JP2003329578A - Device for measuring by utilizing total reflection light - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress the degradation of the measurement accuracy of a total reflection attenuation angle by entering stray light to a light receiving means in a device for measuring by utilizing total reflection light. <P>SOLUTION: A light beam from mutually different light sources from among a light sources 7, 8, and 9 is entered into dielectric blocks 52 individually corresponding to mutually adjacent light receiving means 30, from a means 10 for generating an light beam with a plurality of the light sources 7, 8, and 9 fewer than the dielectric blocks 52 parallelly arranged. The light beam is entered into each of the dielectric blocks 52 with an incident optical system 20 at an incident angle obtained total reflection conditions at an interface between the blocks 52 and a thin film layer 14, and then the strength distribution of the light beam, which are totally reflected at each of the interfaces, individually received with a plurality of the light receiving means 30. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a measuring apparatus using total reflected light, and more particularly to a measuring apparatus using total reflected light provided with a plurality of measuring units for totally reflecting a measuring light beam. Is.

[0002]

2. Description of the Related Art In metals, free electrons collectively vibrate to generate compression waves called plasma waves. The quantized compression wave generated on the metal surface is called surface plasmon.

Conventionally, various surface plasmon measuring devices have been proposed which analyze the characteristics of a substance to be measured by utilizing the phenomenon that the surface plasmon is excited by a light wave.
Among them, one that is particularly well known is one that uses a system called Kretschmann arrangement (see, for example, JP-A-6-167443).

The surface plasmon measuring device using the above system is basically a dielectric block formed in a prism shape, for example, and is contacted with a substance to be measured such as a liquid sample formed on one surface of the dielectric block. A thin film layer made of a metal film or the like, a light source for generating a light beam, and various angles so that total reflection conditions can be obtained at the interface between the dielectric block and the thin film layer with respect to the light beam with respect to the dielectric block. And an optical system for measuring the intensity of the light beam totally reflected at the interface to detect the state of surface plasmon resonance, that is, the attenuated state of total reflection.

In order to obtain various incident angles as described above, a relatively thin light beam may be incident on the interface by changing the incident angle, or may be incident on the light beam at various angles. A relatively thick light beam may be incident on the interface in a convergent light state or a divergent light state so as to include the component. In the former case, the light beam whose reflection angle changes according to the change of the incident angle of the incident light beam is detected by a small photodetector that moves in synchronization with the change of the reflection angle, or the direction of change of the reflection angle. It can be detected by an area sensor extending along. On the other hand, in the latter case, each light beam reflected at various reflection angles can be detected by an area sensor extending in a direction in which all the light beams can be received.

In the surface plasmon measuring device having the above structure, when a light beam is incident on the metal film at a specific incident angle of a total reflection angle or more, an evanescent light having an electric field distribution in the substance to be measured in contact with the metal film. A wave is generated, and the surface plasmon is excited at the interface between the metal film and the substance to be measured by this evanescent wave. When the wave vector of the evanescent light is equal to the wave number of the surface plasmon and the wave number matching is established, both are in a resonance state and the energy of the light is transferred to the surface plasmon, so that at the interface between the dielectric block and the metal film. The intensity of the reflected light sharply decreases.
This decrease in light intensity is generally detected as a dark line by the light receiving means. Note that the above resonance occurs only when the incident beam is p-polarized. Therefore, it is necessary to set in advance that the light beam is incident as p-polarized light.

Incident where this attenuated total internal reflection (ATR) occurs
Angle, that is, the wave of surface plasmon from the total reflection attenuation angle θsp
When the number is known, the dielectric constant of the substance to be measured can be obtained. Ie
Ksp is the wave number of the surface plasmon, and the angular frequency of the surface plasmon
Ω, c is the speed of light in a vacuum, ε _m And ε_s Each gold
Assuming that the genus and the dielectric constant of the substance to be measured have the following relationships.

[0008]

[Equation 1] That is, by knowing the total reflection attenuation angle θsp, which is the incident angle at which the reflected light intensity decreases, the dielectric constant ε of the measured substance
It is possible to obtain a characteristic related to _s , that is, the refractive index.

Further, as a similar measuring apparatus utilizing the attenuated total reflection (ATR), for example, "Spectroscopic Research" Vol. 47, No. 1 (1998), pages 21 to 23 and 26 to 27.
Leakage mode measuring devices described on the page are also known. This leak mode measuring device is basically a dielectric block formed, for example, in a prism shape, a clad layer formed on one surface of the dielectric block, and a clad layer formed on the clad layer for contact with a sample solution. An optical waveguide layer, a light source for generating a light beam, and the light beam with respect to the dielectric block at various angles so that total reflection conditions can be obtained at the interface between the dielectric block and the cladding layer. It comprises an optical system to be incident and a light receiving means for measuring the intensity of the light beam totally reflected at the interface to detect the excited state of the guided mode, that is, the attenuated state of total reflection.

