JP2003172743A - Dispenser holding mechanism used for surface plasmon resonance measurement - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dispenser holding mechanism capable of fine adjustment of the height of the dispenser so that a microchip of the dispenser does not come into contact with the inner bottom face of a measuring chip in SPR measurement. <P>SOLUTION: A device for measuring surface plasmon resonance by injecting a sample liquid 4 into the measuring chip 1 by using the dispenser 5 having the microchip 6 on the tip is equipped with a dispenser holding member 37 for holding the dispenser 5, an arm part 38 having the dispenser holding member 37 mounted thereon, a support mechanism for supporting the arm part 38 movably in the uniaxial direction, a rotary mechanism capable of adjusting the position of the arm part 38 in the uniaxial direction by rotating a part thereof, and a fixing part 39 for fixing the support mechanism on the prescribed position. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention utilizes SPR (Surface Plasmon Resonance) for quantitatively analyzing a substance in a sample injected into a measuring chip (also referred to as a prism cup) by utilizing resonance between surface plasmon and evanescent wave. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasmon resonance) measuring device, and more particularly to a holding mechanism of a dispenser used when injecting a liquid into a measuring chip.

[0002]

2. Description of the Related Art Conventionally, a method for quantitatively analyzing a substance in a sample by utilizing attenuated total reflection has been known.
R measurement is widely used as a biosensor. FIG. 2 is a diagram for explaining the principle of SPR measurement. In the measurement chip 1, the metal thin film 3 is formed on the inner bottom surface of the transparent dielectric 2 by vapor deposition or the like. The metal thin film 3 is
It is designed to come into direct contact with the liquid sample 4 containing the substance to be detected.

Light is made incident on the measuring chip 1 at various incident angles so that total reflection conditions are obtained at the interface between the transparent dielectric 2 and the metal thin film 3 of the measuring chip 1. Here, in order to make the light incident on the measurement chip 1 at various incident angles, the thin light may be incident on the measurement chip 1 while being deflected, or the thick light may be condensed by the condenser lens. However, it may be incident on the measuring chip 1. In FIG. 2, the light emitted from the light source 11 is converged by the condenser lens 12 and is incident on the measurement chip 1.

When light is incident on the metal thin film 3 at an incident angle of total reflection or more, the liquid sample 4 in contact with the metal thin film 3
An evanescent wave having an electric field distribution is generated therein. The evanescent waves excite surface plasmons at the interface between the metal thin film 3 and the liquid sample 4. At this time, when wave number matching is established between the evanescent wave and the surface plasmon, a resonance state is established and the energy of the evanescent wave is transferred to the surface plasmon. As a result, the intensity of the light that is incident on the interface between the transparent dielectric 2 and the metal thin film 3 at a specific incident angle θ ₀ and is totally reflected is sharply reduced. Such a decrease in light intensity is detected by the photodetector 13 as a dark line in the reflected light. Note that such surface plasmon resonance needs to be set in advance so that the incident light becomes p-polarized light.

The wave number k _{SP of the} surface plasmon is determined by the following equation. Here, the wave number of surface plasmon is k _SP , the wave number of light in vacuum is k ₀ , the dielectric constant of metal is ε _M ,
_Let the dielectric constant of the sample be ε _S.

[Equation 1] The wave number k _{E of the} evanescent wave is given by the following equation. Here, the refractive index of the transparent dielectric is n ₀ and the incident angle is θ.
And k _E = k ₀ n ₀ sin θ (2)

At the incident angle θ _{0 at} which the wave number k _{E of the} evanescent wave and the wave number k _{SP of the} surface plasmon are equal, surface plasmon resonance occurs and total reflection attenuation occurs.
Therefore, by observing the incident angle θ _{0 at} which the attenuated total reflection occurs, the dielectric constant when the attenuated total reflection occurs can be calculated based on the equations (1) and (2). Further, the concentration of the substance to be detected in the sample can be obtained from this dielectric constant ε _S by using a calibration curve or the like.

