JP2010160087A - Optical waveguide type chemical sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compact and easily-handleable optical waveguide type chemical sensor measuring even a small amount of a sample highly accurately with high sensitivity. <P>SOLUTION: This optical waveguide type chemical sensor is provided with: an optical waveguide including a core layer 1 and two clad layers (2, 3) for sandwiching and covering the core layer 1; a light emitting means 5; and a light receiving means 6. One clad layer 3 is provided with an opening 3a for exposing a part of the core layer 1 as a detection part 4. In the detection part 4, at least either of a hole-shaped structure and a groove-shaped structure for increasing a surface area of the detection part 4 is bored (longitudinal hole 41) from an exposed surface of the core layer 1 toward the other clad layer 2, and the structure for increasing the surface area formed on the detection part 4 is used for sample arrangement. The light emitting means 5 has a function for irradiating emission light therefrom to a sample arranged in the structure through the core layer 1, and the light receiving means 6 has a function for measuring emission generated from the sample by irradiation. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an optical waveguide type chemical sensor capable of measuring the concentration of a biological substance, an environmental substance, etc. with high accuracy by measuring light emission from a detection region provided in a part of a waveguide core. is there.

  Conventionally, as a sensor that measures the concentration of substances contained in sample solutions and sample gases with high sensitivity, it measures optical changes such as absorption, scattering, reflection, refraction, fluorescence, and luminescence of the light irradiated on the sample. Biochemical sensors have been proposed.

  For example, as a biochemical sensor using a planar (planar) optical waveguide, a sample adsorbed on an adsorption film or the like is placed on the exposed surface of the core layer of the planar optical waveguide, and an external light source is connected via a grating or the like. While the measurement light is incident on the core layer and the evanescent wave is absorbed by the sample, or the evanescent wave is generated when the measurement light introduced into the core layer is reflected, or the sample A method for measuring the concentration of a biological substance, an environmental substance, or the like by analyzing a spectrum of fluorescence, phosphorescence, etc. generated from the light is disclosed (see, for example, Patent Documents 1 to 3).

  On the other hand, the fluorescence spectrum measurement used for the measurement of the concentration of biological substances, environmental substances, etc. is performed using a 10 mm square cell (quartz cell etc.) mainly in the solution system, and excitation light (from one direction to the square cell ( Monochromatic light) is emitted, and the spectrum of emission light (fluorescence) emitted from the direction perpendicular to the optical axis of the excitation light is analyzed.

Japanese Patent Laid-Open No. 9-61346 JP 2004-43120 A JP 2006-85212 A

  However, the conventional biochemical sensor using the optical waveguide as described above requires a large amount of the optical system on the light source side and the spectroscopic side, and uses a weak evanescent wave. In addition, there is a problem that it is difficult to stabilize and increase the sensitivity of the sensor.

  In addition, since the conventional fluorescence spectrum measurement uses a square cell, a certain amount of sample (at least about 2 to 3 ml or more in a solution state) is required, and the entire apparatus including the optical system becomes large. There is a tendency.

  In order to solve such problems, the present invention has been studied by the inventor, and as a result, when light transmitted through the core layer of the optical waveguide is irradiated onto the sample existing in the optical waveguide, the present invention is unique to the sample. The purpose of the present invention is to provide an optical waveguide type chemical sensor that can be measured with high sensitivity and high accuracy even with a small number of samples, and is compact and easy to handle.

  In order to achieve the above object, an optical waveguide type chemical sensor of the present invention comprises an optical waveguide structure comprising a core layer having a long shape in the optical path direction and two clad layers sandwiching and encapsulating the core layer, and a light emitting means. And an opening for exposing a part of the core layer as a detection part, and the detection part has a hole-like structure for increasing the surface area of the detection part. And at least one of the groove-like structures is drilled from the exposed surface of the core layer toward the other cladding layer, and at least one of the hole-like structure and groove-like structure formed in the detection section is a sample arrangement The light emitting means has a function of irradiating the emitted light to the sample disposed in the structure through the core layer, and the light receiving means emits light emitted from the sample by the irradiation. Adopt a configuration of having a constant functions.

  Note that the “hole structure” of the detection unit in the present invention means that each of the three-dimensional structures does not communicate in the vertical and horizontal directions when viewed from the upper surface (exposed surface) of the detection unit. This is a short configuration and includes all hole shapes regardless of the size, depth, opening shape, cross-sectional shape of the hole, and whether or not the bottom of the hole is penetrating / non-penetrating or having a bottom. The “groove-like structure” of the detection unit in the present invention is a relatively long shape in which each of the three-dimensional structures extends in the vertical and horizontal directions when viewed from the upper surface (exposed surface) of the detection unit. This refers to the formed structure, and includes all groove shapes regardless of the groove length, depth, opening shape, cross-sectional shape and communication method, and whether or not the bottom of the groove penetrates or does not penetrate. It is.

  The present invention relates to a chemical sensor or a biochemical sensor using an optical waveguide structure, in which a sample is sufficiently contained in a sample arrangement portion (detection unit) provided by exposing a part of the core layer of the optical waveguide. An intended shape is achieved by forming a concavo-convex shape that can be captured in the sample and irradiating the sample captured in the concavo-convex shape directly with measurement light through the core layer.

