructure or slows down the movement speed of the nanostructure in the mobile phase.

8. The effect separation device 1000 of the first embodiment can separate the target inorganic nanoparticles N1 from the mixture. In doing so, it does not require a high-power laser like optical tweezers technology. Further, during the period in which the plasmon structure-containing layer 130 is irradiated with light, the plasmon structure-containing layer 130 slows down the movement speed of the mobile phase inorganic nanoparticles N1 in the liquid L1, or the inorganic nanoparticles N1 Maintain the state of capturing.

Therefore, this separation device 1000 can be used as an inspection device for separating nanoparticles. Further, the separation device 1000 can also be used as a manufacturing device for separating and mass-producing nanoparticles.

9. Modification 9-1. Multiple layers of plasmon structure-containing layers FIG. 9 is a diagram showing a stationary phase member 200 in a modified example of the first embodiment. The stationary phase member 200 has a base material 110, a supporting layer 120, a first plasmon structure-containing layer 230, a supporting layer 140, a second plasmon structure-containing layer 250, and a supporting layer 160. The first plasmon structure-containing layer 230 and the second plasmon structure-containing layer 250 have plasmon structures exhibiting different plasmon wavelengths. For example, one contains gold nanoparticles and the other contains silver nanoparticles. Therefore, the first plasmon structure-containing layer 230 can capture the first inorganic nanoparticles in the mixture, and the second plasmon structure-containing layer 250 can capture the second inorganic nanoparticles in the mixture. As described above, the stationary phase member may include a plurality of plasmon structure-containing layers.

9-2. Manufacturing process The separated inorganic nanoparticles N1 can be used for inspection. However, the separated inorganic nanoparticles N1 may be sent to the subsequent processing step. As a result, a material using the inorganic nanoparticles N1 as a raw material is produced.

9-3. Wavelength of light The wavelength of light emitted by the light irradiation unit 1100 is as long as it can photoexcitate the surface plasmon resonance of the plasmon structure of the plasmon structure-containing layer 130, and is about the visible light wavelength or the near infrared wavelength. The wavelength of light is, for example, about 400 nm or more and 1000 nm or less. However, wavelengths shorter or longer than this wavelength region may be used.

9-4. Timing of Irradiating Light The light irradiation unit 1100 may irradiate the development tank 1200 with light even before the stationary phase member 100 is arranged inside the development tank 1200.

9-5. Immersion in solvent The stationary phase member 100 may be immersed in a solvent in advance. This is because the mobile phase containing the inorganic nanoparticles N1 may easily rise to a position higher than the stationary phase member 100. Examples of the solvent include chloroform, toluene and oleylamine. Of course, a solvent other than the above may be used.

9-6. The base material stationary phase member 100 has a base material 110. The base material 110 may be omitted as long as the carrier layer 120, the plasmon structure-containing layer 130, and the carrier layer 140 can stand on their own and the characteristics of the stationary phase of the stationary phase member 100 are satisfied.

9-7. Combination The above modified examples may be freely combined.

(Second Embodiment)
A second embodiment will be described. The stationary phase member of the second embodiment is different from the stationary phase member of the first embodiment. Therefore, the stationary phase member will be described.

1. 1. Fixed phase member FIG. 10 is a diagram for explaining the structure of the fixed phase member 300 of the second embodiment. The stationary phase member 300 has a base material 110, a carrier layer 120, a plasmon structure-containing layer 330, and a carrier layer 140. The stationary phase member 300 has an adsorbent and a plasmon structure-containing layer 330 in which a plasmon structure is arranged on the adsorbent. The stationary phase member 300 can be supplied with a mobile phase containing nanostructures and can move the mobile phase along the stationary phase.

As the plasmon structure fixed to the stationary phase, metal compound nanoparticles capable of exciting surface plasmon resonance can be used. The metal compound nanoparticles have a size capable of exciting surface plasmon resonance and a surface plasmon resonance peak. Examples of the size capable of exciting surface plasmon resonance include particles having a particle size of 1 nm or more and 500 nm or less.

Examples of the material of the plasmon structure include metal compounds such as metal oxides and conductive metal composite oxides. Examples of the metal oxide include molybdenum oxide, rhenium oxide, tungsten oxide and the like. Examples of other metal compounds include copper sulfide and silver sulfide. Examples of the conductive metal composite oxide include ITO (Indium Tin Oxide), IZO (Indium Zinc Oxide), and IGZO (Indium Gallium Zinc Oxide).

2. Effect of the second embodiment The plasmon structure-containing layer of the stationary phase member 300 excites surface plasmon resonance during a period in which the light irradiation unit 1100 irradiates the stationary phase member with light. As a result, the plasmon structure captures the inorganic nanoparticles N1 or slows down the moving speed of the inorganic nanoparticles N1 in the mobile phase.

(Third Embodiment)
A third embodiment will be described. The nanostructures of the third embodiment are different from the nanostructures of the first embodiment. Therefore, the nanostructure to be separated will be described.

