JP7626666B2 - Sample Support - Google Patents

Description

This disclosure relates to a sample support.

Technology relating to a sample support used in mass analysis of a sample is known (see, for example, Patent Document 1). In the technology described in Patent Document 1, a sample attached to the fine uneven surface of a sample support is irradiated with laser light, thereby ionizing the sample, and mass analysis of the sample is performed.

Patent No. 4674875

In the above-mentioned techniques, when performing different analyses on a sample, the sample must be attached to each of multiple sample supports, which may make the work complicated. Furthermore, when the sample is attached to each of multiple sample supports, there may be variation in the amount of sample attached to each sample support or the condition of the sample attached to each sample support, which may reduce the accuracy of the analysis of the sample.

The present disclosure aims to provide a sample support that enables highly efficient and highly accurate analysis of samples.

A sample support according to one aspect of the present disclosure is a sample support used for ionizing a sample, and includes a substrate having a surface and a plurality of holes opening into the surface, the substrate having at least a first measurement region including a first surface region of the surface and a second measurement region including a second surface region of the surface, the first surface region being provided with a first conductive layer so as not to block the holes, and the second surface region being free of the first conductive layer.

In this sample support, the substrate has a first measurement region and a second measurement region. Thus, by pressing the sample support against the sample once, the sample can be attached to both the first measurement region and the second measurement region. Moreover, the first surface region of the first measurement region is provided with a first conductive layer, and the second surface region of the second measurement region is not provided with the first conductive layer. Thus, in the first measurement region, for example, mass analysis of the sample can be performed by irradiating the first surface region with an energy beam, and in the second measurement region, an analysis of the sample different from that in the first measurement region can be performed. In this way, according to this sample support, different analyses of the sample can be efficiently performed by one sample support. Furthermore, by pressing the sample support against the sample once, the sample can be attached to both the first measurement region and the second measurement region, so that the variation between the amount of sample attached to the first measurement region and the amount of sample attached to the second measurement region can be suppressed. As a result, the analysis in the first measurement region and the second measurement region can be performed with high accuracy. As described above, according to this sample support, it is possible to perform a highly efficient and highly accurate analysis of the sample.

The first conductive layer may be formed of a material suitable for mass analysis of the sample. This allows the mass analysis of the sample to be suitably performed in the first measurement region.

The second measurement area is optically transparent, and the second surface area of the second measurement area and the surface area of the second measurement area opposite the second surface area may be exposed. This allows light to pass through the second measurement area, allowing the light transmittance of the sample attached to the second measurement area to be analyzed.

The thickness of the substrate may be 5 μm to 50 μm. This ensures the strength of the substrate while ensuring the optical transparency of the second measurement region.

A second conductive layer may be provided on the second surface region of the second measurement region so as not to block the holes and which is made of a material different from that of the first conductive layer. This allows a different analysis of the sample to be performed in the second measurement region than in the first measurement region.

The first and second measurement regions may be connected to each other. This makes it possible to more reliably suppress variation between the amount of sample adhering to the first and second measurement regions while ensuring the areas of the first and second measurement regions.

The sample support may further include a partition provided between the first and second measurement regions. This makes it possible to reinforce the strength of the substrate while clarifying the boundary between the first and second measurement regions.

The substrate may further have a third measurement area including a third surface area of the surface, and the third surface area may be provided with a third conductive layer that does not block the holes and is made of a material different from that of the first conductive layer. This allows the sample to be analyzed in the third measurement area in a manner different from that of the first measurement area.

The substrate has a rectangular plate shape, and may have multiple calibration regions located at different corners of the substrate when viewed in the thickness direction of the substrate. This allows calibration corresponding to the analysis in each measurement region to be performed while ensuring the area of each measurement region.

The present disclosure provides a sample support that enables highly efficient and highly accurate analysis of samples.

FIG. 1 is a plan view of a sample support according to the first embodiment. FIG. 2 is a schematic cross-sectional view of the sample support taken along the line II-II in FIG. FIG. 3 is a schematic cross-sectional view of the sample support taken along line III-III in FIG. FIG. 4 shows an enlarged image of the substrate of the sample support of FIG. FIG. 5 is a diagram showing a comparison result between the light transmittance of a portion including the first measurement region and the first conductive layer and the light transmittance of a second measurement region of the sample support in FIG. FIG. 6 is a diagram showing some of the steps of a mass spectrometry method using the sample support of FIG. FIG. 7 is a diagram showing some of the steps of a mass spectrometry method using the sample support of FIG. FIG. 8 is a diagram showing some of the steps of a mass spectrometry method using the sample support of FIG. FIG. 9 is a diagram showing some of the steps of a mass spectrometry method using the sample support of FIG. FIG. 10 is a plan view of the sample support of the second embodiment. FIG. 11 is a cross-sectional view taken along line XI-XI in FIG. FIG. 12 is a plan view of a sample support according to a first modified example. FIG. 13 is a plan view of a sample support according to a second modified example. FIG. 14 is a schematic cross-sectional view taken along line XIV-XIV in FIG. FIG. 15 is a plan view of a sample support according to a third modified example. FIG. 16 is a schematic cross-sectional view taken along line XVI-XVI in FIG.

Embodiments of the present disclosure will be described below with reference to the drawings. In each drawing, identical or equivalent parts are given the same reference numerals, and duplicated explanations will be omitted. Note that some parts in the drawings are exaggerated to more clearly explain the characteristic parts of the embodiment, and may differ from the actual dimensions.

[First embodiment]
[Configuration of sample support]
A sample support 1A of the first embodiment will be described with reference to Figures 1 to 4. The sample support 1A is an ionization-assisting substrate used for ionizing a sample. In this embodiment, the sample support 1A is used for ionizing a sample applied to human skin (skin surface). More specifically, the sample support 1A is pressed against the sample applied to the human skin, thereby attaching the sample to the sample support 1A. Thereafter, the sample support 1A to which the sample has been attached is ionized by irradiating the sample support 1A with an energy beam such as a laser beam. Examples of samples include medicines, cosmetics, and the like.

