Sample support body

Abstract

To provide a sample support body capable of achieving high accuracy for analysis and improving handling property.SOLUTION: A sample support body 1 comprises a substrate 2 having: a first surface 2a; a second surface 2b opposite to the first surface 2a; a side surface 2c connecting an edge part of the first surface 2a with an edge part of the second surface 2b; and voids 2d distributed so as to open at least to the first surface 2a and the side surface 2c. The substrate 2 is formed of a plurality of particles 20 connected to each other. At least a part of an outer surface of a plurality of side surface particles 20B constituting the side surface 2c among the plurality of particles 20 is made into a rough surface 21a in which an uneven structure 4 is formed.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a sample support.

Background Art

[0002] As a sample support used for ionizing a sample, a sample support including a porous substrate having a main surface and side surfaces is known (see, for example, Patent Document 1). The porous substrate of such a sample support includes voids that are irregularly distributed and open to the main surface. According to the above sample support, it is possible to appropriately adjust the amount of the sample remaining on the main surface of the porous substrate and preferably ionize the components of the sample.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the sample support as described above, higher precision in sample analysis is required, and ease of use (handleability) of the sample support during the analysis operation is required.

[0005] An object of the present disclosure is to provide a sample support capable of achieving higher precision in analysis and improving handleability.

Means for Solving the Problems

[0006] The present disclosure includes the sample supports of [1] to [8].

[0007] [1] A sample support for ionizing a sample, A porous substrate having a first surface, a second surface opposite to the first surface, a side surface connecting an edge of the first surface and an edge of the second surface, and voids distributed so as to open at least in the first surface and the side surface. The porous substrate is formed by a plurality of particles connected to each other. A sample support, wherein at least a part of the outer surfaces of a plurality of side surface particles constituting the side surface among the plurality of particles have a rough surface on which an uneven structure is formed.

[0008] In the sample support of [1] above, the porous substrate includes voids that open to the first surface. Thus, when a sample is introduced onto the first surface of the porous substrate, the sample diffuses appropriately into the voids of the porous substrate, and the amount of the sample remaining on the first surface is appropriately adjusted. As a result, the sample remaining on the first surface can be preferably ionized. Further, the voids of the porous substrate also open to the side surface. Thereby, for example, when the sample support on which the sample is transferred to the first surface is introduced into a vacuum device, degassing of the porous substrate (that is, discharge of the gas accumulated in the voids from the side surface) can be preferably performed. Also, when transferring the sample onto the entire surface of the first surface, the gas introduced from the first surface into the inside of the substrate can escape from the side surface openings, so that the accumulation of unnecessary gas (residual gas) inside the porous substrate can be suppressed, and thus the occurrence of transfer unevenness due to the residual gas can be suppressed. Furthermore, at least a part of the outer surface of the side surface of the porous substrate has a rough surface on which an uneven structure is formed. Thereby, for example, when an operator holds the side surface of the porous substrate with a finger or when holding the side surface of the porous substrate using an instrument for supporting the sample support, the rough surface functions as an anti-slip, so that the handleability of the sample support can be improved. As described above, according to the sample support, high-precision analysis can be achieved and the handleability can be improved.

[0009] [2] The sample support of [1], wherein at least a part of the plurality of side surface particles has a non-rough surface on which the uneven structure is not formed on the side opposite to the rough surface.

[0010] According to the sample support [2] above, by making the inner surface of the side particles non-rough, the bonding strength between the side particles and the particles located inside the side particles can be sufficiently ensured, and spillage of the side particles can be suppressed. Further, by not providing a concavo-convex structure inside the side particles, the gas flow (for example, the flow of the residual gas described above) inside the side particles can be smoothed compared to the case where a concavo-convex structure is also formed inside the side particles, and thus gas venting from the opening on the side can be suitably performed.

[0011] [3] The sample support of [1] or [2], wherein at least a part of the plurality of side particles is formed of a substance that emits ions in response to irradiation with an energy beam.

[0012] [4] The sample support of any one of [1] to [3], wherein a substance that emits ions in response to irradiation with an energy beam is disposed on the rough surface of at least a part of the plurality of side particles.

[0013] According to the sample support of [3] or [4] above, by irradiating an energy beam onto the first surface of the sample support, ionizing the components (molecules) of the sample present on the first surface, and performing mass spectrometry imaging (MSI) to two-dimensionally visualize the spatial distribution of the ionized components (hereinafter referred to as "MSI image"), the portion corresponding to the side surface of the porous substrate (that is, the outer edge of the sample support) can be clarified. More specifically, since the rough surface is provided with a concavo-convex structure (edge structure), the energy of the energy beam is easily absorbed by the edge portion of the rough surface. As a result, the components of the substance at the edge portion are preferably ionized and easily desorbed, so that in the MSI image, the location corresponding to the outer edge of the sample support can be easily and accurately recognized. Further, in the sample support of [4] above, since ionization on the surface of the edge portion is more preferably performed, in the MSI image, the location corresponding to the outer edge of the sample support can be more easily and accurately recognized.

[0014] [5] Further comprising a conductive layer provided on the surface of the porous substrate, The conductive layer includes a first conductive region provided on the first surface so as not to block the openings of the voids on the first surface, and a second conductive region connected to the first conductive region and provided on the side surface so as not to block the openings of the voids on the side surface, The sample support according to any one of [1] to [4], wherein the second conductive region is provided along the surface shape of the concavo-convex structure on the rough surfaces of at least a part of the plurality of side surface particles.