In order to apply the SPR measurement to a biosensor, for example, a medium (hereinafter referred to as “sensing medium”) which causes a specific reaction with a substance to be detected is brought into contact with a metal thin film. The specific reaction is, for example, an antigen-antibody reaction, and when detecting an antigen contained in a sample, an antibody against the antigen is used as a sensing medium. When the antibody is brought into contact with the sample containing the substance to be detected, an antigen-antibody reaction occurs according to the concentration of the antigen contained in the sample. Since this changes the refractive index of the sample, the wave number of surface plasmons generated at the interface between the metal thin film and the sample changes. Along with this, the concentration of the specific substance in the sample can be indirectly measured.

However, since the concentration of the specific substance in the sample in the vicinity of the interface between the metal thin film and the sample is measured by this, it is necessary to make the concentration of the sample uniform in order to perform accurate measurement. There is.

In a 96-well microplate used for culturing, separating and analyzing a sample, a dispenser is used to inject a liquid. Since the microplate is simply used as a container for holding a liquid, there is no problem even if the microchip provided at the tip of the dispenser comes into contact with the bottom surface of the plate.

On the other hand, the measuring chip used for the SPR measurement can hold the injected liquid similarly to the microplate, but when the microchip and the inner bottom surface of the measuring chip come into contact with each other, the reflecting surface and the mirror surface are The metal surface is scratched and the flatness deteriorates. If the flatness becomes poor, light is scattered and the sensitivity becomes poor. In addition, if the metal surface on which the surface plasmon resonance occurs is scratched, the resonance state is affected and the sensitivity deteriorates.

In order to prevent the reflection surface and the metal surface from being damaged, the liquid may be dropped from a height at which the microchip does not come into contact with the inner bottom surface of the measuring chip. It also has the purpose of stirring the liquid by inserting the microchip into the liquid accumulated in the chip. Therefore, it is necessary to adjust the height of the dispenser each time the measuring tip is replaced. Further, even when the dispenser is replaced, the height of the microchip is displaced, so that the height of the dispenser needs to be adjusted.

[0012]

In view of the above points, therefore, in the present invention, in the SPR measurement, the height of the dispenser is adjusted so that the microchip of the dispenser and the inner bottom surface of the measuring chip do not come into contact with each other. An object is to provide a finely adjustable dispenser holding mechanism.

[0013]

In order to solve the above problems, the dispenser holding mechanism according to the first aspect of the present invention uses a dispenser having a microchip at its tip to supply a liquid to a measuring chip. A dispenser holding mechanism used in surface plasmon resonance measurement performed by injection, which includes a dispenser holding member for holding the dispenser, an arm portion to which the dispenser holding member is attached, and an uniaxial direction of the arm portion. A support mechanism that movably supports the arm, a rotation mechanism that allows the position of the arm portion to be adjusted in a uniaxial direction by rotating a part thereof, and a fixing portion that fixes the support mechanism at a predetermined position. To do.

Further, a dispenser holding mechanism according to a second aspect of the present invention is a dispenser used in a surface plasmon resonance measurement performed by injecting a liquid into a measuring chip using a dispenser having a microchip at the tip. A dispenser holding mechanism for holding a dispenser, the dispenser holding member having a screw thread formed at a predetermined position, and the screw thread of the dispenser holding member. It has an arm portion that is formed with matching threads and that movably supports the dispenser holding member in one axial direction, and a fixing portion that fixes the arm portion at a predetermined position.

Further, a dispenser holding mechanism according to a third aspect of the present invention is a dispenser used in a surface plasmon resonance measurement performed by injecting a liquid into a measuring chip using a dispenser having a microchip at the tip. A dispenser holding mechanism for holding a dispenser, an arm portion to which the dispenser holding member is attached, a support mechanism for movably supporting the arm portion in one axial direction, and an arm portion. The motor includes a motor for moving the position of 1 in the uniaxial direction, a controller for controlling the motor, and a fixing portion for fixing the support mechanism at a predetermined position.

