JP2003042945A - Surface plasmon resonance sensor system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To continuously measure and process a large number of samples, to simplify constitution, to facilitate relative movement, to measure with proper precision, and to reduce cost. SOLUTION: This surface plasmon resonance sensor system is provided with a first optical system mounted with plural samples for measuring biochemical reaction on one face; and it is formed with a thin film for causing surface plasmon resonance on the other face constituting reflecting face, a light source for emitting a laser beam for generating plasmon resonance on the reflecting face in the thin film, a second optical system for converting the emitted laser beam, emitted from the light source into a parallel beam, and a photodetecting means for detecting an intensity distribution of reflected light reflected on the light reflecting face. In the first optical system, biochemical reactions in the plural sample are detected at the same time, by conducting irradiation using the laser beam converted into the parallel beam by the second optical system, as a parallel beam for irradiating a sample-mounted area mounted with plural samples in the thin film.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to detecting a minute mass change of a liquid sample which is a target of biochemical measurement.
The present invention relates to a surface plasmon resonance sensor device using the surface plasmon resonance phenomenon, and more particularly to a surface plasmon resonance sensor device capable of simultaneously measuring and processing a large number of samples.

[0002]

2. Description of the Related Art Conventionally, a surface plasmon resonance sensor device using a surface plasmon resonance phenomenon has been known as a method for detecting the amount of physicochemical change of a substance with the progress of biochemical reaction. For example, as shown in FIG. 4, a metal thin film 2 of gold or silver is formed on the surface of a parallel glass substrate (or glass prism) 1 having a diffraction grating by using a film forming technique such as vacuum deposition. When the laser light 3 is irradiated from the glass substrate 1 side toward the interface with the metal thin film 2 at an angle satisfying the total reflection condition, surface plasmon resonance is excited in the metal thin film 2 at a specific incident angle θ. That is.

When surface plasmon resonance is excited, optical energy is absorbed by plasmon waves on the metal thin film 2, so that the intensity of the reflected light 5 totally reflected at the interface between the glass substrate 1 and the metal thin film 2 sharply decreases. To do. FIG. 5 shows the relationship between the incident angle θ and the intensity of the reflected light 5. Here, there is a relation that the incident angle θ at which the surface plasmon resonance occurs depends on the density of the medium such as the sample solution of the measurement unit 4 in contact with the metal thin film 2 (that is, the mass of the metal thin film surface).

Therefore, the reflected light 5 reflected from this optical system
By specifically determining the reflection angle at which the surface plasmon resonance phenomenon occurs, and the incident angle θ when the surface plasmon resonance phenomenon occurs, the density of the medium, that is, the metal It is possible to obtain the change in mass on the surface of the thin film.

As described above, a minute change in the mass of the surface of the metal thin film can be sensitively detected as a large change in the amount of light due to surface plasmon resonance absorption of the metal thin film. Therefore, according to the measurement method to which the surface plasmon resonance phenomenon is applied, it is possible to measure an extremely small amount, and a mass change of 1 picogram can usually be detected. Therefore, it is also applied to biochemical measurement that handles minute amounts that cannot be measured by general measurement methods. For example, as in the two characteristics shown in FIG. 5, D in the measurement unit 4 (see FIG. 4) is
Incident angle θ at which the intensity of the reflected light 5 decreases with or without NA coupling
Therefore, it is possible to detect a minute change in mass due to the binding of DNA.

Generally, the above-mentioned surface plasmon resonance sensor device individually measures a biochemical reaction carried out at one detection site, and since the measurement work efficiency is low, a large number of samples are measured. Devices have been developed to do so. For example, as described in Japanese Patent Laid-Open No. 2000-65730, an apparatus has been developed that efficiently detects the surface plasmon resonance angle of many kinds of sample components. This will be briefly described with reference to FIG. 6. In this conventional device, a prism 8 is attached to a sensor chip 7 provided with a glass substrate 6 on which a metal thin film (not shown) for adsorbing a sample solution is provided. The light from the light irradiation device 9 is incident at a required angle, the light receiving device 10 receives the reflected light from the boundary surface of the metal thin film on the glass substrate 6, and the components of the sample solution are detected by the resonance angle at which the intensity is minimized. To detect. The glass substrate 6 is attached to the lower surface of the cell plate 11 in which a large number of cells 11a having open lower surfaces are arranged at a required interval so as to close the openings of the cells 11a to form the sensor chip 7. The glass substrate 6 in each cell 11a selected in a state where the prism 8 is formed in a size corresponding to the plurality of cells 11a and the glass substrate 6 corresponding to the plurality of cells 11a is selectively adhered to the prism 8 The respective metal thin film boundary surfaces are irradiated with respective lights in a required angular width. The resonance angle of the sample solution dispensed in each cell 11a selected based on the intensity of each reflected light from the metal thin film boundary surface of the glass substrate 6 corresponding to each cell 11a can be simultaneously detected.