[0015] When ionizing the components of the sample remaining on the first surface by irradiation with energy rays (for example, laser desorption ionization method, etc.), it is necessary to apply a voltage to the conductive layer (first conductive region) on the first surface. In order to stably apply a voltage to the first conductive region, it is preferable to also apply a voltage to the side surface, and it is preferable to provide a second conductive region on the side surface. And, since the second conductive region is provided along the surface shape of the concavo-convex structure on the rough surfaces of at least a part of the plurality of side surface particles, the same effect as in the above [4] can be obtained.

[0016] [6] The thickness of the conductive layer in the second conductive region is smaller than the thickness of the conductive layer in the first conductive region, the sample support of [5].

[0017] According to the sample support of the above [6], for the first conductive region on the first surface, a constant thickness can be ensured, so that a voltage can be stably applied to the first surface during analysis. On the other hand, for the second conductive region on the side surface, by reducing the thickness of the conductive layer, the same effect as in the above [4] can be obtained more preferably.

[0018] [7] The first surface has a rectangular shape, The sample support of [5] or [6], wherein the conductive layer is not provided at portions corresponding to the four corners of the first surface.

[0019] According to the sample support [7] above, by not providing a conductive layer in the portions corresponding to the four corners of the first surface, it becomes easy to visually distinguish between the portion where the conductive layer is provided on the first surface and the portions corresponding to the four corners of the first surface. As a result, when performing stage alignment or the like with the sample support placed on the stage of a mass spectrometer, by using the portions corresponding to the four corners of the first surface as marks, the alignment can be facilitated.

[0020] [8] The sample support according to any one of [1] to [7], wherein the side surface includes an inclined region that inclines so as to widen outward from the first surface toward the second surface.

[0021] According to the sample support [8] above, the stability of the sample support when placed on a sample stage or the like during analysis can be improved.

Advantages of the Invention

[0022] According to the present disclosure, it is possible to provide a sample support that can achieve high-precision analysis and improve handling properties.

Brief Description of the Drawings

[0023]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Embodiments for Carrying Out the Invention

[0024] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In each figure, the same or corresponding parts are denoted by the same reference numerals, and redundant descriptions are omitted. In the drawings, there are parts that are exaggerated for easy explanation of the characteristic parts according to the embodiments. For this reason, the dimensional ratios of the respective parts in the drawings may be different from the actual dimensional ratios.

[0025] [Sample Support] The sample support 1 shown in FIGS. 1 to 4 is used for ionizing a sample. The sample contains, for example, a liquid component, and specific examples include biological samples, sections of fruits (e.g., strawberries, etc.). The sample support 1 includes a substrate (porous substrate) 2 and a conductive layer 3.

[0026] The substrate 2 has a first surface 2a, a second surface 2b opposite to the first surface 2a, and a side surface 2c connecting the edge of the first surface 2a and the edge of the second surface 2b. As an example, the substrate 2 is formed in a rectangular plate shape. The thickness of the substrate 2 (the distance from the first surface 2a to the second surface 2b) is, for example, about 100 μm to 1500 μm. In this specification and the drawings, for convenience, the thickness direction of the substrate 2 (that is, the direction in which the first surface 2a and the second surface 2b face each other) is represented as the Z-axis direction, one direction orthogonal to the Z-axis direction (the longitudinal direction of the substrate 2) is represented as the X-axis direction, and the direction orthogonal to the Z-axis direction and the X-axis direction (the short-side direction of the substrate 2) is represented as the Y-axis direction.

[0027] The first surface 2a is the surface on which the sample S to be analyzed (see FIGS. 7 and 8) is placed (transferred). The second surface 2b is the surface that is placed on a predetermined sample stage (as an example, the support substrate 8 shown in FIGS. 7 and 8). As shown in FIG. 2, the side surface 2c includes an inclined region that inclines so as to spread outward as it goes from the first surface 2a toward the second surface 2b. In the present embodiment, the entire side surface 2c is an inclined region that inclines in the shape of a taper as described above.

[0028] As shown in FIGS. 3 and 4, the substrate 2 includes voids 2d that are distributed so as to open at least in the first surface 2a and the side surface 2c. That is, the first surface 2a and the side surface 2c communicate with each other through the voids 2d inside the substrate 2. The voids 2d have, for example, a structure in which they enter the substrate 2 from one inlet (opening) of the first surface 2a or the side surface 2c and branch into a plurality of paths, or a structure in which they enter the substrate 2 from a plurality of inlets (openings) of the first surface 2a or the side surface 2c and merge into one path. In the present embodiment, the voids 2d are irregularly distributed in the substrate 2. That is, the voids 2d have a structure different from a regular structure composed of a plurality of pores extending along a specific one direction. As an example, the substrate 2 is formed of a plurality of particles 20 connected to each other, and the voids 2d are formed by the spaces between adjacent particles 20.