According to the present invention, in SPR measurement, the distance between the dispenser and the inner bottom surface of the measuring tip can be finely adjusted, and damage to the inner bottom surface of the measuring tip can be prevented. Further, when a motor is used to drive the arm portion, the efficiency of SPR measurement is improved by automation.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The same elements will be denoted by the same reference numerals, and the description thereof will be omitted. Figure 1
2 shows an overall configuration of an SPR measuring device using the dispenser holding mechanism according to the first embodiment of the present invention.
Indicates a measuring chip or the like used in this device.

As shown in FIG. 1, the SPR measuring device 10
Is a turntable 22 that holds a plurality of measuring chips 1.
A dispenser holding mechanism 23 for holding a dispenser 5 for injecting a liquid sample into the measurement chip 1, a light source 11 such as a semiconductor laser for generating light for measurement, and a condenser lens forming an incident optical system. 12, a photodetector 13 that detects reflected light, and a processing unit 14 that receives and processes the output signal of the photodetector 13.
And a motor 21 for intermittently rotating the turntable 22 and a control unit 20 for controlling the motor 21 and for controlling the measurement timing in the SPR measuring device 10.

As shown in FIG. 2, the measuring chip 1 includes a transparent dielectric 2 and a metal thin film 3. Transparent dielectric 2
Has a shape of a truncated pyramid whose area of the lower bottom is smaller than that of the upper bottom, and in the present embodiment, is a truncated pyramid.
Voids into which the liquid sample 4 is injected are formed in the upper part of the transparent dielectric 2. The metal thin film 3 is designed to be in direct contact with the liquid sample 4 containing the substance to be detected.

The transparent dielectric 2 is made of polymethylmethacrylate (polymethylmethacrylate).
te: PMMA), polycarbonate, amorphous polyolefin, or a transparent resin containing cycloolefin, glass, or the like. The metal thin film 3 is made of gold,
It contains silver, copper, aluminum, etc., and is formed on the inner bottom surface of the holes of the transparent dielectric 2 by vapor deposition or the like.

Referring again to FIG. 1, the turntable 2
The plurality of measuring chips 1 held by 2 are sequentially replaced while the turntable 22 makes one revolution. In order to make the measuring chip 1 replaceable, for example, the measuring chip 1 is shaped so that its cross-sectional area gradually decreases from the upper bottom toward the lower bottom, and is held by the holes of the turntable 22. good.

The turntable 22 is constructed so as to hold a plurality of measuring chips 1 at equal angular intervals on the circumference centered on the rotation axis thereof. The motor 21 is composed of a stepping motor or the like, and intermittently rotates the turntable 22 by an angle equal to the arrangement angle of the measuring chip 1.

The dispenser 5 has a microchip 6 for injecting a predetermined amount of the liquid sample 4 held by the dispenser 5, and the liquid sample 4 is dropped and supplied to the measuring chip 1 at a predetermined stop position. It is used to

The microchip 6 is made of synthetic resin (polypropylene or the like), glass, ceramics, Teflon (registered trademark) or the like. Although the volume is not limited, it is usually 0.01 μL to 100 mL, for example, 2 μL, 2.5 μL.
L, 10 μL, 20 μL, 100 μL, 200 μL, 1
000 μL, 1.25 mL, 2.5 mL, 5.0 mL. An example of a microchip product is a multi-microchip by Sorenson.

As shown in FIG. 2, the condensing lens 12 condenses the light generated from the light source 11 and makes it enter the transparent dielectric 2, and variously makes an interface between the transparent dielectric 2 and the metal thin film 3. To obtain the incident angle of. The range of the incident angle is a range including the angle under which the condition of total internal reflection of light is obtained at the interface and the surface plasmon resonance can occur. Since the surface plasmon resonance occurs when the incident light is p-polarized light, the light source 11 is set in advance so that the incident light becomes p-polarized light. In addition, the polarization direction of incident light may be adjusted using a wave plate or a polarizing plate.