In the leaky mode measuring device having the above structure,
When a light beam is incident on the cladding layer through the dielectric block at an angle of incidence equal to or more than the total reflection angle, only light with a specific incident angle having a specific wave number is transmitted in the optical waveguide layer after passing through the cladding layer. It propagates in the guided mode. When the guided mode is excited in this manner, most of the incident light is taken into the optical waveguide layer, so that the total reflection attenuation occurs in which the intensity of the light totally reflected at the interface sharply decreases.
Since the wave number of the guided light depends on the refractive index of the substance to be measured on the optical waveguide layer, the refractive index of the substance to be measured and the related measured substance to be measured can be obtained by knowing the specific incident angle at which attenuation of total reflection occurs. The properties of the substance can be analyzed.

As a measuring apparatus using total reflection such as a surface plasmon resonance measuring apparatus or a leaky mode measuring apparatus, light is made incident on an interface at an incident angle at which total reflection conditions are obtained, and an evanescent wave is generated by the light. When measuring the characteristics of the substance to be measured by measuring the change in the state of the light totally reflected at the interface, the device for measuring the specific incident angle that causes the above-mentioned attenuation of total reflection is used. A device that makes a light beam enter the interface and detects the degree of attenuation of total internal reflection for each angular wavelength, or makes the light beam enter the interface and divides a part of this light beam before it enters the interface. There are various types such as a device that interferes the generated light beam with the light beam reflected at the interface and measures the state of this interference.

Further, in order to measure a large number of samples at the same time, a light beam is made incident on the interface between a plurality of dielectric blocks arranged in parallel and a thin film layer formed on each dielectric block, Each light beam totally reflected at each interface,
There is also known a measuring device that individually receives light by a plurality of light receiving means arranged in parallel and detects the state of light totally reflected at the interface.

[0013]

By the way, there is a demand for a measuring device having a plurality of dielectric blocks to measure a larger number of samples in a limited space. The space between the body blocks is narrowed to improve the density of the dielectric blocks, and the space between the light receiving means is narrowed to arrange the light receiving means in a high density to increase the number of samples in a certain space. Are being studied for placement and measurement.

However, as the distance between the light receiving means arranged in parallel decreases, the specific light receiving means of the stray light component branched from the light beam passing through the optical path incident on the light receiving means adjacent to the specific light receiving means. The stray light is received by the specific light receiving means together with the light beam incident on the specific light receiving means when measuring the total reflection attenuation angle, and the total reflection light intensity due to the total reflection attenuation is increased. However, there is a problem that the profile representing the sharp decrease of the total reflection angle fluctuates and the measurement accuracy of the total reflection attenuation angle decreases.

Further, the stray light component interferes with the light beam incident on the specific light receiving means to generate interference fringes on the light receiving surface of the specific light receiving means, and the interference fringes are caused by the interference fringes when measuring the total reflection attenuation angle. There is also a problem that the intensity of the light intensity and the attenuation of the light intensity due to the attenuation of the total reflection are overlapped with each other, and the profile showing the sharp decrease in the intensity of the total reflection light due to the attenuation of the total reflection fluctuates, and the measurement accuracy of the attenuated total reflection angle decreases. .

More specifically, the quantity of stray light mixed in when 96 dielectric blocks are arranged in parallel and measured is 384 dielectric blocks arranged in the same width four times higher in density. It has been confirmed by experiments that the amount of stray light mixed in is about 1/5 when measured by the above method.

The present invention has been made in view of the above circumstances, and provides a measuring apparatus using total reflection light capable of suppressing deterioration in measurement accuracy of the total reflection attenuation angle due to incidence of stray light on the light receiving means. It is intended to be provided.

[0018]

SUMMARY OF THE INVENTION A measuring apparatus using total reflection light according to the present invention comprises a light beam generating means for generating a light beam, a dielectric block transparent to the light beam, and an upper surface of the dielectric block. A plurality of measurement units each having a thin film layer formed on the surface of the thin film layer and a sample holding mechanism for holding a sample on the surface of the thin film layer; An incident optical system that makes an incident angle at which the total reflection condition is obtained at the interface between the block and the thin film layer, and a plurality of light receiving means that individually receives the light beams totally reflected at each interface and measures the intensity of each light beam. Is a measuring device using the total reflection light provided with a light detecting means arranged in parallel, the light beam generating means, a plurality of light sources less than the number of dielectric blocks, the incident optical system, Light receiving means next to each other Light beam incidence means for making light beams from different light sources of a plurality of light sources incident on the corresponding dielectric blocks, or for making light beams incident on adjacent light receiving means at different timings, respectively. It is characterized by having.

