JP2003302399A - Analyzing chip - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently and accurately analyze a liquid test substance in an analyzing chip and inexpensively manufacture the analyzing chip. <P>SOLUTION: In the analyzing chip 1, a chip main with a minute flow path 5 having a slit cross section is provided with a reaction part 6 having a specific binding material facing the minute flow path 5 and fixed at a plurality of points and the liquid test substance Fs flows in the minute flow path 5. The analyzing chip 1 is used for analyzing the liquid test substance Fs in response to a binding state of the specific binding material in the reaction part 6 and comprises a large affinity part 7b having a relatively large affinity to the liquid test substance Fs on at least one of faces for forming long sides 5a of the slit cross section of the chip main and a small affinity part 7a having an affinity to the liquid test substance Fs smaller than the large affinity part 7b. The small affinity part 7a and the large affinity part 7b are provided upstream of the reaction part 6. When the liquid test substance Fs moves from the large affinity part 7b to the small affinity part 7a, a front edge of the liquid test substance Fs is aligned in the width direction B of the minute flow path 5. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a chip body having a microchannel having a slit-shaped cross section, and a plurality of specific binding substances that specifically bind to a predetermined substance are fixed at a plurality of points facing the microchannel. An analysis unit that is equipped with a reaction part that is made up of a liquid sample and is used to analyze a liquid sample according to the binding state of a specific substance and a specific binding substance in the reaction part by circulating a liquid sample in a microchannel. For chips.

More specifically, a part of the solid phase wall surface (wall surface of the chip body facing the minute flow path) is provided with a clearly divided high affinity region-low affinity region, whereby the liquid on the solid phase wall surface is formed. The present invention relates to an analysis chip capable of suppressing the invasion of a liquid sample due to the non-uniform wettability (affinity) with respect to the sample and suppressing the generation of bubbles.

[0003]

2. Description of the Related Art Heretofore, various techniques for detecting a predetermined chemical substance in a liquid sample and analyzing the liquid sample have been proposed and put into practical use. In recent years, a flow-through type analysis chip (microchannel chip) such as a DNA chip or a protein chip has been attracting attention as such a technique.

In the microchannel chip, a channel having a minute cross section is formed in the chip body, and a substance (specifically, a chemical bond that specifically binds to the above-mentioned predetermined chemical substance is formed on the wall surface forming the channel). Some substances have a fixed binding substance. Then, the liquid sample is circulated in this channel to pass over the specific binding substance on the wall surface of the channel, or temporarily stop on the specific binding substance to bring the liquid sample into contact with the specific binding substance. . If the liquid sample contains a predetermined chemical substance (measurement target), this can be detected as a binding reaction of the specific binding substance.

Further, by combining such a microchannel chip and an analysis method based on SPR (Surface Plasmon Resonance) [for example, Biacore (registered trademark)], the substance to be measured and the specific binding substance are bound to each other. It is possible to detect dissociation online. In such an analysis using SPR, not only the same liquid sample is circulated through the microchannel chip for analysis, but also a plurality of liquid samples are continuously circulated with a buffer interposed therebetween, and these liquid samples are analyzed. It is also possible to analyze a series of binding-dissociation between the target substance to be measured and the specific binding substance.

Many liquid specimens analyzed using a microchannel chip have a limited amount of use. For example, in DNA chips and protein chips, liquid samples are various substances (DNA, RNA, peptides, proteins, etc.) collected from various organisms or biochemically synthesized, and the amount used is as small as possible. I want to stay

Therefore, in order to efficiently analyze even a small amount of liquid sample, a microchannel chip having a channel having a small slit-shaped cross section is used. That is, by making the cross section of the flow path into a slit shape so that the flow of the liquid sample has a sheet shape, the wetting length and thus the contact area between the liquid sample and the wall surface of the flow path can be made relatively large.

That is, the flow passage cross-sectional area is made minute so that a small amount of liquid sample can be flown, and the contact area is made relatively large so that a relatively large number of specific binding substances can be fixed on the flow passage wall surface. In this way, even if the liquid sample is a small amount, it can be contacted with a relatively large number of specific binding substances by a single circulation so that the analysis can be performed efficiently.

[0009]

In the above-mentioned conventional microchannel chip, generally, since the liquid sample is allowed to flow from the state where the initial gas (mainly air) is filled in the flow channel, The gas-liquid interface moves inside. At that time, since the cross-section of the flow path is slit-shaped and long in the width direction of the flow path, the wettability of the flow path wall surface may be non-uniform, or the device may vibrate or dust may adhere to the flow path surface.
As shown in (a), the flow direction position of the gas-liquid interface (the tip of the liquid sample Fs) S becomes non-uniform in the flow channel width direction.

Then, from the state shown in FIG.
The leading portion of the liquid interface S wraps around as shown by the arrow F and completely encloses a part of the gas 200 as shown in FIG. 14B, and bubbles 201 are formed in the liquid sample Fs. . In addition, in the flow path having the slit-shaped cross section, the contact interface area between the bubble 201 and the flow path wall surface becomes large, and therefore, even if the liquid transfer is continued,
It is difficult to flush and remove the bubbles 201 in the downstream direction, and the bubbles 201 often stay as they are. It is conceivable that a high pressure is applied to the flow channel to forcefully push the bubbles 201 out of the flow channel, but in this case,
There is a risk that the flow path will be damaged due to a rapid increase in pressure, which is not realistic.

If the bubbles 201 stay in this way, the problems shown in FIGS. 15 to 18 occur. That is, as shown in FIG. 15, the particulate matter 202 in the liquid sample Fs specifically agglomerates and accumulates around the upstream side of the bubble 201, which affects the subsequent distribution process, mixing process, and reaction process. Will end up.

