WO2011155179A1 - Analysis element chip - Google Patents

Abstract

Disclosed is an analysis element chip (10) which is used for surface plasmon resonance analysis devices or surface plasmon resonance fluorescence analysis devices, and which is provided with a prism (11), a metal thin film (15) formed on the surface of a predetermined side (13) of the prism (11) and having a surface (15a) to which a physiologically active substance (16) is affixed, and a flow path member (20) for forming a flow path (21) through which a sample flows while the sample is in contact with the metal thin film (15), wherein the metal thin film (15) attaches to the predetermined side (13) at an attachment strength in which the critical peeling limit value is 60 mN or more or at an attachment strength in which the metal thin film (15) does not peel off from the predetermined side (13) in a predetermined tape peeling test.

Description

Analysis element chip

The present invention relates to an analysis element chip used in a surface plasmon resonance analyzer that analyzes a specimen based on a change in the resonance angle of surface plasmon resonance, and a fluorescent substance contained in the specimen using an evanescent wave generated by surface plasmon resonance. The present invention relates to an analysis element chip used in a surface plasmon resonance fluorescence analyzer for analyzing a specific substance contained in a specimen by measuring the fluorescence by emitting light.

Conventionally, various analysis methods using surface plasmon resonance have been developed as methods for quantitative analysis of trace amounts of substances in sample solutions such as specimens. Many of these analysis methods use a so-called Kretschman arrangement analysis element chip in which a metal film is formed on a prism. The analysis element chip uses a change in the resonance angle of the surface plasmon resonance and an enhanced electric field near the metal film based on the surface plasmon resonance to analyze a very small amount of substance in the sample solution with high sensitivity and high accuracy. (See Patent Document 1).

Specifically, as shown in FIG. 9, the analysis element chip includes a prism 114, a metal film 112 formed on the reflecting surface 114 b of the prism 114, and a sample solution in contact with the surface of the metal film 112. And a flow path member 117 that forms a flow path 116 that flows while flowing.

The light enters the prism 114 of the analysis element chip 110 and is totally reflected by the reflecting surface 114b. When the incident angle of the light with respect to the metal film 112 is an incident angle, the electric field near the surface of the metal film 112 is greatly enhanced. This is because surface plasmon resonance occurs in the metal film 112 when light is incident on the reflecting surface 114b at a certain incident angle (resonance angle), which greatly enhances the electric field near the surface of the metal film 112. This phenomenon responds with high sensitivity to the change in the refractive index on the surface of the metal film 112. Therefore, by utilizing this highly sensitive response, it is possible to detect a very small amount of substance present in the sample solution flowing on the metal film 112.

The analysis method using the above surface plasmon resonance can detect a very small amount of a specific substance with high sensitivity and high accuracy. Therefore, for example, application to the medical field such as diagnosis of early cancer is considered. In such a field, detection of a specific substance (for example, a tumor marker) in a sample solution is performed using an immune reaction or the like. Therefore, the physiologically active substance 112a that captures this specific substance is fixed to the surface of the metal film 112 of the analysis element chip. In such storage of the analysis element chip 110, the physiologically active substance 112a must be placed in a humid environment in order to maintain the activity of the physiologically active substance 112a. Specifically, the analysis element chip 110 is preferably stored in a state where the storage solution is sealed in the flow path 116.

The metal film 112 of the analysis element chip 110 is a thin film having a thickness of about several tens of nanometers in order to cause surface plasmon resonance. In general, a metal film is deteriorated due to film floating due to adhesion of moisture. Therefore, if the inside of the channel 116 is in a humid state (including a state in which the preservation solution is enclosed in the channel 116) and the metal film 112 is placed in a humid environment for several months, the moisture is transferred to the metal film. It is feared that the film floats by entering between 112 and the prism 114. When a defect such as the above-described film floating occurs in the metal film 112 in the analysis element chip 110, a very small amount of substance cannot be detected with high sensitivity and high accuracy.