As shown in Figures 1 to 3, the sample support 1A includes a substrate 2, a frame 3, and a conductive layer (first conductive layer) 5. As shown in Figure 1, the sample support 1A has a substantially rectangular shape in a plan view. In this embodiment, the direction along the long side of the sample support 1A is represented as the X-axis direction, the direction along the short side of the sample support 1A is represented as the Y-axis direction, and the direction perpendicular to the X-axis direction and the Y-axis direction (i.e., the thickness direction of the sample support 1A) is represented as the Z-axis direction. As an example, the length of the sample support 1A in the X-axis direction is about 3 cm, and the length in the Y-axis direction is about 2 cm.

The substrate 2 has a first surface 2a and a second surface 2b opposite to the first surface 2a. As shown in FIG. 3, a plurality of holes 2c are uniformly (uniformly distributed) formed in the substrate 2. Each hole 2c extends along the thickness direction D of the substrate 2 (the direction in which the first surface 2a and the second surface 2b face each other and coincide with the Z-axis direction) and opens to the first surface 2a and the second surface 2b. In other words, each hole 2c is a through hole penetrating the substrate 2. Note that the holes 2c are not shown in FIG. 2. The first surface 2a is the surface that is irradiated with an energy beam such as a laser beam in the process of ionizing the components of the sample attached to the sample support 1A.

The substrate 2 has a rectangular plate shape. When viewed from the thickness direction D, the length of one side of the substrate 2 is, for example, about several centimeters. The thickness of the substrate 2 is, for example, about 1 μm to 50 μm. As an example, the thickness of the substrate 2 is 5 μm to 50 μm. The thickness of the substrate 2 is preferably 5 μm to 20 μm. This ensures the optical transparency of the substrate 2, which will be described later. When viewed from the thickness direction D, the shape of the hole 2c is, for example, approximately circular. The width of the hole 2c is, for example, about 1 nm to 700 nm. The substrate 2 is formed from an insulating material.

The width of the hole 2c is a value obtained as follows. First, images of the first surface 2a and the second surface 2b of the substrate 2 are obtained. FIG. 4 shows an example of an SEM image of a part of the first surface 2a of the substrate 2. In the SEM image, the black parts are the holes 2c, and the white parts are the partitions between the holes 2c. Next, the image of the first surface 2a obtained is subjected to, for example, a binarization process to extract a plurality of pixel groups corresponding to a plurality of first openings (openings on the first surface 2a side of the holes 2c) in the measurement region R, and the diameter of a circle having an average area of the first openings is obtained based on the size per pixel. Similarly, the image of the second surface 2b obtained is subjected to, for example, a binarization process to extract a plurality of pixel groups corresponding to a plurality of second openings (openings on the second surface 2b side of the holes 2c) in the measurement region R, and the diameter of a circle having an average area of the second openings is obtained based on the size per pixel. Then, the average value of the diameter of the circle obtained for the first surface 2a and the diameter of the circle obtained for the second surface 2b is obtained as the width of the hole 2c.

As shown in FIG. 4, a plurality of holes 2c having a substantially uniform width are uniformly formed on the substrate 2. The substrate 2 shown in FIG. 4 is an alumina porous film formed by anodizing Al (aluminum). For example, an anodizing process is performed on the Al substrate, whereby the surface portion of the Al substrate is oxidized and a plurality of pores (portions that will become the pores 2c) are formed on the surface portion of the Al substrate. The oxidized surface portion (anodized film) is then peeled off from the Al substrate, and the peeled anodized film is subjected to a pore widening process to widen the pores, thereby obtaining the substrate 2 described above. The substrate 2 may be formed by anodizing a valve metal other than Al, such as Ta (tantalum), Nb (niobium), Ti (titanium), Hf (hafnium), Zr (zirconium), Zn (zinc), W (tungsten), Bi (bismuth), or Sb (antimony), or may be formed by anodizing Si (silicon).

The frame 3 is provided on the first surface 2a of the substrate 2 and supports the substrate 2 on the first surface 2a side. The frame 3 has a first surface 3h that faces the first surface 2a of the substrate 2 and a second surface 3g that is opposite the first surface 3h. In this embodiment, when viewed from the thickness direction D, the frame 3 is formed in a rectangular plate shape that is larger than the substrate 2.

An opening 3a is formed in the approximate center of the frame 3, penetrating the frame 3 in the thickness direction (i.e., thickness direction D). Openings 31b, 32b are formed in a pair of opposing corners of the frame 3, penetrating the frame 3 in the thickness direction. A recess 3d is provided in the center of the edge 3c in the X-axis direction (i.e., the edge along the Y-axis direction) of the frame 3, recessed inward in the X-axis direction.

The opening 3a is formed in a substantially circular shape. In this embodiment, the opening 3a has a shape in which a part of a circle (parts facing each other in one direction) is cut out in a bow shape. Specifically, the opening 3a has a shape in which a part of a circle is cut out in a bow shape so that both edges in the Y-axis direction are parallel to the X-axis direction. As an example, the width of the opening 3a in the Y-axis direction is about 1.5 cm. The part of the substrate 2 corresponding to the opening 3a (i.e., the part overlapping with the opening 3a when viewed from the thickness direction D) functions as a measurement region R for measuring the sample. That is, the measurement region R is defined by the opening 3a provided in the frame 3. In other words, the opening 3a opens on the first surface 3h and the second surface 3g so as to correspond to the measurement region R. That is, the frame 3 is formed so as to surround the measurement region R of the substrate 2 when viewed from the thickness direction D.

Openings 31b and 32b are formed in a circular shape smaller than opening 3a. As an example, openings 31b and 32b have a diameter of about 1 mm. The portions of substrate 2 corresponding to openings 31b and 32b (i.e., the portions overlapping openings 31b and 32b when viewed from thickness direction D) function as calibration areas C1 and C2 for calibration.

As described above, multiple holes 2c are uniformly formed in the substrate 2, so both the measurement region R and the calibration regions C1 and C2 are regions that include multiple holes 2c. The aperture ratio of the holes 2c in the measurement region R (the proportion of the holes 2c in the measurement region R when viewed from the thickness direction D) is practically 10 to 80%, and preferably 60 to 80%. The multiple holes 2c may be of different sizes, or multiple holes 2c may be partially connected to each other. The same applies to the measurement region R for the calibration regions C1 and C2.