When the flow around the bubble 201 becomes non-uniform due to the retention of the bubble 201, in an extreme case, as shown by an arrow G1 in FIG. 16 (a), between the upstream side of the bubble 201 and the wall surface of the flow path. In some cases, backflow may occur, affecting the analysis. In addition, as shown by an arrow G2 in FIG. 16B, the liquid sample Fs is close to the bubbles 201 in the vicinity of the bubbles 201.
Flows along the circumference of 01 and flows faster than others.

Therefore, in the reaction region 204 where the specific binding substance is immobilized, the number of contacts with the liquid analyte molecule is larger in the vicinity 204a of the bubble 201 than in other regions (the total amount of the liquid analyte that passes through). Will increase). That is, in the reaction region 204, the binding reaction proceeds under different conditions depending on the position, and it becomes impossible to perform accurate analysis of the liquid sample based on the binding reaction state in the reaction region 204.

In addition, as shown in FIG.
When 1 stays in the reaction region 204, the reaction region 20
The contact between the specific binding substance immobilized on No. 4 and the liquid sample is hindered. Moreover, if the bubbles 201 stay in the measurement region 205 as shown in FIG. 17B, the analysis cannot be performed accurately. In particular, in the case of optical measurement, since the measurement becomes impossible if the bubbles 201 stay in the measurement region 205 in this way, the liquid sample is removed from the flow channel, and then the preparation is performed again. The measurement has to be restarted, and the efficiency of the analysis work may be extremely reduced.

In addition, if the bubbles 201 stay in the liquid sample, the difference in heat transfer coefficient between the liquid sample Fs and the bubbles 201 may cause nonuniform temperature in the measurement system, which may affect the analysis result. . Further, if the gas-liquid interface is non-uniform, even if bubbles do not occur due to the inclusion of the liquid sample,
There are the following issues. Schematic plan view 18 (a),
Explaining with reference to (b), reference numerals 206, 206d to 206f in FIGS. 18 (a) and 18 (b) are specific binding substances (spots) fixed in the flow channel, and are along the flow channel width direction. Are arranged in two rows. Reference symbols Sa to Sg are gas-liquid interfaces at predetermined times ta to tg, respectively, and the closer to the left side in the figure, the earlier the time.

As shown in FIG. 18A, the gas-liquid interface Sa
If ~ Sc is uniform in the width direction, it goes without saying that the times ta, tc
The period during which each specific binding substance 206 is in contact with the liquid specimen Fs is substantially the same. On the other hand, FIG.
In the example shown in (b), the period during which the specific binding substance 206d contacts the liquid sample Fs is (tg-td) between the times td and tg, and the period during which the specific binding substance 206e contacts the liquid sample Fs. Is (tg-te), and the period during which the specific binding substance 206f is in contact with the liquid specimen Fs is (tg-tf). That is, when the gas-liquid interfaces Sd to Sg are non-uniform in the width direction as shown in FIG. 18B, the specific binding substances 206d to 206d are generated between the times td to tg.
The periods in which 06e comes into contact with the liquid sample Fs also differ from each other, and as a result, the analysis becomes less reliable.

Techniques relating to the suppression of air bubbles in such a liquid sample are disclosed in the following publications, for example. [Patent Document 1] Japanese Patent Application Laid-Open No. 6-94222 This publication discloses a technique relating to an analysis chip having a minute channel. In this technology, a liquid sample moves in a minute channel due to a capillary phenomenon. For example, in a chip that analyzes the coagulation state of blood, the wall surface that forms the minute channel while ensuring blood flowability. By partially modifying the affinity for blood, the blood flow is stopped as soon as it begins to coagulate. However, this technique does not pay attention to the surrounding of the liquid sample.

Japanese Unexamined Patent Publication No. 2000-65711 This publication discloses a submerged cell for an atomic force microscope in which the cell surface is coated with a layer containing a photocatalyst. In this submerged cell, the photocatalyst is photoexcited to make it highly hydrophilic, resulting in organic substances (dirt) adhering to the cell surface.
Can be disassembled and removed, and the cell can be filled with liquid smoothly and without gaps without creating bubbles.

However, in this technique, the photocatalyst is expensive, which causes a large increase in the manufacturing cost of the cell (chip), and further, the cell is filled with the liquid, and the above-mentioned liquid sample is used. Since it is not a type that performs analysis while circulating, it does not solve the generation of bubbles due to the inclusion of a liquid sample. [Patent Document 1] Japanese Unexamined Patent Publication No. 2001-162817 This publication discloses a recording liquid supply pipe for supplying a recording liquid (ink) to an inkjet head. By imparting lyophilicity to the inner surface of this supply pipe,
It is possible to suppress the adhesion of air bubbles that have entered the supply pipe to the inner surface of the supply pipe, and even if the air bubbles adhere to the inner surface of the supply pipe, the air bubbles are immediately released from the inner surface of the supply pipe and can be removed by the circulation of the liquid in the supply pipe. I have to.

However, this technique is not intended for a channel having a minute cross section and a slit-shaped cross section, and cannot prevent the liquid sample from getting around the channel. Japanese Patent Publication No. 11-508360 discloses a flow-through in which the corners of a flow path for passing a liquid sample are rounded so that the bubbles that have entered the flow path can be prevented from adhering to the corners. A sampling cell is disclosed.

However, this technique also does not suppress the generation of bubbles themselves due to the surrounding of the liquid sample, and the suppression of the adhesion of bubbles is limited to the corners, and it is expected that the effect is small. The present invention was devised in view of such problems, and an object thereof is to provide an analysis chip that can be manufactured at low cost and that can analyze a liquid sample efficiently and accurately. .