Japanese Patent No. 4370383

An object of the present invention is to provide an analytical element chip in which defects are not easily generated in a metal film even when the metal film is placed in a humid environment in order to maintain the activity of a physiologically active substance immobilized on the surface of the metal film. That is.

In the analysis element chip according to the present invention, the metal film formed on the prism is attached to the prism so that the critical peel limit value is 60 mN or more, or the metal film is a tape peel test ( In JIS D2020-1988), it adheres to the prism so as to have an adhesion strength that does not peel off from the prism. For this reason, according to the present invention, even if the metal film is placed in a humid environment in order to maintain the activity of the physiologically active substance fixed on the surface of the metal film, the analysis element chip is less likely to cause defects in the metal film. Can be provided.

The above and other objects, features and advantages of the present invention will become apparent from the following detailed description and the accompanying drawings.

FIG. 1 is a schematic longitudinal sectional view of an analysis element chip according to this embodiment. FIG. 2 is a diagram for explaining the measurement results obtained by the scratch test. FIG. 3 is a diagram showing a measurement result by the scratch test. FIG. 4 is a diagram showing the relationship between the assist coil power in the plasma assisted sputtering method when the cathode power is 100 W and the X-ray main peak intensity of the deposited metal film. FIG. 5 is a diagram showing the relationship between the assist coil power in the plasma assisted sputtering method when the cathode power is 200 W and the X-ray main peak intensity of the deposited metal film. FIG. 6 is a diagram showing the relationship between the film forming temperature in the electron gun heating vacuum deposition method and the X-ray main peak intensity of the formed metal film. FIG. 7 is a diagram showing the relationship between the assist coil power in the plasma assisted sputtering method when the cathode power is 100 W and the half width of the X-ray main peak of the deposited metal film. FIG. 8 is a diagram showing the relationship between the film formation temperature in the electron gun heating vacuum deposition method and the half width of the X-ray main peak of the formed metal film. FIG. 9 is a schematic longitudinal sectional view of a conventional analysis element chip.

Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

The analysis element chip according to the present embodiment includes an analysis device that analyzes a specimen based on a change in the resonance angle of surface plasmon resonance, and a fluorescence that is emitted when a fluorescent substance contained in the specimen is excited by an evanescent wave based on surface plasmon resonance. It is a so-called Kretschmann-arranged sensor chip used in a surface plasmon resonance fluorescence analyzer that measures the above.

Specifically, as shown in FIG. 1, the analysis element chip includes a prism 11, a metal film 15 formed on the surface of the prism 11, a sample solution such as a specimen, a reagent, and a cleaning liquid (hereinafter simply “sample”). Also includes a flow path member 20 that forms a flow path 21 that flows on the metal film 15 while being in contact with the metal film 15.

The prism 11 includes an incident surface 12, a reflecting surface (predetermined surface) 13, and an exit surface 14, and is formed of transparent glass or resin. When the analysis element chip 10 is installed in a surface plasmon resonance fluorescence analyzer or the like to analyze the specimen, the incident surface 12 receives light from a light source (not shown) of the surface plasmon resonance fluorescence analyzer or the like of the prism 11. Incident inside. A metal film 15 is formed on the upper surface of the reflecting surface 13, and the light incident on the prism 11 from the incident surface 12 is reflected by the metal film 15. The exit surface 14 emits the light reflected by the metal film 15 on the reflection surface 13 to the outside of the prism 11. The prism 11 of the present embodiment is made of transparent glass or resin having a refractive index of about 1.40 to 1.75.

Note that the prism is not limited to a shape in which the apex angle portion of the triangular prism is cut off in a side view as in the present embodiment. The prism may have a shape in which the side view has a triangular shape or the like (see the dotted line portion in FIG. 1). That is, the prism includes an incident surface, a reflective surface, and an output surface, and light incident on the prism from the incident surface is totally reflected by the metal film on the reflective surface, and the totally reflected light is reflected on the prism. Any shape may be used as long as it is emitted from the emission surface to the outside of the prism without being irregularly reflected inside.