1. 1. Nanostructures The mobile phase liquid L1 may or may not contain nanostructures. The nanostructure refers to a structure having a size of 0.5 nm or more and 100 nm or less.

Examples of nanostructures include organic compounds. Examples of organic compounds include organic polymers such as polyethylene and polystyrene, macromolecular molecules such as dendrimers and π-conjugated molecules, and biomolecules such as DNA, proteins, peptides, antigens, antibodies, exosomes, viruses, and cells. And bio-related substances. Further, the organic compound may be a nano-sized aggregate of organic molecules such as micelles and vesicles. These are examples, and other compounds may be used.

3. 3. Effect of the Third Embodiment The plasmon structure-containing layer of the stationary phase excites surface plasmon resonance during the period in which the light irradiation unit 1100 irradiates the stationary phase member with light. As a result, the plasmon structure captures the nanostructure or slows down the movement speed of the nanostructure in the mobile phase.

(Combination of embodiments)
The first embodiment and its modifications, the second embodiment, and the third embodiment may be freely combined.

(Experiment)
A. Gold nanoparticles (plasmon structure)
1. 1. Experimental method 1-1. Fixed phase member (fixed phase supporting plate)
Two types of stationary phase supporting plates were prepared. The first type of stationary phase-supporting plate is a normal TLC plate on which a plasmon structure-containing layer is formed. Here, the plasmon structure is gold nanoparticles. This first type of stationary phase supporting plate corresponds to the stationary phase member 100 of the first embodiment. The second type of stationary phase supporting plate is a conventional TLC plate.

An octadecyl group-modified reverse phase silica gel TLC plate (Uniplatate P50013 manufactured by Analtech) was used in which silica gel particles were applied and fixed on a glass plate and the surface thereof was chemically treated. Hydrophilic gold nanoparticles (particle size: 12 nm) whose surface is modified with citric acid are applied to the region located in a band shape in a direction orthogonal to the flow direction of the mobile phase (arrow J1), dried, and contained in a plasmon structure. A layer was formed. These particles do not disperse in an organic solvent such as chloroform. The region for fixing the gold nanoparticles is a region in which the Rf value becomes 0.20 to 0.375 after the development by the mobile phase is finally completed.

1-2. Rice-shaped ZAIS nanoparticles (quantum dots)
Rice-shaped ZAIS nanoparticles were prepared using the method of the literature (ACS Appl. Mater. Interfaces 8 (2016) 27151-27161). Here, ZAIS indicates a solid solution semiconductor between ZnS and AgInS _2, and its composition is represented by (AgIn) _x Zn _{2 (1-x)} S ₂ .

Silver acetate, indium acetate, and zinc acetate are used as metal sources, and their respective ratios are Ag (OAc): In (OAc) ₃ : Zn (OAc) ₂ = x: x: 2 (1-x). did. Rice-shaped ZAIS nanoparticles were obtained by thermally decomposing these mixtures together with a sulfur compound in oleylamine at 150 ° C. to 250 ° C.

By setting the charging ratio x to 0.50 and 0.90, ZAIS nanoparticles having an average particle diameter of 19 nm and 12 nm were obtained, respectively. Here, the particle diameter is the longest length of a particle. Observation was performed with a transmission electron microscope (TEM) to measure the particle size.

FIG. 11 is a TEM image showing rice-shaped ZAIS nanoparticles (average particle diameter 19 nm) obtained by the above method.

The particle size of the ZAIS nanoparticles can be changed by changing the manufacturing conditions.

1-3. Light irradiation unit A red LED light source was used as the light irradiation unit. The red LED light source can irradiate monochromatic light having a peak wavelength of 610 nm.

1-4. Procedure A chloroform solution containing ZAIS nanoparticles was added dropwise to the central position of the region of the carrier layer 120 of the stationary phase member (stationary phase supporting plate). Then, the sample solution was dried, and ZAIS nanoparticles were supported on the stationary phase of the stationary phase supporting plate in dots as target inorganic nanoparticles for light capture.

A stationary phase-supported plate carrying ZAIS nanoparticles was placed in a developing tank. Next, a developing solvent (a mixed solution of oleylamine and chloroform) was placed in the developing tank, and the stationary phase-supported plate was irradiated with monochromatic light having a wavelength of 610 nm. Then, the situation after that was observed.

2. Experimental results 2-1. Presence or absence of plasmon structure-containing layer FIG. 12 is a photograph of a stationary phase member having a gold nanoparticle-containing layer after supplying a mobile phase while irradiating a monochromatic light having a wavelength of 610 nm. As shown by the arrow at the bottom center of FIG. 12, the inorganic nanoparticles (quantum dots: QD) are trapped in the region of the gold nanoparticle-containing layer.

FIG. 13 is a photograph of the stationary phase member having the gold nanoparticle-containing layer after supplying the mobile phase without irradiating the stationary phase member with light. As shown by the arrow near the upper part of FIG. 13, the ZAIS nanoparticles (quantum dots) are located above the region of the gold nanoparticles-containing layer.