[0022]

For this reason, the analysis chip of the present invention (Claim 1) has a specific structure for specifically binding a predetermined substance to a chip body having a microchannel having a slit-shaped cross section. A reaction part is provided in which a binding substance is fixed at a plurality of points facing the microchannel, and a liquid sample is circulated through the microchannel, and the predetermined substance and the specific binding substance in the reaction part In an analysis chip, which is used to perform an analysis on the liquid sample depending on the binding state of the liquid sample, at least one of the surfaces forming the long sides of the slit-shaped cross section of the chip body has an affinity for the liquid sample. And a low affinity portion having a lower affinity for the liquid specimen than the high affinity portion are respectively provided on the upstream side of the reaction portion, and the liquid specimen is used for the high affinity portion. From the liquid to the low affinity portion. The tip of the is characterized in that it is configured to be aligned along the width direction of the fine small channels.

In this case, it is preferable that the low affinity portion is formed in a long strip shape along the long side of the cross section of the slit shape (claim 2). Further, it is preferable that a plurality of the low affinity portions and the high affinity portions are provided alternately along the flow direction of the liquid sample and arranged in plural (claim 3). Further, the chip body has a substrate and a lid,
It is preferable that the passage is formed between the substrate and the lid by assembling the lid to the substrate (claim 4).

Further, the reaction portion is formed, for example, on the substrate and / or the lid portion (claim 5). Further, it is preferable to further comprise a metal layer capable of inducing a surface plasmon wave and a diffraction grating capable of generating an evanescent wave by irradiation of light (claim 6).

[0025]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. In each of the following embodiments, an example in which a water-soluble liquid sample (having a solvent of water) is used will be described. The liquid sample referred to in the present invention is, for example, a measurement target such as protein, nucleic acid, DNA, RNA, peptide, hormone, antigen, antibody, ligand, receptor, enzyme, substrate, low molecular weight organic compound, cell or ion. A liquid containing (or possibly containing) a dispersion system such as a suspension or colloid. (1) First Embodiment FIG. 1 is a view showing an analysis chip as a first embodiment of the present invention, and (a) is a schematic assembly perspective view thereof.
(B) is the typical disassembled perspective view, (c) is a typical transverse sectional view of the flow path, and is an XX sectional view of (a).

The analysis chip 1 is shown in FIGS. 1 (a) and 1 (b).
As shown in FIG. 2, the lid portion 2, the thin spacer 3 and the substrate 4
It is configured with. As shown in FIG. 1A, these members 2, 3 and 4 are superposed in this order from above, and are integrally assembled by a holder (not shown). An opening 31 is provided in the center of the spacer 3 as shown in FIG. 1B, and at the time of chip assembly, the opening 31 is sandwiched between the lid portion 2 and the substrate 4 from above and below, so that the liquid sample Fs It will function as the flow path 5 for circulation.

As shown in FIG. 1C, the flow channel 5 is constituted as a minute flow channel having a horizontally elongated slit-shaped cross section (a cross section perpendicular to the flow direction A of the liquid sample). ing. The minute channel having a slit-shaped cross section in the present invention means that the long side 5a of the slit-shaped cross section is in the range of 3 mm to 100 mm, and the short side 5b of the cross section is in the range of 5 μm to 2 mm. I mean one. The range of the dimensional ratio between the long side 5a and the short side 5b (= long side dimension / short side dimension) is 1.5 to 20,000, preferably 1.
0 to 100. Here, the length W of the long side 5a is 20 mm, and the length of the short side 5b (thickness of the spacer 3).
H is set to 250 μm, respectively.

Further, the lid portion 2 is provided with holes 21 and 22. These holes 21 and 22 are provided at the time of chip assembly.
It is in communication with the end of the opening 31. Hole (inlet) 21
Is connected to a liquid feed pump (for example, a syringe pump) through a connector and a tube (not shown), and the hole (discharge port) 22 is connected to a waste liquid tank through a connector and a tube (not shown). Is operated to allow the liquid sample Fs to flow through the flow path 5.

The substrate 4 is provided with a reaction part 6 facing the flow path 5 at the center of the flow direction. Although the reaction part 6 is shown in a simplified manner in FIGS. 1A to 1C, as shown in FIG. 2, a specific binding substance that specifically binds to a predetermined substance (detection species) is spotted. / A plurality of spots 61 that are fixed and each are aggregated. The general range of (vertical dimension × horizontal dimension) of the reaction part 6 is (3 mm
2 × 3 mm) to (20 mm × 20 mm), which is shown as a small number in FIG. 2 for the sake of convenience, but in general, in this region, a total of 9 to 40 vertical to horizontal 3 to 200 at intervals of 100 μm to 1 mm. 1,000 spots 61 are arranged. Here, specific binding substances (specific binding substances different from each other) that specifically bind to different substances are used for these spots 61.

Specific binding substances include antigen-antibody reaction, complementary DNA binding, receptor / ligand interaction, enzyme /
A substance capable of capturing a detection species (substance to be measured) due to substrate interaction, etc., such as protein, nucleic acid, DN
A, RNA, peptides, hormones, antigens, antibodies, ligands, receptors, enzymes, substrates, low molecular weight organic compounds, cells, etc.

The liquid sample Fs flowing through the flow path 5 comes into contact with these spots 61 during the distribution process,
After the distribution, the liquid sample Fs can be analyzed according to the reaction status of each spot 61. That is, if the reaction of any one of the plurality of spots 61 can be observed, this reacted spot (specific binding substance) 6
It is possible to detect that the predetermined substance corresponding to 1 is contained in the liquid sample Fs.

It is not always necessary to use different specific binding substances for each spot 61, but the same specific binding substances may be used. Whatever it is,
The specific binding substance to be used is appropriately set depending on the purpose of the analysis. Although the reaction site 6 is provided on the substrate 4 side, it may be provided on the lid portion 2 side or on both sides of the lid portion 2 and the substrate 4.