The metal film 15 is a metal thin film formed on the prism 11. The metal film 15 of this embodiment is formed of gold. The metal film 15 is a member for amplifying an evanescent wave generated when light is totally reflected in the prism 11. That is, since the metal film 15 is provided on the reflection surface 13 and surface plasmon resonance occurs, the light is totally reflected on the reflection surface 13 where the metal film 15 is not provided and an evanescent wave is generated. The electric field formed in the vicinity of the surface 13 is enhanced. The metal film 15 is a thin film having a thickness of 100 nm or less so that surface plasmon resonance can be generated. The metal film 15 is preferably formed on the reflecting surface 13 so as to have a film thickness of 40 to 60 nm.

The physiologically active substance 16 is fixed to the surface (surface opposite to the prism) 15a of the metal film 15. This physiologically active substance 16 captures a specific antigen or the like in the specimen. The physiologically active substance 16 of this embodiment is an antibody. The physiologically active substance 16 is fixed to the surface 15a of the metal film 15 by surface treatment. The physiologically active substance 16 fixed to the metal film 15 does not show activity when dried. Therefore, when the analytical element chip 10 is not used and stored for a long period (several months), the metal film 15 is kept in a humid environment in order to maintain the activity of the physiologically active substance 16. . That is, the inside of the flow path 21 is kept in a humid state. In the present embodiment, the analysis element chip 10 is stored in a state in which a storage solution is sealed in the flow path 21.

Such a metal film 15 is attached to the reflective surface 13 so that the critical peeling limit value is an adhesion strength of 60 mN or more. Alternatively, the metal film 15 is attached to the reflecting surface 13 so as to have an adhesion strength that does not peel from the reflecting surface 13 in a predetermined tape peeling test.

The predetermined tape peel test is a cross-cut tape peel test in accordance with JIS (Japanese Industrial Standard) D0202-1988, which is an industrial standard in Japan. This test is performed as follows. A metal film 15 is formed on a grid-like plate. When the cellophane tape is pressed by the belly of the finger, it is brought into close contact with the metal film 15. Thereafter, the cellophane tape is peeled off. At this time, the adhesion force of the metal film 15 is evaluated based on the number of grids from which the metal film 15 has not been peeled off.

Further, the metal film 15 is formed on the reflective surface 13 so that the orientation intensity of the main peak in X-ray diffraction is 3000 cps or more, or the half width of the main peak in X-ray diffraction is 0.353 or less. Yes. The metal film 15 is attached to the reflecting surface 13 so as to have the adhesion strength as described above and has the above filling density (dense density), so that the metal film 15 remains in a humid environment. Thus, even if the analytical element chip 10 is stored, defects in the metal film 15 such as film floating are less likely to occur.

Here, the critical peeling limit value is a load value applied to the diamond indenter when the film is broken in the scratch test by scratching the film with the tip of the diamond indenter. Specifically, in the scratch test, the coating (metal film 15 in the present embodiment) is scratched by the tip while applying a load to the diamond indenter. And the adhesive force of a film is evaluated by the value of the load when the film breaks. FIG. 2 is a diagram illustrating an example of a measurement result in the scratch test. In this figure, the thick line indicates the load applied to the coating, and the thin line indicates the friction force generated at the tip of the diamond indenter. In this scratch test, the load on the diamond indenter is increased until the coating is peeled off, and the load value when the coating is broken is defined as a critical peeling limit value.

Further, the orientation intensity of the main peak of X-ray diffraction is the orientation intensity of the main peak in the measurement result obtained by measuring the metal film 15 formed on the prism 11 by the thin film X-ray diffraction method. The thin film X-ray diffraction method is a test method for evaluating the crystallinity of a thin film formed on a substrate. The half width is the half width of the main peak.

The metal film 15 having the above adhesion force and the above packing density is formed in a state where the prism 11 is heated at a high temperature of about 150 to 350 ° C., for example. When the prism 11 is made of resin or the like and cannot be heated at a high temperature, the metal film 15 is formed using ion energy. The metal film 15 may not be formed from a single material. For example, the metal film 15 may be formed by forming a chromium (Cr) underlayer on the prism 11 and laminating a gold film thereon. Further, the metal film 15 may be formed by raising the degree of vacuum at the time of film formation. Further, the metal film 15 may be formed so that the film formation speed is slow.