[0029] Examples of the substrate 2 include a structure in which a plurality of particles 20 are joined or adhered to each other. For example, the plurality of particles 20 are joined to each other by fusion so that a state of being in contact with each other and connected is maintained. The diameter of the particles 20 is, for example, about several tens of μm. There may be some variation in the shape or size (diameter) of each particle 20. In the present embodiment, the particles 20 are formed of an insulating material. As an example, the particles 20 are formed of glass, ceramic, or the like. From the viewpoint of facilitating the production of a structure in which a plurality of particles 20 are joined by fusion, soda glass, which has a relatively low melting point among glasses, may be used as the material of the particles 20. Further, the particles 20 are formed in a substantially spherical shape. Examples of such substantially spherical particles 20 include glass beads and the like.

[0030] As shown in FIGS. 3 and 5, the first surface 2a is constituted by the one-side surface 21 of a plurality of particles 20A located in the outermost layer on one side in the Z-axis direction among the plurality of particles 20. Note that FIG. 5 is an SEM image of a partial region A of the first surface 2a of the substrate 2 (as shown in FIG. 1) in a state before the conductive layer 3 is provided. In the present embodiment, the surface 21 of the particles 20A constituting the first surface 2a is a smooth surface (non-rough surface), which is different from the outer surface (rough surface 21a) of the side surface particles 20B described later.

[0031] As shown in FIGS. 4 and 6, the side surface 2c is constituted by the outer surfaces (surfaces facing outward when viewed from the Z-axis direction) of a plurality of side surface particles 20B located in the outermost layer in the X-axis direction or the Y-axis direction among the plurality of particles 20. The particles located in the outermost layer on the above-mentioned one side in the Z-axis direction among the plurality of side surface particles 20B also correspond to the above-mentioned particles 20A. Note that FIG. 6 is an SEM image of a partial region B of the side surface 2c of the substrate 2 (as shown in FIG. 1) in a state before the conductive layer 3 is provided. The outer surfaces of at least a part of the plurality of side surface particles 20B are rough surfaces 21a including a fine concavo-convex structure 4. For example, the concavo-convex structure 4 can be constituted by a plurality of convex portions 4a protruding outward (sharp) and a plurality of concave portions 4b recessed inward. The plurality of convex portions 4a and the plurality of concave portions 4b may be formed regularly or irregularly. Note that the concavo-convex structure 4 in the present embodiment is a structure formed on one particle 20 itself, and is not a concavo-convex structure generated by arranging a plurality of particles 20 adjacent to each other (for example, a concavo-convex structure in which a groove portion between adjacent particles 20 is regarded as a concave portion).

[0032] The rough surface 21a can be formed by various known roughening processes for roughening the outer surface of the side particles 20B. Examples of the roughening process include sandblasting, laser processing, etching (dry etching), molding using a mold, and the like. As an example, the substrate 2 can be formed by cutting a base substrate (a porous substrate having an area larger than that of the substrate 2 when viewed from the Z-axis direction) formed by an aggregate of a plurality of particles 20. However, the rough surface 21a may be formed in a cutting step of cutting the base substrate using a cutting method such as blade dicing, water jet machining, or laser cutting. The above-described base substrate is, for example, a sintered body of a plurality of particles 20. As an example, in a state where a plurality of particles 20 are pressed by a press or the like and heated at a high temperature below the melting point of the particles 20, the surfaces of the plurality of particles 20 are fused together, and a sintered body (base substrate) composed of the plurality of particles 20 is obtained. In the present embodiment, since the particles 20 are formed of an insulating material, the base substrate has insulating properties.

[0033] As shown in FIG. 4, the side particle 20B has a non-rough surface 21b on the side opposite to the rough surface 21a where the concavo-convex structure 4 is not formed. That is, the outer surface of the side particle 20B is the rough surface 21a as described above, but the inner surface of the side particle 20B is a smooth surface (non-rough surface 21b) similar to the surface 21 of the particle 20A constituting the first surface 2a.

[0034] The conductive layer 3 is provided on the surface of the substrate 2. As shown in FIGS. 1 and 2, in the present embodiment, the conductive layer 3 is provided so as to cover the first surface 2a and the side surface 2c. That is, by covering the first surface 2a and the side surface 2c of the substrate 2 formed from the above-described insulating base substrate with the conductive layer 3 to make it conductive, a structure in which a specific voltage can be applied to the first surface 2a and the side surface 2c of the substrate 2 is realized. Further, the conductive layer 3 is not provided at portions corresponding to the four corners of the first surface 2a. That is, at the four corners of the first surface 2a, no conductive layer 3 is provided, and a region where the first surface 2a (the surface 21 of the particles 20A) of the substrate 2 is exposed is provided. In other words, substantially the entire surface except for the portions corresponding to the four corners of the first surface 2a is covered with the conductive layer 3. Further, the side surface 2c covered with the conductive layer 3 is arranged so as to surround the first surface 2a covered with the conductive layer 3, and the conductive layer 3 on the first surface 2a and the conductive layer 3 on the side surface 2c are electrically connected. Thereby, substantially the entire surface of the first surface 2a becomes the same potential, and the side surface 2c surrounding the first surface 2a also becomes the same potential as the first surface 2a, so that the potential of the first surface 2a can be stabilized.

[0035] As shown in FIG. 3, the conductive layer 3 has a first conductive region 31 provided on the first surface 2a so as not to block the opening of the gap 2d in the first surface 2a. For example, the first conductive region 31 is formed along the surface 21 of each particle 20A so as not to completely cover the opening of the gap 2d in the first surface 2a. That is, the first conductive region 31 is continuously formed on the first surface 2a of each particle 20A, but is provided so as not to block the gap 2d when viewed from the Z-axis direction. Thereby, a part of the sample S transferred to the first surface 2a (for example, an excess liquid component) can be made to penetrate into the substrate 2.

