EP4679488A1

EP4679488A1 - Sample support

Info

Publication number: EP4679488A1
Application number: EP24818965.6A
Authority: EP
Inventors: Takamasa Ikeda; Masahiro Kotani; Keisuke Inoue
Original assignee: Hamamatsu Photonics KK
Current assignee: Hamamatsu Photonics KK
Priority date: 2023-06-07
Filing date: 2024-02-07
Publication date: 2026-01-14
Also published as: JP7506802B1; JP2024175786A; WO2024252726A1; CN121263870A

Abstract

A sample support is used for ionizing a sample. The sample support includes a porous substrate that includes a first surface, a second surface opposite to the first surface, and voids irregularly distributed and opened to at least the first surface. The porous substrate includes a measurement region including a part of the first surface and an occluded region positioned outside the measurement region as viewed from a direction perpendicular to the first surface. A porosity of the occluded region is smaller than a porosity of the measurement region.

Description

Technical Field

The present disclosure relates to a sample support.

Background Art

A sample support including a porous substrate including a main surface and a side surface has been known as a sample support used for analysis of a biological sample or the like (see, for example, Patent Literature 1). The porous substrate of such a sample support includes voids irregularly distributed and opened to the main surface.

Citation List

Patent Literature

Patent Literature 1: Japanese Unexamined Patent Publication No. 2022-43571

Summary of Invention

Technical Problem

According to the sample support described above, since the amount of samples remaining on the main surface of the porous substrate is appropriately adjusted, components of the samples are suitably ionized, and as a result, high accuracy of analysis of the samples is realized. Further improvement in the accuracy of sample analysis may be required in such a sample support.
An object of the present disclosure is to provide a sample support that enables high accuracy of analysis.

Solution to Problem

A sample support according to one aspect of the present disclosure is [1] "a sample support for ionizing samples, including a porous substrate that includes a first surface, a second surface opposite to the first surface, and voids irregularly distributed and opened to at least the first surface, in which the porous substrate includes a measurement region including a part of the first surface and an occluded region positioned outside the measurement region as viewed from a direction perpendicular to the first surface, and a porosity of the occluded region is smaller than a porosity of the measurement region.".
The porous substrate of the sample support includes the voids irregularly distributed and opened to at least the first surface. When the samples are introduced into the first surface of the porous substrate, since the samples moderately diffuse into the voids of the porous substrate, the amount of samples remaining on the first surface is appropriately adjusted. Thus, the samples remaining on the first surface can be suitably ionized. Moreover, the porosity of the occluded region is smaller than the porosity of the measurement region. As a result, even though foreign matter adheres to the hand of an operator holding the side surface of the porous substrate, since the foreign matter hardly passes through the occluded region, the entry of the foreign matter into the measurement region is suppressed. Accordingly, generation of noise due to the ionization of the foreign matter is suppressed. Thus, according to this sample support, high accuracy of analysis is realized.
The sample support according to one aspect of the present disclosure may be [2] "the sample support according to the above [1], in which the occluded region surrounds the measurement region as viewed from the direction perpendicular to the first surface.". As a result, the entry of the foreign matter into the measurement region is more reliably suppressed.
The sample support according to one aspect of the present disclosure may be [3] "the sample support according to the above [1] or [2], in which the voids in the occluded region are occluded by the same material as the porous substrate.". As a result, it is possible to reduce the porosity of the occluded region while increasing the rigidity of the porous substrate.
The sample support according to one aspect of the present disclosure may be [4] "the sample support according to any one of the above [1] to [3], in which the occluded region includes a body part whose thickness gradually increases from the second surface toward the first surface.". As a result, the rigidity of the region of the porous substrate close to the first surface where the voids are opened can be enhanced. Thus, as a result of maintaining the flatness of the first surface used as the surface on which the sample remains, high accuracy of analysis is realized.
The sample support according to one aspect of the present disclosure may be [5] "the sample support according to any one of the above [1] to [4], in which a side surface of the porous substrate includes an inclined region inclined toward an outside of the second surface from the second surface toward the first surface.". As a result, when the side surface of the porous substrate is gripped in a state where the first surface faces upward in a vertical direction, the porous substrate can be appropriately gripped while a load on the porous substrate is reduced.
The sample support according to one aspect of the present disclosure may be [6] "the sample support according to any one of the above [1] to [5], in which the occluded region includes a protruding part protruding from the measurement region on the first surface.". As a result, dropping of the samples remaining on the first surface from the first surface to the side surface of the porous substrate is suppressed.
The sample support according to one aspect of the present disclosure may be [7] "the sample support according to any one of the above [1] to [6], in which a boundary part between a side surface of the porous substrate and the second surface has a curved surface shape.". As a result, even though the hand of the operator comes into contact with the boundary part between the side surface of the porous substrate and the second surface, the injury of the operator is suppressed.
The sample support according to one aspect of the present disclosure may be [8] "the sample support according to any one of the above [1] to [7], further including a conductive layer provided on surfaces of the porous substrate, in which the conductive layer includes a first conductive region provided in the measurement region so as not to occlude openings of the voids in the first surface, and a second conductive region provided in the occluded region so as to be connected to the first conductive region.". Since the porosity of the occluded region is smaller than the porosity of the measurement region, the second conductive region provided in the occluded region is more excellent in continuity than the first conductive region provided in the measurement region. Thus, a voltage is applied to the second conductive region, and thus, the voltage can be stably applied to the first conductive region via the second conductive region.
The sample support according to one aspect of the present disclosure may be [9] "the sample support according to any one of the above [1] to [7], in which the porous substrate has conductivity.". As a result, even in a case where conductivity is required for at least a part of the sample support, the conductive layer can be omitted.
The sample support according to one aspect of the present disclosure may be [10] "the sample support according to any one of the above [1] to [7], in which the porous substrate has an insulating property.". As a result, it is possible to use the sample support in a case where conductivity is not required for the sample support.