Specifically, the metal film 15 is formed by an electron gun heating vacuum deposition method, a resistance heating vacuum deposition method, a macnetron sputtering method, an ion assisted deposition method, a plasma assisted sputtering method, an ion plating method, a molecular beam epitaxy method, or the like. The film is formed on the reflection surface 13.

The flow path member 20 is provided on the reflecting surface 13 of the prism 11 and has a flow path 21 through which a sample solution such as a specimen flows. The flow path member 20 is formed of a transparent resin. The flow path member 20 of the present embodiment is a plate-like member that expands in the horizontal direction. The channel 21 includes a detection unit 22 and a plurality of guide units 23. The detection unit 22 performs an antigen-antibody reaction. The guide unit 23 guides the sample solution from the outside of the analysis element chip 10 to the detection unit 22 or guides the sample solution from the detection unit 22 to the outside.

Specifically, the detection unit 22 is surrounded by a groove provided on the back surface (lower surface in FIG. 1) 20 b of the flow path member 20 and the metal film 15 on the prism 11. That is, in the detection unit 22, the sample solution flows while being in contact with the surface of the metal film 15 (surface on which the physiologically active substance 16 is fixed) 15 a. One end portion of each guide portion 23 is open on the surface (upper surface in FIG. 1) 20a of the flow path member 20. The other end (the end opposite to the one end) of each guide 23 is connected to the detector 22. Thus, the guide part 23, the detection part 22, and the guide part 23 are connected in order, and the one flow path 21 is formed.

The flow path member 20 is bonded (bonded) to the prism 11 with an adhesive. In the present embodiment, a seal member 25 is provided at a position surrounding the detection unit 22 from the horizontal direction and between the flow path member 20 and the prism 11. The seal member 25 is formed of an elastic body. The seal member 25 prevents the sample solution from leaking from the joint portion between the flow path member 20 and the prism 11. The joining of the flow path member 20 and the prism 11 is not limited to adhesion, and may be laser welding, ultrasonic welding, pressure bonding using a clamp member, or the like. As long as the flow path member 20 and the prism 11 are joined in a liquid-tight manner, the seal member 25 surrounding the detection unit 22 may be omitted.

According to the analytical element chip 10 described above, the metal film 15 adheres to the reflecting surface 13 so that the critical peeling limit value is 60 mN or more, or in the tape peeling test (JIS D0202-1988). By adhering to the reflecting surface 13 so as to have an adhesion strength that does not peel from the moisture 13, it becomes difficult for moisture to enter between the metal film 15 and the prism 11. Therefore, in order to maintain the activity of the physiologically active substance 16 fixed on the surface of the metal film 15, the metal film 15 remains in a humid environment (that is, the flow path 21 remains humid). Even if the analytical element chip 10 is stored, defects such as film floating are unlikely to occur in the metal film 15.

Further, the metal film 15 has a packing density (denseness) such that the orientation intensity of the main peak in X-ray diffraction is 3000 cps or more, or the half width of the main peak in X-ray diffraction is 0.353 or less. In addition, moisture is less likely to enter between the metal film 15 and the prism 11. For this reason, defects in the metal film 15 are less likely to occur when the analysis element chip 10 is stored while the metal film 15 is left in a humid environment.

The analytical element chip of the present invention is not limited to the above-described embodiment, and it is needless to say that various changes can be made without departing from the gist of the present invention.

For example, in the analysis element chip 10 of the above embodiment, the metal film 15 is attached to the reflective surface 13 so that the critical peel limit value is 60 mN or more, or the reflective surface in the tape peel test (JIS D0202-1988). The adhesion intensity of the main peak in the X-ray diffraction of the metal film 15 is 3000 cps or more, or the half width of the main peak in the X-ray diffraction is 0.353 or less. However, it is not limited to this. That is, the metal film 15 adheres to the reflective surface 13 so that the critical peel limit value is 60 mN or more, or does not peel from the reflective surface 13 in a predetermined tape peel test (JIS D0202-1988). It is only necessary to adhere to the reflecting surface 13 so that Since the metal film 15 adheres to the prism 11 so as to have such adhesion strength, even if the inside of the flow path 21 is in a humid environment and the analysis element chip 10 is stored, moisture is absorbed into the metal film 15 and the prism. 11 is less likely to cause defects in the metal film 15.