The frame 3 is, for example, a metal or a ceramic. In this embodiment, the frame 3 is made of a material that is non-magnetic and acid-resistant. Examples of such materials include titanium and stainless steel (SUS). In this embodiment, the frame 3 is made of SUS. The outer shape of the sample support 1A is determined mainly by the frame 3. The length of the frame 3 in the X-axis direction is about 3 cm, and the length of the frame 3 in the Y-axis direction is about 2 cm. The thickness of the frame 3 is, for example, 3 mm or less. As an example, the thickness of the frame 3 is 0.2 mm.

In this embodiment, as shown in FIG. 1, when viewed from the thickness direction D, the substrate 2 is contained between a pair of edges 3e along the X-axis direction of the frame 3, and is also contained between the bottoms 3f of a pair of recesses 3d of the frame 3. Portions of the substrate 2 other than the measurement region R and the calibration regions C1 and C2 are bonded to the frame 3 by an adhesive layer 6. By bonding and supporting the substrate 2 to the frame 3 in this manner, handling of the sample support 1A is facilitated, and deformation of the substrate 2 due to temperature changes, etc. is suppressed.

As shown in FIG. 3, the frame 3 is bonded to the first surface 2a of the substrate 2 by an adhesive layer 6. The adhesive layer 6 is formed between the first surface 2a of the substrate 2 and the first surface 3h of the frame 3, and bonds the substrate 2 and the frame 3. Note that the adhesive layer 6 is not shown in FIG. 2. The adhesive layer 6 may be formed, for example, of an adhesive that emits little gas (for example, low-melting-point glass, vacuum adhesive, etc.). The adhesive layer 6 may be formed of a conductive adhesive, or may be formed by applying a metal paste. The adhesive layer 6 may be formed of a UV-curable adhesive (photo-curable adhesive) or an inorganic binder, etc. Examples of UV-curable adhesives include acrylic adhesives and epoxy adhesives. Examples of inorganic binders include Ceramabond (registered trademark) manufactured by Odec Co., Ltd. and Aronceramic (registered trademark) manufactured by Toagosei Co., Ltd. As an example, in this embodiment, the adhesive layer 6 is formed of a UV-curable adhesive.

The conductive layer 5 is provided on the first surface 2a of the substrate 2. As shown in FIG. 3, the conductive layer 5 is formed continuously (integrally) on a part of the region of the first surface 2a of the substrate 2 corresponding to the opening 3a of the frame 3 (i.e., a part of the measurement region R), the inner surface of the opening 3a, and the second surface 3g of the frame 3 at the periphery of the opening 3a. The conductive layer 5 covers the part of the first surface 2a of the substrate 2 where the holes 2c are not formed in the measurement region R. That is, the conductive layer 5 is provided so as not to block each hole 2c. Therefore, in the measurement region R, each hole 2c is exposed to the opening 3a. The conductive layer 5 is also formed continuously (integrally) on the region of the first surface 2a of the substrate 2 corresponding to the opening 31b of the frame 3 (i.e., the calibration region C1), the inner surface of the opening 31b, and the second surface 3g of the frame 3 at the periphery of the opening 31b. The conductive layer 5 covers the part of the first surface 2a of the substrate 2 where the holes 2c are not formed in the calibration region C1. In other words, the conductive layer 5 is provided so as not to block each hole 2c. Therefore, in the calibration area C1, as in the measurement area R, each hole 2c is exposed to the opening 31b.

The conductive layer 5 is formed of a conductive material. The conductive layer 5 is formed of a material suitable for mass analysis of the sample. Specifically, the conductive layer 5 is formed of, for example, Pt (platinum) or Au (gold). For the reasons described below, it is preferable to use a metal that has low affinity (reactivity) with the sample and high conductivity as the material for the conductive layer 5.

For example, if the conductive layer 5 is made of a metal such as Cu (copper) that has a high affinity with samples such as proteins, during the sample ionization process described below, the sample may be ionized with Cu atoms added to the sample molecules, and the detection results may be shifted by the amount of the added Cu atoms in the mass spectrometry method described below. Therefore, it is preferable to use a metal that has a low affinity with samples as the material for the conductive layer 5.

On the other hand, the higher the conductivity of the metal, the easier and more stable the application of a constant voltage. Therefore, when the conductive layer 5 is made of a metal with high conductivity, it becomes possible to uniformly apply a voltage to the first surface 2a of the substrate 2 in the measurement region R. In addition, the higher the conductivity of the metal, the higher the thermal conductivity tends to be. Therefore, when the conductive layer 5 is made of a metal with high conductivity, it becomes possible to efficiently transmit the energy of the laser light (energy ray) irradiated to the substrate 2 to the sample via the conductive layer 5. Therefore, it is preferable to use a metal with high conductivity as the material for the conductive layer 5.

From the above viewpoints, it is preferable to use, for example, Pt, Au, etc. as the material of the conductive layer 5. In this embodiment, the conductive layer 5 is Pt. The conductive layer 5 is formed to a thickness of about 1 nm to 350 nm by, for example, deposition or sputtering. Note that, for example, Cr (chromium), Ni (nickel), Ti (titanium), Ag (silver), etc. may also be used as the material of the conductive layer 5.

The sample support 1A is fixed to a slide glass (reinforcing substrate) 8 by a conductive tape 4. The conductive tape 4 is made of a conductive material. The conductive tape 4 is, for example, an aluminum tape, a carbon tape, or the like. The thickness of the conductive tape 4 is, for example, 100 μm.

The conductive tape 4 is attached onto the second surface 3g of the frame 3. In this embodiment, the conductive tape 4 is provided on both sides of the frame 3 in the X-axis direction. Specifically, the conductive tape 4 has a conductive tape 41 provided on one side of the frame 3 in the X-axis direction (the left side in FIG. 1 ) and a conductive tape 42 provided on the other side of the frame 3 in the X-axis direction (the right side in FIG. 1 ).