Advantageous Effects of Invention

According to the present disclosure, it is possible to provide a sample support that enables high accuracy of analysis.

Brief Description of Drawings

FIG. 1 is a plan view of a sample support according to one embodiment.
FIG. 2 is a sectional view taken along line II-II illustrated in FIG. 1.
FIG. 3 is a schematic view of a porous structure of a porous substrate illustrated in FIG. 1.
FIG. 4 is an SEM image of a first surface of the porous substrate illustrated in FIG. 1.
FIG. 5 is an SEM image of a side surface of the porous substrate illustrated in FIG. 1.
FIG. 6 is an SEM image of a section of the porous substrate illustrated in FIG. 1.

Description of Embodiments

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. Note that, in the drawings, the same or corresponding parts are denoted by the same reference signs, and redundant description will be omitted.

[Sample Support]

A sample support 1 illustrated in FIGS. 1 and 2 is used for ionizing samples. The samples are biological samples. The samples are, for example, slices of a fruit (lemon). The sample support 1 includes a substrate (porous substrate) 2 and a conductive layer 3. The substrate 2 has, for example, a rectangular plate shape. The substrate 2 includes a first surface 2a, a second surface 2b opposite to the first surface 2a, and a side surface 2c. A thickness of the substrate 2 (a distance from the first surface 2a to the second surface 2b) is, for example, about 100 µm to 1500 µm. Note that, in FIG. 1, illustration of the conductive layer 3 is omitted.
The substrate 2 includes a measurement region 21 and an occluded region 22. The measurement region 21 is positioned inside the side surface 2c of the substrate 2 as viewed from a Z-axis direction (a direction perpendicular to the first surface 2a). The measurement region 21 is separated from the side surface 2c. The measurement region 21 has, for example, a rectangular shape as viewed from the Z-axis direction. The measurement region 21 includes a part of the first surface 2a and a part of the second surface 2b. The samples are ionized in the measurement region 21.
The occluded region 22 is positioned outside the measurement region 21 as viewed from the Z-axis direction. The occluded region 22 surrounds the measurement region 21 as viewed from the Z-axis direction. The occluded region 22 has, for example, a rectangular frame shape as viewed from the Z-axis direction. In the present embodiment, the occluded region 22 is a region of the substrate 2 other than the measurement region 21. In the present embodiment, the occluded region 22 includes the side surface 2c of the substrate 2. That is, the side surface 2c of the substrate 2 is constituted by an outer surface 22c of the occluded region 22.
The occluded region 22 includes a body part 221 and a protruding part 222. The body part 221 is a part (a part extending in the same region as the measurement region 21) of the occluded region 22 overlapping the measurement region 21 as viewed from a direction perpendicular to the Z-axis direction (for example, an X-axis direction or a Y-axis direction). The body part 221 surrounds the measurement region 21 as viewed from the Z-axis direction. The body part 221 has a rectangular frame shape as viewed from the Z-axis direction.
A thickness of the body part 221 gradually increases from the second surface 2b toward the first surface 2a. The thickness of the body part 221 is a distance (a distance in the X-axis direction or the Y-axis direction) between an outer edge of the body part 221 and an inner edge of the body part 221 as viewed from the Z-axis direction. The thickness of the body part 221 in a first section parallel to an XY plane is larger than the thickness of the body part 221 in a second section parallel to the XY plane. The first section is positioned on the first surface 2a side with respect to the second section. An average thickness of the body part 221 is substantially the same as a diameter of the particle 23 to be described later.
An outer surface 22d of the body part 221 is inclined toward an outside of the second surface 2b from the second surface 2b toward the first surface 2a. That is, the outer surface 22d is inclined in a direction away from the second surface 2b in the XY plane from the second surface 2b toward the first surface 2a. The outer surface 22d is inclined so as to be away from the measurement region 21 from the second surface 2b toward the first surface 2a. The outer surface 22d is an inclined region of the side surface 2c of the substrate 2. An outer peripheral length of the body part 221 in the first section is larger than an outer peripheral length of the body part 221 in the second section.
The protruding part 222 is a part of the occluded region 22 that does not overlap the measurement region 21 as viewed from the direction perpendicular to the Z-axis direction (for example, the X-axis direction or the Y-axis direction). The protruding part 222 is positioned on one side (first surface 2a side) in the Z-axis direction with respect to the body part 221. The protruding part 222 protrudes from the measurement region 21 on the first surface 2a. The protruding part 222 surrounds the measurement region 21 as viewed from the Z-axis direction. The protruding part 222 has a rectangular frame shape as viewed from the Z-axis direction. The protruding part 222 can also be said to be a wall-shaped member formed so as to surround an outer periphery of the measurement region 21. In the present embodiment, a region of the substrate 2 opposite to the measurement region 21 with respect to an inner surface of the protruding part 222 is the occluded region 22.