A metal film was formed on the prism by the plasma-assisted sputtering method under the following conditions. The adhesion (film adhesion) of the metal film to the reflecting surface was measured by a tape peeling test (cross cut tape peeling test: conforming to JIS D0202-1988). Then, in order to place the metal film in a humid environment, the surface of the metal film is stored in a state where water is accumulated on the surface of the metal film after 6 months have passed. ) Was observed. In this example, the base layer (the material is Cr; the film thickness is t = 1 nm) is formed, thereby improving the adhesion strength of the metal film to the prism.

<Film formation conditions>
・ Achieving vacuum: 1 × 10 ⁻⁷ Torr
・ Deposition vacuum: 5 × 10 ⁻⁴ Torr
Gas: 99.9999% argon Cathode power: 100W
・ Support coil power: 50W
・ Film thickness: 50 nm
・ Film formation structure: Au / Cr (underlayer)
-Substrate (prism): BK7 (glass)

As a comparative example, the film formation configuration is only Au (that is, only a gold film is formed without forming an underlayer), and other film formation conditions are the same as those in Example 1. Thus, a metal film was formed. Then, the same observation as described above was performed. The results are shown in Table 1 below. Table 1 also shows the main peak intensity and the half-value width of the X-ray diffraction of the metal film formed under the above film forming conditions. The main peak intensity and half-value width of this X-ray diffraction were measured with an X-ray diffractometer.

In Table 1, ○ in the column of adhesion strength indicates that the metal film did not peel in the tape peel test, and × indicates that the metal film peeled in the tape peel test. In the column of metal film defects, ○ indicates that no metal film defect occurred after 6 months, and x indicates that a metal film defect occurred after 6 months. Here, the metal film defect phenomenon refers to a phenomenon in which a circular bulge having a diameter φ of 20 to 30 μm and a height of about 2 μm occurs when left standing for a long time with a liquid stored on the metal film.

From this result, the following could be confirmed.

The prism in which the metal film was not peeled by the tape peeling test does not cause a metal film defect phenomenon (film floating) even after 6 months with the metal film in a humid environment.

In addition, even if the main peak intensity of X-ray diffraction is not less than 3000 cps or the half-value width of X-ray diffraction is not 0.353 or less in the metal film, if no peeling occurs in the tape peeling test, the defect of the metal film is not observed after 6 months. The phenomenon does not occur.

A metal film was formed on the prism by the plasma-assisted sputtering method under the following conditions. The adhesion force of the metal film to the reflecting surface was measured by a tape peeling test (cross cut tape peeling test: conforming to JIS D0202-1988). Then, in order to place the metal film in a humid environment, the surface of the metal film is stored in a state where water is accumulated on the surface of the metal film after 6 months have passed. ) Was observed. In this example, the adhesion strength of the metal film to the prism was improved by controlling the film formation rate.

<Film formation conditions>
・ Achieving vacuum: 1 × 10 ⁻⁷ Torr
・ Deposition vacuum: 5 × 10 ⁻⁴ Torr
Gas: 99.9999% argon Cathode power: 100W
・ Support coil power: 50W
・ Film thickness: 50 nm
・ Film structure: Au
Film formation rate: First, a film is formed at 0.035 nm / sec for 5.95 minutes, and then a film is formed at 0.1 nm / sec for 6.25 minutes. (Total film formation time: 12.2 minutes)
* Use a mask to reduce the rate at low rates.
・ Substrate: BK7

As a comparative example, the metal film is formed so that the film formation rate is 0.1 nm / sec (film formation time: 8.3 minutes) and the other film formation conditions are the same as those in Example 2. It was done. Then, the same observation as described above was performed. The results are shown in Table 2 below. Table 2 also shows the main peak intensity and the half-value width of the X-ray diffraction of the metal film formed under the above film forming conditions. The main peak intensity and half-value width of this X-ray diffraction were measured with an X-ray diffractometer.