[0007]

Since the conventional device is constructed as described above, it has the following problems.
That is, in order to keep the detection accuracy of the resonance angle in the arbitrary cells 11a arranged in a matrix constant, the lower surface of the glass substrate 6 and the upper surface of the prism 8 that compose the sensor chip 7 that relatively moves while making contact with each other. The two must be mechanically moved while maintaining an optically tight coupling between them. In order to maintain the optical coupling, a matching oil or a silicone rubber sheet having a refractive index substantially equal to that of the prism 8 and the glass substrate 6 is interposed between the glass substrate 6 and the prism 8 so that bubbles are not mixed. Therefore, there is a problem in that relative movement is extremely difficult and the configuration is complicated.

Further, since the glass substrate 6 is moved in contact with the prism 8, the total analysis speed of a large number of samples is slow and the measurement accuracy is poor. Further, since the cell 11a is required for each sample and the cells 11a are separated and independent, the sensor chip 7 becomes large, and it is not practical to handle a large number of samples.

Therefore, the present invention has been made in order to solve the above-mentioned problems of the prior art, and is capable of simultaneously measuring and processing a large number of samples and having a simple structure.
The main object of the present invention is to provide a surface plasmon resonance sensor device which has good measurement accuracy and is inexpensive.

[0010]

In the surface plasmon resonance sensor device of the present invention, a plurality of samples for biochemical reaction measurement are mounted on one surface, and surface plasmon resonance is generated on the other surface constituting the reflection surface. A first optical system having a thin film formed thereon, a light source that emits laser light for causing plasmon resonance on the reflection surface of the thin film, and a second optical system that converts the laser light emitted from the light source into parallel light. A light detecting means for detecting an intensity distribution of reflected light reflected by the light reflecting surface, wherein the first optical system converts the laser light converted into parallel light by the second optical system into the thin film of the thin film. By irradiating parallel light for irradiating the sample mounting area on which a plurality of samples are mounted, the biochemical reactions in the plurality of samples can be simultaneously detected, and the first optical system has a semicircular cross section. Semi-cylindrical region of A substrate having a first region in which a flat portion is in contact with the reflective surface of the thin film and a second region including a plate-shaped region excluding the first region, the first region being more than the second region. Is also configured to be ion-exchanged so that the refractive index is increased, and the second optical system is configured to include an assembly of a plurality of cylindrical lenses according to the number of samples to be simultaneously detected.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of a surface plasmon resonance sensor device according to the present invention will be described in detail below with reference to the drawings. The same or equivalent parts as those of the conventional device are designated by the same reference numerals, and the description thereof will be omitted.

FIG. 1 is a diagram schematically showing the structure of a surface plasmon resonance sensor device according to a first embodiment of the present invention. As shown in FIG. 1, in the surface plasmon resonance sensor device of the present invention, the metal thin film 2 is formed on the flat surface 15A of the first cylindrical lens 15 having a semicircular cross section, which is the first optical system, by vapor deposition or the like. , A plurality of samples for biochemical reaction measurement 14A to 14D are provided on the surface of the metal thin film 2.
They are arranged linearly along the longitudinal direction of the cylindrical lens 15. 1 shows the surface side of the metal thin film 2, the flat surface 15 of the first cylindrical lens 15 is shown.
The back surface side that contacts A functions as a reflection surface for the laser light emitted from the light irradiation device 9.

Further, a second cylindrical lens 16 which is a second optical system having an arcuate cross section is disposed between the first cylindrical lens and the light irradiating device 9 which is a light source. The emitted laser light 9A is converted into parallel light 9B by the second cylindrical lens 16.

Here, the parallel light 9B is incident on the first cylindrical lens 15 and is reflected on the reflection surface of the metal thin film 2 (the surface of the metal thin film 2 contacting the first cylindrical lens 15 in FIG. 1). The plurality of samples 14A
14D is a parallel light having an irradiation range for irradiating the sample mounting area of the metal thin film 2 on which 14D are mounted.

The parallel light 9B is reflected by the reflecting surface of the metal thin film 2 and becomes reflected light 9C, which is a light detecting means 2
The three-dimensional array sensor 17 receives the light and measures the light intensity distribution. The two-dimensional array sensor 17 includes a plurality of samples 14
This is a light-receiving element capable of simultaneously measuring the reflected light 9C from A to 14D, and four samples (samples 14A to 14D) as shown in FIG.
14D) In some cases, four samples 14A-14D can be analyzed simultaneously. The analysis result is configured to be displayed separately for each sample, and it is possible to efficiently detect in which sample a minute change in mass has occurred.