A boundary part 223 between the side surface 2c and the second surface 2b of the substrate 2 has a curved surface shape. The boundary part 223 is curved so as to protrude from an inside to an outside of the side surface 2c and the second surface 2b. That is, the side surface 2c and the second surface 2b are smoothly coupled.
As illustrated in FIG. 3, the substrate 2 includes voids (pores) 2d that are irregularly distributed and open to the first surface 2a. That is, the substrate 2 has an irregular porous structure. The "irregular porous structure" is, for example, a structure in which the voids 2d extend in irregular directions and are irregularly distributed in three dimensions. For example, a structure in which the voids enter the substrate 2 from one inlet (opening) on the first surface 2a side and branch into along a plurality of paths, a structure in which the voids enter the substrate 2 from a plurality of inlets (openings) on the first surface 2a side and join along one path, and the like are also included in the irregular porous structure. On the other hand, for example, a structure in which a plurality of pores extending along the Z-axis direction are provided as main pores (that is, a regular structure constituted by pores mainly extending in one direction) is not included in the irregular porous structure.
As illustrated in FIG. 3, the substrate 2 is formed by an aggregate of a plurality of particles. The aggregate of the plurality of particles is a structure in which the plurality of particles are gathered so as to come into contact with each other. Examples of the aggregate of the plurality of particles include a structure in which the plurality of particles are bonded or adhere to each other. That is, in order to form a structure in which the plurality of particles are fixed in a state of coming into contact with each other, the plurality of particles may be directly connected by fusion or the like, or may be indirectly connected via another member. In the present embodiment, the plurality of particles are bonded to each other by fusion. In the present embodiment, the substrate 2 is formed by using a plurality of particles 23 coupled to each other. The particle 23 has, for example, a spherical shape. A shape or a diameter of each particle 23 may vary slightly. The diameters of the particles 23 may be the same as or different from each other.
The void 2d of the substrate 2 is a gap between the particles 23. In the present embodiment, the voids 2d are opened not only on the first surface 2a but also on the second surface 2b. Components of the samples introduced to the first surface 2a can escape from the second surface 2b to an outside of the substrate 2 through the voids 2d. That is, in the present embodiment, in the measurement region 21, the first surface 2a and the second surface 2b communicate with each other via the voids 2d between the particles 23.
In the present embodiment, a material of the particles 23 has light absorbency. The particles 23 absorb, for example, energy of laser light applied to the surfaces of the substrate 2. The particles 23 melt when the particles absorb a predetermined amount of energy. The particles 23 are made of, for example, an insulating material. The material of the particles 23 is, for example, glass, ceramic, or the like. In the present embodiment, from the viewpoint of facilitating the manufacturing of the aggregate structure, soda glass having a relatively low melting point among glasses is used as the material of the particles 23. The particles 23 are, for example, glass beads. In the present embodiment, the substrate 2 has electrical insulation.
As illustrated in FIGS. 2 and 3, the conductive layer 3 is provided on the surfaces of the substrate 2. The conductive layer 3 covers the entire region of the first surface 2a and the side surface 2c of the substrate 2. Specifically, the conductive layer 3 includes a first conductive region 31 and a second conductive region 32. The first conductive region 31 is provided in the measurement region 21. The first conductive region 31 is provided on the first surface 2a so as not to occlude the openings of the voids 2d in the first surface 2a.
The first conductive region 31 covers the first surface 2a along an uneven shape of the first surface 2a formed by the plurality of particles 23. That is, a thickness of the first conductive region 31 is very thin with respect to a size (diameter) of the particle 23. As a result, an outer surface of the conductive layer 3 formed on a surface of the particle 23 has a shape following an original surface shape of the particle 23. Accordingly, as illustrated in FIG. 3, the uneven shape of the first surface 2a is maintained even in a state after the first conductive region 31 is formed.
