JP2008268146A - Prismless spr sensor and refractive index measuring apparatus using same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem wherein a sensor becomes complicated, large and expensive, and a measuring device also becomes large and expensive, due to requiring fairly high-degree knowledge and skill for its handling and measurement, since matching oil and a prism must be arranged in close contact on a substrate of forming a metallic thin film for holding a reaction part such as an antibody, in the sensor used for a measuring method of a conventional SPR strength method. <P>SOLUTION: The problem is solved by constituting a measuring object sample holding substrate for only requiring to optically polish only one surface out of cut-out four surfaces, by cutting out of an inexpensive optical glass plate available on the market, and constituting so as to directly make the measuring light incident from a side surface of the measuring object sample holding substrate. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  In the following, the measuring device that can measure the refractive index or the change in the refractive index is referred to as a refractive index measuring device, and the present invention provides a substance that adjusts the refractive index such as matching oil between the prism and the prism. A substance that interacts with a measurement object or a measurement object (hereinafter referred to as a measurement object or a substance that interacts with the measurement object) using measurement of a surface plasmon resonance (hereinafter referred to as SPR) phenomenon without being interposed. A prismless SPR sensor that can be used to detect the presence / absence, refractive index, or change in refractive index of a sample to be measured with high accuracy, unless one or both of them is specifically required to be distinguished More specifically, it relates to a refractive index measuring device using the same, and is used for measuring influenza antigens easily and with high accuracy. Inexpensive can Rukoto relates prism-less SPR sensor and inexpensive refractive index measuring instrument easy to use a compact using the same can also be used as a disposable sensor.

  In recent years, there have been many problems that greatly affect people's health, such as measures against influenza and environmental pollution, and detection of those causative substances has become increasingly important socially. In many cases, detection of these substances requires detection of an extremely small amount of an organic compound, and high reliability is required for the measurement result.

  To detect organic compounds, for example, influenza virus antigens, as is well known, gas chromatography / mass spectrometry, liquid chromatography, a method of measuring light based on a chemical reaction using a fluorescent reagent or a luminescent reagent. Various measurement methods are possible, but complicated steps are required to prepare the sample to be measured, measurement results cannot be obtained in real time, the equipment is expensive, and advanced expertise and skill are required for operation. I had many challenges.

  As one of important measurement methods used for the detection of organic compounds, various measurement apparatuses and measurement sensors using the SPR measurement method have been proposed in order to solve the above problems.

  As is well known, for example, when incident light is incident on a metal thin film at a certain angle via a prism, the wave number of the evanescent wave and the wave number of the surface plasmon depend on the state of the dielectric on the surface of the metal thin film. Is a phenomenon in which the reflected light intensity from the metal thin film is attenuated.

  The advantages of the measurement method using the SPR phenomenon for the detection of organic compounds are that the measurement accuracy is not easily affected by the color and opacity of the organic compound to be measured, the amount of the organic compound to be measured is small, and on the metal surface Therefore, the surface can be used by fixing the substance that interacts with the measurement object, the measurement can be performed with high accuracy in a short time, and the detection result of the organic compound can be obtained in real time.

  As is well known as a method for detecting an organic compound using the SPR method, once the object to be measured is determined, the intensity of the reflected light from the metal thin film is changed by changing the incident angle while fixing the wavelength of the light incident on the metal thin film. There are an intensity method for measuring the change in the light intensity and a spectroscopic method for measuring the change in the intensity of the reflected light from the metal thin film by changing the wavelength of the incident light while fixing the incident angle of the incident light on the metal thin film.

  The intensity method is almost the same as the conventional ellipsometer, and the change in reflected light intensity is measured by continuously changing the incident angle to the metal thin film.

  In the spectroscopic method, there is a method in which the angle of incidence on the metal thin film is fixed and the wavelength of incident light is changed, or a broad light source is measured with a spectroscope. The spectroscopic method is used, for example, in a fiber type sensor by utilizing the fact that the reflection angle in an optical fiber is substantially constant.

  14 and 15 show a typical example of a conventional SPR sensor described in Japanese Patent Application Laid-Open No. 2003-232725 (hereinafter referred to as Patent Document 1) and an example of its measurement system, in which a metal thin film is formed. This is an example in which a columnar prism having a trapezoidal cross section is used as the prism attached to the substrate. FIG. 14 is a diagram for explaining an SPR sensor, FIG. 15 is a diagram for explaining a chemical reaction analysis sensor using an SPR measurement method, reference numeral 101 is a prism, 102 is a metal thin film, 103 is a planar microchannel through which a sample flows, 104 is a syringe pump for feeding liquid, 105 is a quartz glass substrate on which a microchannel 103 is formed, 105a is a photoresist film applied to a quartz glass substrate 105 having a thickness of 0.7 mm, and 106 is 0.5 mm in thickness. BK7 glass plate, 107 and 108 are tubes for introducing and discharging samples, 110 is a laser diode, 111 and 120 are lenses, 112 is a single mode optical fiber, 113 is a collimator, 121 is a P polarizer, and 122 is a CCD camera. , 123 is a computer, 130 is a sensor chip, 131 is a light source means, 132 is a measurement means, and 134 is an input. Light, 135 reflected light, the incident angle 136, 137 is the refractive index matching oil.

  In FIG. 15, the sample to be measured is caused to flow through the microchannel 103 by the action of the syringe pump 104 for feeding liquid, and the light from the laser diode 110 is transmitted from the prism 101 to the metal thin film 102 via the single mode optical fiber 112 and the collimator 113. The SPR phenomenon is measured on the surface of the metal thin film 102 that is in contact with the sample of the microchannel 103 by entering at a predetermined incident angle indicated by reference numeral 136 so that the total reflection angle is obtained.

  As shown in FIG. 14, in the sensor chip 130, the prism 101 is disposed on the lower surface of the glass plate 106 of BK7 having the metal thin film 102 formed on the upper surface via the refractive index matching oil 137, and the incident surface of the prism 101 (FIG. 15). The incident light is incident from the upper surface of the prism 101 and is incident on the glass plate 106 through the refractive index matching oil 137 from the upper surface of the prism 101, and reaches the metal thin film 102 at a resonance angle to cause the SPR phenomenon. The reflected light is incident on the prism 101 through the refractive index matching oil 137 from the lower surface of the glass plate 106, and the emitted light 135 is emitted from the emission surface of the prism 101 (the surface from which the emitted light 135 shown in FIG. 15 is emitted). And is detected by the measuring means 132 in FIG. 101A.

  As a typical example different from the above-described example of the conventional SPR sensor, instead of the prismatic prism having a trapezoidal section, an example using a triangular prism having a triangular section or a semicylindrical prism having a semicircular section is used. There is an example to use. In particular, in the case of using a semi-cylindrical prism having a semicircular cross section, when the incident angle of incident light is changed in the intensity method of the SPR method, the incident light is perpendicular to the incident surface of the prism at any incident angle. It is one of the features that it has the advantage that it can be made incident on.