A major feature of the present invention is shown in FIG.
As shown in (a) to (c), a plurality of (4 in this case) 4 are provided on the upstream side of the reaction section 6 on the flow path wall surface (here, the lid 2) of the flow path 5.
Hydrophobic portions (low affinity portions) 7a are arranged side by side in the flow direction A of the liquid specimen Fs, and each hydrophobic portion 7a is formed in a long strip shape along the flow channel width direction B. The hydrophobic portion 7a referred to here is a portion having a lower hydrophilicity with respect to the water-soluble liquid specimen Fs than the wall surface of the channel (that is, the surface of the chip substrate 1 and the lid 2 facing the channel 5). As a result, the hydrophobic portion 7a along the flow direction A of the liquid specimen Fs and the high affinity portion (high hydrophilicity here) having a higher affinity for the liquid specimen Fs than the hydrophobic portion 7a (here, high hydrophilicity) are formed on the channel wall surface. Hydrophilic part)
7b will be arranged alternately.

Here, each hydrophobic portion 7a is formed over the entire width of the flow path 5 as shown in FIG.
Further, the thicknesses (dimensions in the flow direction of the liquid sample) t are set to be the same as each other, and the mutual intervals d of the hydrophobic portions 7a (thicknesses of the hydrophilic portions 7b) are set to the same dimension. The thickness t is appropriately set according to various conditions, but is generally 10 μm to 1000 mm or less.

The flow direction A of the liquid sample Fs means the main flow direction in the flow channel, and for example, in the flow channel 5'as shown in FIG. 3, the flow direction is the direction indicated by the solid arrow. . Liquid sample Fs explained as a problem of the prior art
The generation of bubbles (surrounding of gas) due to the inclusion of the gas is caused by the nonuniformity of the gas-liquid interface in the flow channel width direction of the liquid sample Fs. Therefore, in the present embodiment, the hydrophobic portion 7a is provided as described above so that the upstream side of the reaction portion 6 has a structure including the hydrophobic portion 7a and the other hydrophilic portion 7b.

As a result, as shown in FIG. 4A, when a part of the liquid sample Fs arrives at the hydrophobic part 7a in advance, the hydrophobic part 7a is difficult to circulate, so that the liquid sample Fs becomes the hydrophobic part 7a. The state where the brake is just applied at the contact portion of the liquid sample Fs and the subsequent liquid sample Fs flows toward the hydrophilic portion 7b side where the liquid sample Fs has not yet reached, that is, a region where the liquid sample Fs does not easily flow, that is, the arrow F1. It will flow as indicated by F3.

As a result, part of the liquid specimen Fs reaches the hydrophobic portion 7a over the entire width of the flow path, and a part of the liquid specimen Fs reaches the hydrophobic portion 7a.
You will be restrained from moving over. That is, as shown in FIG. 4B, the tip (gas-liquid interface) S of the liquid sample Fs can be aligned along the width direction B. Here, as described above, the hydrophobic portion 7a is the lid portion 2
However, the hydrophobic portion 7a is provided only on the wall surface forming at least one long side of the slit-shaped cross section of the flow path 5, that is, in the case of the present embodiment, at least the lid portion 2 and the substrate 4. It suffices that it is provided so as to face the flow path 5 for either one. Although it is most preferable to form it over the entire circumference of the cross section of the flow path 5 as shown by the thick line in FIG. 5, since the flow path 5 has a very small equivalent diameter, the resistance received from the flow path wall surface is large. Even if only the lid portion 2 is provided with the hydrophobic portion 7a as in the embodiment, it is possible to suppress the flow of the liquid sample Fs and align the tip positions of the liquid sample Fs as described above. Further, if possible, the hydrophobic portion may be provided on the wall surface (the portion of the spacer 3 facing the flow path 5 in the present embodiment) forming the short side of the slit-shaped cross section of the flow path 5. good.

The lid portion 2, the spacer 3, the substrate 4 and the hydrophobic portion 7 will be further described below. First, the lid portion 2, the spacer 3 and the substrate 4 will be described. The material of the chip body, that is, the lid portion 2, the spacer 3 and the substrate 4 is not particularly limited in type such as resin, ceramics, glass, metal, etc., but the portion forming the hydrophilic portion 7b is not limited to the hydrophobic portion 7a.
Since it needs to have a higher affinity for the liquid sample Fs than that, it is necessary to understand its affinity characteristics.

When the binding between the detection species and the specific binding substance is optically measured by utilizing fluorescence, luminescence, color development, phosphorescence or the like, the measurement can be performed without disassembling the chip. It is preferable to form the lid portion 2 and the substrate 4, especially the lid portion 2 with a transparent material. Examples of transparent materials include acrylic resin, polycarbonate, polystyrene,
Resins such as polydimethylsiloxane and glass such as Pyrex (borosilicate glass) and quartz glass.

Although the lid 2, the spacer 3 and the substrate 4 are physically assembled by a holder (not shown) so that they can be disassembled, the analysis chip 1 can be easily assembled. The spacer 3 may be bonded to the lid portion 2 or the substrate 4. The lid 2 of the spacer 3 or the substrate 4
The bonding to the adhesive layer is adhesive bonding, resin bonding using a primer, diffusion bonding, anodic bonding, eutectic bonding, heat bonding, ultrasonic bonding, laser melting, solvent / solvent, etc. Alternatively, an adhesive tape, an adhesive tape, or a self-adsorbing agent may be used, or pressure bonding, spacer 3, lid portion 2 or substrate 4 may be performed.
You may make it engage with and provide unevenness.