The second conductive region 32 is provided in the occluded region 22. The second conductive region 32 is provided on the outer surface 22c of the occluded region 22 (the side surface 2c of the substrate 2). The second conductive region 32 extends to the inner surface of the protruding part 222. The second conductive region 32 is connected to the first conductive region 31. A thickness of the second conductive region 32 may be larger than the thickness of the first conductive region 31.
The conductive layer 3 is made of a conductive material. As the material of the conductive layer 3, metal having low affinity (reactivity) with the samples and high conductivity is preferably used. From the above-described viewpoint, for example, Au (gold), Pt (platinum), or the like is preferably used as the material of the conductive layer 3. The conductive layer 3 is formed to have a thickness of about 1 nm to 350 nm by, for example, a plating method, an atomic layer deposition (ALD) method, a vapor deposition method, a sputtering method, or the like. Note that, for example, chromium (Cr), nickel (Ni), or titanium (Ti) may be used as the material of the conductive layer 3.
A porosity of the occluded region 22 is smaller than a porosity of the measurement region 21. An opening ratio of the void 2d on the side surface 2c of the substrate 2 is smaller than an opening ratio of the void 2d on the first surface 2a. A volume of the void 2d included in the occluded region 22 per unit volume is smaller than a volume of the void 2d included in the measurement region 21 per unit volume. In the present embodiment, the occluded region 22 hardly includes the void 2d. A fluid such as air or a liquid is less likely to pass through the occluded region 22 than the measurement region 21. In the present embodiment, the porosity of the measurement region 21 is, for example, about 25% to 40%, and the porosity of the occluded region 22 is, for example, about 10% or less.
The substrate 2 is manufactured, for example, by cutting a base substrate formed by using the aggregate of the plurality of particles 23 by laser cutting. The occluded region 22 is formed by the particles 23 fused by irradiation with laser light. Parts of the particles 23 melted and deformed by the irradiation with the laser light are embedded in the voids 2d included in a planned occluded region to become the occluded region 22 in the base substrate. That is, the voids 2d in the occluded region 22 are occluded by the same material (fused particles 23) as the substrate 2. As described above, the measurement region 21 is not affected by the irradiation of the laser light at the time of laser cutting, and is a region not including the particles 23 solidified after being melted by the irradiation of the laser light. On the other hand, the occluded region 22 is a region including the particles 23 melted and then solidified by the irradiation with the laser light.
The porosity of each of the measurement region 21 and the occluded region 22 is acquired as follows, for example. First, an image of the surface or the section of the substrate 2 is acquired. Subsequently, for example, binarization processing is performed on the image to extract a plurality of pixel groups corresponding to the voids 2d included in a target region (predetermined range in the image), and an area of the voids 2d is acquired based on a size per pixel. Subsequently, the porosity is acquired by dividing the area of the voids 2d by an area of the target region.
FIG. 4 is an example of an SEM image of the first surface 2a of the substrate 2. In the SEM image illustrated in FIG. 4, black parts are the voids 2d, circular white parts are the particles 23, and a white part continuously extending along the Y-axis direction is the occluded region 22. When the SEM image of the first surface 2a illustrated in FIG. 4 is observed, it can be recognized that the porosity of the occluded region 22 is smaller than the porosity of the measurement region 21.
FIG. 5 is an example of an SEM image of the side surface 2c of the substrate 2. In the SEM image illustrated in FIG. 5, a planar white part is the occluded region 22. When the SEM image illustrated in FIG. 5 is observed, it can be recognized that the voids 2d are not opened to the side surface 2c. Note that, in the SEM image illustrated in FIG. 5, circular white parts and black parts between the circular white parts can be recognized, but the white parts and the black parts are the particles 23 and the voids 2d present inward from the occluded region 22.
FIG. 6 is an example of an SEM image of the section of the substrate 2. In the SEM image illustrated in FIG. 6, a white part is the measurement region 21, and a gray part is the occluded region 22. When the SEM image illustrated in FIG. 6 is observed, it can be recognized that the thickness of the body part 221 of the occluded region 22 gradually increases from the second surface 2b toward the first surface 2a, the protruding part 222 of the occluded region 22 protrudes on the first surface 2a, and the boundary part 223 between the side surface 2c and the second surface 2b of the substrate 2 has a curved surface shape.