The conductive tape 41 is provided on one side (the left side in FIG. 1) of the center in the X-axis direction of the frame 3 so as not to cover the measurement region R and the calibration region C2. The conductive tape 42 is provided with a circular opening 41a for exposing the calibration region C2. As shown in FIG. 1, in this embodiment, the edge of the conductive tape 41 is slightly spaced from the edges 3c and 3e of the frame 3, the edge of the opening 3a of the frame 3, and the edge of the opening 32b of the frame 3. On the other hand, the conductive tape 41 is also provided at a position overlapping the space formed by the recess 3d of the frame 3 when viewed from the thickness direction D. That is, the conductive tape 41 has a portion 4b that does not overlap the frame 3 when viewed from the thickness direction D (i.e., a portion that overlaps the space formed by the recess 3d).

The conductive tape 42 is provided on the other side (the right side in FIG. 1) of the center in the X-axis direction of the frame 3 so as not to cover the measurement region R and the calibration region C1. The conductive tape 42 is provided with a circular opening 42a for exposing the calibration region C1. As shown in FIG. 1, in this embodiment, the edge of the conductive tape 42 is slightly spaced from the edges 3c and 3e of the frame 3, the edge of the opening 3a of the frame 3, and the edge of the opening 31b of the frame 3. On the other hand, the conductive tape 42 is also provided at a position overlapping the recess 3d of the frame 3 when viewed from the thickness direction D. That is, the conductive tape 42 has a portion 4b that does not overlap the frame 3 when viewed from the thickness direction D (i.e., a portion that overlaps with the space formed by the recess 3d). The portions 4b of the conductive tapes 41 and 42 are attached to the mounting surface 8a of the slide glass 8, thereby fixing the sample support 1A to the slide glass 8.

The slide glass 8 is a glass substrate on which a transparent conductive film such as an ITO (Indium Tin Oxide) film is formed, and the surface of the transparent conductive film serves as the mounting surface 8a. The slide glass 8 is fixed to the substrate 2 so as to cover at least the entire second surface 2b of the measurement region R of the substrate 2. As an example, the slide glass 8 has a rectangular shape larger than the outer shape of the frame 3 when viewed from the thickness direction D (Z-axis direction). That is, when viewed from the thickness direction D, all of the elements (substrate 2, frame 3, etc.) constituting the above-mentioned sample support 1A are contained within the slide glass 8. That is, the slide glass 8 covers not only the measurement region R but also the entire substrate 2. The sample support 1A is reinforced by the slide glass 8. Note that a substrate other than the slide glass 8 may be used as the reinforcing substrate for the sample support 1A.

Next, the substrate 2 and the measurement area R will be described in detail. The substrate 2 is optically transparent. Specifically, the partitions between the holes 2c of the substrate 2 are optically transparent. The substrate 2 is formed of an optically transparent material. The light is, for example, ultraviolet light or visible light. As described above, the measurement area R is defined by the opening 3a of the frame 3. The measurement area R is a part of the substrate 2. In other words, the measurement area R includes a part of the first surface 2a, a part of the second surface 2b, and a plurality of holes 2c.

The measurement region R has a first measurement region R1 and a second measurement region R2. When viewed from the thickness direction D, the first measurement region R1 is approximately half of the measurement region R on one side in the Y-axis direction (the lower side in FIG. 1). When viewed from the thickness direction D, the second measurement region R2 is approximately half of the measurement region R on the other side in the Y-axis direction (the upper side in FIG. 1). The first measurement region R1 and the second measurement region R2 are connected to each other. Specifically, the first measurement region R1 and the second measurement region R2 are each a continuous part of the substrate 2. In other words, the first measurement region R1 and the second measurement region R2 are not separated from each other. The first measurement region R1 and the second measurement region R2 are not separated by any other region. The boundary line B between the first measurement region R1 and the second measurement region R2 extends linearly along the X-axis direction.

The first measurement region R1 includes the first surface region 21a of the first surface 2a. The first surface region 21a is provided with a conductive layer 5. The second measurement region R2 includes the second surface region 22a of the first surface 2a. The second surface region 22a is not provided with a conductive layer 5. The second surface region 22a is exposed. That is, no film is formed on the second surface region 22a. The surface region opposite the second surface region 22a in the second measurement region R2 (a part of the second surface 2b of the substrate 2) is exposed. That is, no film is formed on the surface region opposite the second surface region 22a in the second measurement region R2. In this embodiment, the entire second surface 2b of the substrate 2 is exposed. That is, no film is formed on the entire second surface 2b.

The portion of the sample support 1A corresponding to the second measurement region R2 transmits light. For example, light irradiated from one side of the sample support 1A in the thickness direction D to the second measurement region R2 transmits through the sample support 1A and exits toward the other side of the sample support 1A in the thickness direction D. As shown in FIG. 5, the light transmittance of the portion of the sample support 1A corresponding to the second measurement region R2 is greater than the light transmittance of the portion of the sample support 1A corresponding to the first measurement region R1. This is because the light irradiated to the second measurement region R2 transmits through the sample support 1A, while the light irradiated to the first measurement region R1 is blocked by the conductive layer 5.

The calibration areas C1 and C2 are parts of the substrate 2. That is, the calibration areas C1 and C2 include a part of the first surface 2a, a part of the second surface 2b, and a plurality of holes 2c. The calibration areas C1 and C2 are located at different corners of the substrate 2. The calibration area C1 is adjacent to the first measurement area R1. Specifically, the calibration area C1 is located on the opposite side of the second measurement area R2 with respect to the boundary line B between the first measurement area R1 and the second measurement area R2 when viewed from the thickness direction D. The calibration area C1 is located at one corner of the substrate 2 adjacent to the first measurement area R1 when viewed from the thickness direction D. The surface area of the calibration area C1 (a part of the first surface 2a) is provided with a conductive layer 5.

The calibration area C1 can be used as an area for mass calibration. For example, before starting a sample measurement (a mass spectrometry method described below), a mass calibration sample (e.g., a peptide, etc.) can be placed in the calibration area C1 and the measurement can be performed, thereby correcting the mass spectrum. By performing such mass spectrum correction before measuring the sample to be measured, it is possible to obtain an accurate mass spectrum of the sample to be measured when the sample to be measured is measured.