[0036] As shown in Fig. 4, the conductive layer 3 has a second conductive region 32 provided on the side surface 2c so as not to block the opening of the gap 2d in the side surface 2c. For example, the second conductive region 32 is formed along the surface (rough surface 21a) of each side particle 20B, so as not to completely cover the opening of the gap 2d in the side surface 2c. That is, the second conductive region 32 is continuously formed on the surface of each side particle 20B, but is provided so as not to block the gap 2d when viewed from the X-axis direction or the Y-axis direction. The second conductive region 32 is connected to the first conductive region 31. That is, the second conductive region 32 is continuously formed with the first conductive region 31. The second conductive region 32 is provided along the surface shape of the uneven structure 4 on the rough surfaces 21a of a plurality of side particles 20B. That is, the thickness of the second conductive region 32 is very thin with respect to the size (diameter) of the side particles 20B. Thereby, the shape of the outer surface of the conductive layer 3 formed on the surface of the side particles 20B follows the surface shape (uneven shape) of the uneven structure 4. Therefore, as shown in Fig. 4, even in the state after the conductive layer 3 is formed, the uneven shape of the side surface 2c (that is, the uneven shape of the rough surface 21a of each side particle 20B) is maintained.

[0037] The conductive layer 3 is formed of a conductive material. As the material of the conductive layer 3, a metal having low affinity (reactivity) with the sample to be analyzed and high conductivity is preferably used. From such a viewpoint, as the material of the conductive layer 3, for example, Au (gold), Pt (platinum), etc. are preferably used. The conductive layer 3 is formed to a thickness of about 1 nm to 350 nm by, for example, a plating method, an atomic layer deposition method (ALD: Atomic Layer Deposition), a vapor deposition method, a sputtering method, etc. Note that, as the material of the conductive layer 3, for example, Cr (chromium), Ni (nickel), Ti (titanium), etc. may also be used.

[0038] The conductive layer 3 is formed of a conductive material. As the material of the conductive layer 3, a metal with low affinity (reactivity) with the sample and high conductivity is preferably used. From this perspective, as the material of the conductive layer 3, for example, Au (gold), Pt (platinum), etc. are preferably used. The conductive layer 3 is formed to a thickness of about 1 nm to 350 nm by, for example, plating, atomic layer deposition (ALD: Atomic Layer Deposition), evaporation, sputtering, etc. Note that as the material of the conductive layer 3, for example, Cr (chromium), Ni (nickel), Ti (titanium), etc. may also be used.

[0039] [Mass spectrometry method] An example of a mass spectrometry method using the sample support 1 (a method using laser desorption ionization) will be described. With reference to FIGS. 7 and 8, a mass spectrometry method using an example of a mass spectrometer (mass spectrometer 10) will be described. First, the sample support 1 is prepared (first step). Subsequently, the sample S is placed (transferred) on the first surface 2a of the substrate 2 (second step). The sample S is, for example, a section of a fruit (such as a strawberry). For example, by pressing the sample S against the first surface 2a of the substrate 2, the sample S (a part of the sample S) is adhered onto the first surface 2a.

[0040] Subsequently, after the sample S adheres to the first surface 2a, while applying a voltage to the first surface 2a (conductive layer 3), the first surface 2a is irradiated with an energy beam to ionize the components (molecules) of the sample S (third step). The above-described third step can be implemented, for example, by using the mass spectrometer 10 shown in FIG. 8. The mass spectrometer 10 includes a support portion 12, an irradiation portion 13, a voltage application portion 14, an ion detection portion 15, a camera 16, a control portion 17, and a sample stage 18.

[0041] As shown in FIGS. 7 and 8, as an example, the sample support 1 is fixed on the support substrate 8 via the conductive tape 9 in a state where the second surface 2b of the substrate 2 is placed on the support surface 8a of the support substrate 8. In a state where the sample support 1 is fixed on the support substrate 8 in this way, the support substrate 8 is placed on the support portion 12. As shown in FIG. 7, as an example, the conductive tape 9 is provided at the central portion in the short-side direction (Y-axis direction) of both side edges in the longitudinal direction (X-axis direction) of the substrate 2, and is a part of the first conductive region 31 on the first surface 2a, a part of the second conductive region 32 on the side surface 2c, and is arranged across the support surface 8a of the support substrate 8. Thereby, the conductive layer 3 is electrically connected to the support surface 8a of the support substrate 8 via the conductive tape 9. The support substrate 8 is, for example, a slide glass. As an example, the support substrate 8 is a glass substrate (ITO slide glass) on which a transparent conductive film such as an ITO (Indium Tin Oxide) film is formed, and the surface of the transparent conductive film is the support surface 8a. That is, in the present embodiment, the entire support surface 8a has conductivity.

[0042] The irradiation unit 13 irradiates the first surface 2a of the sample support 1 with energy rays such as laser light L. The voltage application unit 14 applies a voltage to the first surface 2a of the sample support 1. The ion detection unit 15 detects the components of the ionized sample (sample ions SI). The camera 16 acquires a camera image including the irradiation position of the laser light L by the irradiation unit 13. The camera 16 is, for example, a small CCD camera attached to the irradiation unit 13. The control unit 17 controls the operations of the sample stage 18, the camera 16, the irradiation unit 13, the voltage application unit 14, and the ion detection unit 15. The control unit 17 is, for example, a computer device including a processor (for example, a CPU, etc.) and a memory (for example, a ROM, a RAM, etc.).