However, even if the case where a metal thin film is directly attached to the prism as a principle measurement, if a detailed explanation is given, a flat substrate with a metal thin film is actually independent of the prism. It is currently considered that it must be used in contact with one surface of the prism via a refractive index matching oil.
JP 2003-232725 A

  As described above, the measurement method of the SPR intensity method for organic compounds such as influenza viruses using the conventional measurement of refractive index or refractive index change due to the SPR phenomenon can obtain highly accurate measurement results in real time. However, the metal thin film for measurement needs to have a good optical surface, and it is located between the substrate on which the metal thin film for measurement is formed and the light source along the optical path through which incident light enters the substrate. In addition, since it is essential that the prism and the matching oil for matching the refractive index be arranged between the prism and the substrate, the sensor for placing the object to be measured is a reaction of an antibody or the like. In addition to the substrate on which the metal thin film that holds the part is formed, the substrate, the matching oil, and the prism must be placed in close contact with each other. The take considerable advanced knowledge and skill for the handling and measurement, the sensor becomes complicated and large, the price is high, there is a problem that becomes expensive measuring device is also large.

  The present invention has been made in view of the above points, and the greatest object of the present invention is that the influenza antigen and the antibody can be detected without requiring special advanced knowledge and skill regarding refractive index measurement using the SPR phenomenon. An object of the present invention is to provide an inexpensive SPR sensor that can be used in a disposable manner that can easily change the refractive index or the refractive index due to reaction or the like in real time, and a small-sized measuring instrument using the SPR sensor.

  In order to solve the problem, the SPR sensor of the present invention has a refractive index matching oil and a prism arranged in close contact with a substrate in addition to a substrate on which a metal thin film, which has been considered impossible in the past, is formed. The SPR phenomenon can be easily measured and the refractive index of the sample to be measured or the change in refractive index can be easily measured. It is small, easy to use, and can detect the presence of influenza antigens with high reliability. It is an inexpensive prismless SPR sensor that can be used.

The first invention (hereinafter referred to as invention 1) as an example of the present invention is a single substance without interposing a substance for adjusting the refractive index such as prism and matching oil in the optical path, and the refractive index or refractive index of the sample to be measured. A prismless SPR sensor that can be used to measure the change in intensity by an intensity method using the SPR phenomenon,
A substrate having a metal thin film brought into contact with the sample to be measured on its surface is called a sample holding substrate to be measured.
The prismless SPR sensor has a frame portion having at least one hole and a measured sample holding substrate at the bottom of at least one hole of the frame portion,
In the sample holding substrate to be measured, at least a pair of metal thin films are formed on at least a part of the surface on the side of forming the bottom of the hole of the frame portion as the upper surface of the substrate, and there is a translucent portion. A substrate protruding from the frame portion to the opposite side of the upper surface of the substrate as a protruding portion having opposite side surfaces of
The sample holding substrate to be measured has an incident surface that allows a light beam having a predetermined wavelength (hereinafter referred to as measurement light) to enter the metal thin film through the inside of the substrate near a resonance angle. An emission surface on one side of the opposite side surfaces of the substrate and further capable of emitting a measurement light beam totally reflected by the metal thin film on the other side surface of the pair of opposite side surfaces of the substrate. And
The cross-sectional shape perpendicular to the surface (hereinafter referred to as the sample holding surface) that includes the optical path of the measurement light of the sample holding substrate to be measured and on which the metal thin film is formed is a quadrilateral or more polygon.
Further, the sample holding substrate to be measured is formed such that at least the sample holding surface, the incident surface, and the exit surface are optical surface grade surfaces.
The prismless SPR sensor uses the prismless SPR sensor to measure the refractive index of the sample to be measured or the change in refractive index using the SPR phenomenon, and the measurement light source and the sample holding substrate to be measured. From the incident surface of the sample holding substrate to be measured without arranging a substance for adjusting the refractive index such as matching oil and a prism in close contact with the prismless SPR sensor in the optical path of the measurement light beam between the incident surfaces of A measurement light beam is incident to cause an SPR phenomenon in the metal thin film portion, and the intensity of the measurement light beam that is totally reflected by the metal thin film and exits from the exit surface is brought into close contact with the prismless SPR sensor, and matching oil or the like A sample to be measured in contact with the metal thin film by measuring without interposing a prism and a substance that adjusts the refractive index of A prism-less SPR sensor, which is a prism-less SPR sensor which can be used to measure changes in refractive index or refractive index.

  A second invention (hereinafter referred to as invention 2) as an example of the invention made by developing invention 1 is the prismless SPR sensor according to invention 1, wherein the frame portion and the measured sample holding substrate are integrated. It is a prismless SPR sensor characterized by being formed.

  A third invention (hereinafter referred to as invention 3) as an example of the present invention developed from invention 1 is the prismless SPR sensor according to invention 1, in which the frame portion and the measured sample holding substrate are respectively It is a prismless SPR sensor characterized by being formed as an independent part.

  A fourth invention (hereinafter referred to as invention 4) as an example of the present invention developed by developing inventions 1 to 3 is the prismless SPR sensor according to any one of inventions 1 to 3, in which the measurement light beam is incident. The prismless SPR sensor, wherein the incident surface at the point and the exit surface at the exit point of the measurement light beam are planes parallel to each other.

  A fifth invention (hereinafter referred to as invention 5) as an example of the invention made by developing inventions 1 to 4 is the prismless SPR sensor according to any one of inventions 1 to 4, wherein the hole of the frame body is provided. Is a prismless SPR sensor characterized by having an oval opening.

  A sixth invention (hereinafter referred to as invention 6) as an example of the present invention developed by developing inventions 3 to 5 is the prismless SPR sensor according to any one of inventions 3 to 5, wherein the substrate and the frame A prismless SPR sensor characterized in that the body can be assembled in a detachable manner.

  A seventh invention (hereinafter referred to as invention 7) as an example of the present invention developed by developing the inventions 3 to 6 is the prismless SPR sensor according to any one of the inventions 3 to 6, wherein the sample to be measured is held. A prismless SPR sensor characterized in that the substrate is a polyhedron of hexahedron or more having three surfaces of the incident surface, the exit surface, and the sample holding surface that are optically polished.

  An eighth invention (hereinafter referred to as invention 8) as an example of the present invention developed by developing the invention 7 is the prismless SPR sensor according to the invention 7, wherein the polyhedron is a rectangular parallelepiped, and the entrance surface and the exit surface. The prism-less SPR sensor is characterized in that the sample holding surface forms three continuous surfaces.