The calibration area C2 is adjacent to the second measurement area R2. Specifically, when viewed from the thickness direction D, the calibration area C2 is located on the opposite side of the boundary line B between the first measurement area R1 and the second measurement area R2 from the first measurement area R1. When viewed from the thickness direction D, the calibration area C2 is located at one corner of the substrate 2 adjacent to the second measurement area R2. No conductive layer 5 is provided on the surface area of the calibration area C2 (part of the first surface 2a). The surface area of the calibration area C2 is exposed. In other words, no film is formed on the surface area of the calibration area C2.

The calibration area C2 can be used as a background measurement area. For example, the light transmittance of the calibration area C2, where no sample is attached, and the glass slide 8 can be measured, and the light transmittance of the second measurement area R2, where a sample is attached, and the glass slide 8 can be measured. Then, the difference between these light transmittances can be calculated to obtain the light transmittance of the sample alone. Note that a part of the second measurement area R2 may be used as the background measurement area. In this case, it is preferable to provide a mask or the like in advance to prevent the sample from adhering to the background measurement area.

Mass spectrometry method
Next, an example of a mass spectrometry method (including an ionization method) using the sample support 1A will be described with reference to Figures 6 to 9. Note that in Figures 6 to 9, the hole 2c, the conductive layer 5, and the adhesive layer 6 are omitted.

First, the above-mentioned sample support 1A is prepared in advance. Then, as shown in FIG. 6, the sample S is applied to the human skin 50 (the surface of the skin 50). The skin 50 is the skin of any part of the human body. The skin 50 can be determined according to the type and usage of the sample S. For example, if the sample S is a medicine or the like to be applied to the face, the skin 50 may be the skin of the forehead. Also, if the sample S is a sunscreen cream or the like, the skin 50 may be the skin of the arm. Also, before applying the sample S, the surface of the skin 50 may be disinfected with alcohol or the like. Alternatively, if the sample S is a cosmetic or the like and it is desired to analyze the state of the sample S during normal use (i.e., the state in which sebum and the sample S are mixed), it is possible not to disinfect the skin 50 before applying the sample S.

Next, with the first surface 2a of the substrate 2 facing the sample S applied to the human skin 50, the sample support 1A is pressed against the skin 50 to attach the sample S to the measurement region R. In other words, the sample S is transferred to the measurement region R. For example, in order to attach a sufficient amount of sample to the measurement region R of the sample support 1A, it may be necessary to press the sample support 1A against the sample S with a relatively large force. On the other hand, the substrate 2 of the sample support 1A is very thin. For this reason, if the force with which the sample support 1A is pressed against the sample S on the skin 50 is too strong, the substrate 2 (measurement region R portion) may be damaged.

Because the sample support 1A is reinforced by the glass slide 8, damage to the sample support 1A (particularly the substrate 2) during the process of attaching the sample S to the sample support 1A can be effectively suppressed. More specifically, the glass slide 8 as a reinforcing substrate increases the strength of the portion of the substrate 2 that includes the measurement region R, so that damage to the sample support 1A (substrate 2) can be suitably suppressed during the process of attaching the sample S and the subsequent process of detaching the sample support 1A from the skin 50.

As shown in FIG. 7, component S1, which is part of sample S on skin 50, adheres to measurement region R. Component S1 adheres to both first measurement region R1 and second measurement region R2. Component S1 adheres to both first measurement region R1 and second measurement region R2 by one sampling, that is, by pressing sample support 1A against sample S once. Therefore, the amount of component S1 adhering to first measurement region R1 and the amount of component S1 adhering to second measurement region R2 are approximately the same. The amount of component S1 adhering to measurement region R refers to the amount of component S1 per unit area.

Next, as shown in FIG. 8, the sample support 1A is placed on the support 12 of the mass spectrometer 10 while being previously integrated with the slide glass 8. The sample support 1A may be fixed to the slide glass 8 by conductive tapes 41 and 42, or may be fixed to the slide glass 8 via, for example, double-sided tape.

The mass spectrometer 10 includes a support 12, a sample stage 18, a camera 16, an irradiation unit 13, a voltage application unit 14, an ion detection unit 15, and a control unit 17. The support 12 is placed on the sample stage 18. The irradiation unit 13 irradiates the first surface 2a of the sample support 1A with an energy beam such as laser light L. The voltage application unit 14 applies a voltage to the first surface 2a of the sample support 1A. The ion detection unit 15 detects the components of the ionized sample S (sample ions S2). The camera 16 is a device that acquires a camera image including the position irradiated with 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 operation 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 equipped with a processor (e.g., a CPU, etc.) and a memory (e.g., a ROM, a RAM, etc.).

Then, the voltage application unit 14 applies a voltage to the conductive layer 5 (see FIG. 2) of the sample support 1A via the mounting surface 8a of the slide glass 8 and the conductive tape 4. The control unit 17 then operates the irradiation unit 13 based on the image acquired by the camera 16. Specifically, the control unit 17 operates the irradiation unit 13 so that the laser light L is irradiated to the first surface 2a within the laser irradiation range (e.g., the region of the first measurement region R1 where the component S1 identified based on the image acquired by the camera 16 exists).

As an example, the control unit 17 moves the sample stage 18 and controls the irradiation operation (irradiation timing, etc.) of the laser light L by the irradiation unit 13. That is, the control unit 17 confirms that the sample stage 18 has moved a predetermined distance, and then 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 raster scan the laser irradiation range. Note that the irradiation position on the first surface 2a may be changed by moving the irradiation unit 13 instead of the sample stage 18, or by moving both the sample stage 18 and the irradiation unit 13.