FIG. 14 is a photograph of the stationary phase member after supplying the mobile phase while irradiating the stationary phase member having no gold nanoparticle-containing layer with monochromatic light having a wavelength of 610 nm. The light irradiation was performed at the same position as the stationary phase member having the gold nanoparticle-containing layer of FIG. As shown in FIG. 14, ZAIS nanoparticles (quantum dots) are present near the arrow at the top of the stationary phase member. This position was almost the same as the position of the ZAIS nanoparticles in FIG.

FIG. 15 is a photograph of the stationary phase member after supplying the mobile phase without irradiating the stationary phase member having no gold nanoparticle-containing layer with light. As shown in FIG. 15, ZAIS nanoparticles (quantum dots) are present near the arrow at the top of the stationary phase member. This position was approximately the same as the position of the ZAIS nanoparticles in FIGS. 13 and 14.

Table 1 is a table summarizing the above results. As shown in Table 1, only when the stationary phase member 100 of the first embodiment is irradiated with light, the stationary phase member 100 contains ZAIS nanoparticles (quantum dots) in a gold nanoparticle-containing layer (plasmon structure-containing layer). Can be captured in.

[Table 1]
Sample Gold nanoparticle-containing layer Light capture sample 1 Yes Yes Yes ○
Sample 2 Yes No ×
Sample 3 None Yes Yes ×
Sample 4 None None ×

2-2. Particle size dependence of quantum dots as separation targets Rice-shaped ZAIS nanoparticles with particle sizes of 7.7 nm, 12 nm, and 19 nm are based on the method of the literature (ACS Appl. Mater. Interfaces 8 (2016) 27151-27161). It was prepared by changing the reaction conditions. Spherical AgInGaS nanoparticles having particle diameters of 3.0 nm, 4.5 nm, and 6.0 nm were prepared by improving the method of the literature (ACS Appl. Mater. Interfaces 10 (2018) 42844-42855). These particles were used as quantum dots.

FIG. 16 is a graph showing the relationship between the particle size and the arrival position of the quantum dots. The horizontal axis of FIG. 16 is the particle diameter of the quantum dots. The vertical axis of FIG. 16 is the Rf value of the arrival position of the quantum dot in the stationary phase member. The region of the gold nanoparticle-containing layer is a region in which the Rf value becomes 0.20 to 0.375 after the development of the mobile phase. The gold nanoparticle-containing layer region was irradiated with LED light having a wavelength of 610 nm at an output of 0.89 W / cm ² , and quantum dots were developed by the mobile phase.

As shown in FIG. 16, even if light irradiation is performed, inorganic nanoparticles having a particle diameter of about 8 nm or less pass through the region of the gold nanoparticles-containing layer. On the other hand, by light irradiation, inorganic nanoparticles having a particle size larger than about 8 nm are captured by the gold nanoparticle-containing layer. As described above, the separation device 1000 tends to capture inorganic nanoparticles having a larger particle size.

2-3. Light intensity dependence FIG. 17 shows a stationary phase member after light irradiation is performed on a stationary phase member of a gold nanoparticles-containing layer by changing the irradiation light intensity when developing rice-shaped ZAIS nanoparticles having a particle diameter of 19 nm by a mobile phase. It is a photograph of. As shown in FIG. 17, when the particle size is 19 nm, when the stationary phase member is irradiated with LED light having a wavelength of 610 nm at an output of 0.63 W / cm ² or more, the gold nanoparticles-containing layer captures the inorganic nanoparticles. We were able to.

FIG. 18 is a photograph of the stationary phase member after light irradiation is performed on the stationary phase member of the gold nanoparticles-containing layer by changing the light intensity when developing rice-shaped ZAIS nanoparticles having a particle diameter of 12 nm by the mobile phase. As shown in FIG. 18, when the particle size is 12 nm, when the stationary phase member is irradiated with LED light having a wavelength of 610 nm at an output of 0.76 W / cm ² or more, the gold nanoparticle-containing layer captures inorganic nanoparticles. We were able to.

FIG. 19 is a graph showing the relationship between the intensity of monochromatic light having a wavelength of 610 nm irradiating the gold nanoparticles-containing layer and the arrival position of the rice-shaped ZAIS nanoparticles. The horizontal axis of FIG. 19 is the intensity of monochromatic light irradiating the gold nanoparticle-containing layer. The vertical axis of FIG. 19 is the Rf value of the arrival position of the inorganic nanoparticles in the stationary phase member. FIG. 19 is a graph summarizing the results of FIGS. 17 and 18.

As shown in FIG. 19, if the light intensity is increased regardless of the particle size, the gold nanoparticles-containing layer can suitably capture the inorganic nanoparticles. Further, even when the light intensity is not sufficient for capturing the inorganic nanoparticles, the Rf value at the arrival position of the nanoparticles is smaller than that when no light is irradiated. This indicates that the movement speed of the inorganic nanoparticles in the mobile phase can be reduced by irradiating the gold nanoparticles-containing layer with light.