The light beam generating means has a first light source and a second light source for generating respective light beams incident on the light receiving means adjacent to each other, and the light beam incident means is The first light source and the second light source may be turned on at different timings.

The light beam incident means individually cuts off or deflects the optical paths of the light beams directed to the respective light receiving means to remove the light beams from the optical path, and the light receiving means adjacent to each other. It may be provided with a control means for controlling the light limiting means so that the light beams are made incident at different timings.

The measuring apparatus may be configured such that the thin film layer is made of a metal film and the measurement is performed by utilizing the effect of the surface plasmon resonance described above.

In the measuring device, the thin film layer is composed of a clad layer formed on the upper surface of the dielectric block and an optical waveguide layer formed on the clad layer.
The measurement may be performed by utilizing the effect of excitation of the waveguide mode in the optical waveguide layer.

Furthermore, in the measuring device according to the present invention, there are various methods for analyzing the sample by measuring the intensity of the light beam totally reflected at the interface by the light receiving means. The position of the dark line (angle) generated by the attenuation of total reflection is measured by making the light beam incident at various incident angles that obtain the conditions for total reflection, measuring the intensity of the light beam totally reflected at the interface at each position corresponding to each incident angle. Sample analysis may be carried out by detection of DVnoort, K.johanse
n, C.-F.Mandenius, Porous Gold in Surface Plasmon R
esonance Measurement, EUROSENSORS XIII, 1999, pp.5
As described in 85-588, light beams of multiple wavelengths are incident on the interface at an angle of incidence at which total reflection conditions are obtained, and the intensity of the light beam totally reflected at the interface is measured for each wavelength. Then, the sample analysis may be performed by detecting the degree of total reflection attenuation for each wavelength.

Also, PINikitin, ANGrigorenko, AAB
eloglazov, MVValeiko, AISavchuk, OASavchuk, Sur
face Plasmon Resonance Interferometry for Micro-Ar
rayBiosensing, EUROSENSORS XIII, 1999, pp.235-238
The light beam is incident at an angle of incidence such that total internal reflection conditions are obtained at the interface, and a portion of the light beam is split before the light beam enters the interface; The sample analysis may be performed by causing the divided light beam to interfere with the light beam totally reflected at the interface and measuring the intensity of the light beam after the interference.

Further, the dielectric block may be formed as one block having all the surface on which the light beam is incident and emitted and the surface on which the thin film layer is formed, or Two parts, a part having a surface on which the light beam enters and exits and a part having a surface on which the thin film layer is formed, may be joined via a refractive index matching means.

The plurality of measuring units may be individually formed one by one, or may be one-dimensionally or two-dimensionally arranged and integrally formed. Further, the measurement unit may be provided with a sample supplying / discharging means for continuously supplying the sample onto the surface of the thin film layer and continuously discharging the supplied sample.

[0027]

According to the measuring apparatus using the totally reflected light of the present invention, the light beam generating means is provided with a plurality of light sources smaller than the number of dielectric blocks, and the incident optical systems are adjacent to each other. Stray light deviated from the optical path of the light beam incident on the light receiving means adjacent to the specific light receiving means by making light beams from different light sources of the plurality of light sources incident on the dielectric blocks respectively corresponding to the light receiving means. The coherence between the component and the light beam incident on this particular light receiving means is reduced to suppress the generation of interference fringes, or the light receiving means adjacent to each other among the plurality of light receiving means are provided at different timings. By providing the light beam incidence means for injecting the light beam, the stray light component deviated from the optical path of the light beam incident on the light receiving means adjacent to the particular light receiving means to the particular light receiving means Since so as to reduce Shako amount, it is possible to suppress a decrease in measurement accuracy of the ATR angle due to the incidence of the stray light component of the light receiving means.

Further, the light beam generating means has a first light source and a second light source for generating respective light beams incident on the light receiving means adjacent to each other, and the light beam incident means is The first light source and the second light source may be turned on at different timings, or the light beam incident means may be provided by individually blocking or deflecting the optical path of the light beam toward each light receiving means. A light receiving means for removing the light from the optical path, and a control means for controlling the light limiting means so that the light beams are made to enter the light receiving means adjacent to each other at different timings. And more reliably reduce the amount of stray light component incident on the specific light receiving means which is deviated from the optical path of the light beam incident on the adjacent light receiving means to the specific light receiving means. Door can be.

[0029]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a side view showing a schematic configuration of a surface plasmon measuring device for measuring the state of totally reflected light according to an embodiment of the present invention, FIG. 2 is a plan view of the surface plasmon measuring device, and FIG. 3 is a measurement plate. FIG. 4 is a perspective view, FIG. 4 is a cross-sectional view of the measurement plate, FIG. 5 is a view showing the relationship between the incident angle and the reflected light intensity of the light beam received by the light receiving means, and FIG. 6 is a dark line due to the interference fringes and total reflection attenuation. FIG. 7 is a diagram showing a light intensity pattern in which overlapping portions are overlapped with each other, and FIG.
FIG. 8 is a diagram showing a reflected light intensity profile that is shifted in the direction in which the intensity is high due to the stray light component.