  The ninth invention (hereinafter referred to as invention 9) as an example of the present invention developed from the invention 7 is the prismless SPR sensor according to the invention 7, wherein the polyhedron is a cube, and the entrance surface and the exit surface. The prism-less SPR sensor is characterized in that the sample holding surface forms three continuous surfaces.

  A tenth invention (hereinafter referred to as invention 10) as an example of the present invention developed by developing inventions 3 to 9 is the prismless SPR sensor according to any one of inventions 3 to 9, wherein the sample to be measured is held. A prismless SPR sensor characterized in that the substrate material is glass, and at least three surfaces of the entrance surface, the exit surface, and the sample holding surface are optically polished to at least a quarter wavelength level of measurement light. .

  An eleventh invention (hereinafter referred to as invention 11) as an example of the present invention developed by developing invention 10 is the prismless SPR sensor according to invention 10, in which the substrate is polished at least a quarter wavelength level. A prismless SPR sensor characterized in that it is a small glass piece cut out from a parallel flat plate glass plate and having at least one of the cut surfaces optically polished.

  A twelfth invention (hereinafter referred to as invention 12) as an example of the present invention developed from inventions 1 to 11 is the prismless SPR sensor according to any one of inventions 1 to 11, wherein the incident angle The prism, which is represented by an angle with respect to the normal line of the metal thin film at a reflection point, is a substrate on which the measurement light beam can be incident at an acute incident angle near 70 °. Less SPR sensor.

  A thirteenth invention (hereinafter referred to as invention 13) as an example of the present invention developed by developing inventions 1 to 12 is the prismless SPR sensor according to any one of inventions 1 to 12, wherein the incident angle is θ Substrate on which the measured sample holding substrate can enter a measurement light beam including an incident light beam having an incident angle in the range of θ ± Δθ in the metal thin film portion, where Δθ is a deviation from θ. This is a prismless SPR sensor.

  A fourteenth invention as an example of the present invention developed from the first to thirteenth inventions (hereinafter referred to as the fourteenth invention) is the prismless SPR sensor according to any one of the first to thirteenth inventions. Is a prismless SPR sensor characterized in that it is gold formed after forming chromium and chromium.

  A fifteenth invention (hereinafter referred to as invention 15) as an example of the present invention developed by developing the inventions 1-14 is the prismless SPR sensor according to any one of the inventions 1-14, wherein the prismless SPR sensor Is a prismless SPR sensor characterized in that it is a sensor capable of detecting the presence or absence of an antigen.

  A sixteenth invention (hereinafter referred to as invention 16) as an example of the present invention developed by developing the invention 15 is the prismless SPR sensor according to the invention 15, wherein the antigen to be detected is an influenza antigen. This is a feature of a prismless SPR sensor.

  A seventeenth invention (hereinafter referred to as an invention 17) as an example of the present invention developed from the inventions 1 to 16 is the prismless SPR sensor according to any one of the inventions 1 to 16, wherein the sample to be measured is held. Each antibody holding part for holding at least two types of antibodies and a blank part (a part into which no sample is to be measured) are arranged on a metal thin film formed on the sample holding surface of the substrate. This is a prismless SPR sensor.

  An eighteenth invention (hereinafter referred to as invention 18) as an example of the present invention developed from the inventions 1 to 17 is the prismless SPR sensor according to any one of the inventions 1 to 17, wherein the prismless SPR sensor is the prismless SPR sensor. A prismless SPR sensor characterized in that the SPR sensor is a disposable sensor.

According to a nineteenth aspect of the present invention (hereinafter referred to as the nineteenth aspect), a prism-less SPR sensor is used alone without using a substance that adjusts the refractive index, such as a prism and matching oil, in the optical path. A refractive index measuring device capable of measuring the refractive index or the change of the refractive index by an intensity method using the SPR phenomenon,
A substrate having a metal thin film on the surface on which a sample to be measured can be mounted is referred to as a sample holding substrate to be measured.
The prismless SPR sensor has a frame portion having at least one hole and a measured sample holding substrate at the bottom of at least one hole of the frame portion,
In the sample holding substrate to be measured, at least a pair of metal thin films are formed on at least a part of the surface on the side of forming the bottom of the hole of the frame portion as the upper surface of the substrate, and there is a translucent portion. A substrate protruding from the frame portion to the opposite side of the upper surface of the substrate as a protruding portion having opposite side surfaces of
The measurement sample holding substrate has an incident surface on one side surface of the pair of opposing side surfaces of the substrate through which the measurement light beam can be incident on the metal thin film through the inside of the substrate in the vicinity of a resonance angle. And an emission surface capable of emitting a measurement light beam totally reflected by the metal thin film is provided on the other side surface of the pair of opposed side surfaces of the substrate,
The shape of the cross section perpendicular to the sample holding surface including the optical path of the measurement light of the sample holding substrate to be measured is a quadrilateral or more polygon,
Further, the sample holding substrate to be measured is formed such that at least the sample holding surface, the incident surface, and the exit surface are optical surface grade surfaces.
When the refractive index measuring device measures the refractive index of the sample to be measured or the change in the refractive index using the prismless SPR sensor and utilizing the SPR phenomenon, the light source of the measurement light and the sample holding substrate to be measured are measured. Measuring light from the incident surface of the sample holding substrate to be measured without interposing a substance for adjusting the refractive index such as matching oil and a prism in close contact with the prismless SPR sensor in the optical path of the measuring light between the incident surfaces. A beam is incident to cause an SPR phenomenon in the metal thin film portion, and a measurement light beam that is totally reflected by the metal thin film and exits from the exit surface is brought into close contact with the prismless SPR sensor to change the refractive index of matching oil or the like. Before measuring the intensity of the emitted light by receiving light with a two-dimensional sensor or linear sensor without arranging the substance to be adjusted and the prism A refractive index measuring device, characterized in that a measuring device capable of measuring changes in the refractive index or the refractive index of a measured sample in contact with the metal thin film.

  The twentieth invention (hereinafter referred to as invention 20) as an example of the present invention developed by developing the invention 19 is the refractive index measuring device according to the invention 19, wherein the incident angle is θ and the deviation from θ is Δθ. The refractive index measuring instrument, wherein the measuring light beam incident on the incident surface is incident as a measuring light beam including an incident light beam having an incident angle in a range of θ ± Δθ in the metal thin film portion. It is.

  The twenty-first invention (hereinafter referred to as invention 21) as an example of the present invention developed by developing the invention 19 or 20 is the refractive index measuring device according to the invention 19 or 20, wherein the refractive index measuring device is the 2 A refractive index measuring instrument comprising a display unit that displays differently according to the light detection intensity at a light detection position of a dimension sensor or a linear sensor.