The photodetector 13 is constructed by using a line sensor in which a large number of light receiving elements are arranged in a line, and the light receiving elements are arranged so that they are arranged in the X direction in FIG. . The light generated from the light source 11 is reflected by the inner bottom surface of the measurement chip 1, emitted from the surface facing the incident surface, and detected by the photodetector 13. At this time,
When surface plasmon resonance occurs in the measuring chip, a dark line is observed in the detected light. Photo detector 1
3 outputs a detection signal representing the detected light to the processing unit 14 shown in FIG.

The processing unit 14 obtains the angle at which the dark line is observed on the basis of the detection signal output from the photodetector 13, and further performs calculation processing using this angle to detect the detection target contained in the sample. Find the concentration of the substance. The control unit 20 receives a position signal indicating the rotation stop position from the motor 21 and receives the motor 21 based on a predetermined sequence.
A drive signal for driving the SPR measurement device 10 is output and the measurement timing in the SPR measurement device 10 is controlled.

FIG. 3 shows a dispenser holding mechanism and a measuring tip according to the first embodiment of the present invention. In the dispenser holding mechanism 23, the dispenser 5 having the microchip 6 at the tip thereof is held by the dispenser holding member 37 attached to the arm portion 38. The arm portion 38 is supported by the guide portion 30, which is a support mechanism, so as to be movable in the height direction with respect to the fixed portion 39. In this embodiment, the micrometer 31 and the spring 32 are used to adjust the position of the arm portion 38 in the height direction. The guide 35, the main body of the micrometer 31, the spring 32, and the like are covered with a case 35.

By the action of the guide portion 30, the arm portion 3
8 maintains an angle of approximately 90 ° with respect to the fixed portion 39. Further, the arm portion 38 is in contact with the micrometer 31 by receiving a force upward due to the elastic force of the spring 32, one of which is fixed to the fixing portion 39. Here, when the knob provided on the rotating mechanism of the micrometer 31 is turned, this rotating movement is converted into vertical movement, and the arm portion 3
8 moves up and down. As a result, the microchip 6 attached to the tip of the dispenser 5 can be moved to a desired height, and the liquid sample 4 can be injected into the measuring chip 1 or the injected liquid sample 4 can be stirred. it can. At that time, the height of the microchip 6 is finely adjusted within a range in which the microchip 6 does not come into contact with the metal thin film 3 on the inner bottom surface of the measurement chip 1 to prevent damage to the reflective surface of the measurement chip and the surface of the metal thin film. You can Then, the microchip 6 is lifted higher than the upper bottom surface of the measurement chip 1 to replace the measurement chip 1 or the dispenser 5.

Next, a second embodiment of the present invention will be described. FIG. 4 shows a dispenser holding mechanism and a measuring tip according to the second embodiment of the present invention. In this dispenser holding mechanism, a screw thread is formed at a predetermined position of the dispenser holding member 47 holding the dispenser 5, and the dispenser holding member is provided at a corresponding position of the arm portion 48. Threads are formed that are integrated with the 47 threads. In addition, in the present embodiment, the arm portion 48 and the fixed portion 49 are integrally formed.

In the present embodiment, the dispenser holding member 4
A male screw is formed on the lower side surface of 7 and the arm portion 48
Female threads are formed at the corresponding positions. By accumulating the threads of the dispenser holding member 47 and the arm portion 48, the arm portion 48 can support the dispenser holding member 47 movably in the height direction. When the dispenser holding member 7 is rotated, the dispenser 5 held by the dispenser holding member 7 moves up and down. As a result, the microchip 6 attached to the tip of the dispenser 5 can be moved to a desired height, and the liquid sample 4 can be injected into the measuring chip 1 or the injected liquid sample 4 can be stirred. it can. At that time, the height of the microchip 6 is finely adjusted within a range in which the microchip 6 does not come into contact with the metal thin film 3 on the inner bottom surface of the measurement chip 1 to prevent damage to the reflective surface of the measurement chip and the surface of the metal thin film. You can Then, the microchip 6 is lifted higher than the upper bottom surface of the measurement chip 1 to replace the measurement chip 1 or the dispenser 5.