In this way, by applying a voltage to the conductive layer 5 and irradiating the first surface 2a within the laser irradiation range with the laser light L, the component S1 attached to the first measurement region R1 is ionized and the sample ion S2 (ionized component S1) is released. Specifically, energy is transmitted from the conductive layer 5 that absorbs the energy of the laser light L to the component S1 attached to the first measurement region R1, and the component S1 that has acquired the energy is vaporized and acquires an electric charge, becoming the sample ion S2. Each of the above steps corresponds to a method for ionizing component S1 using the sample support 1A (here, as an example, laser desorption ionization as part of a mass spectrometry method).

The released sample ions S2 move while accelerating toward a ground electrode (not shown) provided between the sample support 1A and the ion detection unit 15. In other words, the sample ions S2 move while accelerating toward the ground electrode due to the potential difference generated between the conductive layer 5 to which a voltage is applied and the ground electrode. The sample ions S2 are then detected by the ion detection unit 15.

The detection result of the sample ions S2 by the ion detection unit 15 is associated with the irradiation position of the laser light L. Specifically, the ion detection unit 15 detects the sample ions S2 individually for each position within the laser irradiation range. As a result, a distribution image (MS mapping data) showing the mass distribution of the sample S is obtained. Furthermore, the two-dimensional distribution of the molecules that make up the sample S can be imaged. In other words, imaging mass analysis can be performed. Note that the mass spectrometer 10 here is a mass spectrometer that utilizes time-of-flight mass spectrometry (TOF-MS).

Then, the light transmittance of the component S1 attached to the second measurement region R2 is measured. Specifically, as shown in FIG. 9, the sample support 1A is fixed to the slide glass 8 and placed on the support 23 of the light measurement device 20. The light measurement device 20 includes a light source 21, a light detection unit 22, and a support 23. The light source 21 irradiates light such as ultraviolet light U onto the first surface 2a of the sample support 1A. The light detection unit 22 detects the ultraviolet light U that has passed through the sample support 1A. The operations of the light source 21, the light detection unit 22, and the support 23 are controlled by the control unit. The control unit is a computer device having a configuration similar to that of the control unit 17.

Then, the light source 21 irradiates ultraviolet light U onto the surface region of the calibration region C2 and the second surface region 22a of the second measurement region R2. The ultraviolet light U irradiated onto the surface region of the calibration region C2 passes through the calibration region C2 and the slide glass 8, and is then detected by the light detection unit 22. The ultraviolet light U irradiated onto the second surface region 22a of the second measurement region R2 passes through the second measurement region R2, the component S1 attached to the second measurement region R2, and the slide glass 8, and is then detected by the light detection unit 22. Next, the difference between the light transmittance in the calibration region C2 and the light transmittance in the second measurement region R2 is calculated. This allows the light transmittance of the component S1 attached to the second measurement region R2 to be obtained. Next, the correlation between the results obtained using the first measurement region R1 (the results of imaging mass spectrometry) and the results obtained using the second measurement region R2 (the results of light transmittance) is analyzed.

As described above, in the sample support 1A, the substrate 2 has the first measurement region R1 and the second measurement region R2. This allows the sample S to be attached to both the first measurement region R1 and the second measurement region R2 by pressing the sample support 1A against the sample S once. Moreover, the conductive layer 5 is provided on the first surface region 21a of the first measurement region R1, and the conductive layer 5 is not provided on the second surface region 22a of the second measurement region R2. This allows the first surface region 21a to be irradiated with laser light L in the first measurement region R1 to perform mass analysis of the sample S, and the second measurement region R2 to perform an analysis of the sample S different from that in the first measurement region R1. Furthermore, by analyzing the correlation between the results obtained using the first measurement region R1 and the results obtained using the second measurement region R2, a more detailed analysis of the sample S can be performed. In this way, according to the sample support 1A, different analyses of the sample S can be efficiently performed by one sample support 1A. Furthermore, by pressing the sample support 1A against the sample S once (one sampling), the sample S can be attached to both the first measurement region R1 and the second measurement region R2, so that the variation between the amount of sample S attached to the first measurement region R1 and the amount of sample S attached to the second measurement region R2 can be suppressed. This allows the analysis in the first measurement region R1 and the second measurement region R2 to be performed with high accuracy. If the variation between the amount of sample S attached to the first measurement region R1 and the amount of sample S attached to the second measurement region R2 is suppressed, the accuracy of the above correlation analysis is further improved. As described above, the sample support 1A makes it possible to perform a highly efficient and highly accurate analysis of the sample S.

The conductive layer 5 is formed of a material suitable for mass analysis of the sample S. This allows mass analysis of the sample S to be performed favorably in the first measurement region R1.

The second measurement region R2 is optically transparent. The second surface region 22a of the second measurement region R2 and the surface region opposite the second surface region 22a in the second measurement region R2 (the second surface 2b of the substrate 2) are exposed. This allows light to pass through the second measurement region R2, making it possible to analyze the optical transmittance of the sample S attached to the second measurement region R2.

The thickness of the substrate 2 is 5 μm to 50 μm. This ensures the strength of the substrate 2 while ensuring the optical transparency of the second measurement region R2.

The first measurement region R1 and the second measurement region R2 are connected to each other. This ensures the areas of the first measurement region R1 and the second measurement region R2 while more reliably suppressing the variation between the amount of sample S adhering to the first measurement region R1 and the amount of sample S adhering to the second measurement region R2. That is, compared to when the first measurement region R1 and the second measurement region R2 are separated from each other, the distance between the first measurement region R1 and the second measurement region R2 is closer, so the above-mentioned variation is suppressed. Furthermore, when the first measurement region R1 and the second measurement region R2 are connected to each other, each measuring device (e.g., a probe, etc.) can be brought closer to the first surface 2a throughout the entire measurement region R, improving the accuracy of the measurement.

The substrate 2 has a rectangular plate shape. When viewed from the thickness direction D, the substrate 2 has calibration areas C1 and C2 located at different corners of the substrate 2. This allows calibration corresponding to analysis in each of the first measurement area R1 and the second measurement area R2 to be performed while ensuring the area of the first measurement area R1 and the second measurement area R2.