The surface plasmon measuring apparatus according to the embodiment of the present invention is formed by a light beam generating means 10 for generating a light beam, a dielectric block 52 transparent to the light beam, and an upper surface of the dielectric block 52. Thin film layer 14, and sample holding mechanism 5 for holding a sample on the surface of this thin film layer 14.
A plurality of measuring units 55 (55a to 55)
e) a measurement plate 50 formed by arranging (e in FIG. 2).
(See FIG. 4 showing the II-II cross section) and the light beam to the dielectric block 52 of each measurement unit 55 (55a to 55e).
With respect to (52a to 52e), the incident optical system 20 is made to enter at an incident angle at which the total reflection condition is obtained at the interface 54 between the dielectric block 52 and the thin film layer 14, and the respective interfaces 54 (54a to 5e).
4e) a plurality of light receiving means 30 (30a-3) for individually receiving the light beams totally reflected and measuring the intensity of each light beam.
0e) are arranged in parallel, and the light beam generating means 10 includes a laser light source 9, a laser light source 8 and a laser light source 7, which are a plurality of light sources smaller than the number of dielectric blocks 52. The incident optical system 20 has dielectric blocks 52 (5) corresponding to the light receiving means 30 adjacent to each other.
2a to 52e), laser light source 9 and laser light source 8
Light beams from different light sources of the laser light source 7 are made incident. That is, the light from the laser light source 9 and the laser light source 7 which are the first light source for the dielectric block 52a, the dielectric block 52c, and the dielectric block 52e respectively corresponding to the light receiving means 30a, the light receiving means 30c, and the light receiving means 30e. Beam is made incident, and light receiving means 30
b, the light beam from the laser light source 8 as the second light source is made incident on the dielectric block 52b and the dielectric block 52d corresponding to the light receiving means 30d.

Each measuring unit 55 includes a sample holding mechanism 53.
A plurality of wells (liquid reservoirs) 51 (51a to 5a) formed by
The sample 15 to be measured is stored and held in 1e). The measurement unit 55 is made of, for example, a transparent resin, and the well 5
1 is a truncated cone shape. The bottom surface of the well 51 serves as the top surface of the dielectric block 52, and the metal film 12 and the sensing substance 13 are laminated in this order on the top surface of the dielectric block 52 to form the thin film layer 14. Then, the measuring light beam L is made to enter the interface 54 between the dielectric block 52 and the metal film 12. Note that, here, the dielectric block 52 and the sample holding mechanism 53 that form the measurement unit 55 are integrally formed.

Further, the measuring plate 50 is formed by linearly arranging a plurality of measuring units 55 (55a to 55e) (arranged in the direction of the arrow Y axis in the figure) and integrating them. A plurality of 50 are arranged in a direction orthogonal to the Y-axis direction (the X-axis direction of the arrow in the figure) and placed on a support (not shown), and these measurement plates are sequentially transferred and used for measurement. It The X axis and the Y axis shown in the figure are axes parallel to the horizontal plane, and the Z axis is a vertical axis orthogonal to the horizontal plane.

The incident optical system 20 comprises the light beam generating means 10
, A half mirror 21a for branching the light beam L emitted from the laser light source 9 as parallel light having a small diameter, a mirror 21c for reflecting the branched light beam L, and a parallel light having a small diameter from the laser light source 8 of the light beam generating means 10. A half mirror 22d for branching the light beam L emitted as light, a mirror 22b for reflecting the branched light beam L, the branched light beam L and a light beam emitted as parallel light of a small diameter from the laser light source 7. The diameter of the light flux of L is expanded only in the XZ plane parallel to the paper surface of FIG. 1 by the cylindrical beam expander 24 and the cylindrical beam expander 24 so that the diameter is expanded in only one direction (only in the XZ plane). The light beam L emitted from the light source 10 is measured by a cylindrical lens 26 that condenses the light beam only in the XZ plane. Parallel is incident on the interface 54 of the unit 55. That is, the light beam emitted from the laser light source 9 and transmitted through the half mirror 21 a is the dielectric block 5.
The light beam that enters the laser beam source 2a, is emitted from the laser light source 9, is branched by the half mirror 21a, and is reflected by the mirror 21c is incident on the dielectric block 52c, and the light beam that is emitted from the laser light source 8 and transmitted through the half mirror 22d is dielectric. The light beam that is incident on the body block 52d, is emitted from the laser light source 8, is branched by the half mirror 22d, and is reflected by the mirror 22b is incident on the dielectric block 52b.
The light beam emitted from is incident on the dielectric block 52e. At this time, each light beam L has its own interface 54.
On the other hand, the light is incident with various incident angle components. The light beam reflected by each of the interfaces 54 again diverges only in the XZ plane and is emitted from the dielectric block 52 while the diameter thereof is expanded in one direction.