Next, a third embodiment of the present invention will be described. FIG. 5 shows a dispenser holding mechanism and a measuring tip according to a third embodiment of the present invention. In this dispenser holding mechanism, a dispenser 5 having a microchip 6 at the tip
However, the dispenser holding member 57 attached to the arm portion 58
Is held by. The arm portion 58 has a fixed portion 59.
It is supported by a guide portion 50 which is a support mechanism so as to be movable in the height direction. In this embodiment, in order to adjust the position of the arm portion 58 in the height direction, a motor, a gear and the like provided in the gear box 51 are used. The gear in the gear box 51 meshes with the gear 52 of the fixed portion. The guide unit 50,
The gear box 51 and the like are covered with a case 55. Further, this dispenser holding mechanism is provided with a gearbox 51.
It includes a controller 53 for controlling the internal motor and a photoelectric sensor 54 for detecting the position of the microchip 6.

By the action of the guide portion 50, the arm portion 5
8 maintains an angle of approximately 90 ° with respect to the fixed portion 59. Further, when the controller 53 drives the motor in the gearbox 51, the gear in the gearbox 51 rotates and the arm portion 8 moves up and down. As a result, the microchip 6 attached to the tip of the dispenser 5 can be moved to a desired height, and the liquid sample 4 can be injected into the measuring chip 1 or the injected liquid sample 4 can be stirred. it can.

The photoelectric sensor 54 detects the position of the microchip 6 attached to the tip of the dispenser 5. For example, when the microchip 6 approaches the measuring chip 1,
When the photoelectric sensor 54 detects the microchip 6, a signal is sent from the photoelectric sensor 54 to the controller 53. The controller 53 drives the motor in the gearbox 51 to further lower the microchip 6 by a distance determined in advance for each shape of the measuring chip 1. This makes it possible to inject the liquid sample 4 into the measuring chip 1 or to stir the infused liquid sample 4. Then, the microchip 6 is lifted higher than the upper bottom surface of the measurement chip 1 to replace the measurement chip 1 or the dispenser 5. According to this embodiment, not only the reflection surface of the measurement chip and the surface of the metal thin film are prevented from being damaged by the contact of the microchip, but also the efficiency of the SPR measurement is improved by automation.

The preferred embodiments of the present invention as described below are summarized as follows. The dispenser holding mechanism according to the present invention is a dispenser holding mechanism used in surface plasmon resonance measurement performed by injecting a liquid into a measurement chip using a dispenser having a microchip at the tip, and the dispenser For holding the dispenser, an arm portion to which the dispenser holding member is attached, a support mechanism for movably supporting the arm portion in the uniaxial direction, and a position of the arm portion by rotating a part thereof. A rotation mechanism that can be adjusted in one axis direction and a fixing portion that fixes the support mechanism at a predetermined position are provided.

Here, the rotating mechanism may include a micrometer.

The dispenser holding mechanism according to the present invention is a dispenser holding mechanism used in surface plasmon resonance measurement performed by injecting a liquid into a measuring chip using a dispenser having a microchip at the tip, A dispenser holding member for holding the dispenser, wherein a dispenser holding member having a screw thread formed at a predetermined position and a screw thread accumulating with the screw thread of the dispenser holding member are formed. An arm portion that supports the dispenser holding member so as to be movable in one axis direction, and a fixing portion that fixes the arm portion at a predetermined position.

Here, the arm portion and the fixed portion may be integrally formed.