  One of the particularly important features of the prismless SPR sensor of the present invention is, as will be described later, one of four cut-out surfaces obtained by cutting out from a commercially available optical glass flat plate as a sample holding substrate to be measured. Even if it is optically polished, a substrate that can be manufactured in a manufacturing process is used, and the measurement light is directly incident from the side surface of the sample holding substrate to be measured. It has been realized.

  As described above, the present invention measures a large amount of specimens in real time, simply and inexpensively, and promptly takes appropriate measures when a new influenza or the like occurs and may become a major social problem. It makes it possible to take measures and, in turn, removes social anxiety, so that it exerts great social, industrial and economic effects.

  Examples of embodiments of the present invention will be described below with reference to the drawings. The drawings used for the description schematically show the dimensions, shapes, arrangement relationships, and the like of each component to the extent that an example of the present invention can be understood. For convenience of explanation of the present invention, there may be cases where the enlargement ratio is partially changed for illustration, and the drawings used for explanation of the examples of the present invention may not necessarily be similar to the actual objects and descriptions of the embodiments. Moreover, in each figure, about the same component, it attaches and shows the same number, The overlapping description may be abbreviate | omitted.

  FIG. 1 is a perspective view of a prismless SPR sensor as an example of the present invention. Reference numeral 1 is a prismless SPR sensor, 2 is a plastic frame portion, 2a is a substrate of the frame portion 2, 3 is a sample holding substrate to be measured, 4 is a hole provided in the substrate 2a of the frame portion 2, 5 is an inclined surface of the hole 4, 6 is a sample holding surface, 7 is a portion that is a through hole of the hole 4 before the sample holding surface 6 is arranged, 11a ˜11d are side surfaces of the sample holding substrate 3 to be measured. The side surfaces 11a and 11c are surfaces facing each other, and the side surfaces 11b and 11d are surfaces facing each other.

  FIG. 2 is a perspective view for explaining the sample holding substrate 3. Reference numeral 11 denotes a glass substrate of the sample holding substrate 3, 12 denotes a chromium vapor deposition layer as a first metal thin film formed on the substrate 11, Reference numeral 13 denotes a gold vapor deposition layer as a second metal thin film formed on the first metal thin film 12 on the substrate 11, and 6 a arranges a first type influenza antibody as a part of the sample holding surface 6. The sample holding surface 6c is a sample holding surface on which the second type influenza antibody as a part of the sample holding surface 6 is arranged, and 6b is a sample holding member on which the influenza antibody as a part of the sample holding surface 6 is not arranged. The surface, W is the width of the substrate 11, T is the thickness of the substrate 11, and L is the length dimension of the substrate 11.

  One of the particularly important features of the prismless SPR sensor of the present invention is that the incident light for causing the surface plasmon resonance phenomenon on the sample holding surface 6 can be used without using an optical fiber or a prism and refractive index matching oil. 11 is configured to directly enter from one of the side surface 11a and the side surface 11c and to exit from the other, and the thickness T and width W of the substrate 11 are determined in consideration of this. Although not limited to this, the thickness T and the width W are approximately the same in this embodiment.

  The bottom part of the hole 4 of the frame part 2 in FIG. 1 is closed by the sample holding substrate 3 to be measured.

  The side surfaces 11 a and 11 c of the glass substrate 11 of the sample holding substrate 3 to be measured are parallel to each other, and the sample holding surfaces 6 a to 6 c of the glass substrate 11 of the sample holding substrate 3 to be measured are the bottoms of the holes 4. In this case, the hole 4 is arranged in the ellipse portion of the through hole 7 in parallel with the major axis direction.

  One of the side surfaces 11a and 11c of the glass substrate 11 of the sample holding substrate 3 to be measured is a light incident surface when measuring the refractive index or the refractive index change for detecting a virus of the sample using the SPR phenomenon. One surface is a light incident surface, which is an optical surface having a surface roughness of at least a quarter wavelength of incident light.

  The upper surface of the glass substrate 11 of the sample holding substrate 3 to be measured, that is, the surface on which the first metal thin film is formed is also an optical surface of the same level as the side surfaces 11a and 11c.

  3 to 7 are diagrams for explaining the frame part 2. FIG. 3 is a plan view of the frame part 2 as viewed from the opening side of the hole 4 in FIG. 1, and FIG. 4 is Y1-Y2 of the frame part 2 in FIG. FIG. 5 is a cross-sectional view at the position X1-X2 of the frame part 2 in FIG. 3, and FIGS. 6 and 7 are side views of the frame part 2 in FIG. Reference numerals 2a1 to 2a4 denote side surfaces of the frame portion 2, 2a5 and 2a6 denote upper and lower surfaces of the frame portion 2, and 21 and 22 denote cross sections provided on the side surface 2a1 of the frame portion 2 (cross sections cut perpendicular to the side surfaces). The cross section provided on the side surface 2a3 of the frame 2 is a V-shaped groove, and X1-X2 and Y1-Y2 are cross-sectional views of the frame 2 shown in FIGS. 4 and 5, respectively. It is a code | symbol explaining the position of.

  Although not shown, the sample holding surface V-shaped grooves 21 to 24 can be used to change the relative positions of the sensor and the measuring instrument by abutting the pin and plunger of the measuring instrument, for example.

  The frame portion 2 is formed by plastic molding, and the upper surface 2a5 and the lower surface 2a6 are planes parallel to each other.

  The frame portion 2 has a shape in which an oval through-hole portion 7 and a hole 4 having an inclined surface 5 formed in the periphery thereof are formed in a substantially central portion of the substrate 2a, which is a plane in which the upper surface 2a5 and the lower surface 2a6 are parallel. . As shown in the cross-sectional views of FIGS. 4 and 5, the oval through-hole portion 7 and the hole 4 in which the inclined surface 5 is formed in the periphery thereof have a relatively wide opening on the upper surface 2a5 side of the substrate 2a. The substantially central portion of the inclined surface 5 is an oval through-hole penetrating to the lower surface 2a6 side, and the through-hole portion 7 is used to measure the sample holding surfaces 6a to 6c of the sample holding substrate 3 to be measured shown in FIG. The frame portion 2 and the sample holding substrate 3 to be measured are formed in dimensions and shapes so that necessary portions are positioned.

  The prismless SPR sensor 1 shown in FIG. 1 has a sample holding substrate 3 described with reference to FIG. 2 and a frame 2 described with reference to FIGS. The sample holding substrate 3 to be measured is attached to the through hole portion 7 of 2a6 and its periphery so that the main parts of the sample holding surfaces 6a to 6c are located inside the through hole portion 7.

  Various conventional techniques such as adhesion and fitting can be used to attach the sample holding substrate 3 to be measured to the frame 2.