[Method for Manufacturing Sample Support]

The sample support 1 is manufactured, for example, as follows. First, the base substrate formed by the aggregate of the plurality of particles 23 is prepared. The base substrate has one surface and the other surface opposite to the one surface. Subsequently, the other surface of the base substrate is irradiated with the laser light. The particles 23 in the region irradiated with the laser light on the other surface are melted. As a result, a groove constituted by the welded particles 23 is formed on the other surface of the base substrate. A width of the groove gradually decreases from the other surface toward the one surface.
When the other surface of the base substrate is continuously irradiated with the laser light, the groove becomes deep, and as a result, the base substrate is cut. As a result, the substrate 2 described above is formed. The occluded region 22 of the substrate 2 is formed by the irradiation with the laser light. The boundary part 223 between the side surface 2c and the second surface 2b of the substrate 2 is formed at an initial stage when the other surface of the base substrate is irradiated with the laser light. The protruding part 222 of the occluded region 22 is formed by moving the melted particles 23 to one surface side of the base substrate by an action of an air pressure when the base substrate is cut.

[Mass Spectrometry Method]

A mass spectrometry method using the sample support 1 will be described. First, the sample support 1 is prepared (first step). The sample support 1 may be prepared by being manufactured by a practitioner of an ionization method and a mass spectrometry method, or may be prepared by being delivered from a manufacturer, a seller, or the like of the sample support 1. Subsequently, the samples are transferred into the measurement region 21 of the substrate 2 (second step). The samples are, for example, slices of a fruit (lemon). For example, the samples are pressed against the first surface 2a of the substrate 2, and thus, a part of the samples adheres to the first surface 2a. Subsequently, the sample support 1 is mounted in an ionization chamber of a mass spectrometer. Subsequently, a region of the first surface 2a of the substrate 2 where the samples are present is irradiated with the laser light, and a voltage is applied to the second conductive region 32 of the conductive layer 3. As a result, the components of the samples on the first surface 2a are ionized. Subsequently, the ionized components (sample ions) of the samples are detected.

[Actions and Effects]

The substrate 2 of the sample support 1 includes the voids 2d that are irregularly distributed and opened to the first surface 2a. When the samples are introduced into the first surface 2a of the substrate 2, since the samples are appropriately diffused into the voids 2d of the substrate 2, the amount of samples remaining on the first surface 2a is appropriately adjusted. Thus, when the first surface 2a is irradiated with an energy ray (for example, laser light), the samples remaining on the first surface 2a are suitably ionized. Moreover, the porosity of the occluded region 22 is smaller than the porosity of the measurement region 21. As a result, even though foreign matter adheres to the hand of an operator who grips the side surface 2c of the substrate 2, since the foreign matter hardly passes through the occluded region 22, the entry of the foreign matter into the measurement region 21 is suppressed. Similarly, even in a case where the side surface 2c of the substrate 2 comes into contact with a fixing member or the like of a measuring device (analysis device), even though the foreign matter adheres to the fixing member, since the foreign matter hardly passes through the occluded region 22, the entry of the foreign matter into the measurement region 21 is suppressed. Accordingly, generation of noise due to the ionization of the foreign matter is suppressed. Thus, according to the sample support 1, high accuracy of analysis is realized. In addition, since the samples present in the voids 2d of the measurement region 21 hardly pass through the occluded region 22, adhering of the samples to the hand of the operator in contact with the side surface 2c of the substrate 2, the fixing member of the measuring device, or the like is suppressed.