Since the surface plasmon resonance sensor device according to the first embodiment of the present invention is configured as described above, it is possible to simultaneously and efficiently measure a plurality of samples 14A to 14D for biochemical reaction measurement. . In addition, the metal thin film 2 is directly formed on the flat surface 15A of the first cylindrical lens 15 as described above, and the sample 14 for biochemical reaction measurement is formed thereon.
Since A to 14D are directly mounted, the interval between each sample can be narrowed from about 1 cm to a minimum of about 1 μm, and the efficiency of detection work can be greatly improved.

Although the case where the metal thin film 2 is formed on the plane 15A of the first cylindrical lens 15A has been described here, a semiconductor thin film may be used as long as it can induce surface plasmon resonance and has a function as a reflector. It may be configured. Further, FIG. 1 shows the case where four samples 14A to 14D for biochemical reaction measurement are arranged in a straight line, but the number of samples may be any number, and the samples may be arranged in a plurality of rows to detect all at the same time. Alternatively, a plurality of samples may be divided into several groups for detection.

Embodiment 2. FIG. 2 is a configuration diagram schematically showing a configuration of a main part of a surface plasmon resonance sensor device according to a second embodiment of the present invention. As shown in FIG. 2, in the surface plasmon resonance sensor device according to the second embodiment of the present invention, the first cylindrical lens that is the first optical system is a semi-cylindrical portion having a semicircular cross section, and the flat portion is made of metal. Thin film 2
The first cylindrical lens 20A composed of the first region that comes into contact with the reflective surface of is used. Other configurations are similar to those of the surface plasmon resonance sensor device according to the first embodiment shown in FIG.

The first cylindrical lens 20A is
The lens is ion-exchanged so that the refractive index thereof is larger than that of the second region of the glass plate 20 made of soda lime glass excluding the first region. That is, by subjecting the glass plate 20 to the first region, for example, potassium ion exchange, the glass plate 20 is moved to the cylindrical lens 2 in the first region.
0A and a low-refractive-index portion 20B that is a second region formed of a plate-shaped body excluding the first region, and the first region that is a light-refractive-index portion has a lens effect.

As described above, the metal thin film 2 is formed on the upper surface of the first cylindrical lens 20A formed by imparting a lens effect to a part of the glass plate 20 by ion exchange.
And a plurality of samples 14A to
If 14D is mounted, as in the case of the first embodiment, it is possible to simultaneously and efficiently measure minute changes in the mass of the plurality of biochemical reaction measurement samples 14A to 14D.

The size of the first cylindrical lens is, for example, 1 mm to 30 mm in width and 5 in the longitudinal direction.
It is about mm to 100 mm. Although the case where the first region of the soda lime glass is exchanged with potassium ions to give the lens effect is described here, the refractive index of the first region described above can be set to be larger than the refractive index of the second region. In that case, the first cylindrical lens 20A may be configured using a glass plate made of another material.

Embodiment 3. FIG. 3 is a diagram schematically showing a configuration of a main part of a surface plasmon resonance sensor device according to a third embodiment of the present invention. In FIG. 3, the surface plasmon resonance sensor device according to the third embodiment of the present invention is shown in FIG.
Instead of the second cylindrical lens 16 shown in FIG.
The optical system includes a second cylindrical lens 30 including a plurality of cylindrical lenses 31A to 31D. Other configurations are similar to those of the surface plasmon resonance sensor device according to the first embodiment shown in FIG.

In the second cylindrical lens 30, the lenses 31A to 31D are fixed by fixing the cylindrical lenses 31A to 31D corresponding to the numbers of the samples 14A to 14D with the frame 32 so that the optical axes thereof are parallel to each other. The laser light that passes through is derived in parallel.

As described above, in the surface plasmon resonance sensor device according to the third embodiment of the present invention, the second cylindrical lens 30 in which the plurality of cylindrical lenses 31A to 31D are fixed by the frame 32 so that their optical axes are parallel to each other is used. As a result, similar to the case of the first embodiment, it is possible to efficiently and simultaneously measure minute changes in the mass of the plurality of biochemical reaction measurement samples 14A to 14D.

Incidentally, FIG. 3 shows the cylindrical lens 3
Although the second cylindrical lens 30 in which 1A to 31D are arranged in a row is shown, when the samples for biochemical reaction measurement are arranged in a plurality of rows, the cylindrical lenses of a plurality of rows are arranged in the frame 32 accordingly. The second cylindrical lens 30 may be fixed and configured.