The incident angle θ that is incident on the interface 54 at various angles is set to be an angle equal to or larger than the total reflection angle. Therefore, the light beam totally reflected at the interface 54 contains components totally reflected at various reflection angles. The incident optical system 20 may be configured so that the light beam is incident on the interface 54 in a defocused state. By doing so, the light beam L is spread over a wider area on the interface 54.
Is totally reflected, the detection error in the attenuated total reflection state is averaged, and the measurement accuracy of the total reflection elimination angle can be improved.

The laser light sources 9, 8 and 7 are arranged so that the light beams emitted from the laser light sources, which are linearly polarized light, enter the interface 54 in the p-polarized state. In addition, in order to make the light beam incident on the interface 54 as p-polarized light, the polarization direction of the light beam may be controlled by a wave plate.

Each of the light receiving means 30a to 30e is composed of a line sensor in which a large number of photodiodes are arranged in a line. In the arrangement direction of the photodiodes, the light beam is reflected at the interface 54 and the dielectric block 52 is arranged. Is a direction in which the diameter is expanded in one direction in the XZ plane.

The sample analysis by the surface plasmon measuring device having the above structure will be described below.

The light beam L emitted from each laser light source of the light beam generating means 10 is incident on the interface 54 between the dielectric block 52 and the metal film 12 in a converged state through the incident optical system 20. The light beam L totally reflected at the interface 54 is emitted from the dielectric block 52 and received by the light receiving means 30a.
Received by ~ 30e. Each light receiving means 30a-30
Since a large number of photodiodes are formed linearly in each of the e directions in the divergence direction of the light beam L, the components at each angle of the light beam totally reflected at various reflection angles at the interface 54 are obtained. , Are received by different photodiodes arranged in a line. As a result, a signal indicating the intensity distribution of the light beam detected by each photodiode is output from each of the light receiving means 30a to 30e.

The component of the light beam incident on the interface 54 at the specific incident angle θ _SP excites the surface plasmon at the interface 54 between the metal film 12 and the liquid sample 15. Therefore, the light incident at this angle is reflected light. The strength sharply decreases. That is, the specific incident angle θ _SP is a total reflection elimination angle, and the reflected light intensity shows a minimum value at this angle θ _SP . The area where the reflected light intensity decreases is observed as a dark line in the divergent reflected light beam. If the permittivity of the substance in contact with the metal film 12 on the bottom surface of the well 51, that is, the refractive index changes,
In response to this, the angle at which the reflected light intensity exhibits a minimum value changes, and a change in the state of the totally reflected light is detected.

The relationship between the incident angle θ of the light beam L on the interface 54 and the reflected light intensity I of the light beam received by each light receiving means is as follows:
As shown in FIG. 5, a reflected light intensity profile F having a minimum value only at a specific incident angle θ _SP is shown. After dropping the sample liquid, the reflected light intensity profile of the light beam is monitored and the change in the dark line is observed, whereby the state of the total reflected light can be observed as described above.

Here, the light beam incident on the specific light receiving means and the stray light component deviating from the optical path incident on the light receiving means adjacent to the specific light receiving means are on the light receiving surface of the specific light receiving means. The effect of suppressing the generation of interference fringes will be described.

The specific light receiving means is the light receiving means 30b, and the light receiving means 30 which is a light receiving means adjacent to the light receiving means 30b.
a and stray light components Ea and E which are incident on the light receiving means 30b as stray light, which are deviated from the optical paths entering the light receiving means 30c.
It is assumed that the stray light components Ea and Ec and the light beam Lb incident on the light receiving means 30b through a predetermined optical path interfere with each other on the light receiving surface of the light receiving means 30b to generate an interference fringe, as shown in FIG. On the light receiving surface of the light receiving means 30b, a light intensity pattern 83 in which the light and shade 81 due to the interference fringes and the dark line 82 due to the attenuated total reflection overlap is generated, and the light receiving means 30b
Angle θ of incidence of the light beam on the interface 54 based on
As shown in FIG. 7, the relationship between the reflected light intensity I of the light beam received by the light receiving means 30b and the reflected light intensity profile F1 in which the light intensity is reduced by the attenuated total reflection shows the intensity pattern of the light intensity due to the interference fringes. The reflected light intensity profile F2 on which the profile is superimposed indicates that the specific incident angle θ _SP is difficult to specify, and the measurement accuracy of the total reflection attenuation angle may be reduced. A line sensor in which the above-mentioned many photodiodes are linearly arranged is located at a position overlapping the light intensity pattern 83.