The occluded region 22 surrounds the measurement region 21 as viewed from the Z-axis direction. As a result, the entry of the foreign matter into the measurement region 21 is more reliably suppressed.
The voids 2d in the occluded region 22 are occluded by the same material as the substrate 2. As a result, it is possible to reduce the porosity of the occluded region 22 while increasing the rigidity of the substrate 2.
The occluded region 22 includes the body part 221 whose thickness gradually increases from the second surface 2b toward the first surface 2a. As a result, the rigidity of a region of the substrate 2, which is close to the first surface 2a where the voids 2d are opened can be increased. Thus, as a result of maintaining the flatness of the first surface 2a on which the samples remain and which is used as the surface to be irradiated with the energy ray, high accuracy of analysis is realized. In addition, since the thickness of the body part 221 increases as the body part approaches the first surface 2a, the entry of the foreign matter into the first surface 2a, which is used as the surface on which the samples remain and which is irradiated with the energy ray, is more effectively suppressed.
The side surface 2c of the substrate 2 includes the inclined region (the outer surface 22d of the body part 221) inclined toward the outside of the second surface 2b from the second surface 2b toward the first surface 2a. As a result, in a case where the side surface 2c of the substrate 2 is gripped in a state where the first surface 2a faces upward in a vertical direction, the substrate 2 can be appropriately gripped while a load on the substrate 2 is reduced. In addition, as described above, the thickness of the body part 221 can be gradually increased from the second surface 2b toward the first surface 2a while the area of the measurement region 21 is maintained as viewed from the Z-axis direction.
The occluded region 22 includes the protruding part 222 protruding from the measurement region 21 on the first surface 2a. As a result, dropping of the samples remaining on the first surface 2a from dropping from the first surface 2a to the side surface 2c of the substrate 2 is suppressed. In addition, in a case where the side surface 2c of the substrate 2 is gripped by the hand of the operator, particularly in a case where the side surface 2c of the substrate 2 is gripped in a state where the first surface 2a of the substrate 2 faces the hand of the operator, contacting of the measurement region 21 with the hand of the operator is suppressed. In addition, in a case where the thickness of the protruding part 222 is larger than the thickness of the body part 221 (particularly, a thickness of the region of the body part 221 close to the second surface 2b), the above-described effect becomes more remarkable.
The boundary part 223 between the side surface 2c and the second surface 2b of the substrate 2 has the curved surface shape. As a result, even though the hand of the operator comes into contact with the boundary part 223 between the side surface 2c of the substrate 2 and the second surface 2b, the injury of the operator is suppressed.
The sample support 1 includes the conductive layer 3 provided on the surfaces of the substrate 2. The conductive layer 3 includes the first conductive region 31 provided in the measurement region 21 so as not to occlude the openings of the voids 2d in the first surface 2a, and the second conductive region 32 provided in the occluded region 22 so as to be connected to the first conductive region 31. Since the porosity of the occluded region 22 is smaller than the porosity of the measurement region 21, the second conductive region 32 provided in the occluded region 22 is more excellent in continuity than the first conductive region 31 provided in the measurement region 21. Thus, the voltage is applied to the second conductive region 32, and thus, a voltage can be stably applied to the first conductive region 31 via the second conductive region 32.