2-4. Separation of Quantum Dot Mixtures with Different Particle Diameters FIG. 20 is a transmission electron micrograph of a quantum dot mixture composed of elliptical spherical ZAIS nanoparticles and dumbbell-shaped ZAIS nanoparticles. Dumbbell-shaped ZAIS nanoparticles were prepared using the method of the literature (J. Phys. Chem. C. 122, 25, (2018) 13705-13715). Elliptical spherical ZAIS nanoparticles are present in the circles on the left side of FIG. 20. Dumbbell-shaped ZAIS nanoparticles are present in the circles on the right side of FIG. 20.

FIG. 21 is a particle size distribution showing the particle size and the ratio of the elliptical spherical ZAIS nanoparticles and the dumbbell-shaped ZAIS nanoparticles contained in the quantum dot mixture. The horizontal axis of FIG. 21 is the particle size of the ZAIS nanoparticles. The vertical axis of FIG. 21 is the frequency of appearance of ZAIS nanoparticles having that particle size.

FIG. 22A is a photograph of the stationary phase member after developing the quantum dot mixture in the mobile phase while irradiating the quantum dot mixture with LED light having a wavelength of 610 nm (light intensity: 0.63 W / cm ² ). It can be seen that the quantum dots captured by the gold nanoparticle-containing layer, which is the plasmon structure-containing layer, and the quantum dots expanded above it were separated.

FIG. 22B is a graph showing the particle size distribution of ZAIS nanoparticles at a position above the gold nanoparticle-containing layer. FIG. 22C is a graph showing the particle size distribution of ZAIS nanoparticles at the position of the gold nanoparticles-containing layer.

As shown in FIGS. 22 (b) and 22 (c), the gold nanoparticle-containing layer selectively captures ZAIS nanoparticles having a particle size larger than about 8 nm, and captures smaller ZAIS nanoparticles having a particle size of 8 nm or less. There wasn't. In this way, the separation device can separate nanoparticles having different particle diameters according to the particle diameter.

2-5. Effect of wavelength of irradiation light FIG. 23 shows the diffuse reflection spectrum (vertical axis: Kubelker-Munk function), red LED light (wavelength: 610 nm), and Xe lamp light of the gold nanoparticles-containing layer, which is the plasmon structure-containing layer. It is a graph which shows the relationship with the wavelength region of the near infrared light (wavelength: 820 nm) which became monochromatic by passing through a pass filter. The horizontal axis of FIG. 23 is the wavelength. Both the wavelength region of red light with a wavelength of 610 nm and the wavelength region of near-infrared light with a wavelength of 820 nm overlap the broad surface plasmon resonance peak of the gold nanoparticles. Therefore, surface plasmon resonance can be effectively photoexcited.

FIG. 24 is a graph showing the spectra of near-infrared light (wavelength: 820 nm) converted into monochromatic light by passing red LED light (wavelength: 610 nm) and Xe lamp light through a bandpass filter. The horizontal axis of FIG. 24 is the wavelength of light. The vertical axis of FIG. 24 is the intensity of light. The vertical axis is standardized by the value of the maximum peak intensity of each optical spectrum.

When the rice-shaped ZAIS nanoparticles having a particle diameter of 19 nm were developed by the mobile phase, the stationary phase member of the gold nanoparticles-containing layer was irradiated with light by changing the irradiation light wavelength.

FIG. 25 is a graph showing the relationship between the light intensity and the Rf value when monochromatic light having a wavelength of 820 nm having the spectrum of FIG. 24 is irradiated. The horizontal axis of FIG. 25 is the intensity of light. The vertical axis of FIG. 25 is the Rf value. Compared with the case where rice-shaped ZAIS nanoparticles having a particle diameter of 19 nm were developed while irradiating monochromatic light having a wavelength of 610 nm (FIG. 19), the light intensity of the Rf value was also when irradiated with light having a wavelength of 820 nm (FIG. 25). There was no significant difference in dependence.

In the diffuse reflection spectrum (FIG. 23) of the gold nanoparticle-containing layer, which is the plasmon structure-containing layer, the values of the Kubelker-Munk function at the wavelength of 610 nm and the wavelength of 820 nm are almost the same. Therefore, when the stationary phase member is irradiated with light at the same light intensity, the excitation efficiencies of surface plasmon resonance at wavelengths of 610 nm and 820 nm are almost the same. Therefore, there is almost no difference in the Rf value.

2-6. Effect of Particle Number Density of Supported Gold Nanoparticles A plasmon structure-containing layer was prepared by changing the particle number density of gold nanoparticles.

FIG. 26 is a graph showing the relationship between the diffuse reflection spectrum of the gold nanoparticle-containing layer and the particle number density of the gold nanoparticles. The horizontal axis of FIG. 26 is the wavelength of light. The vertical axis of FIG. 26 is the value of the Kubelker-Munch function. As shown in FIG. 26, the higher the particle number density of the gold nanoparticles as the plasmon structure, the larger the value of the Kubelker-Munk function.

Using a stationary phase member having a gold nanoparticle-containing layer as the plasmon structure-containing layer of FIG. 26, rice-shaped ZAIS nanoparticles having a particle diameter of 19 nm are developed by a mobile phase, and at that time, the irradiation light intensity is changed to change the wavelength. The LED light of 610 nm was irradiated.