However, in the present embodiment,
Since the light beam Lb and the stray light component Ea and the light beam Lb and the stray light component Ec are light emitted from different laser light sources with extremely low coherence, almost no interference fringes occur.
Even if the stray light components Ea and Ec are received by the light receiving means 30b together with the light beam Lb, as shown in FIG. 8, the reflected light intensity profile F1 of the light beam Lb whose light intensity sharply decreases due to the total reflection attenuation is the stray light component Ea. And Ec are measured as the reflected light intensity profile F3 that is only affected by the shift of the intensity toward the higher direction, and the reflected light intensity profile is hardly deformed, so that the decrease in the measurement accuracy of the total reflection attenuation angle is suppressed. be able to.

In the above embodiment, the measuring plate 50 is formed by arranging the measuring units 55 (55a to 55e) side by side. However, each measuring unit, that is, each dielectric block is not necessarily formed in the Y-axis direction. It is not necessary to arrange the dielectric blocks accurately and regularly, and even if the pitches in the Y-axis direction, the Z-direction position, the X-direction position, and the like in which the dielectric blocks are arranged are deviated, the measurement accuracy of the total reflection attenuation angle decreases. The effect of suppressing can be obtained.

Further, it is possible to provide a light beam incidence means for making the light beams incident on the light receiving means adjacent to each other at different timings. Specifically, as shown in FIG. 9, the laser light source 9 and the laser light source 7 which are the first light sources of the light beam incidence means and the laser light source 8 which is the second light source of the light beam incidence means are different from each other. The light beam incidence control unit 60 that turns on at a timing may be further included. That is, the first light source is turned on by the light beam incidence control unit 60, and the light receiving means 30a,
The light beam La, and the light receiving means 30c and the light receiving means 30e,
When Lc and Le are incident, the light receiving means 30b and the light receiving means 30d are turned on without turning on the second light source.
The light beams Lb and Ld are controlled so that they do not enter. Therefore, for example, when the light beam Lc is incident on the light receiving means 30c, the stray light component E which enters the light receiving means 30c as stray light is deviated from the optical paths entering the light receiving means 30b and the light receiving means 30d adjacent to the light receiving means 30c.
Since b and Ed are not generated, the reflected light intensity profile representing the relationship between the incident angle θ of the light beam Lc on the interface 54 and the reflected light intensity I of the light beam received by the light receiving means 30c is as described above. The effect of shifting in the direction of higher intensity is also eliminated, and the reflected light intensity profile is hardly deformed, and the effect of further suppressing the decrease in measurement accuracy of the attenuated total reflection angle can be obtained. The second light source is turned on by the light beam incidence controller 60, and the light beams Lb and L are transmitted to the light receiving means 30b and the light receiving means 30d.
When d is incident, the light receiving means 30a, the light receiving means 30c, and the light receiving means 3 are turned on without turning on the first light source.
The light beams La, Lc, and Le are controlled so as not to enter 0e.

Further, instead of the light beam incidence control section, as light beam incidence means for injecting light beams into adjacent light receiving means at different timings,
As shown in FIG. 10, the optical path of each light beam directed to each light receiving means 30 is individually blocked or deflected to remove the light beam from each optical path, and the light limiting means 70 composed of a shutter, an acousto-optic element, or the like, and A control means 75 for controlling the light limiting means 70 so that the light beams are made to enter adjacent light receiving means at different timings may be provided. With this configuration, the control unit 75 controls the light limiting unit 70 so that the light beams are incident on the light receiving units adjacent to each other at different timings to perform the measurement. As a result, the stray light component branched from the light beam passing through the optical path entering the light receiving means adjacent to the specific light receiving means can measure the state of the total reflection light without entering the specific light receiving means. In the same manner as above, since the reflected light intensity profile showing the relationship between the incident angle θ created based on the light beam received by each light receiving means and the reflected light intensity I of the light beam is hardly deformed, total reflection is performed. It is possible to suppress a decrease in the measurement accuracy of the attenuation angle.

In the above surface plasmon measuring device, a leak mode sensor can be obtained by changing a part of the structure of the measuring unit. Hereinafter, an embodiment in which the leaky mode sensor is used as the measuring device of the present invention will be described.

FIG. 11 shows a measuring unit 56 (56a to 5a) used for the measuring plate 59 for the leak mode sensor.
It is a figure which shows an example of 6e). In FIG. 11, elements that are the same as the elements in FIG. 4 showing the measurement plate for the surface plasmon measurement device are given the same numbers, and explanations thereof will be omitted unless necessary.

Each measuring unit 56 of the measuring plate 59
In (56a to 56e), as the thin film layer 19, the cladding layer 17 and the optical waveguide layer 18 are formed in this order on the dielectric block 52. The other structure is the same as that of the surface plasmon measuring device described above.