[Modifications]

Although the embodiment of the present disclosure has been described above, the present disclosure is not limited to the above-described embodiment. The material and shape of each configuration are not limited to the material and shape described above, and various materials and shapes can be employed. In addition, some configurations included in the sample support 1 according to the above embodiment may be omitted or changed as appropriate. For example, in the above embodiment, some characteristic configurations included in the sample support 1 and some effects exhibited by each configuration have been described, but the sample support according to the present disclosure does not necessarily need to be configured to exhibit all the effects described in the above embodiment, and may be configured to exhibit only some of the effects described in the above embodiment. In the latter case, the sample support is only required to have a configuration essential for exerting at least the partial effect, and a configuration that is not essential for exerting the partial effect may be omitted or changed as appropriate. Note that, in a case where one effect is focused on, the configuration essential for exerting the one effect should be reasonably grasped based on the technical common sense and the description of the present specification on the basis of those skilled in the art. Hereinafter, some specific modifications of the sample support according to the present disclosure will be illustrated.
In the embodiment, although it has been illustrated that the occluded region 22 surrounds the measurement region 21, the occluded region 22 may not surround the measurement region 21. The occluded region 22 may be, for example, a pair of regions of the substrate 2 facing each other with the measurement region 21 interposed therebetween.
In the embodiment, although it has been illustrated that the substrate 2 is manufactured by laser cutting, the substrate 2 may not be manufactured by laser cutting. The substrate 2 may be manufactured by cutting the base substrate with, for example, a blade or the like. In this case, the occluded region 22 of the substrate 2 may be formed by melting the cut surface by, for example, heat treatment or chemical treatment. The voids 2d in the occluded region 22 may not be occluded by the fused particles 23. When the porosity of the occluded region 22 is smaller than the porosity of the measurement region 21, that is, when the opening ratio of the voids 2d in the side surface 2c of the substrate 2 is smaller than the opening ratio of the voids 2d in the first surface 2a, the voids 2d in the occluded region 22 may be occluded by, for example, fine particles or powder of the same material as the particles 23, or may be occluded by a material (for example, resin) different from the particles 23. In addition, the occluded region 22 may be a plate material or the like fixed to the side surface 2c of the substrate 2 and having a porosity smaller than the porosity of the measurement region 21.
In the embodiment, although it has been illustrated that the occluded region 22 hardly includes the voids 2d, when the porosity of the occluded region 22 is smaller than the porosity of the measurement region 21, the occluded region 22 may include the voids 2d. The voids 2d of the occluded region 22 may be narrower than the voids 2d of the measurement region 21.
In the embodiment, although it has been illustrated that the side surface 2c of the substrate 2 is constituted by the outer surface 22c of the occluded region 22, the occluded region 22 may be separated from the side surface 2c of the substrate 2 inside the side surface 2c of the substrate 2, for example. The occluded region 22 may be positioned between the measurement region 21 and the side surface 2c of the substrate 2.
In the embodiment, although it has been illustrated that the voids 2d are also opened to the second surface 2b of the substrate 2, the voids 2d may not be opened to the second surface 2b of the substrate 2, for example. The voids 2d may be opened to at least the first surface 2a of the substrate 2. For example, the substrate 2 may include a flat plate including the second surface 2b and a porous structure provided on a surface of the plate opposite to the second surface 2b. As an example, the substrate 2 may include a glass plate and a porous structure provided on the glass plate.
In the embodiment, although it has been illustrated that the conductive layer 3 covers the entire region of the first surface 2a and the side surface 2c of the substrate 2, the second conductive region 32 of the conductive layer 3 may not be provided, for example, in a partial region of the outer surface 22c of the occluded region 22.
In the embodiment, although it has been illustrated that the material of the particles 23 is glass, ceramic, or the like, the material of the particles 23 may be, for example, a metal such as aluminum. That is, the substrate 2 may have conductivity. In this case, even in a case where conductivity is required for at least a part of the sample support 1, the conductive layer 3 can be omitted.
In a case where the substrate 2 has electrical insulation, the sample support 1 may not include the conductive layer 3. In this case, the sample support 1 can be used in a case where conductivity is not required for the sample support 1 (in a case where electrical insulation is required). For example, the sample support 1 can be used in a desorption electrospray ionization (DESI) method or the like in which the first surface 2a of the substrate 2 is irradiated with charged microdroplets.
The sample is not limited to the slice of the fruit (lemon) illustrated in the embodiment. The sample may have a flat surface or an uneven surface. In addition, the sample may be other than the fruit, and may be, for example, a leaf of a plant or the like. In this case, a component of a surface of the leaf, which is the sample, is transferred onto the first surface 2a, and thus, imaging analysis of the surface (leaf vein) of the leaf can be performed.
The particle 23 is not limited to the spherical shape, and may have a shape other than the spherical shape.
In the embodiment, although it has been illustrated that the sample support 1 is used for the mass spectrometry method, the sample support 1 may be used for various analyses on samples. The sample support 1 may be used for ionizing the sample.