[0043] A voltage is applied to the support surface 8a of the support substrate 8 by the voltage application unit 14. Thereby, a voltage is applied to the conductive layer 3 via the support surface 8a and the conductive tape 9. Subsequently, the control unit 17 operates the irradiation unit 13 based on the camera image acquired by the camera 16. Specifically, the control unit 17 operates the irradiation unit 13 so that the laser irradiation range (for example, the entire substrate 2 specified based on the camera image) is irradiated with the laser light L.

[0044] As an example, the control unit 17 moves the sample stage 18 and controls the irradiation operation (such as irradiation timing) of the laser light L by the irradiation unit 13. That is, after the control unit 17 confirms that the sample stage 18 has moved by a predetermined interval, the control unit 17 causes the irradiation unit 13 to irradiate the laser light L. For example, the control unit 17 repeats the movement (scanning) of the sample stage 18 and the irradiation of the laser light L by the irradiation unit 13 so as to perform raster scanning within the laser irradiation range. Note that the change in the irradiation position with respect to the first surface 2a may be performed by moving the irradiation unit 13 instead of the sample stage 18, or may be performed by moving both the sample stage 18 and the irradiation unit 13.

[0045] By the third step described above, the components of the sample S on the first surface 2a are ionized, and sample ions SI are released. Specifically, energy is transferred from the conductive layer 3 that has absorbed the energy of the laser light L to the components of the sample S on the first surface 2a. The components that have acquired energy vaporize and acquire charges to become sample ions SI. The released sample ions SI move while accelerating toward a ground electrode (not shown) provided between the sample support 1 and the ion detection unit 15. That is, the sample ions SI move while accelerating toward the ground electrode due to the potential difference generated between the conductive layer 3 to which a voltage is applied and the ground electrode. Then, the sample ions SI are detected by the ion detection unit 15 (fourth step).

[0046] The above-described first to third steps correspond to an ionization method using the sample support 1. Further, the above-described first to fourth steps correspond to a mass spectrometry method using the sample support 1. Also, by mapping the intensity of the sample ions SI detected in the fourth step for each irradiation position of the laser beam L, an MSI image showing the two-dimensional distribution of the sample molecules can be obtained. Thereby, mass spectrometry imaging (MSI) can be performed.

[0047] [Function and Effect] In the sample support 1, as shown in FIGS. 3 and 5, the substrate 2 includes a void 2d that opens to the first surface 2a. Thereby, when the sample S is introduced onto the first surface 2a of the substrate 2 (in this embodiment, the first conductive region 31 on the first surface 2a; the same applies hereinafter), the sample S diffuses moderately into the void 2d of the substrate 2, and the amount of the sample S remaining on the first surface 2a is appropriately adjusted. As a result, the sample S remaining on the first surface 2a can be preferably ionized.

[0048] Also, as shown in FIGS. 4 and 6, the void 2d of the substrate 2 also opens to the side surface 2c. That is, the first surface 2a and the side surface 2c communicate with each other through the void 2d inside the substrate 2. Thereby, for example, when the sample support 1 having the sample S transferred onto the first surface 2a of the sample support 1 is introduced into a vacuum device (a part of the above-described mass spectrometer 10), degassing of the substrate 2 (that is, discharge of the gas accumulated in the void 2d from the side surface 2c) can be preferably performed. That is, as shown in FIG. 9(A), since the side surface 2c is not blocked, the gas accumulated inside the substrate 2 can be discharged to the outside from the side surface 2c, so that the speed of the degassing operation (vacuum attainment speed) can be improved. Further, since it is difficult for gas to remain inside the substrate 2, it is possible to suppress the detection of the sample ions SI by the ion detection unit 15 from being inhibited by the residual gas in the above-described ionization step (third step).

[0049] Also, as shown in FIG. 9(B), when transferring the sample S onto the entire surface of the first surface 2a, the gas introduced from the first surface 2a into the inside of the substrate 2 can escape from the opening of the side surface 2c. Therefore, it is possible to suppress the accumulation of unnecessary gas (residual gas) inside the substrate 2, and thus suppress the occurrence of transfer unevenness caused by the residual gas. Additionally, as shown in FIG. 9(B), when transferring the sample S, a protective tape T or the like may be provided on the second surface 2b, so that the second surface 2b may not be exposed to the outside. For this reason, even if the void 2d inside the substrate 2 communicates from the first surface 2a to the second surface 2b, when the side surface 2c is blocked, there will be no escape path for the gas introduced from the first surface 2a into the inside of the substrate 2 during transfer. On the other hand, in the sample support 1, as described above, since the void 2d is configured to also open to the side surface 2c, even when transferring the sample S onto the entire surface of the first surface 2a, degassing during transfer can be suitably performed. Further, when using a plurality of sample supports 1 arranged in the X-axis direction or the Y-axis direction (for example, when the size of the sample S to be analyzed does not fit within the measurement surface (first surface 2a) of one sample support 1), the side surfaces 2c of the substrates 2 of the respective sample supports 1 are open, so that the continuity of the adjacent sample supports 1 (substrates 2) can be maintained.