In Table 2, ○ in the column of adhesion strength indicates that the metal film did not peel off in the tape peel test, and × indicates that the metal film peeled off in the tape peel test. In the column of metal film defects, ○ indicates that no metal film defect occurred after 6 months, and x indicates that a metal film defect occurred after 6 months.

From this result, the following could be confirmed.

In the prism in which the metal film was not peeled by the tape peeling test, the metal film defect phenomenon does not occur even if the metal film is left in a humid environment for 6 months.

In addition, even if the main peak intensity of X-ray diffraction is not less than 3000 cps or the half-value width of X-ray diffraction is not 0.353 or less in the metal film, if no peeling occurs in the tape peeling test, the defect of the metal film is not observed after 6 months. The phenomenon does not occur.

A metal film was formed on the prism under the following conditions.

<Film formation conditions>
・ Film formation method A: Plasma assisted sputtering method B: Ion assist method ・ Film structure A-1: Au
A-2: Au + Cr
B-1: Au
B-2: Au + Cr
・ Sample 1: BK7
2: COP (cycloolefin) resin (1)
3: COP resin (2)
4: OKP resin

The critical peel load value of each sample was measured by a scratch test. In order to place the metal film of each sample in a humid environment, the surface of the metal film was observed after 6 months in a state where water was stored on the surface of the metal film. The results are shown in Table 3 below and FIG. Table 3 also shows the results when the same tape peeling test as in Example 1 and Example 2 was performed on each sample of this example.

In Table 3, ○ in the column of adhesion strength indicates that the metal film did not peel in the tape peel test, and × indicates that the metal film peeled in the tape peel test. In the column of metal film defects, ○ indicates that no metal film defect occurred after 6 months, and x indicates that a metal film defect occurred after 6 months.

From this result, the following could be confirmed.

The prism with a critical peel load value of 60 mN or more does not cause a metal film defect phenomenon even after 6 months have passed in a state where the metal film is placed in a humid environment.

Also, the presence or absence of a metal film defect phenomenon after 6 months of the metal film having an adhesive force with a critical peel load value of 60 mN or more and the metal film in which no peeling occurred in the tape peeling test coincides. The presence or absence of a metal film defect phenomenon after the lapse of 6 months in the metal film having an adhesive force with a critical peeling load value of less than 60 mN and the metal film in which peeling occurred in the tape peeling test coincide. From the above, the critical peel load value in the scratch test is 60 mN for the adhesive force of the metal film that did not peel in the tape peel test.

A metal film was formed on the prism by the plasma-assisted sputtering method under the following conditions. In this example, the crystallinity (X-ray peak intensity) of the metal film was controlled by controlling the assist coil power.

<Film formation conditions>
・ Achieving vacuum: 1 × 10 ⁻⁷ Torr
・ Deposition vacuum: 5 × 10 ⁻⁴ Torr
・ Gas: 99.9999% argon ・ Cathode power: 100 W, 200 W (13.56 MHz)
-Support coil power: Variable (13.56 MHz)
・ Film thickness: 50 nm
・ Film structure: Au
Film formation rate: 0.1 nm / sec when cathode power is 100 W
0.2nm / sec when cathode power is 200W
・ Substrate: COP resin

The main peak intensity of X-ray diffraction in the metal film formed under the film forming conditions was measured by an X-ray diffractometer. In order to place the metal film in a humid environment, the surface of the metal film was observed after 6 months in a state where water was accumulated on the surface of the metal film. The results are shown in Tables 4 and 5 below, and FIGS.

In Tables 4 and 5, ○ in the column of metal film defects indicates that no metal film defects occurred after 6 months, and x indicates that metal film defects occurred after 6 months.

From these results, the following could be confirmed.