[Second embodiment]
A sample support 1B of the second embodiment will be described with reference to Figures 10 and 11. As shown in Figure 10, the sample support 1B includes a substrate 2B, a frame 3B, a conductive layer 5, a conductive layer (third conductive layer) 53, and a conductive layer 54. As an example, the length of the sample support 1B in the X-axis direction is about 5 cm, and the length of the sample support 1B in the Y-axis direction is about 2 cm. The length of the substrate 2B in the X-axis direction is greater than the length of the substrate 2 in the X-axis direction. The rest of the substrate 2B is the same as the substrate 2.

The length of frame 3B in the X-axis direction is greater than the length of frame 3 in the X-axis direction. The opening 3a of frame 3B is formed in a rectangular shape extending along the X-axis direction. In this embodiment, the opening 3a is formed in a shape in which each corner of the rectangle is linearly cut out.

Openings 31b, 32b, 33b, and 34b are formed at each corner of frame 3B, penetrating the frame 3B in the thickness direction. Each opening 31b, 32b, 33b, and 34b is formed in a shape similar to that of openings 31b and 32b of frame 3. The portions of substrate 2B corresponding to each opening 31b, 32b, 33b, and 34b function as calibration areas C1, C2, C3, and C4 for calibration. The rest of frame 3B is the same as frame 3. Like sample support 1A, sample support 1B is fixed to slide glass 8 by conductive tape 4.

The conductive layers 53 and 54, like the conductive layer 5, are provided on the first surface 2a of the substrate 2B so as not to block the holes 2c. The conductive layers 53 and 54 are formed of a material different from that of the conductive layer 5. In this embodiment, the conductive layer 53 is, for example, Au, and the conductive layer 54 is, for example, Ag.

In addition to the first and second measurement regions R1 and R2, the substrate 2B further has a third and fourth measurement region R3 and R4. In this embodiment, the first, second, third and fourth measurement regions R1, R2, R3 and R4 are arranged in this order from one side (the left side in FIG. 10) of the sample support 1B in the X-axis direction to the other side (the right side in FIG. 10). The first and second measurement regions R1 and R2 are connected to each other. The second and third measurement regions R3 are connected to each other. The third and fourth measurement regions R3 and R4 are connected to each other. The boundaries B1, B2 and B3 of the first, second, third and fourth measurement regions R3 and R4 extend linearly along the Y-axis direction.

The rest of the first measurement region R1 is the same as the first measurement region R1 of the first embodiment. The rest of the second measurement region R2 is the same as the second measurement region R2 of the first embodiment. The third measurement region R3 includes a third surface region 23a of the first surface 2a. A conductive layer 53 is provided in the third surface region 23a. The fourth measurement region R4 includes a fourth surface region 24a of the first surface 2a. A conductive layer 54 is provided in the fourth surface region 24a.

When viewed from the thickness direction D, the calibration areas C1 and C2 are located at two corners of the substrate 2B adjacent to the first measurement area R1. When viewed from the thickness direction D, the calibration areas C2 and C3 are located at two corners of the substrate 2B adjacent to the fourth measurement area R4.

A conductive layer 5 is provided on the surface area of calibration area C1 (part of the first surface 2a). The conductive layers 5, 53, and 54 are not provided on the surface area of calibration area C2 (part of the first surface 2a). The surface area of calibration area C2 is exposed. In other words, no film is formed on the surface area of calibration area C2. A conductive layer 53 is provided on the surface area of calibration area C3 (part of the first surface 2a). A conductive layer 54 is provided on the surface area of calibration area C4 (part of the first surface 2a).

In the first measurement region R1 and the second measurement region R2, imaging mass analysis and analysis of the light transmittance of the sample S can be performed, respectively, in the same manner as in the sample support 1A. In the third measurement region R3, for example, imaging mass analysis different from that in the first measurement region R1 can be performed. In the third measurement region R3, for example, surface enhanced Raman scattering (SERS) can be generated. In the fourth measurement region R4, for example, imaging mass analysis different from that in the first measurement region R1 can be performed. In the fourth measurement region R4, for example, surface enhanced Raman scattering can be generated. In the fourth measurement region R4, for example, secondary ion mass spectrometry (SIMS) can be performed.

The conductive tape 41 has circular openings 41a and 42a for exposing the calibration areas C1 and C2. The conductive tape 42 has circular openings 43a and 44a for exposing the calibration areas C3 and C4.

As described above, sample support 1B, like sample support 1A, makes it possible to perform highly efficient and highly accurate analysis of sample S. Furthermore, in each of the third measurement region R3 and the fourth measurement region R4, an analysis of sample S different from that in the first measurement region R1 can be performed.

[Modification]
As shown in FIG. 12, in the sample support 1A, the boundary line B between the first measurement region R1 and the second measurement region R2 may extend linearly along the Y-axis direction. The arrangement of the first measurement region R1 and the second measurement region R2 may be set arbitrarily as necessary. In addition, a conductive layer 52 (second conductive layer) may be provided in the second surface region 22a of the second measurement region R2 so as not to block the hole 2c. The conductive layer 52 may be, for example, Al. In this case, the conductive layer 52 is provided in the surface region of the calibration region C2. With this configuration, for example, surface-enhanced Raman scattering can be generated in the second measurement region R2.

As shown in FIG. 13 and FIG. 14, in the sample support 1A, the first measurement region R1 and the second measurement region R2 may be separated from each other. Specifically, the frame 3 may have a partition portion 31. The partition portion 31 crosses the opening 3a. When viewed from the thickness direction D, the partition portion 31 extends linearly along the X-axis direction. The partition portion 31 is provided between the first measurement region R1 and the second measurement region R2. The portion of the substrate 2 that overlaps with the partition portion 31 is bonded to the partition portion 31 by the adhesive layer 6. With this configuration, the strength of the substrate 2 can be reinforced while clarifying the boundary between the first measurement region R1 and the second measurement region R2.

As shown in FIG. 15 and FIG. 16, in the sample support 1B, the first measurement region R1 and the second measurement region R2 may be separated from each other. The second measurement region R2 and the third measurement region R3 may be separated from each other. The third measurement region R3 and the fourth measurement region R4 may be separated from each other. The third measurement region R3 and the fourth measurement region R4 may be separated from each other. Specifically, the frame 3B may have a plurality of partition portions 31.