Reference Signs List

1: sample support

2: substrate
2a: first surface
2b: second surface
2c: side surface
2d: void
21: measurement region
22: occluded region
3: conductive layer
31: first conductive region
32: second conductive region
22d: outer surface (inclined region)
221: body part
222: protruding part
223: boundary part

Claims

A sample support for ionizing a sample, comprising:
a porous substrate including a first surface, a second surface opposite to the first surface, and voids irregularly distributed and opened to at least the first surface,

wherein the porous substrate includes a measurement region including a part of the first surface and an occluded region positioned outside the measurement region as viewed from a direction perpendicular to the first surface, and

a porosity of the occluded region is smaller than a porosity of the measurement region.
The sample support according to claim 1, wherein the occluded region surrounds the measurement region as viewed from the direction perpendicular to the first surface.
The sample support according to claim 1, wherein the voids in the occluded region are occluded by the same material as the porous substrate.
The sample support according to claim 1, wherein the occluded region includes a body part whose thickness gradually increases from the second surface toward the first surface.
The sample support according to claim 1, wherein a side surface of the porous substrate includes an inclined region inclined toward an outside of the second surface from the second surface toward the first surface.
The sample support according to claim 1, wherein the occluded region includes a protruding part protruding from the measurement region on the first surface.
The sample support according to claim 1, wherein a boundary part between a side surface of the porous substrate and the second surface has a curved surface shape.
The sample support according to claim 1, further comprising:
a conductive layer provided on surfaces of the porous substrate,

wherein the conductive layer includes a first conductive region provided in the measurement region so as not to occlude openings of the voids in the first surface, and a second conductive region provided in the occluded region so as to be connected to the first conductive region.
The sample support according to claim 1, wherein the porous substrate has conductivity.
The sample support according to claim 1, wherein the porous substrate has an insulating property.