The prism having a main peak intensity of X-ray diffraction of 3000 cps or more of the metal film does not cause a metal film defect phenomenon even if the metal film is left in a humid environment for 6 months.

Therefore, the metal film adheres to the prism so that the peeling does not occur in the tape peeling test or the critical peeling limit value is 60 mN or more, and the main peak intensity of X-ray diffraction of this metal film is 3000 cps or more. Then, the metal film defect phenomenon is less likely to occur.

A metal film was deposited on the prism by the electron gun heating vacuum deposition method under the following conditions. In this example, the crystallinity (X-ray peak intensity) of the metal film was controlled by controlling the film formation temperature.

<Film formation conditions>
・ Achieving vacuum: 1 × 10 ⁻⁷ Torr
・ Deposition vacuum: 3 × 10 ⁻⁷ Torr
・ Electron gun power: 6kV, 80mA
・ Film thickness: 55nm
・ Film structure: Au
・ Deposition rate: 1 nm / sec
・ Deposition temperature: variable ・ Substrate: BK7

The main peak intensity of X-ray diffraction in the metal film formed under the film forming conditions was measured by an X-ray diffractometer. In order to place the metal film in a humid environment, the surface of the metal film was observed after 6 months in a state where water was accumulated on the surface of the metal film. The results are shown in Table 6 below and FIG.

In Table 6, ○ in the column of the metal film defect indicates that no metal film defect occurred after 6 months, and × indicates that the metal film defect occurred after 6 months.

From these results, the following could be confirmed.

The prism having a main peak intensity of X-ray diffraction of 3000 cps or more of the metal film does not cause a metal film defect phenomenon even if the metal film is left in a humid environment for 6 months.

Therefore, the metal film adheres to the prism so that the peeling does not occur in the tape peeling test, or the critical peeling limit value is 60 mN or more, and the main peak intensity of X-ray diffraction of this metal film is 3000 cps or more. Then, the metal film defect phenomenon is less likely to occur.

A metal film was formed on the prism by the plasma-assisted sputtering method under the following conditions. In this example, the crystallinity (half-value width of the X-ray peak) of the metal film was controlled by controlling the assist coil power.

<Film formation conditions>
・ Achieving vacuum: 1 × 10 ⁻⁷ Torr
・ Deposition vacuum: 5 × 10 ⁻⁴ Torr
Gas: 99.9999% argon Cathode power: 100 W (13.56 MHz)
-Support coil power: Variable (13.56 MHz)
・ Film thickness: 50-55nm
・ Film structure: Au
・ Deposition rate: 0.1 nm / sec
・ Substrate: COP resin

The half-value width of the main peak of X-ray diffraction in the metal film formed under this film forming condition was measured by an X-ray diffractometer. In order to place the metal film in a humid environment, the surface of the metal film was observed after 6 months in a state where water was accumulated on the surface of the metal film. The results are shown in Table 7 below and FIG.

In Table 7, “◯” in the column of the metal film defect indicates that no metal film defect occurred after 6 months, and “x” indicates that the metal film defect occurred after 6 months.

From these results, the following could be confirmed.

The prism with the half-width of the main peak of the X-ray diffraction of the metal film being 0.353 or less does not cause the metal film defect phenomenon even if the metal film is left in a humid environment for 6 months.

Therefore, the metal film is adhered to the prism so that the adhesion does not occur in the tape peeling test or the adhesion force of the critical peeling limit value of 60 mN or more, and the half width of the X-ray diffraction of this metal film is 0.353. Below, the metal film defect phenomenon is less likely to occur.

A metal film was deposited on the prism by the electron gun heating vacuum deposition method under the following conditions. In this example, the crystallinity (X-ray peak intensity) of the metal film was controlled by controlling the film formation temperature.