FIG. 27 is a graph showing the relationship between the light intensity and the Rf value of the ZAIS nanoparticles and the dependence of the particle number density of the gold nanoparticles. The horizontal axis of FIG. 27 is the intensity of light. The vertical axis of FIG. 27 is the Rf value. The number in FIG. 27 is the particle number density of the supported gold nanoparticles. As shown in FIG. 27, the higher the particle number density of the gold nanoparticles as the plasmon structure, the weaker the irradiation light intensity can capture the ZAIS nanoparticles.

FIG. 28 shows the particle number density of gold nanoparticles in the plasmon structure-containing layer and the minimum irradiation light intensity (Imin) (irradiation) capable of capturing rice-shaped ZAIS nanoparticles (particle size 19 nm) in the gold nanoparticles-containing layer. It is a graph which shows the relationship with the light wavelength (610 nm). The horizontal axis of FIG. 28 is the particle number density of gold nanoparticles. The vertical axis of FIG. 28 is the intensity of the irradiation light. As shown in FIG. 28, the higher the particle number density of the gold nanoparticles, the weaker the intensity of light, the more ZAIS nanoparticles having a particle size of 19 nm can be captured.

2-7. Shape Dependency of Gold Nanoparticles Used as Plasmon Structure FIG. 29 is an electron micrograph of gold nanoparticles used as a plasmon structure. As shown in FIG. 29, spherical gold nanoparticles having a particle size of 12 nm, octahedral gold nanoparticles having a particle size of 75 nm, and spherical gold nanoparticles having a particle size of 82 nm are formed into a plasmon structure. Using. The octahedral particle size is the length of one side of the octahedron.

The gold nanoparticles of FIG. 29 were used for the plasmon structure-containing layer.

FIG. 30 is a table summarizing the number of gold atoms in the gold nanoparticle-containing layer and the particle density of the gold nanoparticles.

FIG. 31 shows the Rf value when rice-shaped ZAIS nanoparticles (particle size 19 nm) irradiated with LED light having a wavelength of 610 nm using the gold nanoparticles-containing layers of various shapes of FIG. 30 as the plasmon structure-containing layer. It is a graph which shows the relationship between and the irradiation light intensity. The horizontal axis of FIG. 31 is the intensity of light. The vertical axis of FIG. 31 is the Rf value.

As shown in FIG. 31, there was no significant difference in light intensity dependence between the octahedral gold nanoparticles having a particle diameter of 75 nm and the spherical gold nanoparticles having a particle diameter of 82 nm. Regardless of which particle was used, the ZAIS nanoparticles were captured by the gold nanoparticle-containing layer at a light intensity of about 1 W / cm ² or more. On the other hand, when spherical gold nanoparticles having a smaller particle diameter of 12 nm were used, the ZAIS nanoparticles were not captured by the gold nanoparticles-containing layer at any light intensity. It is suggested that the size of the plasmon structure is greatly related to the success or failure of the capture of ZAIS nanoparticles.

B. Silver nanoparticles (plasmon structure)
1. 1. Experimental method 1-1. Preparation of Silver Nanoparticles 4.8 mL of an aqueous solution containing 2 mM NaBH ₄ and 2 mM trisodium citrate was prepared. After holding this aqueous solution at 60 ° C. for 30 minutes, 0.2 mL of a 1.17 mM AgNO ₃ aqueous solution was added. The temperature of this mixed solution was raised to 90 ° C., a 0.01 M aqueous NaOH solution was added, and the mixture was heated for 20 minutes. The pH of the aqueous NaOH solution was 10.5. In this way, silver nanoparticles having a particle size of 10 nm were obtained.

Then, silver nanoparticles were applied to the above-mentioned octadecyl group-modified reversed-phase silica gel TLC plate and dried.

2. Experimental results 2-1. Light intensity dependence FIG. 32 is a graph showing a diffuse reflection spectrum of a plasmon structure-containing layer using silver nanoparticles. The horizontal axis of FIG. 32 is the wavelength of light. The vertical axis of FIG. 32 is the value of the Kubelker-Munch function. Surface plasmon resonance peaks were observed between about 400 nm and 600 nm. In order to photoexcit the surface plasmon resonance peak, a blue LED capable of irradiating monochromatic light having a peak wavelength of 460 nm was used as the light irradiation unit.

FIG. 33 is a photograph of a stationary phase member after developing rice-shaped ZAIS nanoparticles (19 nm) while using silver nanoparticles as a plasmon structure and irradiating the portion with blue LED light having a wavelength of 460 nm at various light intensities. Is. As shown in FIG. 33, as the light intensity is increased, the moving distance of the ZAIS nanoparticles becomes smaller, and the ZAIS nanoparticles can be effectively captured.