Here, the spacer 3 is made to have a function as a gasket (that is, a material suitable for the gasket is selected as the material of the spacer 3), but the lid portion 2, the spacer 3 and A gasket may be separately provided between each of the substrates 4. Next, the method of forming the hydrophobic portion 7 will be described. For example, the method of forming the hydrophobic portion 7 is, for example, the flow passage wall surface (here, the flow passage 5 of the lid portion 2 in particular).
(A flat surface facing the surface) is partially made hydrophobic (low affinity), and conversely, a predetermined portion of the wall surface of the flow path (hydrophobic portion 7)
There is a method of hydrophilizing (higher affinity) the part excluding.

When a hydrophobic material having a relatively low affinity such as acrylic resin, polycarbonate, polystyrene, silicon, polyurethane, polyolefin, polytetrafluoroethylene, polypropylene, polyethylene, or thermoplastic elastomer is used for the wall surface of the channel, this is used. Hydrophilic methods include surface coating, wet chemical modification,
Gas modification, surfactant treatment, corona discharge, surface roughening, metal deposition, metal sputtering, UV treatment, a method involving application of hydrophilic functional groups or molecules to the surface depending on the processing atmosphere (plasma Method, ion implantation method, laser treatment, etc.).

When a hydrophilic material having a relatively high affinity such as glass, metal or ceramics is used for the wall surface of the flow path, an adhesive,
Examples include surface coating of hydrophobic substances such as wax, surface grafting, and methods involving the addition of hydrophobic functional groups or molecules to the surface depending on the processing atmosphere (plasma method, ion implantation method, laser treatment, etc.). To be

When the channel wall surface is modified (hydrophilized or hydrophobized) as described above, the above treatment may be performed only on the portion of the channel wall surface to be modified, or the unmodified portion. It is also possible to mask the above and carry out the above processing collectively on the entire wall surface of the flow path. It is also possible to form a partial pattern by assembling different kinds of hydrophilic and hydrophobic materials. That is, for example, a hydrophobic material may be attached to the wall surface of the hydrophilic channel to form the hydrophobic portion.

Since the analysis chip as the first embodiment of the present invention is configured as described above, the liquid sample Fs
It is possible to suppress the generation of bubbles due to the inclusion of the bubbles. That is, as shown in FIG. 6A, the tip of the liquid sample Fs, that is, the gas-
The liquid interface S becomes non-uniform in the flow channel width direction, and
As shown in FIG. 6B, even if a part of the leading part reaches the hydrophobic portion 7a on the most upstream side, when the hydrophobic portion 7a is crossed over, as shown in FIG. The variation of S is suppressed. After that, every time it passes through the hydrophobic portion 7a,
The gas-liquid interface S becomes more uniform in the flow channel width direction. Then, as shown in FIG. 6D, the liquid sample Fs flows into the reaction section 6 almost at the same time in the entire width of the flow channel. In this way, since the gas-liquid interface S becomes uniform in the flow channel width direction, it is possible to prevent the liquid sample Fs from getting around and enclosing the gas (formation of bubbles).

Therefore, according to the present analysis chip 1, adverse effects due to retention of air bubbles (inhibition of flow of the liquid sample Fs, inhibition of contact between the reaction part 6 and the liquid sample Fs, heat transfer coefficient of the liquid Fs and air bubbles). There is an advantage that it is possible to eliminate the nonuniformity of the temperature of the measurement system due to the difference) and improve the reliability of the analysis. Furthermore, the work of removing bubbles becomes unnecessary,
It has the advantage that analysis work can be performed efficiently.

In addition, since the period during which the liquid specimen Fs is in contact with each spot 61 of the reaction section 6 becomes uniform, there is an advantage that the reliability of analysis can be improved also in this respect. Then, the extremely useful effects as described above are realized at a low cost without using an expensive photocatalyst as in the above-mentioned conventional technique, and with a simple configuration such that a hydrophobic portion is provided in the flow path of the conventional analysis chip. There is an advantage that it can be done.

Further, it is possible to easily provide a hydrophobic portion in the flow path, and it is possible to easily change the shape of the hydrophobic portion, so that a wide variety of analysis chips can be easily manufactured (suitable for mass products). ) Also has the advantage. (2) Second Embodiment An analysis chip as a second embodiment of the present invention is an analysis chip used in an SPR sensor using surface plasmon resonance (SPR) (hereinafter, referred to as an SPR sensor chip or Sensor chip).

The SPR sensor and the SPR sensor chip will be described below with reference to FIGS. 7 and 8. 7 and 8 are diagrams showing a second embodiment of the present invention. FIG. 7 is a schematic system configuration diagram of an SPR sensor, and FIG.
It is a typical exploded perspective view for explaining the composition of a PR sensor chip. The parts described in the above-described first embodiment are given the same reference numerals, and the description thereof will be omitted.

As shown in FIG. 7, the SPR sensor has an SP
R sensor chip 1 ', a light source 100 for irradiating the sensor chip 1'with light, and a detector for detecting the reflected light from the sensor chip 1' [here, CCD (Charge Coupl
ed Device) camera] 101. The sensor chip 1 ′ is configured to have a slit-shaped cross-sectional flow path 5 similarly to the analysis chip 1 (see FIG. 1) of the above-described first embodiment, and liquid is supplied to this flow path 5 by a liquid sending pump. The sample Fs is distributed.

As shown in FIG. 8, the sensor chip 1'has a different substrate 4 structure from the analysis chip 1 of the first embodiment, and the lid 2 is made of a particularly transparent material. A metal layer 41 is coated on one surface of the substrate 4 facing the flow path 5 during chip assembly. In addition, a diffraction grating 42 is formed on the surface coated with the metal layer 41.
And the reaction part 6 is formed as in the first embodiment.
Are formed.