[0026]

The surface plasmon resonance sensor device of the present invention has a plurality of samples for biochemical reaction measurement mounted on one surface,
A first optical system in which a thin film that causes surface plasmon resonance is formed on the other surface that constitutes the reflecting surface, a light source that emits laser light that causes plasmon resonance at the reflecting surface of the thin film, and a light source that emits light from the light source A second optical system for converting the reflected laser light into parallel light; and a light detecting means for detecting the intensity distribution of the reflected light reflected by the light reflecting surface.
The optical system converts the laser light converted into parallel light by the second optical system into parallel light that illuminates the sample mounting area of the thin film on which the plurality of samples are mounted, and irradiates the laser light to generate parallel light in the plurality of samples. Since it is possible to detect chemical reactions at the same time, it is possible to greatly improve the efficiency of multiple measurements for biochemical reaction measurement, and to mount the sample for biochemical reaction measurement directly on the thin film formed on the first optical system. Therefore, the interval between each sample can be significantly narrowed as compared with the conventional one, and the efficiency of the detection work can be greatly improved. Also, the first
The optical system includes a first region, which is a semi-cylindrical region having a semicircular cross section, and a plane portion of which is in contact with the reflecting surface of the thin film, and a second region which is a plate-shaped region excluding the first region. Since the first region is ion-exchanged so that the first region has a larger refractive index than the second region, a simple and inexpensive first optical system is used to simultaneously perform biochemical reactions on a plurality of samples. A surface plasmon resonance sensor device capable of detection can be provided. Further, since the second optical system is composed of an assembly of a plurality of cylindrical lenses according to the number of samples to be simultaneously detected, a simple and inexpensive second optical system is used to simultaneously detect biochemical reactions in a plurality of samples. A surface plasmon resonance sensor device capable of being provided can be provided.

[Brief description of drawings]

FIG. 1 is a diagram schematically showing a configuration of a surface plasmon resonance sensor device according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram schematically showing a configuration of a main part of a surface plasmon resonance sensor device according to a second embodiment of the present invention.

FIG. 3 is a diagram schematically showing a configuration of a main part of a surface plasmon resonance sensor device according to a third embodiment of the present invention.

FIG. 4 is a diagram conceptually showing a detection principle for detecting a mass change using surface plasmon resonance.

FIG. 5 is a characteristic diagram showing a relationship between an incident angle θ and the intensity of reflected light in detection of a mass change using surface plasmon resonance.

FIG. 6 is a schematic diagram showing a conventional apparatus for efficiently detecting surface plasmon resonance angles of various kinds of sample components.

[Explanation of symbols]

1 glass substrate 2 metal thin film 3 laser light 4 measuring section 5 reflected light 6 glass substrates 7 sensor chip 8 prism 9 Light irradiation device 9A laser light 9B parallel light 9C reflected light 10 Light receiving device 11 cell plate 11a cell 14A-14D sample 15 First cylindrical lens 15A plane 16 Second cylindrical lens 17 Two-dimensional array sensor 20 glass plates 20A cylindrical lens 20B Low refractive index part 30 Second Cylindrical Lens 31A Cylindrical lens 32 frames

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Satoshi Tahara             1-8 Koura, Kanazawa-ku, Yokohama-shi, Kanagawa               Mitsubishi Heavy Industries, Ltd. Basic Technology Research Center (72) Inventor Hiromitsu Inuzuka             1-8 Koura, Kanazawa-ku, Yokohama-shi, Kanagawa               Mitsubishi Heavy Industries, Ltd. Basic Technology Research Center (72) Inventor Jun Utsumi             1-8 Koura, Kanazawa-ku, Yokohama-shi, Kanagawa               Mitsubishi Heavy Industries, Ltd. Basic Technology Research Center F term (reference) 2G059 AA01 BB12 CC16 EE02 FF11                       GG01 JJ11 KK04 PP01

Claims (3)

[Claims] 1. A first optical system in which a plurality of samples for biochemical reaction measurement are mounted on one surface, and a thin film which causes surface plasmon resonance is formed on the other surface constituting a reflecting surface, and a reflection of the thin film. A light source that emits laser light for causing plasmon resonance on the surface, a second optical system that converts the laser light emitted from the light source into parallel light, and an intensity distribution of the reflected light reflected by the light reflecting surface. The first optical system irradiates the laser beam converted into parallel light by the second optical system onto the sample mounting region of the thin film on which the plurality of samples are mounted. A surface plasmon resonance sensor device, which is capable of simultaneously detecting biochemical reactions in a plurality of samples by irradiating it as light. 2. The first optical system is a semi-cylindrical region having a semi-circular cross section, and a flat region excluding the first region and a flat region in contact with a reflecting surface of the thin film. 2. A surface plasmon resonance sensor according to claim 1, wherein the surface plasmon resonance sensor is a substrate having a second region composed of regions, and the first region is ion-exchanged so as to have a larger refractive index than the second region. apparatus. 3. The surface plasmon resonance sensor device according to claim 1, wherein the second optical system comprises an assembly of a plurality of cylindrical lenses according to the number of samples to be simultaneously detected.