<Film formation conditions>
・ Achieving vacuum: 1 × 10 ⁻⁷ Torr
・ Deposition vacuum: 3 × 10 ⁻⁷ Torr
・ Electron gun power: 6kV, 80mA
・ Film thickness: 50-55nm
・ Film structure: Au
・ Deposition rate: 1 nm / sec
・ Deposition temperature: variable ・ Substrate: BK7

The half-value width of the main peak of X-ray diffraction in the metal film formed under this film forming condition was measured by an X-ray diffractometer. In order to place the metal film in a humid environment, the surface of the metal film was observed after 6 months in a state where water was accumulated on the surface of the metal film. The results are shown in Table 8 below and FIG.

In Table 8, ○ in the column of the metal film defect indicates that no metal film defect occurred after 6 months, and × indicates that the metal film defect occurred after 6 months.

From these results, the following could be confirmed.

The prism with a half peak width of the X-ray diffraction main peak of 0.353 or less of the metal film does not cause the metal film defect phenomenon even if the metal film is left in a humid environment for 6 months.

Also from this, the metal film adheres to the prism so that the peeling does not occur in the tape peeling test or the adhesion force of the critical peeling limit value of 60 mN or more, and the half width of the X-ray diffraction of this metal film is 0. If it is 353 or less, the metal film defect phenomenon is less likely to occur.

[Outline of the embodiment]
The above embodiment is summarized as follows.

The analysis element chip according to the present embodiment is a surface plasmon resonance analyzer that analyzes a sample based on a change in the resonance angle of surface plasmon resonance, or a fluorescent substance contained in the sample is excited by an evanescent wave based on surface plasmon resonance. An analysis element chip for use in a surface plasmon resonance fluorescence analyzer for measuring emitted fluorescence, comprising a prism and a metal film formed on a surface of a predetermined surface of the prism, on which a physiologically active substance is fixed And a flow path member that forms a flow path in which the specimen flows in contact with the metal film, and the metal film is attached to the predetermined surface with an adhesion strength of a critical peeling limit value of 60 mN or more. Or it adheres with the adhesion strength which does not peel from the said predetermined | prescribed surface in a tape peeling test (JISD2020-1988).

When the metal film adheres to the prism so as to have such adhesion strength, it becomes difficult for moisture to enter between the metal film and the prism. Therefore, in order to maintain the activity of the physiologically active substance fixed on the surface of the metal film (the surface opposite to the prism), the metal film is in a humid environment (that is, the channel is in a humid condition). ), Even if the analytical element chip is stored, defects such as film floating are less likely to occur in the metal film.

In the analytical element chip, the orientation strength of the main peak in the X-ray diffraction of the metal film is 3000 cps or more, or the half width of the main peak in the X-ray diffraction of the metal film is 0.353 or less. It is preferable.

Such a metal film having a high packing density makes it difficult for moisture to enter between the metal film and the prism. As a result, defects in the metal film are less likely to occur when the analytical element chip is stored in a state where the metal film is placed in a humid environment.

As described above, the analysis element chip according to the present invention is useful for an analysis element chip used in a surface plasmon resonance analyzer and an analysis element chip used in a surface plasmon resonance fluorescence analyzer, and is fixed to the surface of a metal film. In order to maintain the activity of the bioactive substance formed, it is suitable for an analysis element chip in which the metal film is placed in a humid environment.

Claims (3)

A surface plasmon resonance analyzer that analyzes a specimen based on a change in the resonance angle of surface plasmon resonance, or a surface plasmon resonance fluorescence that measures fluorescence emitted when a fluorescent substance contained in the specimen is excited by an evanescent wave based on surface plasmon resonance. An analysis element chip used in an analysis device,
A prism, a metal film formed on a predetermined surface of the prism, on which a physiologically active substance is fixed, and a channel member that forms a channel through which the specimen flows in contact with the metal film Prepared,
The metal film adheres to the predetermined surface with an adhesion strength of a critical peeling limit value of 60 mN or more, or adheres with an adhesion strength that does not peel from the predetermined surface in a tape peeling test (JIS D0202-1988). An analytical element chip characterized by comprising: The analytical element chip according to claim 1, wherein the orientation strength of the main peak in the X-ray diffraction of the metal film is 3000 cps or more. The analytical element chip according to claim 1, wherein the half width of the main peak in the X-ray diffraction of the metal film is 0.353 or less.

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