Then, when the substrate 4 is irradiated with light from the light source 100 through the transparent lid portion 2, the surface plasmon wave generated on the surface of the metal layer 41 by this light is caused by the diffraction grating 42 to form a metal layer. Resonating with the evanescent wave induced in 41, the energy of the light component of a specific incident angle or a specific wavelength of the light irradiated on the metal layer 41 is the metal layer 41.
Is absorbed by. Therefore, in the reflected light from the metal layer 41, the energy of the light component of the specific incident angle or the specific wavelength becomes weak.

The angle and wavelength of the evanescent wave generated on the metal layer 41 change depending on the amount of the detection species trapped by the specific binding substance immobilized on the metal layer 41, and are absorbed accordingly. The angle and wavelength of the reflected light are changed. Therefore, the concentration of the detected species in the test fluid can be measured in real time by monitoring the light intensity of the reflected light from each spot 61 of the reaction section 6 by the CCD camera 100 and detecting the change in the angle and the wavelength. .

The material of the metal layer 41 is not limited as long as it can induce a surface plasmon wave, for example, gold,
Examples include silver and aluminum. The diffraction grating 42 can be embodied on the surface of the metal layer 41 by forming irregularities on the surface of the substrate 4 and then thinly laminating a metal thereon by sputtering or the like to form the metal layer 41. Also,
The unevenness formed to provide the diffraction grating 42 on the substrate 4 is
For example, it may be formed by cutting the substrate 4, and the cutting method may be mechanical or may be chemically performed by an etching technique or the like. When the substrate 4 is made of a resin material, the unevenness can be formed by pressing the stamper having the unevenness by, for example, photolithography or the like on the substrate 4 before the resin material is completely solidified. The uneven shape may be transferred from the stamper by injection molding.

In the SPR sensor chip, the hydrophobic portion 7a is usually provided only on the lid 2 and is not provided on the substrate 4 coated with the metal layer.
Since the sensor chip according to the second embodiment of the present invention is configured as described above, it is possible to suppress the generation of bubbles due to the liquid sample Fs getting around. Therefore, according to the analysis chip of the present embodiment, the same effect as that of the analysis chip of the first embodiment can be obtained. Further, a major feature of the SPR sensor is that the state of the binding reaction in the reaction part 6 is optically and online detected, and if air bubbles stay in the reaction part (that is, the measurement region) 6, it is peculiar. Not only will the binding between the reactant and the detection species be hindered, but the optical measurement described above will not be possible. According to the SPR sensor chip of the present embodiment, it is possible to suppress the generation of bubbles, and thus there is an advantage that the online analysis by such optical measurement can be stably performed. (C) Third Embodiment FIG. 9 is a schematic exploded perspective view showing a configuration of an analysis chip as a third embodiment of the present invention.

As shown in FIG. 9, the analysis chip of this embodiment comprises cases 2A and 2B and a substrate 4. Spaces 2Aa and 2Ba for accommodating the substrate 4 are provided inside the cases 2A and 2B, respectively. The thickness of these spaces 2Aa, 2Ba is
The thickness is set larger than the thickness of the substrate 4, and the case 2A
An inlet 21 and an outlet 22 for the liquid sample Fs communicating with the space 2Aa are provided in the upper part of the space, and the substrate 4 is housed in the assembled state of the chip, that is, the spaces 2Aa, 2Ba and the cases 2A, 2B are assembled. In this state, a flow path is formed above the substrate 4 and between the cases 2A, 2B and the substrate 4 to circulate the liquid sample Fs.

On the surface of the substrate 4 facing the flow path, a plurality of hydrophobic parts 7a and reaction parts 6 are formed in this order from the upstream side. Since the analysis chip as the third embodiment of the present invention is configured as described above, it is possible to suppress the generation of bubbles due to the liquid sample Fs getting around as in the first embodiment.

As a modified example of the analysis chip of the present embodiment, for example, the configuration shown in FIGS. 10 (a) to 10 (d) can be mentioned. 10 is different from the configuration shown in FIG. 9 described above.
In (a), the space 2Ba is not formed in the case 2B, and the case 2B forms the downstream end wall surface of the flow path formed above the substrate 4. In addition, cases 2A, 2B
A gasket (not shown) is interposed between and.

In addition, in the configuration shown in FIG.
0 (a), the inlet 21 and the outlet 22 are case 2
Liquid sample Fs is formed on the front and rear walls of A and 2B.
Are introduced horizontally into the flow path. Further, in the configuration shown in FIG. 10C, the inlet 21 and the outlet 22
Is provided in the lower part of the case 2A in communication with the space 2Aa, and the substrate 4 has through holes 43 and 44 which are connected to the inlet 21 and the outlet 22 when accommodated in the case 2A. It is provided. As a result, the injection port 21
The liquid specimen Fs injected into the above-mentioned flow-through flows into the flow path formed above the substrate 4 through the through hole 43, and is discharged from the discharge port 22 through the through hole 44.

Further, the configuration shown in FIG.
In contrast to the configuration shown in (a), the case 2B and the substrate 4 are integrally formed. In the case where the analysis chip of this embodiment is formed as an SPR sensor chip, the second chip
Similar to the embodiment, the diffraction grating may be formed on the substrate 4, a metal layer may be formed on the surface on which the diffraction grating is formed, and the hydrophobic portion 7a and the reaction portion 6 may be provided on the metal layer. (D) Others The analysis chip of the present invention is not limited to the above-described embodiment, and can be variously modified without departing from the spirit of the present invention.

For example, in each of the above-described embodiments, a plurality of strip-shaped hydrophobic portions 7a formed over the entire width of the flow path are arranged along the flow direction, but the hydrophobic portions 7a are located upstream of the reaction portion 6. The liquid sample Fs is formed on the long side of the cross section of the slit-shaped flow channel upstream from the reaction part 6 so that the liquid sample Fs can be held in a state where its tip position (gas-liquid interface) is aligned to prevent the liquid sample Fs from getting around. The width dimension, the number of the elements arranged in the flow direction, the mutual interval, and the shape thereof are not limited thereto.