FIG. 34 is a graph showing the relationship between the irradiation light intensity in FIG. 33 and the Rf value of the rice-shaped ZAIS nanoparticles. The horizontal axis of FIG. 34 is the intensity of blue LED light having a wavelength of 460 nm. The vertical axis of FIG. 34 is the Rf value. As shown in FIG. 34, when the light intensity is 0.30 W / cm ² or more, the silver nanoparticle-containing layer, which is a plasmon structure, can capture ZAIS nanoparticles.

2-2. Wavelength Dependence of Irradiation Light Fig. 35 shows the wavelength of monochromatic light (λirrad) irradiating the silver nanoparticles-containing layer, which is the plasmon structure-containing layer, and the rice-shaped ZAIS nanoparticles (19 nm) in the silver nanoparticles-containing layer. It is a graph which shows the relationship with the minimum required light intensity (Imin). The horizontal axis of FIG. 35 is the wavelength of light. The vertical axis of FIG. 35 is the minimum light intensity required to capture ZAIS nanoparticles in the gold nanoparticles-containing layer. As shown in FIG. 35, when silver nanoparticles are used as the plasmon structure, the minimum light intensity required for capturing the ZAIS nanoparticles decreases as the wavelength of the irradiation light shortens from 820 nm to 460 nm.

In the diffuse reflection spectrum of the silver nanoparticle-containing layer of FIG. 32, the value of the Kubelker-Munk function increases as the wavelength becomes shorter from 820 nm to 460 nm. From these facts, it is possible to capture ZAIS nanoparticles with a smaller light intensity by using irradiation light having a short wavelength capable of more effectively photoexciting surface plasmon resonance. That is, when light of 820 nm, which is a wavelength region where the value of the Kubelka-Munk function is small, is irradiated near the hem of the peak of surface plasmon resonance, ZAIS nanoparticles should be captured unless the light intensity is sufficiently high. I can't.

2-3. Particle size dependence of the nanostructure that is the separation target When a silver nanoparticle-containing layer is used as the plasmon structure-containing layer, quantum dots (ZAIS nanoparticles or AgInGaS nanoparticles) of various particle sizes are developed to develop the separation target. The relationship between the particle size of the quantum dots and the capture efficiency was investigated. The ZAIS nanoparticles and AgInGaS nanoparticles used were prepared in the same manner as when gold nanoparticles were used as the plasmon structure-containing layer.

Using silver nanoparticles as the plasmon structure, quantum dots of various sizes were developed while irradiating blue LED light with a wavelength of 460 nm.

FIG. 36 is a graph showing the relationship between the particle size of the quantum dots used and the Rf value. The horizontal axis of FIG. 36 is the particle size of the quantum dot which is the separation target. The vertical axis of FIG. 36 is the Rf value. As shown in FIG. 36, when the particle size is 7.8 nm or more, the plasmon structure can capture ZAIS nanoparticles or AgInGaS nanoparticles.

C. ITO particles (plasmon structure)
1. 1. Experimental Method An stationary phase-supporting plate was produced by applying ITO particles (manufactured by Aldrich) as a plasmon structure-containing layer to the above-mentioned octadecyl group-modified reverse phase silica gel TLC plate and drying it. The particle size of the ITO particles was 100 nm. The number density of ITO particles in the plasmon structure-containing layer was 1.1 × 10 ¹³ particles / cm ³ . Rice-shaped ZAIS nanoparticles with a particle diameter of 19 nm were used as the nanostructure as the separation target.

FIG. 37 is a graph showing the diffuse reflection spectrum of the ITO particle-containing layer. The horizontal axis of FIG. 37 is the wavelength of light. The vertical axis of FIG. 37 is the Kubelker-Munch function. As shown in FIG. 37, a broad surface plasmon resonance peak exists in the near infrared region of 600 nm or more. At a wavelength of 820 nm, it is the base of the surface plasmon resonance peak. However, the value of the Kubelker-Munch function at 820 nm in FIG. 37 is similar to the value of the Kubelker-Munch function at the irradiation wavelength in FIGS. 23 and 32. Therefore, the surface plasmon resonance of the ITO particles is sufficiently effectively photoexcited by irradiating with near-infrared monochromatic light having a wavelength of 820 nm.

2. Experimental Results FIG. 38 shows rice-shaped ZAIS nanoparticles (particle size: 19 nm) while irradiating 820 nm monochromatic light extracted from Xe lamp light using a plasmon structure-containing layer supporting ITO particles as a plasmon structure. It is a photograph of a stationary phase supporting plate after unfolding. As shown in FIG. 38, when not irradiated with light, the ZAIS nanoparticles moved to the upper part of the stationary phase supporting plate with little capture by the ITO particle-containing layer. However, when the light intensity was 0.31 W / cm ² , the moving distance of the ZAIS nanoparticles was shorter than that when the light was not irradiated. When the light intensity was 0.45 W / cm ² or more, rice-shaped ZAIS nanoparticles were captured in the ITO particle-containing layer portion of the stationary phase-supported plate.