Each partition 31 crosses the opening 3a. When viewed from the thickness direction D, each partition 31 extends linearly along the Y-axis direction. When viewed from the thickness direction D, each partition 31 is lined up in the X-axis direction at a predetermined interval. Each partition 31 is provided between the first measurement region R1, the second measurement region R2, the third measurement region R3, and the fourth measurement region R4. The portions of the substrate 2B that overlap with each partition 31 are bonded to each partition 31 by an adhesive layer 6.

Although an example has been shown in which the sample S is applied onto human skin 50, the sample S does not have to be a sample applied onto human skin 50. The sample S may be, for example, a biological sample. The sample S may be, for example, a slice of an animal organ or a plant.

In the above example, the sample S is attached to the measurement region R by pressing the sample support 1A against the skin 50 while the first surface 2a of the substrate 2 faces the sample S. However, the sample S may be attached to the measurement region R by pressing the sample support 1A against the skin 50 while the second surface 2b of the substrate 2 faces the sample S. This allows the component S1 of the sample S to move from the second surface 2b side to the first surface 2a side through the holes 2c by capillary action. As a result, the first surface 2a can be made suitable for ionizing the component S1 of the sample S. In such a case, the sample support 1A is not fixed to the slide glass 8.

Although an example has been shown in which each hole 2c is a through hole penetrating the substrate 2, each hole 2c does not have to penetrate the substrate 2. Each hole 2c does not have to open to, for example, the second surface 2b. In other words, the portion of each hole 2c on the second surface 2b side may be blocked. Each hole 2c only needs to open to at least the first surface 2a.

The materials of the conductive layers 5, 52, 53, and 54 are not limited. As long as the conductive layers 52, 53, and 54 are different from the conductive layer 5, the materials of each conductive layer 5, 52, 53, and 54 may have various combinations.

The second measurement region R2 may be used for Desorption Electrospray Ionization (DESI), a method of desorbing and ionizing a sample by irradiating charged droplets. The second measurement region R2 may also be used for Nuclear Magnetic Resonance (NMR). In this case, if the partition 31 is provided, only the second measurement region R2 can be easily peeled off from the sample supports 1A and 1B. The second measurement region R2 may also be used for imaging analysis by Raman spectroscopy, or infrared spectroscopy.

The sample support 1B may have at least one of the second measurement region R2, the third measurement region R3, and the fourth measurement region R4. For example, the sample support 1B may not have at least one of the third measurement region R3 or the fourth measurement region R4.

The conductive layers 5, 53, and 54 may be provided at least on the first surface 2a. In addition to the first surface 2a, the conductive layers 5, 53, and 54 may also be provided, for example, on the second surface 2b, or on the entire or part of the inner surface of each hole 2c.

The target to which the voltage is applied by the voltage application unit 14 is not limited to the mounting surface 8a. For example, the voltage may be applied directly to the frame 3, 3B or the conductive layers 5, 53, 54.

The mass spectrometer 10 may be a scanning type mass spectrometer or a projection type mass spectrometer. In the case of the scanning type, a signal of one pixel having a size corresponding to the spot diameter of the laser light L is obtained for each irradiation of the laser light L by the irradiation unit 13. That is, scanning (changing the irradiation position) and irradiation of the laser light L are performed for each pixel. On the other hand, in the case of the projection type, a signal of an image (multiple pixels) corresponding to the spot diameter of the laser light L is obtained for each irradiation of the laser light L by the irradiation unit 13. In the case of the projection type, if the spot diameter of the laser light L includes the entire measurement region R, imaging mass analysis can be performed by irradiating the laser light L once. Note that in the case of the projection type, if the spot diameter of the laser light L does not include the entire measurement region R, a signal of the entire measurement region R can be obtained by scanning and irradiating the laser light L in the same way as the scanning type. The above-mentioned ionization method can also be used for other measurements and experiments such as ion mobility measurements.

The use of the sample support is not limited to ionizing a sample by irradiation with laser light L. The sample support can be used to ionize a sample by irradiation with energy rays such as laser light, ion beams, and electron beams. In the above-mentioned ionization method and mass analysis method, the sample can be ionized by irradiation with such energy rays.

1A, 1B... Sample support, 2... Substrate, 2a... First surface, 2c... Hole, 5... First conductive layer, 21a... First surface area, 22a... Second surface area, 23a... Third surface area, 24a... Fourth surface area Area, 31...Partition part, 52...Second conductive layer, 53...Third conductive layer, C1, C2...Calibration area, R1...First measurement area, R2...Second measurement area, R3...Third measurement area, S...Sample.

Claims (9)

A sample support for use in ionizing a sample, comprising:
A substrate having a surface and a plurality of holes opening onto the surface,
the substrate has at least a first measurement area including a first surface area of the surface, and a second measurement area including a second surface area of the surface;
a first conductive layer is provided on the first surface region so as not to block the hole;
The second surface region is free of the first conductive layer. 2. The sample support of claim 1, wherein the first conductive layer is formed of Pt, Au, Cr, Ni, Ti or Ag . The second measurement area has optical transparency,
3. The sample support according to claim 1, wherein the second surface area of the second measurement area and a surface area of the second measurement area opposite the second surface area are exposed. The sample support according to claim 3, wherein the thickness of the substrate is 5 μm to 50 μm. The sample support according to claim 1 or 2, wherein a second conductive layer is provided on the second surface region of the second measurement region so as not to block the holes and which is made of a material different from that of the first conductive layer. The sample support according to any one of claims 1 to 5, wherein the first measurement area and the second measurement area are connected to each other. The sample support according to any one of claims 1 to 5, further comprising a partition provided between the first measurement area and the second measurement area. the substrate further comprises a third measurement area including a third surface area of the surface;
The sample support according to any one of claims 1 to 7, wherein the third surface region is provided with a third conductive layer formed of a material different from that of the first conductive layer so as not to block the holes. The substrate has a rectangular plate shape,
The sample support according to any one of claims 1 to 8, wherein the substrate has a plurality of calibration areas located at different corners of the substrate when viewed in a thickness direction of the substrate.

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