  8 and 9 are perspective views for explaining an example of the manufacturing method of the sample holding substrate 3 to be measured described with reference to FIG. 2. Reference numeral 30 is a glass plate, and 30a is polished to the optical surface level of the glass plate 30. FIG. An upper surface 30b is a bottom surface polished to the optical surface level of the glass plate 30, 31a to 31f are glass rods cut to the same dimensions, 32 is a remaining cutting portion, 31aa, 31ba, 31ca, 31da. , 31ea, 31fa are upper surfaces of glass rods, 31ab, 31bb, 31cb, 31db, 31eb, 31fb are lower surfaces of the glass rods, 31fc is a side surface of the glass rod 31f, 33 is a glass rod 31a-31f cut from the glass plate 30. Glass rod group arranged with one cut surface facing up for polishing, 33a is the upper surface of the arranged glass rod group 33, 33b is the arranged glass The lower surface of the group 33, 34 is a group of glass rods whose upper surface 33a is polished, 35 is a group of glass rods having the upper surface 33a polished and cut into predetermined dimensions, 31e1 to 31e3, 31f1 to 31f3 are predetermined Glass pieces in a state of being cut into dimensions, 31e4 and 31f4 are remaining cut portions, 31fd is a cut surface, 31fd0 is a cut surface polished to an optical surface, and 36 is a thickness on the upper surface after removing the remaining cut portions from the glass rod group 35. A glass piece group having a 5 nm chromium thin film and a gold thin film having a thickness of about 55 nm formed thereon, 36 a is an upper surface of the glass piece group 36 on which a metal thin film comprising the chromium thin film and the gold thin film formed thereon is formed; Reference numeral 36 b denotes a lower surface of the glass piece group 36.

  The glass 30 shown in FIG. 8A is, for example, a glass having a thickness of 2 mm, and its upper surface 30a and lower surface 30b are polished to an optical surface. This optical surface is an optical surface of at least λ / 4 level where λ is the wavelength of incident light used for SPR. Such a plate glass 30 is a commercially available product and can be obtained at low cost.

  The glass 30 is cut into glass rods 31a to 31f having a predetermined width as shown in FIG. FIG. 8C illustrates the cut glass rod 31f, and the upper surface 31fa (a part of the upper surface 30a) and the lower surface 31fb (a part of the lower surface 30b) have a λ / 4 level or more as described above. The surface that is an optical surface and faces the side surface 31fc is a cut surface (the surface cut in FIG. 8C).

  Next, the glass rods 31a to 31f cut in FIG. 8B are rotated by 90 °, and the optical surfaces of adjacent glass rods are brought into contact with each other as shown in FIG. 8D. As shown in FIG. 9E, at least one of the upper and lower surfaces (for example, the upper surface 33a) is polished into an optical surface of at least λ / 4 level as shown in FIG. 9E. .

  Next, the glass rod group 34 is formed into glass pieces such as glass pieces 31e1 to 31e3 and 31f1 to 31f3 having predetermined dimensions as shown in FIG. 9F.

  By forming these glass pieces into a rectangular parallelepiped or cube formed as three continuous surfaces of the entrance surface, the sample holding surface and the exit surface, it can be easily incorporated into the SPR sensor of the present invention and can be used for measurement. It can be greatly reduced. In addition to a rectangular parallelepiped and a cube, the shape in a cross section that includes the optical path and is perpendicular to the sample holding surface is a polygon that is equal to or greater than a quadrangle, so that it is easy to handle and the cost can be reduced. Further, forming the ridge portion of the rectangular parallelepiped or the cube into a tapered shape or a curved surface has an advantage that it becomes easier to handle. In the present invention, these shapes are also formed as three surfaces in which the incident surface, the sample holding surface, and the output surface are continuous. It is included in rectangular parallelepipeds and cubes.

  FIG. 9G shows the one glass piece 31f1. The upper surface 31fd0, the side surface 31fa, and the side surface 31fb are optical surfaces polished to at least a λ / 4 level.

  The cut glass residue of FIG. 9 (F) is removed, and the cleaned glass piece is placed in a state where the cut residue of FIG. 9 (F) is removed again, and a vacuum deposition apparatus is used, for example, by a method such as sputtering or ion-assisted vapor deposition. In the glass piece group of FIG. 9H, a chromium thin film having a thickness of about 5 nm is formed on the upper surface of each glass piece, and then a gold thin film having a thickness of about 55 nm is formed thereon.

  Although formation of the sample holding surfaces 6a to 6c is not shown, for example, the entire surface of the sample holding surface 6 is covered with a mask in which only the portion of the sample holding surface 6a is an opening, and the sample holding surface 6a is covered from above the mask. The first type influenza antibody as an example of the substance that interacts with the measurement object to be held is applied, and then the sample holding surface 6 is masked with only the sample holding surface 6c being an opening. It can be formed by applying a second type of influenza antibody as an example of a substance that covers the entire surface and is held on the sample holding surface 6c from above the mask and interacts with the measurement target.

  Each glass piece of the glass piece group 36 of FIG. 9H becomes the sample holding substrate 3 to be measured shown in FIG. 2, and the upper surface 36 a on which the metal thin film is formed constitutes the sample holding surface 6.

  Although the frame part 2 described with reference to FIGS. 3 to 7 can be manufactured by cutting, it can be manufactured by an integral molding technique by molding using plastic as a material, and the manufacturing cost can be extremely reduced.

  The manufacturing cost of the prismless SPR sensor 1 of the present invention having such a configuration is extremely low, and can be economically realized as a disposable sensor, and its practical effect is extremely large. Moreover, as can be seen from the configuration, even a user who does not have advanced knowledge of SPR can learn a simple operation method necessary for use in a short time, and is inexpensive with a small and simple configuration as described later. The refractometer of the present invention can easily detect an antigen or the like anywhere.

  Although the sample holding surface 6 of the sample holding substrate 3 to be measured has three sample holding surfaces 6a to 6c, for example, two types of antigens of influenza A type and influenza B type can be detected, the present invention has been described. The number of sample holding surfaces in is not limited to this and can be further increased.

  Next, as an example of the present invention, the prismless SPR sensor 1 of FIG. 1 created as described above can be used to measure the refractive index of the sample or a change in the refractive index with high accuracy using the SPR. The refractive index measuring device will be described.

  FIG. 10 and FIG. 11 show examples of the present invention that can measure the refractive index of the sample or changes in the refractive index with high accuracy using the SPR using the prismless SPR sensor 1 as an example of the present invention. FIG. 10 is a diagram illustrating a model using a cross section along the optical path as viewed from the side, and FIG. 11 is a diagram illustrating the model as viewed from above. Reference numeral 50 denotes a refractive index measuring device, 51 denotes a laser diode (hereinafter referred to as LD) as a light source, 52 and 52a to 52g denote a light beam emitted from the LD 51, 53 denotes a plano-convex lens of f30, and 54 denotes f15. A cylindrical lens 55, holes formed in the support frames 55 a and 55 b, 56 holes formed in the support frames 56 a and 56 b, and 57 a to 57 e, a code for explaining the reflected light beam reflected by the sample holding surface 6, 58 is a photodetection system using CMOS, 59 is a positioning pin, 60 is a plunger, and 70 is a normal line of the metal thin film at the total reflection point.