FIG. 39 is a graph showing the relationship between the light intensity and the Rf value when rice-shaped ZAIS nanoparticles (particle diameter 19 nm) are developed while irradiating monochromatic light of 820 nm using ITO particles as a plasmon structure. .. The horizontal axis of FIG. 39 is the intensity of light. The vertical axis of FIG. 39 is the Rf value of the rice-shaped ZAIS nanoparticles. As shown in FIG. 39, when the stationary phase supporting plate is irradiated with light having an intensity of about 0.45 W / cm ² or more, rice-shaped ZAIS nanoparticles can be captured in the ITO particle-containing layer portion. As described above, not only metal nanoparticles but also nanoparticles made of a metal compound such as a metal oxide can be used as a plasmon structure.

D. Light capture when an organic compound is used as the nanostructure that is the separation target 1. Experimental Method A stationary phase-supported plate in which gold nanoparticles were supported as a plasmon structure-containing layer on the above-mentioned octadecyl group-modified reverse-phase silica gel TLC plate was produced. The particle size of the gold nanoparticles was 12 nm. The number density of gold nanoparticles was 3.5 × 10 ¹³ / cm ³ . Fluorescent polystyrene beads (manufactured by Thermo SCIENTIFIC) having a particle diameter of 47 nm were used as the target nanostructure. The developing solvent was methanol.

2. Experimental Results FIG. 40 is a photograph of a stationary phase-supported plate after developing polystyrene beads as nanostructures with methanol while irradiating LED light having a wavelength of 610 nm with various light intensities. As shown in FIG. 40, when the light intensity is increased, the gold nanoparticle-containing layer can capture polystyrene beads. When the light intensity was 0.63 W / cm ² , most polystyrene beads could be captured in the upper part of the gold nanoparticle-containing layer. When the light intensity was 0.88 W / cm ² , all polystyrene beads could be captured in the central part of the gold nanoparticle-containing layer.

FIG. 41 is a graph showing the relationship between the moving distance of polystyrene beads and the irradiation light intensity when the polystyrene beads are developed with methanol from the position (origin) where the polystyrene beads are dropped and fixed on the TLC. The horizontal axis of FIG. 41 is the intensity of light. The vertical axis of FIG. 41 is the moving distance (cm) from the origin of the polystyrene beads. As shown in FIG. 41, the plasmon structure can capture the polystyrene beads by irradiating the stationary phase-supported plate with light of sufficient intensity.

E. Summary of Experiments By irradiating the surface of the gold nanoparticles-containing layer, which is a plasmon structure, with light of sufficient intensity at a wavelength capable of exciting plasmon resonance, the gold nanoparticles-containing layer becomes inorganic nanoparticles (quantum dots) in the mobile phase. ) Was able to be captured. The higher the light intensity, the stronger the ability of the gold nanoparticles-containing layer to capture the inorganic nanoparticles. Further, the smaller the particle size of the inorganic nanoparticles, the more difficult it is for the gold nanoparticles-containing layer to capture the inorganic nanoparticles.

Moreover, even when the light intensity was not sufficient for capturing the inorganic nanoparticles, the moving speed of the inorganic nanoparticles in the mobile phase could be reduced. As a result, the stop position of the inorganic nanoparticles has a smaller Rf value than when no light is irradiated.

The plasmon structure is not limited to metal nanoparticles. The material of the plasmon structure is not particularly limited as long as it is a particle capable of exciting surface plasmon resonance, such as gold nanoparticles, silver nanoparticles, and ITO particles.

The nanostructure that is the capture target or the separation target may be either an inorganic compound or an organic compound. For example, it may be a conductor, a semiconductor, or an insulator. Even with a highly insulating material such as polystyrene beads, an attractive force is generated between the plasmon structure and the nanostructure due to the microscopic localized electric field generated by the plasmon structure.

(Additional note)
The separation device in the first aspect includes a stationary phase member having a stationary phase, a developing tank capable of accommodating the stationary phase member and the mobile phase, and a light irradiation unit that irradiates light toward the stationary phase member. The stationary phase has an adsorbent and a plasmon structure-containing layer in which a plasmon structure is arranged on the adsorbent. The stationary phase member can be supplied with a mobile phase containing nanostructures and can move the mobile phase along the stationary phase.

In the separation device of the second aspect, the light irradiation unit irradiates the plasmon structure with light capable of exciting surface plasmon resonance.

In the separation device of the third aspect, the plasmon structure captures the nanostructure or the nanostructure in the mobile phase while the light-irradiating unit irradiates the stationary phase member with light. Decelerate the movement speed of.

In the separation device of the fourth aspect, the stationary phase has a first carrier layer and a second carrier layer that do not contain a plasmon structure but contain an adsorbent. The plasmon structure-containing layer is arranged at a position between the first carrier layer and the second carrier layer.

In the separation device of the fifth aspect, the plasmon structure is a metal nanoparticle having a surface plasmon resonance peak.

In the separation device according to the sixth aspect, the plasmon structure is a metal compound nanoparticles having a surface plasmon resonance peak.

In the separation device according to the seventh aspect, the nanostructure is nanoparticles composed of an inorganic compound or an organic compound.