[0050] Furthermore, at least a part of the outer surface of the side surface 2c of the substrate 2 is a rough surface 21a on which the concavo-convex structure 4 is formed. Thereby, for example, when an operator holds the side surface 2c of the substrate 2 with a finger or holds the side surface of the substrate 2 using a tool for supporting the sample support 1, the rough surface 21a (concavo-convex structure 4) exhibits an anti-slip function, so that the handleability of the sample support 1 can be improved. As described above, according to the sample support 1, high-precision analysis can be achieved and the handleability can be improved.

[0051] As shown in FIG. 4, the side particle 20B has a non-rough surface 21b on the side opposite to the rough surface 21a where the concavo-convex structure 4 is not formed. By setting the inner surface of the side particle 20B as the non-rough surface 21b, the bonding strength between the side particle 20B and the particle 20 located inside the side particle 20B can be sufficiently ensured, and spillage of the side particle 20B can be suppressed. Further, by not providing the concavo-convex structure 4 inside the side particle 20B, the gas flow (for example, the flow of the residual gas described above) inside the side particle 20B can be made smoother compared to the case where the concavo-convex structure 4 is also formed inside the side particle 20B, and thus, gas venting from the opening of the side surface 2c can be preferably performed.

[0052] On the rough surface 21a of the side particle 20B, a substance (hereinafter referred to as "specific substance") that emits ions in response to irradiation with the laser beam L is disposed. Examples of the specific substance include a metal film, a substance having light absorption properties (for example, an organic material that absorbs ultraviolet light, a dye, etc.). In the present embodiment, as shown in FIG. 4, a conductive layer 3 (second conductive region 32) is disposed on the rough surface 21a. Since the conductive layer 3 is a metal film, it corresponds to the specific substance. According to the sample support 1, by irradiating the entire first surface 2a of the sample support 1 (the whole including the side surface 2c when viewed from the Z-axis direction) with the laser beam L, the components (molecules) of the sample S present on the first surface 2a are ionized, and in the imaging result (the MSI image described above) obtained by performing mass spectrometry imaging (MSI) for two-dimensionally visualizing the spatial distribution of the ionized components, the portion corresponding to the side surface 2c of the substrate 2 (that is, the outer edge of the sample support 1) can be clarified. More specifically, since the rough surface 21a is provided with the concavo-convex structure 4 (edge structure), the energy of the laser beam L is easily absorbed by the edge portion of the rough surface 21a. As a result, the components of the specific substance (a part of the conductive layer 3 (second conductive region 32) in the present embodiment) on the surface of the edge portion are preferably ionized and easily desorbed, and thus, in the MSI image, the location corresponding to the outer edge of the sample support 1 can be easily and accurately recognized.

[0053] Referring to FIG. 10, the above effects will be supplemented. In FIG. 10, the overall image P is a part of a camera image (scan image) obtained by a camera (for example, the camera 16 of the mass spectrometer 10 described above). The image P is obtained by arranging the sample support 100 of the comparative example and the sample support 1 of the example side by side on a predetermined support plate (a black plate having a plurality of groove portions shown in the central portion of the image P), and photographing a part of one outer edge (a portion including the side surface 2c) of the comparative example and a part of one outer edge (a portion including the side surface 2c) of the example. The sample support 100 of the comparative example is different from the sample support 1 in that the outer surface of the side particles 20B is a smooth surface similar to the surface 21 of the particles 20A (that is, the rough surface 21a like the side particles 20B of the sample support 1 is not formed).

[0054] In FIG. 10, the partial images P1 and P2 arranged so as to be superimposed on the image P show the imaging results (a part of the MSI image) at the corresponding locations. That is, the image P1 shows a part of the MSI image of the portion including the outer edge (side surface 2c) of the comparative example (sample support 100). The image P2 shows a part of the MSI image of the portion including the outer edge (side surface 2c) of the example (sample support 1). As shown in the images P1 and P2 of FIG. 10, it was confirmed that a higher signal intensity was obtained at the outer edge (side surface 2c) of the sample support (substrate 2) in the example (image P2) than in the comparative example (image P1). That is, it was confirmed that by making the outer surface of the side particles 20B a rough surface 21a, an image P2 with higher clarity of the outer edge of the sample support 1 than the image P1 was obtained. As a result, the position of the outer edge (the boundary line corresponding to the side surface 2c) of the sample support 1 in the MSI image can be easily and accurately grasped. As a result, for example, it becomes possible to easily and accurately perform the alignment between the camera image (image P) and the MSI image (the image including the image P2), and the accuracy of the analysis (mass spectrometry imaging) can be improved.