The dielectric block 57 (57a to 57e) of each measuring unit 56 can be formed using, for example, synthetic resin or optical glass such as BK7. On the other hand, the clad layer 17 is formed in a thin film shape using a dielectric material having a lower refractive index than the dielectric block 57 or a metal such as gold. The optical waveguide layer 18 is also formed in a thin film shape by using a dielectric material having a higher refractive index than the cladding layer 17, for example, PMMA. The clad layer 17 has a film thickness of, for example, 36.5 nm when formed from a gold thin film, and the optical waveguide layer 18 has a film thickness of approximately 700 nm when formed from PMMA, for example.

In the leaky mode sensor having the above structure,
When the light beam emitted from the light beam generation means 10 is made to enter the interfaces 58 (58a to 58e) between the dielectric blocks 57 and the cladding layer 17 through the dielectric blocks 57 at an incident angle of not less than the total reflection angle. Although many components of the light beam are totally reflected at the interface 58, the light of a specific wave number that has passed through the cladding layer 17 and is incident on the optical waveguide layer 18 at a specific incident angle is guided by the optical waveguide layer 18 in the waveguide mode. It will be propagated. When the guided mode is excited in this way, most of the incident light that has entered at the specific incident angle is taken into the optical waveguide layer 18, so that the intensity of the light that is incident on the interface 58 at the specific incident angle and totally reflected is sharp. Decreasing total internal reflection attenuation occurs. The wave number of the guided light in the optical waveguide layer 18 is
Since it depends on the refractive index of the liquid sample 15 above, the presence or absence of the specific substance can be obtained by knowing the variation in the total reflection elimination angle, which is the specific incident angle at which the total reflection attenuation occurs.

The measuring apparatus of each of the above-mentioned embodiments makes the light beam from the light source incident on the interface at various angles, measures the reflected light from this interface, and changes the incident angle to form a dark line. Although the state of reflection attenuation is measured to obtain the binding state between the analyte and the sensing substance, the incident angle of the light beam is set to a predetermined angle that satisfies the condition of total reflection at the interface,
Incident light beams with various wavelengths are changed, or the wavelengths of incident light beams are changed, the reflected light from the interface is measured, and the binding state between the analyte and the sensing substance is determined by the attenuated total reflection for each wavelength. May be obtained.

The surface plasmon measuring device may be a surface plasmon measuring device for measuring the state of totally reflected light by using the phase of light.

That is, as shown in FIG. 12, the light source 334, which is a light beam generating means, is disposed on the light beam incident surface U side of the dielectric blocks 342a to 342e of the measurement plate 350, which is an assembly of the measurement units 340a to 340e. And the incident optical system 320 are arranged, and the dielectric blocks 342a to
CCD as a light receiving means on the light beam emission surface V side of 342e
360a-360e are arranged. The incident optical system 320 in the optical path of the light beam from the light source 334 to the CCDs 360a to 360e includes a collimator lens 350, a light beam branching optical system 359, an interference optical system described later, condenser lenses 355a to 355e, and an aperture 356a to. 35
6e is provided.

The interference optical system includes a polarization filter 351a.
-351e, beam splitters 352a-352e, beam splitters 353a-353e, and mirror 354.
a to 354e.

Further, the CCDs 360a to 360e are connected to the signal processing unit 361, and the signal processing unit 361 is connected to the display unit 362.

The measurement of the sample by the surface plasmon measuring device will be described below. Here, of the measurement units 340a to 340e of the measurement plate 350, the measurement unit 340a that is in a state of being aligned with the CCD 360a will be described as an example, but the measurement is similarly performed in other measurement units. .

The light source 334 is turned on, and the light beam 330 is emitted from the light source 334 in a divergent state. The light beam 330 is collimated by the collimator lens 350 and is branched by the light beam branching optical system 359 into the optical path toward the measurement units 340a to 340e.
It is incident on the polarization filter 351a. Polarization filter 351
The light beam 330 transmitted through a and made incident on the interface 141a as p-polarized light is transmitted by the beam splitter 352.
A part of the light beam is split as a reference light beam 330R by a, and the remaining light beam 330S transmitted through the beam splitter 352a is incident on the interface 141a. This interface 1
The light beam 330S totally reflected by 41a and the mirror 3
The reference light beam 330R reflected by 54a enters the beam splitter 353a and is combined. The combined light beam 330G is condensed by the condenser lens 355a, passes through the aperture 356a, and is detected by the CCD 360a. At this time, the light beam 330G detected by the CCD 360a generates interference fringes according to the state of interference between the light beam 330S and the reference light beam 330R.

In the sample 15, when the refractive index of the sensing substance changes according to the binding state between the specific substance and the sensing substance, the interference state between the light beam totally reflected at the interface and the reference light beam changes, so that the interference occurs. The presence or absence of coupling can be detected according to the change in stripes.

The signal processing section 361 detects the presence or absence of the above reaction based on the above principle, and the result is displayed on the display section 362.