For example, as shown in FIGS. 11 (a) to (i) and FIGS. 12 (a) and 12 (b), a hydrophobic portion 7a is formed on both wall surfaces or one side wall surface forming the long side of the slit-shaped channel cross section. It may be formed and arranged. That is, as shown in FIG. 11A, the hydrophobic portion 7a may not be completely formed over the entire width of the flow path. The width Wa of the hydrophobic portion 7a is 6 with respect to the flow path width W.
It is preferably 0% or more (Wa ≧ 0.6 W), and 80
% Or more (Wa ≧ 0.8 W) is more preferable.
Of course, it is most preferable that the entire width of the flow path is provided as in the above embodiment (Wa = W).

Further, the mutual distance and the dimension in the flow direction of the hydrophobic portions 7a are appropriately set according to various conditions. For example, as shown in FIG. It is also possible to widen the mutual intervals of the reaction part 6 and the reaction part 6, and it is also possible to increase the dimension of the hydrophobic part 7a in the flow direction as shown in FIG. 11 (c). Of course, it is also possible to reduce the mutual distance between the hydrophobic portion 7a and the reaction portion 6 or to reduce the dimension in the flow direction of each hydrophobic portion 7a as compared with the above embodiments. Further, it is also possible to make the mutual intervals of the hydrophobic part 7a and the reaction part 6 non-uniform as shown in FIGS.

Furthermore, as shown in FIG. 11 (f), the flow direction dimension and width dimension of each hydrophobic portion 7a are different, or the hydrophobic portion 7a is different.
The distance between a and the reaction part 6 may be different from each other. Further, as shown in FIG. 11 (g), the lid portion 2 and the substrate 4 having a relatively low affinity are subjected to a hydrophilic treatment to make the hydrophobic portion 7
The a and the hydrophilic parts 7b may be arranged alternately in the flow direction. Further, as shown in FIGS. 11 (h) and 11 (i), the hydrophobic portion 7a may have a non-linear shape.

If the gas-liquid interface of the liquid sample Fs does not have an extremely uneven shape in the flow direction, the liquid sample Fs
Since it is possible to suppress the entrapment of air in FIG.
As shown in (a) and (b), it is also possible to arrange the strip-shaped hydrophobic portion 7a inclining with respect to the flow direction. Further, it is sufficient that at least one hydrophobic portion 7a is provided on the upstream side of the reaction portion 6. Of course, it is preferable that a plurality of hydrophobic parts 7a provided on the upstream side of the reaction part 6 are arranged in the flow direction as in the above embodiment. That is, if there is a large variation in the tip of the liquid sample Fs at the time of reaching the hydrophobic portion 7a, it will be difficult to suppress this sufficiently, and therefore, by arranging a plurality of the hydrophobic portions 7a in the flow direction, the liquid sample Fs is repeated.
By aligning the tips of the, it is possible to reliably prevent the inclusion of air.

Further, the hydrophobic portion 7a is provided on the lid portion 2 to form the substrate 4
In the case where the reaction part 6 is provided on the substrate 4, or when the reaction part 6 is provided on the lid part 2 and the hydrophobic part 7a is provided on the substrate 4,
It is preferable that the hydrophobic part 7a is provided not only on the upstream side of the reaction part 6 but also on the opposite side of the reaction part 6 (at the same position as the reaction part 6 in the flow direction with the flow path 5 sandwiched therebetween). In addition, FIG.
(A) to (c) will be exemplified with reference to unfavorable shapes and arrangements of the hydrophobic portion 7a. In FIG. 13 (a),
Since the width dimension of the hydrophobic portion 7a is extremely short, the function of aligning the tips of the liquid specimen Fs by the hydrophobic portion 7a acts only on a very small portion of the liquid specimen Fs corresponding to this width dimension, and thus the liquid specimen Fs is surrounded. Cannot be fully prevented. FIG.
In (b), since the hydrophobic portion 7a is on the downstream side of the reaction portion 6, it is naturally impossible to prevent the liquid sample Fs from flowing around on the upstream portion of the reaction portion 6. In FIG. 13C, since the hydrophobic portion 7a is formed along the flow direction, the liquid sample Fs comes to flow through the hydrophilic portion 7b, which rather makes the gas-liquid interface uneven in the width direction.

In the above-mentioned embodiment, the flow path 5 is
Although the spacer 3 having the opening is formed between the lid 2 and the substrate 4, the flow path 5 may be directly formed in the lid 2 and / or the substrate 4. As a method of forming the flow path 5 in the lid portion 2 or the substrate 4, for example, a transfer technique typified by machining, injection molding or compression molding, or dry etching (R
IE, IE, IBE, plasma etching, laser etching, laser ablation, blasting, electrical discharge machining, LIGA, electron beam etching, FAB),
There is wet etching (chemical erosion).

The chip body may be integrally formed with the flow path 5 and without forming the lid 2 and the substrate 4 into a divided structure.
A fine structure is formed by coating various materials in layers, vapor deposition, sputtering, and depositing and partially removing S
It is possible by urface Micro-machining.

Further, in the above embodiment, the means for transporting the liquid sample Fs is constituted by the liquid feed pump,
The means for transporting the liquid sample Fs is not limited to this, and of course a pressure type other than the liquid feed pump may be used to generate a flow (electroosmotic flow) of the liquid sample Fs by applying an electric field to the flow path 5. In addition, transport by capillary phenomenon may be combined therewith.

In each of the above embodiments, an example in which the liquid sample is water-soluble has been described. However, the liquid sample may be oil-based, and in this case, the hydrophobic part is replaced with an oleophobic part (relatively lipophilic). Low site), and the hydrophilic site may be replaced with a lipophilic site that is more lipophilic than the lipophobic site.