[0055] As shown in FIG. 4, the second conductive region 32 is provided along the surface shape of the concavo-convex structure 4 on at least a part of the rough surfaces 21a of the plurality of side particles 20B. For example, when ionizing the components of the sample S remaining on the first surface 2a by the laser desorption ionization method or the like as described above, it is necessary to apply a voltage to the conductive layer 3 (the first conductive region 31) on the first surface 2a. In order to stably apply a voltage to the first conductive region 31, it is preferable to also apply a voltage to the side surface 2c, and it is preferable to provide the second conductive region 32 on the side surface 2c. And since the second conductive region 32 is provided along the surface shape of the concavo-convex structure 4 on at least a part of the rough surfaces 21a of the plurality of side particles 20B, the above-described effect (clarification of the outer edge of the sample support 1 in the MSI image) can be obtained. Further, as a configuration for applying a voltage to the first conductive region 31, the sample support 1 is placed on a conductive sample stage (in this embodiment, the support substrate 8), and the support substrate 8 and the conductive layer 3 of the sample support 1 are connected by a conductive tape 9. Thus, a configuration in which a voltage is applied to the conductive layer 3 via the support substrate 8 and the conductive tape 9 can be considered. According to the sample support 1, in the case of adopting such a configuration, the conductive tape 9 is provided so as to cover the conductive layer 3 on the rough surface 21a of the side particle 20B (that is, a portion having the same surface shape as the concavo-convex structure 4 of the rough surface 21a of the side particle 20B in the second conductive region 32). Thereby, the anchor effect by the concavo-convex structure 4 can be exerted, and the adhesive force of the conductive tape 9 to the second conductive region 32 can be enhanced. As a result, it becomes possible to stably and surely apply a voltage to the conductive layer 3.

[0056] The thickness (average thickness) of the conductive layer 3 in the second conductive region 32 may be made smaller than the thickness (average thickness) of the conductive layer 3 in the first conductive region 31. For example, the amount (film formation amount) of the second conductive region 32 per unit area may be made less than the amount (film formation amount) of the first conductive region 31 per unit area. For example, when the conductive layer 3 is formed by vapor deposition, the conductive layer 3 may be formed so that "the thickness of the second conductive region 32 < the thickness of the first conductive region 31" by making the vapor deposition direction with respect to the first surface 2a different from the vapor deposition direction with respect to the side surface 2c. According to the above configuration, for the first conductive region 31 on the first surface 2a, a constant thickness can be ensured, and a voltage can be stably applied to the first surface 2a during analysis. On the other hand, for the second conductive region 32 on the side surface 2c, by reducing the thickness of the conductive layer 3, the above effects (that is, the improvement of the adhesive force of the conductive tape 9 to the second conductive region 32 due to the anchor effect, and the clarification of the outer edge of the sample support 1 in the MSI image) can be obtained more preferably.

[0057] As shown in FIGS. 1 and 7, the first surface 2a of the substrate 2 has a rectangular shape, and the conductive layer 3 is not provided at the portions corresponding to the four corners of the first surface 2a. In the present embodiment, as an example, regions where the first surface 2a is exposed in a triangular shape are provided at the four corners of the first surface 2a. By not providing the conductive layer 3 at the portions corresponding to the four corners of the first surface 2a, it becomes easy to visually distinguish the portion where the conductive layer 3 is provided on the first surface 2a (that is, the first conductive region 31) from the portions corresponding to the four corners of the first surface 2a. Thereby, when aligning the sample stage 18 in a state where the sample support 1 is placed on the sample stage 18 of the mass spectrometer 10, etc., the alignment can be facilitated by using the portions corresponding to the four corners of the first surface 2a as marks.

[0058] As shown in FIGS. 2 and 8, the side surface 2c includes an inclined region that inclines so as to spread outward from the first surface 2a toward the second surface 2b. According to the above configuration, when the sample support 1 is placed on a sample stage or the like (in this embodiment, the support substrate 8) during analysis, the stability of the sample support 1 can be improved. Further, when the conductive tape 9 as described above is provided so as to cover the edge of the first surface 2a, the inclined region of the side surface 2c, and the upper surface (support surface 8a) of the support substrate 8, the adhesion between the conductive tape 9 and the sample support 1 can be enhanced. That is, since it is possible to suppress the occurrence of a gap between the conductive tape 9 and the side surface 2c and the support surface 8a of the sample support 1, the sample support 1 can be stably fixed to the support surface 8a, and the peeling of the conductive tape 9 can be suppressed. Further, by inclining the side surface 2c as described above, in the laser desorption ionization method described above, the laser light L is likely to hit the rough surface 21a of the side particles 20B, so that the above-described effect (that is, the clarification of the outer edge of the sample support 1 in the MSI image) described with reference to FIG. 10 can be obtained more preferably.

[0059] [Modification Example] The present disclosure is not limited to the above-described embodiments. For the materials and shapes of each component, various materials and shapes can be adopted, not limited to the materials and shapes described above. Further, some components 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. However, the sample support according to the present disclosure does not necessarily have 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 only needs to include a configuration essential for exhibiting at least the part of the effects, and a configuration not essential for exhibiting the part of the effects may be omitted or changed as appropriate. Hereinafter, some modification examples of the sample support of the present disclosure will be exemplified.

[0060] In the above-described embodiment, glass, ceramic, etc. were exemplified as the material of the particles 20. However, the particles 20 may be formed of a conductive material (for example, a metal such as aluminum). In this case, the conductive layer 3 in the above-described embodiment can be omitted.

[0061] In the above-described embodiment, since the ionization method by the laser desorption ionization method was used, the conductive layer 3 was provided on the surface of the insulating substrate 2 in order to impart conductivity to the sample support 1. However, when conductivity is not required for the sample support 1 (or when electrical insulation is required), the conductive layer 3 may be omitted. In this case, it becomes possible to use the sample support 1 for a desorption electrospray ionization method (DESI: Desorption Electrospray Ionization) or the like that irradiates charged microdroplets onto the first surface 2a of the substrate 2.