The stationary phase member in the eighth aspect has a stationary phase. The stationary phase has an adsorbent and a plasmon structure-containing layer in which a plasmon structure is arranged on the adsorbent. The stationary phase member can be supplied with a mobile phase containing nanostructures and can move the mobile phase along the stationary phase.

In the stationary phase member of the ninth aspect, the plasmon structure captures the nanostructure or the rate of movement of the nanostructure in the mobile phase during the period of irradiation of the stationary phase member with light. Decelerate.

In the stationary phase member according to the tenth aspect, the stationary phase has a first carrier layer and a second carrier layer that do not contain a plasmon structure but contain an adsorbent. The plasmon structure-containing layer is arranged at a position between the first carrier layer and the second carrier layer.

In the stationary phase member in the eleventh aspect, the plasmon structure has a surface plasmon resonance peak.

In the method for separating nanostructures in the twelfth aspect, a liquid chromatograph using a liquid as the mobile phase and a solid as the stationary phase is used. A stationary phase containing a plasmon structure capable of exciting surface plasmon resonance is used. A liquid containing nanostructures is used as the mobile phase. By irradiating the plasmon structure with light, the surface plasmon resonance is excited in the plasmon structure. The plasmon structure captures the nanostructures or slows the rate of movement of the nanostructures in the mobile phase.

In the method for separating nanostructures in the thirteenth aspect, the plasmon structure is irradiated with light to excite surface plasmon resonance in the plasmon structure, and an attractive force is generated between the plasmon structure and the nanostructure. Let me.

1000 ... Separation device 1100 ... Light irradiation unit 1200 ... Development tank 100 ... Fixed phase member 110 ...

Base material

120, 140 ... Carrier layer 130 ... Plasmon structure-containing layer L1 ... Liquid P1 ... Gold nanoparticles N1 ... Inorganic nanoparticles

Claims

A stationary phase member having a stationary phase and
An expansion tank capable of accommodating the stationary phase member and the mobile phase,
A light irradiation unit that irradiates light toward the stationary phase member,
Have,
The stationary phase is
Adsorbent and
It has a plasmon structure-containing layer in which a plasmon structure is arranged on the adsorbent.
The stationary phase member is
It is possible to supply the mobile phase containing nanostructures and
A separator comprising the ability to move the mobile phase along the stationary phase.
In the separation device according to claim 1,
The light irradiation unit is
A separator comprising irradiating the plasmon structure with light capable of exciting surface plasmon resonance.
In the separation device according to claim 1 or 2.
The plasmon structure is
During the period when the light irradiation unit irradiates the stationary phase member with light,
A separator comprising capturing the nanostructures or slowing the movement rate of the nanostructures in the mobile phase.
In the separation device according to any one of claims 1 to 3.
The stationary phase is
It has a first carrier layer and a second carrier layer that do not contain the plasmon structure but contain the adsorbent.
The plasmon structure-containing layer is
A separation device including being arranged at a position between the first carrier layer and the second carrier layer.
In the separation device according to any one of claims 1 to 4.
The plasmon structure is
Separator comprising being metal nanoparticles with surface plasmon resonance peaks.
In the separation device according to any one of claims 1 to 4.
The plasmon structure is
Separator comprising being a metal compound nanoparticles with a surface plasmon resonance peak.
In the separation device according to any one of claims 1 to 6.
The nanostructure is
A separator comprising being nanoparticles composed of an inorganic compound or an organic compound.
In a stationary phase member having a stationary phase,
The stationary phase is
Adsorbent and
It has a plasmon structure-containing layer in which a plasmon structure is arranged on the adsorbent.
The stationary phase member is
It is possible to supply the mobile phase containing nanostructures and
A stationary phase member comprising the ability to move the mobile phase along the stationary phase.
In the stationary phase member according to claim 8,
The plasmon structure is
During the period of irradiating the stationary phase member with light,
A stationary phase member comprising capturing the nanostructures or reducing the moving speed of the nanostructures in the mobile phase.
In the stationary phase member according to claim 8 or 9.
The stationary phase is
It has a first carrier layer and a second carrier layer that do not contain the plasmon structure but contain the adsorbent.
The plasmon structure-containing layer is
A stationary phase member including being arranged at a position between the first carrier layer and the second carrier layer.
The stationary phase member according to any one of claims 8 to 10.
The plasmon structure is
A stationary phase member comprising having a surface plasmon resonance peak.
Using a liquid chromatograph that uses a liquid as the mobile phase and a solid as the stationary phase,
Using the stationary phase containing a plasmon structure capable of exciting surface plasmon resonance,
A liquid containing nanostructures was used as the mobile phase.
By irradiating the plasmon structure with light, the surface plasmon resonance is excited in the plasmon structure.
A method for separating nanostructures, which comprises causing the plasmon structure to capture the nanostructures or slowing down the moving speed of the nanostructures in the mobile phase.
In the method for separating nanostructures according to claim 12,
By irradiating the plasmon structure with light, the surface plasmon resonance is excited in the plasmon structure.
A method for separating nanostructures, which comprises generating an attractive force between the plasmon structure and the nanostructures.