  By using a linear sensor or a two-dimensional optical sensor for the light detection unit, the incident angle in the measurement by the intensity method using the SPR phenomenon is, for example, 70 ° ± 2 ° when the measurement object is mainly water. In addition, it is possible to eliminate the movable parts on the light source side and the light receiving unit side related to changing within a range of ± 2 ° centering on 70 °.

  For example, in FIG. 10, the light beam emitted from the light source LD51 is converted into a parallel beam having the width indicated by reference numerals 52b and 52c by the lens 53, and the light beam having the incident angle indicated by reference numeral 52a by the lens 54 is θ. FIG. 11 shows a beam including a beam having an incident angle of θ + Δθ indicated by 52d and a beam having an incident angle of θ−Δθ indicated by reference numeral 52e, that is, a beam having an incident angle of θ ± Δθ. The light is incident on the back surfaces of the sample holding surfaces 6a to 6c as parallel beams having the widths indicated by 52f and 52g to cause the SPR phenomenon, and the reflected light is detected by a light detection system 58 using a CMOS arranged two-dimensionally. The reflectance for the measurement light having different incident angles can be detected in correspondence with the detection position in the light detection unit of the light detection system. That is, the movable part for changing the incident angle within the range of θ ± Δθ can be eliminated in the refractive index measuring device of FIGS. This leads to further downsizing and cost reduction of the measuring instrument.

  The positioning pin 59 and the plunger 60 can change the relative position of the sample to be measured with respect to the incident light beam 52a.

  In FIG. 10, the light beam 52 emitted from the LD 51 is focused by the lenses 53 and 54 around the beam 52 a indicated by the arrow, and the holes 55 are condensed by the lenses 53 and 54. As described above, the light enters from the incident surface 11a which is the side surface of the sample holding substrate 3 and enters the sample holding surface 6 of the prismless SPR sensor 1 of the present invention, and the metal thin film, the sample to be measured, and the SPR on the sample holding surface 6 A phenomenon occurs, and the reflected light beam is emitted from the incident surface 11c which is the side surface of the sample holding substrate 3 to be measured, passes through the hole 56, and is detected by the light detection system 58 as indicated by reference numerals 57a to 57c. A CMOS image sensor is used as the light detection sensor of the light detection system 58.

  In addition, many light sources, such as LED (light emitting diode) and another white light source, can be used instead of LD51. By using the LD as the light source, the measurement resolution can be increased. In addition, by using the LED, the measuring device can be made smaller and less expensive.

  The plano-convex lens 53 is not limited to this, and any lens that can convert the incident light beam into a parallel beam may be used.

  The photodetection system 58 using CMOS has at least a photodetection unit. The photodetection unit may use a linear sensor such as a CCD or PD (photodiode) array or a two-dimensional photosensor in addition to the CMOS.

  Further description will be made with reference to FIG. 11. The incident light beam emitted from the LD 51 is a light beam having a rectangular cross section of 5 × 2 mm at the position indicated by reference numeral 61. The measurement line at the position indicated by reference numeral 62 is linear.

  One of the most important features of the refractive index measuring device of the present invention using the prismless SPR sensor 1 of the present invention having such a configuration is that the incident light at the time of SPR measurement is directed toward the sample holding surface to be measured. In the measurement of the SPR intensity method as described with reference to FIGS. 10 and 11, the incident light is incident from one of the side surfaces 11 a and 11 c of the glass substrate 11 of the holding substrate 3 and the reflected light is emitted from the other. In order to make incident light incident on a glass substrate on which a metal thin film as a sample holding substrate to be measured is formed, which has been indispensable in the past, and to guide the reflected light from the metal thin film to a detector, a cylindrical or It is not necessary to provide prisms such as triangular prisms and refractive index matching oil between the prism and the sample holding surface, and it is possible to provide an extremely small, easy to handle, and inexpensive refractive index measuring instrument. It is.

  The refractive index measuring instrument of the above example can be housed in a case with a size of 5 cm or less in one piece, can be operated with a DC power source of 5 V (5 volts) or less, and the power source can be a battery.

  FIGS. 12 and 13 show examples of measurement data measured using the prismless SPR sensor 1 of the present invention and the refractive index measuring device of the present invention, and reflection using a detector having a two-dimensionally arranged CMOS sensor. As shown in the figure, the measurement result of the light intensity is three-dimensionally with the incident angle of the measurement light on the horizontal axis, the reflectance on the vertical axis, and the sensor width (position in the width direction of the sensor) in the oblique depth direction. It is a represented graph.

  Graph A has a type A reactant immobilized on the metal surface as a reactant, Graph B has a type B reactant immobilized on the metal surface as a reactant, and Graph N has no metal surface as a reactant. 12 is a graph of the SPR in the case of not being fixed to FIG. 12. FIG. 12 shows only water that does not contain the substance that reacts with the reactant A and the substance that reacts with the reactant B in the hole 4 of the prismless SPR sensor 1. FIG. 13 shows data when mucus of a person who seems to have a cold or flu is put in the hole 4 of the prismless SPR sensor 1. As can be seen from the data, the peak positions of graphs A, N, and B are aligned in a straight line in FIG. 12, and only the peak position of graph A is shifted to the right from the peak positions of graphs N and B in FIG. Yes. This means that the SPR resonance angle at the peak position of the graph A is different from the SPR resonance angle at the peak positions of the graphs N and B. From this, it reacts to the mucus placed in the hole 4 of the prismless SPR sensor 1. It can be seen that the substance A does not contain the substance that reacts with the reactant B but contains the reacting substance.

  As described above, the embodiment of the present invention has been described mainly with reference to the drawings. However, the present invention is not limited to this, and many variations are possible from the above description. It is also obvious.

  For example, the frame body 2 and the measured sample holding substrate 3 can be formed integrally.

  Further, as the metal thin film, a thin layer of chromium is formed on a substrate by sputtering or vapor deposition, and a thin gold layer is formed thereon by sputtering or vapor deposition to be used as a stable metal thin film. However, silver can be used as a means for improving detection efficiency. Moreover, although the example which forms the thin layer of chromium in order to improve adhesiveness between gold | metal | money or silver and a board | substrate was demonstrated, nickel, nickel, and chromium can also be used.