The dispenser holding mechanism according to the present invention is a dispenser holding mechanism used in a surface plasmon resonance measurement performed by injecting a liquid into a measuring chip using a dispenser having a microchip at its tip, A dispenser holding member for holding the dispenser, an arm portion to which the dispenser holding member is attached,
A support mechanism that supports the arm portion so as to be movable in one axis direction,
The motor includes a motor that moves the position of the arm portion in one axis direction, a controller that controls the motor, and a fixing portion that fixes the support mechanism at a predetermined position.

Here, the motor may include a pulse motor or a linear motor, a sensor for detecting the position of the microchip of the dispenser may be further provided, and the motor may be controlled by the controller based on the output signal of the sensor. May be controlled, and the sensor may include a photoelectric sensor.

[0041]

As described above, according to the present invention, SP
In the R measurement, the distance between the dispenser and the inner bottom surface of the measuring tip can be finely adjusted, and damage to the inner bottom surface of the measuring tip can be prevented. In addition, when a motor is used to drive the arm part, it is possible to automate the SPR.
Measurement efficiency is also improved.

[Brief description of drawings]

FIG. 1 is a diagram showing an overall configuration of an SPR measurement device using a dispenser holding mechanism according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a measuring chip and the like used in the SPR measuring device shown in FIG.

FIG. 3 is a diagram showing a dispenser holding mechanism and a measurement tip according to the first embodiment of the present invention.

FIG. 4 is a diagram showing a dispenser holding mechanism and a measuring tip according to a second embodiment of the present invention.

FIG. 5 is a view showing a dispenser holding mechanism and a measuring chip according to a third embodiment of the present invention.

[Explanation of symbols]

1 measuring chip 2 Transparent dielectric 3 metal thin film 4 Liquid sample 5 dispenser 6 microchips 10 SPR measuring device 11 light source 12 Condensing lens 13 Photodetector 14 Processing unit 20 Control unit 21 motor 22 turntable 23 Dispenser holding mechanism 30,50 Guide part 31 micrometers 32 spring 35, 55 cases 37, 47, 57 Dispenser holding member 38, 48, 58 Arm 39, 49, 59 Fixed part 51 gearbox 52 gears 53 Controller 54 Photoelectric sensor

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 2G057 AA02 AB04 AB07 AC01 BA01                       BA03 BB01 BB06 HA04                 2G058 AA09 CC17 CD04 CF16 EA11                       ED03 ED07 GA02                 2G059 AA01 BB04 BB12 CC16 DD12                       EE02 EE05 GG01 GG04 JJ11                       JJ12 JJ19 JJ20 KK04

Claims (3)

[Claims] 1. A dispenser holding mechanism used in a surface plasmon resonance measurement performed by injecting a liquid into a measurement chip using the dispenser, wherein the dispenser holding member holds the dispenser, An arm part to which a dispenser holding member is attached, a support mechanism for movably supporting the arm part in one axis direction, and a position of the arm part can be adjusted in one axis direction by partially rotating the arm part. Dispenser holding mechanism including: a rotating mechanism; and a fixing portion that fixes the supporting mechanism at a predetermined position. 2. A dispenser holding mechanism used in surface plasmon resonance measurement performed by injecting a liquid into a measuring chip using the dispenser, which is a dispenser holding member for holding the dispenser. , The dispenser holding member having a screw thread formed at a predetermined position and a screw thread that is integrated with the screw thread of the dispenser holding member are formed, and the dispenser holding member is moved in one axis direction. A dispenser holding mechanism comprising an arm portion that supports the arm portion and a fixing portion that fixes the arm portion at a predetermined position. 3. A dispenser holding mechanism used in surface plasmon resonance measurement performed by injecting a liquid into a measuring chip using the dispenser, wherein the dispenser holding member holds the dispenser, An arm unit to which a dispenser holding member is attached, a support mechanism that movably supports the arm unit in the uniaxial direction, a motor that moves the position of the arm unit in the uniaxial direction, and a controller that controls the motor. A dispenser holding mechanism, comprising: a fixing portion that fixes the support mechanism at a predetermined position.