[0062] In the above-described embodiment, since the substrate 2 is constituted by an aggregate of a plurality of particles 20 (a sintered body of glass beads) as shown in FIGS. 5 and 6, the void 2d opens to the first surface 2a and the side surface 2c and also opens to the second surface 2b. However, the void 2d does not necessarily have to open to the second surface 2b. For example, the substrate 2 may be constituted by a flat plate including the second surface 2b and a porous structure (that is, a plurality of particles 20) provided on the surface of the plate opposite to the second surface 2b. As an example, the substrate 2 may be constituted by a glass plate and a porous structure provided on the glass plate.

[0063] In the above-described embodiment, as shown in FIG. 6, the outer surfaces of the side particles 20B in substantially the entire region constituting the side surface 2c (the outermost surface when viewed from the Z-axis direction) are made into a rough surface 21a including the concavo-convex structure 4. However, it is not necessarily the case that the outer surfaces of the side particles 20B in substantially the entire region are made into the rough surface 21a. That is, it is sufficient that the outer surfaces of at least a part of the plurality of side particles 20B constituting the side surface 2c are made into the rough surface 21a. For example, only the outer surfaces of the side particles 20B belonging to a partial range (a partial region continuous with the first surface 2a) on the first surface 2a side of the side surface 2c may be made into the rough surface 21a.

[0064] In the above embodiment, as shown in FIG. 2, the entire side surface 2c is formed as an inclined region that inclines outward as it extends from the first surface 2a toward the second surface 2b. However, only a part of the side surface 2c (for example, a part on the side connected to the first surface 2a) may be inclined. Further, it is not essential for the side surface 2c to include an inclined region. For example, the side surface 2c may be formed to extend along a direction (Z-axis direction) perpendicular to the first surface 2a and the second surface 2b.

[0065] In the above embodiment, the conductive layer 3 continuously provided on the first surface 2a and the side surface 2c is used as a specific substance. However, in the case where the conductive layer 3 itself is omitted as described above, for the purpose of obtaining only the effect (clarification of the outer edge of the sample support 1 in the MSI image) as described with reference to FIG. 10, a specific substance different from the conductive layer 3 may be disposed (for example, formed into a film) on the rough surface 21a. Alternatively, at least a part of the plurality of side particles 20B (for example, the side particles 20B themselves) may be formed of a specific substance. In this case, the side particles 20B themselves are ionized. Even with such a configuration, an MSI image in which the outer edge of the sample support 1 is clarified can be obtained.

[0066] The shape of the particles 20 is not limited to a substantially spherical shape and may have a shape other than a substantially spherical shape.

[0067] In the above embodiment, an example in which the sample support 1 is used in a mass spectrometry method is shown. However, the sample support 1 can be used for various analysis applications including ionization of samples other than mass spectrometry. Further, the use of the sample support 1 is not limited to ionization of a sample by irradiation with a laser beam L such as the laser desorption ionization method shown in the above embodiment. The sample support 1 can also be used for ionization of a sample by irradiation with an energy beam other than a laser beam. For example, the sample support 1 can also be used for ionization of a sample by irradiation with an energy beam such as electrospray, an ion beam, or an electron beam. In the ionization method and mass spectrometry method described above, a sample can be ionized by irradiation with such an energy beam.

Explanation of Symbols

[0068] 1…Sample support, 2…Substrate (porous substrate), 2a…First surface, 2b…Second surface, 2c…Side surface, 2d…Void, 3…Conductive layer, 4…Uneven structure, 20, 20A…Particles, 20B…Side surface particles, 21…Surface, 21a…Rough surface, 21b…Non-rough surface, 31…First conductive region, 32…Second conductive region, L…Laser beam (energy beam), S…Sample.

Claims

1. A sample support for ionizing a sample, comprising: a porous substrate having a first surface, a second surface opposite to the first surface, a side surface connecting an edge of the first surface and an edge of the second surface, and voids distributed so as to open at least in the first surface and the side surface; the porous substrate is formed by a plurality of particles connected to each other; a sample support, wherein at least a part of the outer surfaces of a plurality of side particles constituting the side surface among the plurality of particles are rough surfaces on which an uneven structure is formed.

2. The sample support according to claim 1, wherein at least a part of the plurality of side particles has a non-rough surface on which the uneven structure is not formed on the side opposite to the rough surface.

3. The sample support according to claim 1, wherein at least a part of the plurality of side particles is formed of a substance that emits ions in response to irradiation with energy rays.

4. The sample support according to claim 1, wherein a substance that emits ions in response to irradiation with energy rays is disposed on at least a part of the rough surface of the plurality of side particles.

5. further comprising a conductive layer provided on the surface of the porous substrate, the conductive layer includes a first conductive region provided on the first surface so as not to block the opening of the void in the first surface, and a second conductive region connected to the first conductive region and provided on the side surface so as not to block the opening of the void in the side surface; The sample support according to claim 1, wherein the second conductive region is provided along the surface shape of the uneven structure on at least a part of the rough surface of the plurality of side particles.

6. The sample support according to claim 5, wherein the thickness of the conductive layer in the second conductive region is smaller than the thickness of the conductive layer in the first conductive region.

7. The first surface has a rectangular shape, The sample support according to claim 5, wherein the conductive layer is not provided at portions corresponding to the four corners of the first surface.

8. The sample support according to claim 1, wherein the side surface includes an inclined region that inclines so as to spread outward from the first surface toward the second surface.

Images