The surface plasmon measuring device having such a structure can also be applied with the technique for suppressing the decrease in the measurement accuracy of the attenuated total reflection angle. That is, the light beam generating means is provided with a plurality of light sources smaller than the number of dielectric blocks, and the incident optical system is provided with a plurality of light sources for the dielectric blocks corresponding to the light receiving means adjacent to each other. Interference due to interference of light beams from different light sources and incident on a specific light receiving means with stray light components deviating from the optical path of the light beams incident on the light receiving means adjacent to the specific light receiving means. Measurement of the attenuated total reflection angle by suppressing the occurrence of stripes, or by providing a light beam incidence means for injecting a light beam into adjacent light receiving means of a plurality of light receiving means at different timings. It is possible to suppress a decrease in accuracy.

Needless to say, the structure of the surface plasmon measuring device for measuring the state of the totally reflected light using the phase of the light can be used for the leaky mode sensor as in the above.

[Brief description of drawings]

FIG. 1 is a side view showing a schematic configuration of a surface plasmon measuring device according to a first embodiment of the present invention.

FIG. 2 is a plan view showing a surface plasmon measuring device.

FIG. 3 is a perspective view of a measurement plate

FIG. 4 is a view showing a II-II cross section of the measurement plate.

FIG. 5 is a diagram showing a relationship between an incident angle θ and a reflected light intensity I of a light beam received by a light receiving means.

FIG. 6 is a diagram showing a light intensity pattern in which light and shade due to interference fringes and a dark line of attenuated total reflection overlap.

FIG. 7 is a diagram showing a reflected light intensity profile when light and shade due to interference fringes occur on the light receiving means.

FIG. 8 is a diagram showing a reflected light intensity profile that is shifted in a direction in which the intensity is high due to a stray light component.

FIG. 9 is a diagram showing a surface plasmon measuring device provided with light beam incidence means for making light beams incident on adjacent light receiving means at different timings.

FIG. 10 is a view showing a surface plasmon measuring device provided with a light limiting means and a control means for controlling the light limiting means.

FIG. 11 is a diagram showing a measurement unit used for a measurement plate for a leak mode sensor.

FIG. 12 is a diagram showing a surface plasmon measuring device for measuring the state of totally reflected light by the phase of light.

[Explanation of symbols] 10 Light beam generating means 14 Thin film layer 20 Incident optical system 30 light receiving means 50 measuring plate 52 Dielectric block 53 Sample holding mechanism 54 Interface 55 Measuring unit

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Claims (4)

[Claims] 1. A light beam generating means for generating a light beam, a dielectric block transparent to the light beam, a thin film layer formed on the upper surface of the dielectric block, and a sample on the surface of the thin film layer. A plurality of measurement units each having a sample holding mechanism for holding the light beam, and the light beam, with respect to the dielectric block of each measurement unit, a total reflection condition is obtained at an interface between the dielectric block and the thin film layer. An incident optical system that makes the incident angle of incidence
A measuring device utilizing total reflection light, comprising: a light detecting means for individually receiving a light beam totally reflected at each of the interfaces, and for arranging a plurality of light receiving means for measuring the intensity of the light beam. Wherein the light beam generating means includes a plurality of light sources smaller than the number of the dielectric blocks, and the incident optical system includes a plurality of light sources for the dielectric blocks respectively corresponding to the light receiving means adjacent to each other. A measuring device using total reflection light, characterized in that light beams from different light sources of the light sources are made incident. 2. A light beam generating means for generating a light beam, a dielectric block transparent to the light beam, a thin film layer formed on the upper surface of the dielectric block, and a sample on the surface of the thin film layer. A plurality of measurement units each having a sample holding mechanism for holding the light beam, and the light beam, for each dielectric block of the measurement unit, a total reflection condition is obtained at an interface between the dielectric block and the thin film layer. An incident optical system for making incident light at an incident angle that is set, and a light detecting means that is provided with a plurality of light receiving means that respectively receive the light beams totally reflected at the respective interfaces and measure the intensity of each light beam. A measuring apparatus using the total reflected light, comprising light beam incidence means for making the light beams enter the adjacent light receiving means at different timings. Measuring apparatus utilizing total reflection light. 3. The light beam generating means includes a first light source and a second light source for generating respective light beams incident on the light receiving means adjacent to each other, and the light beam incident means. 3. The measuring apparatus using total reflection light according to claim 2, wherein the first light source and the second light source are turned on at different timings. 4. The light beam incident means separates the light paths of the light beams directed to the respective light receiving means from each other by blocking or deflecting the light paths to separate the light beams from the light path, and the light receiving means adjacent to each other. The measuring device using the total reflection light according to claim 2, further comprising: a control unit that controls the light limiting unit so that the light beams are incident at different timings.