  In addition, as an example of the prismless SPR sensor as an embodiment of the present invention, a metal thin film on which an antibody is placed is arranged at the bottom of the hole 4, and the measurement object is placed in the hole 4. As an example, the type of measuring the change in the dielectric constant on the metal thin film due to the reaction with the above has been described. However, the structure of the hole 4 may be a flow type in which the measurement object flows. Also in this case, the above-described effects of the present invention can be exhibited.

  As described above, a large amount of specimens can be obtained in real time when a new influenza or the like may occur and become a serious social problem using the prismless SPR sensor of the present invention and a refractive index measuring device using the prismless SPR sensor. It is easy to measure at a low price, and can take appropriate measures as soon as possible. It is.

  Furthermore, the prismless SPR sensor of the present invention and the refractometer using the same can be used not only for measurement of antigens such as influenza but also for the measurement of refractive index widely, and can exhibit the same effect. The present invention can be used in a wide range of industrial fields such as the optical field, and can exert a remarkable effect, thus making a great contribution to the industry.

It is a perspective view of a prismless SPR sensor as an embodiment of the present invention. It is a perspective view explaining the to-be-measured sample holding substrate 3 of FIG. It is a top view of the frame part 2 which comprises the prismless SPR sensor as an example of embodiment of this invention. It is sectional drawing in the position of Y1-Y2 of the frame part 2 of FIG. It is sectional drawing in the position of X1-X2 of the frame part 2 of FIG. It is a side view of the frame part 2 of FIG. It is a side view of the frame part 2 of FIG. It is a perspective view explaining the example of the manufacturing method of the to-be-measured sample holding substrate 3 of FIG. It is a perspective view explaining the example of the manufacturing method of the to-be-measured sample holding substrate 3 of FIG. It is a figure explaining the refractive index measuring device as an example of an embodiment of the invention. It is a figure explaining the refractive index measuring device as an example of an embodiment of the invention. It is an example of the measurement data measured using the prismless SPR sensor 1 and refractive index measuring device of this invention. It is an example of the measurement data measured using the prismless SPR sensor 1 and refractive index measuring device of this invention. It is a figure explaining the example of the conventional SPR sensor. It is a figure explaining the SPR measuring method using the conventional SPR sensor.

Explanation of symbols

1: prismless SPR sensor 2: frame 2a: substrate 2 of frame 2 2a1-2a4: side surface of frame 2 2a5: upper surface of frame 2 2a6: lower surface of frame 2 3: measured sample holding substrate 4: hole 5: Slope of hole 6, 6a to 6c: Sample holding surface 7: Through hole 11: Substrate 11a to 11d: Side surface of substrate to be measured 12, 13, 102: Metal thin film 21, 22, 23, 24: V-shaped groove 30: Glass plate 30a: Upper surface of glass plate 30b: Lower surface of glass plate 30 31a to 31f: Glass rod 31aa, 31ba, 31ca, 31da, 31ea, 31fa: Upper surface of glass rod 31ab, 31bb, 31cb, 31db, 31eb, 31fb: lower surface of the glass rod 31e1-31e3, 31f1-31f3: glass pieces 31e4, 31f4, 32: remainder of cutting 31fc: Side surface of glass rod 31f 31fd: Cut surface 31fd0: Cut surface polished to optical surface 33, 34, 35: Glass rod group 33a: Upper surface of glass rod group 33 33b: Lower surface of glass rod group 33 36: Glass piece Group 36a: Upper surface of glass piece group 36b: Lower surface of glass piece group 50: Refractive index measuring instrument 51, 110: Laser diode 52, 52a to 52g: Reference numerals 53, 54, 111 for explaining light beams emitted from the laser diode , 120: lenses 55, 56: holes opened in the support frame 57a to 57e: reference numerals for explaining reflected light 58: light detection system 59: positioning pin 60: plunger 70: normal line of the metal thin film at the total reflection point DESCRIPTION OF SYMBOLS 101: Prism 103: Planar microchannel 104: Syringe pump for liquid feeding 105: Quartz which formed the microchannel Glass substrate 107a: BK7 glass plate 107, 108: Tube for sample introduction / discharge 112: Single mode optical fiber 113: Collimator 121: P polarizer 122: CCD camera 123: Computer 130: Sensor chip 131: Light source means 132: Measuring means 134: Incident light 135: Reflected light 136: Incident angle 137: Refractive index matching oil L: Length of substrate 11 T: Thickness of substrate 11 W: Width of substrate 11 X1-X2, Y1 -Y2: code for explaining the position of the cross-sectional view of the frame 2

Claims (21)