[0071]

As described above in detail, according to the analysis chip of the present invention, the tip of the liquid sample flowing through the minute channel is aligned when moving from the high affinity portion to the low affinity portion. , It is possible to suppress the entrapment of air (generation of bubbles), so that the reaction between the low affinity portion and the low affinity portion allows the predetermined substance and the specific binding substance to be bound under optimal conditions. There is an advantage that analysis of a sample can be performed with high accuracy.

Further, since the frequency of re-execution of the analysis work due to the generation of bubbles is reduced, there is an advantage that the analysis can be efficiently performed. Furthermore, since it has a simple structure in which the high affinity portion and the low affinity portion are provided on the upstream side of the reaction portion, there is also an advantage that it can be manufactured at low cost.

[Brief description of drawings]

1A and 1B are views showing an analysis chip as a first embodiment of the present invention, in which FIG. 1A is a schematic assembly perspective view thereof, FIG. 1B is a schematic exploded perspective view thereof, and FIG. FIG. 3 is a schematic cross-sectional view of the flow path (cross section perpendicular to the flow direction A of the liquid sample), which is an XX cross-sectional view of (a).

FIG. 2 is a schematic enlarged view showing a configuration of a reaction section according to the first embodiment of the present invention.

FIG. 3 is a schematic diagram for explaining the definition of the flow direction of a liquid sample.

4 (a) and 4 (b) are views for explaining the operation of the analysis chip of the present invention, and are schematic plan views of relevant parts of the analysis chip.

FIG. 5 is a view for explaining a preferred form of the analysis chip of the present invention, and is a schematic transverse cross-sectional view of a flow channel.

FIG. 6 is a schematic plan view of the analysis chip for explaining the action and effect of the analysis chip as the first embodiment of the present invention, and (a) to (d) of FIG. The distribution status is shown.

FIG. 7 is a schematic perspective view showing the overall configuration of an SPR sensor according to a second embodiment of the present invention.

FIG. 8 is a schematic exploded perspective view showing a configuration of an analysis chip as a second embodiment of the present invention.

FIG. 9 is a schematic exploded perspective view showing a configuration of an analysis chip as a third embodiment of the present invention.

10 (a) to 10 (d) are schematic exploded perspective views showing the configuration of a modified example of the analysis chip as the third embodiment of the present invention.

11 (a) to (i) are schematic plan views of relevant parts showing a modification of the analysis chip of each embodiment of the present invention.

12 (a) and 12 (b) are schematic plan views of essential parts showing a modification of the analysis chip of each embodiment of the present invention.

13 (a) to 13 (c) are schematic plan views of relevant parts illustrating an unfavorable embodiment of the low affinity part according to the present invention.

14 (a) and (b) are views for explaining the problems of the conventional analysis chip, and are schematic plan views of the essential parts of the analysis chip.

FIG. 15 is a diagram for explaining the problem of the conventional analysis chip, and is a schematic plan view of a main part of the analysis chip.

16 (a) and 16 (b) are views for explaining the problems of the conventional analysis chip, and are schematic plan views of relevant parts of the analysis chip.

17 (a) and 17 (b) are views for explaining the problems of the conventional analysis chip, and are schematic plan views of relevant parts of the analysis chip.

FIG. 18 is a schematic plan view of a main part of an analysis chip for explaining the problems of the conventional analysis chip, wherein (a) shows a state in which a liquid sample is evenly distributed in the flow channel width direction. Figure,
FIG. 6B is a diagram showing a state in which the liquid sample is non-uniformly distributed in the flow channel width direction.

[Explanation of symbols]

1,1 'Analysis chip 2 lid 2A, 2B case 2Aa, 2Ba Internal space of cases 2A, 2B 3 spacers 4 substrates 5 channels 6 Reaction part 7a Hydrophobic part (low affinity part) 7b Hydrophilic part (high affinity part) 21 Inlet 22 Outlet 31 opening 41 metal layer 42 diffraction grating 43,44 through holes 61 spots 100 light sources 101 detector Fs liquid sample S gas-liquid interface W channel width Wa Width of hydrophobic part (low affinity part) 7a

Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G01N 37/00 101 G01N 37/00 101 102 102

Claims (6)

[Claims] 1. A reaction part comprising a chip body having a microchannel having a slit-shaped cross section, and a plurality of specific binding substances which are specifically bound to a predetermined substance and fixed to the microchannel facing the microchannel. And a liquid sample is circulated through the microchannel,
In an analysis chip used for performing an analysis on the liquid specimen according to a binding state between the predetermined substance and the specific binding substance in the reaction part, a length of the slit-shaped cross section of the chip body A high-affinity portion having a relatively high affinity for the liquid specimen and a low-affinity portion having a lower affinity for the liquid specimen than the high-affinity portion are formed on at least one of the surfaces forming the side than the reaction portion. Each of them is provided on the upstream side, and is configured such that when the liquid sample moves from the high affinity part to the low affinity part, the tip of the liquid sample is aligned along the width direction of the minute flow path. An analytical chip characterized by: 2. The analysis chip according to claim 1, wherein the low affinity portion is formed in a long strip shape along the long side of the cross section of the slit shape. 3. The analysis chip according to claim 1, wherein the low-affinity portion and the high-affinity portion are provided alternately and in plural along the flow direction of the liquid specimen. . 4. The chip body includes a substrate and a lid,
4. The assembly according to claim 1, wherein the flow path is formed between the substrate and the lid by assembling the lid with the substrate. The analysis chip described in. 5. The analysis chip according to claim 4, wherein the reaction part is formed on the substrate and / or the lid part. 6. A metal layer capable of inducing a surface plasmon wave, and a diffraction grating for generating an evanescent wave upon irradiation with light, further comprising a diffraction grating. The analytical chip according to item.