A substance that interacts with the object to be measured or the object to be measured (hereinafter, a substance that interacts with the object to be measured or the object to be measured). A prismless SPR sensor that can be used to measure a refractive index of a sample to be measured) or a change in refractive index by an intensity method using a surface plasmon resonance (hereinafter referred to as SPR) phenomenon,
A substrate having a metal thin film brought into contact with the sample to be measured on its surface is called a sample holding substrate to be measured.
The prismless SPR sensor has a frame portion having at least one hole and a measured sample holding substrate at the bottom of at least one hole of the frame portion,
In the sample holding substrate to be measured, at least a pair of metal thin films are formed on at least a part of the surface on the side of forming the bottom of the hole of the frame portion as the upper surface of the substrate, and there is a translucent portion. A substrate protruding from the frame portion to the opposite side of the upper surface of the substrate as a protruding portion having opposite side surfaces of
The sample holding substrate to be measured has an incident surface that allows a light beam having a predetermined wavelength (hereinafter referred to as measurement light) to enter the metal thin film through the inside of the substrate near a resonance angle. An emission surface on one side of the opposite side surfaces of the substrate and further capable of emitting a measurement light beam totally reflected by the metal thin film on the other side surface of the pair of opposite side surfaces of the substrate. And
The cross-sectional shape perpendicular to the surface (hereinafter referred to as the sample holding surface) that includes the optical path of the measurement light of the sample holding substrate to be measured and on which the metal thin film is formed is a quadrilateral or more polygon.
Further, the sample holding substrate to be measured is formed such that at least the sample holding surface, the incident surface, and the exit surface are optical surface grade surfaces.
The prismless SPR sensor uses the prismless SPR sensor to measure the refractive index of the sample to be measured or the change in refractive index using the SPR phenomenon, and the measurement light source and the sample holding substrate to be measured. From the incident surface of the sample holding substrate to be measured without arranging a substance for adjusting the refractive index such as matching oil and a prism in close contact with the prismless SPR sensor in the optical path of the measurement light beam between the incident surfaces of A measurement light beam is incident to cause an SPR phenomenon in the metal thin film portion, and the intensity of the measurement light beam that is totally reflected by the metal thin film and exits from the exit surface is brought into close contact with the prismless SPR sensor, and matching oil or the like A sample to be measured in contact with the metal thin film by measuring without interposing a prism and a substance that adjusts the refractive index of Prism-less SPR sensor, which is a prism-less SPR sensor which can be used to measure changes in refractive index or refractive index.   2. The prismless SPR sensor according to claim 1, wherein the frame portion and the measured sample holding substrate are integrally formed.   2. The prismless SPR sensor according to claim 1, wherein the frame portion and the measured sample holding substrate are formed as independent parts.   4. The prismless SPR sensor according to claim 1, wherein the incident surface at the incident point of the measurement light beam and the emission surface at the emission point of the measurement light beam are planes parallel to each other. Characteristic prismless SPR sensor.   The prismless SPR sensor according to any one of claims 1 to 4, wherein the hole of the frame body has an oval opening.   The prismless SPR sensor according to any one of claims 3 to 5, wherein the substrate and the frame can be assembled in a detachable manner.   The prismless SPR sensor according to any one of claims 3 to 6, wherein the sample holding substrate to be measured is a polyhedron of hexahedron or more having three surfaces of the incident surface, the emitting surface, and the sample holding surface, which are optically polished. A prismless SPR sensor characterized by being.   8. The prismless SPR sensor according to claim 7, wherein the polyhedron is a rectangular parallelepiped and forms three surfaces in which the entrance surface, the exit surface, and the sample holding surface are continuous.   8. The prismless SPR sensor according to claim 7, wherein the polyhedron is a cube, and the entrance surface, the exit surface, and the sample holding surface are formed on three continuous surfaces.   The prismless SPR sensor according to any one of claims 3 to 9, wherein a material of the sample holding substrate to be measured is glass, and at least three surfaces of the incident surface, the exit surface, and the sample holding surface are at least measuring light. A prismless SPR sensor, which is optically polished to a quarter wavelength level.   11. The prismless SPR sensor according to claim 10, wherein the substrate is a small piece of glass that is cut out from a parallel plate glass plate that has been polished at least a quarter wavelength level, and at least one of the cut surfaces is optically polished. A prismless SPR sensor characterized by being.   The prismless SPR sensor according to any one of claims 1 to 11, wherein the sample holding substrate to be measured is measured by expressing an incident angle as an angle with respect to a normal line of the metal thin film at the total reflection point. A prismless SPR sensor, which is a substrate on which a light beam can be made incident at an acute incident angle near 70 °.   The prismless SPR sensor according to any one of claims 1 to 12, wherein the sample holding substrate to be measured is θ ± Δθ in the metal thin film portion, where the incident angle is θ and the deviation from θ is Δθ. A prismless SPR sensor, which is a substrate on which a measurement light beam including an incident light beam having an incident angle in a range can be incident.   The prismless SPR sensor according to any one of claims 1 to 13, wherein the metal of the metal thin film is chromium formed after chromium and chromium are formed.   The prismless SPR sensor according to any one of claims 1 to 14, wherein the prismless SPR sensor is a sensor capable of detecting the presence or absence of an antigen.   The prismless SPR sensor according to claim 15, wherein the antigen to be detected is an influenza antigen.   The prismless SPR sensor according to any one of claims 1 to 16, wherein each antibody holding unit holds at least two types of antibodies on a metal thin film formed on a sample holding surface of the sample holding substrate to be measured. A prismless SPR sensor, wherein a portion and a blank portion (portions into which nothing is to be measured) are arranged.   The prismless SPR sensor according to any one of claims 1 to 17, wherein the prismless SPR sensor is a disposable sensor. In the following, a refractive index or a measuring device that can measure the refractive index is referred to as a refractive index measuring device, and a prismless SPR sensor is provided with a substance that adjusts the refractive index, such as a prism and matching oil, in the optical path. Surface plasmon resonance is the refractive index of a measurement object or a substance that interacts with the measurement object (hereinafter, the measurement object or a substance that interacts with the measurement object is referred to as a sample to be measured). A refractive index measuring instrument capable of measuring by an intensity method using a phenomenon (hereinafter referred to as SPR),
A substrate having a metal thin film on the surface on which a sample to be measured can be mounted is referred to as a sample holding substrate to be measured.
The prismless SPR sensor has a frame portion having at least one hole and a measured sample holding substrate at the bottom of at least one hole of the frame portion,
In the sample holding substrate to be measured, at least a pair of metal thin films are formed on at least a part of the surface on the side of forming the bottom of the hole of the frame portion as the upper surface of the substrate, and there is a translucent portion. A substrate protruding from the frame portion to the opposite side of the upper surface of the substrate as a protruding portion having opposite side surfaces of
The measurement sample holding substrate has an incident surface through which the light beam having a predetermined wavelength (hereinafter referred to as measurement light) can enter the metal thin film near the resonance angle. An emission surface on one side of the opposite side surfaces of the substrate and further capable of emitting a measurement light beam totally reflected by the metal thin film on the other side surface of the pair of opposite side surfaces of the substrate. And
The cross-sectional shape perpendicular to the surface (hereinafter referred to as the sample holding surface) that includes the optical path of the measurement light of the sample holding substrate to be measured and on which the metal thin film is formed is a quadrilateral or more polygon.
Further, the sample holding substrate to be measured is formed such that at least the sample holding surface, the incident surface, and the exit surface are optical surface grade surfaces.
When the refractive index measuring device measures the refractive index of the sample to be measured or the change in the refractive index using the prismless SPR sensor and utilizing the SPR phenomenon, the light source of the measurement light and the sample holding substrate to be measured are measured. Measuring light from the incident surface of the sample holding substrate to be measured without interposing a substance for adjusting the refractive index such as matching oil and a prism in close contact with the prismless SPR sensor in the optical path of the measuring light between the incident surfaces. A beam is incident to cause an SPR phenomenon in the metal thin film portion, and a measurement light beam that is totally reflected by the metal thin film and exits from the exit surface is brought into close contact with the prismless SPR sensor to change the refractive index of matching oil or the like. Before measuring the intensity of the emitted light by receiving light with a two-dimensional sensor or linear sensor without arranging the substance to be adjusted and the prism Refractive index measuring device, characterized in that a measuring device capable of measuring changes in the refractive index or the refractive index of a measured sample in contact with the metal thin film.   The refractive index measuring instrument according to claim 19, wherein an incident angle is θ and a deviation from θ is Δθ, and a measurement light beam incident on the incident surface is incident on the metal thin film portion with an incident angle in a range of θ ± Δθ. A refractive index measuring instrument that is incident as a measurement light beam including an incident light beam.   21. The refractive index measuring device according to claim 19 or 20, further comprising a display unit for displaying based on a measurement result corresponding to a light detection intensity at a light detection position of the two-dimensional sensor or linear sensor. Refractive index measuring device characterized by that.

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