  That is, in the optical waveguide type chemical sensor of the present invention, an opening that exposes a part of the core layer as a detection portion is provided in one of the two clad layers that sandwich the core layer, and the other surface is exposed from the exposed surface of the core layer. To the cladding layer, at least one of a hole-like structure and a groove-like structure for increasing the surface area of the detection unit is drilled, a measurement sample is disposed therein, and the emitted light from the light emitting means is emitted. By adopting a configuration in which the sample in the structure is directly irradiated through the core layer, and the light emission generated from the sample is measured by the light receiving means, it is possible to perform highly sensitive and accurate measurement using direct light. Therefore, the optical waveguide type chemical sensor of the present invention can measure light emission with high sensitivity and high accuracy even with a small number of samples.

  In particular, in the present invention, even when the amount of the sample is small, the sample is fitted in the hole-shaped structure or the like, and the irradiated area (measurement target area) and measurement of the sample with respect to the measurement light irradiated through the core layer are measured. The number of times of contact with light can be increased. In addition, among a small number of samples, the amount of samples actually involved in the measurement (effective volume as a sensor) can be increased.

  Among them, in particular, the light emitting means is disposed at a position away from the detection unit in the optical path direction, is in contact with the outer surface of any one of the cladding layers, or instead of any one of the cladding layers, In the case where the light emitting system is formed so as to be in direct contact with the core layer, the sensor can be configured compactly because the light emitting system is integrally provided around the optical waveguide structure.

  Similarly, when the light receiving means is disposed on the outer surface of the other cladding layer adjacent to the detection unit, the light receiving system is integrally disposed around the optical waveguide structure, It can be configured compactly.

  Further, the optical waveguide sensor device in which the light emitting means and the light receiving means are integrally provided so as to be in contact with the optical waveguide structure can be configured compactly. The device does not require adjustment of the optical system on both the light emitting side and the light receiving side. Furthermore, this optical waveguide sensor device is highly general, and measurement can be performed at any place as long as a power supply device is supplied to the device. Therefore, the optical waveguide sensor device using the present invention can easily cope with not only the inside of a laboratory but also an urgent measurement in the field such as medical treatment or disaster.

  On the other hand, in the optical waveguide type chemical sensor, a sealing member is disposed in the opening of the one clad layer so that the detection unit is sealed before use, and peeled off during use to expose the detection unit. In this case, there is little possibility that impurities or the like enter the detection unit until just before using the sensor, and the detection unit can be kept clean. Therefore, in the optical waveguide type chemical sensor of the present invention, factors that reduce accuracy such as dust and impurities are eliminated as much as possible, and high measurement accuracy can be maintained over a long period of time.

It is a typical sectional view of the length direction which shows the composition of the optical waveguide type chemical sensor in a 1st embodiment of the present invention. It is the side view which looked at the optical waveguide type chemical sensor of Drawing 1 from the arrow X direction. (A)-(e) is a top view which shows the example of a shape of the "three-dimensional structure which increases a surface area" formed in the detection part of the optical waveguide type chemical sensor in 1st Embodiment. (A) is a typical sectional view of the length direction showing a modification of the optical waveguide type chemical sensor in the first embodiment of the present invention, and (b) is a top view of this optical waveguide type chemical sensor. It is a typical sectional view of the length direction which shows the composition of the optical waveguide type chemical sensor in a 2nd embodiment of the present invention.

  Next, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a schematic cross-sectional view in the length (longitudinal) direction showing the configuration of the optical waveguide type chemical sensor according to the first embodiment of the present invention, and FIG. 2 shows the optical waveguide type chemical sensor in FIG. FIG. 3 is a top view of the optical waveguide type chemical sensor of FIG. 1 viewed from the direction of arrow Z. In addition, the white arrow in each figure represents light transmission, and the black arrow represents light emission. 1 to 3 show the thickness of each member with emphasis, and omit illustrations of a control unit, a power supply unit, and the like for operating the sensor.

  The optical waveguide type chemical sensor in this embodiment is for measuring the fluorescence intensity or the fluorescence spectrum of a sample arranged in the detection region, such as a chemical substance, a biological substance, and an environmental substance. As shown in FIGS. 1 and 2, the chemical sensor of the present invention has a long strip shape in the optical axis (x-axis) direction, and includes a core layer 1 and two clad layers (an under clad layer 2 and an over clad). Sensor device comprising an optical waveguide formed of layer 3), a detection unit 4 formed in an end region in the length direction of the core layer 1, and a light emitting means (light source 5) and a light receiving means (light receiving element 6). It is configured as.

  In the detection unit 4, the upper surface of the over clad layer 3 is an exposed surface exposed to the outside, and this exposed surface is usually covered with a seal member 10 disposed in the opening 3a. It is protected until the sensor is first used. Further, the detection unit 4 includes “at least one of a hole-like structure and a groove-like structure for increasing the surface area of the detection unit” described later (hereinafter collectively referred to as “a three-dimensional structure for increasing the surface area”). Is formed from the upper surface toward the under cladding layer 2.

  In order to use this optical waveguide type chemical sensor, the seal member 10 is removed, the upper surface of the detection unit 4 is exposed, and the sample (usually liquid) is contained in the three-dimensional structure formed thereon to increase the surface area. Is injected using a dropper or the like. Next, light (excitation light) is emitted from the light source 5 to the core layer 1, and the light is irradiated onto the sample in the three-dimensional structure that increases the surface area. The light receiving element 6 emits light such as fluorescence emitted from the sample. By receiving the light and measuring the amount of received light, the spectrum, and the like, the component in the sample is specified.

  Next, the structure of the optical waveguide type chemical sensor in the present embodiment will be described in detail.

  The optical waveguide used in the present invention is obtained by laminating a core layer 1 made of a photosensitive resin on an undercladding layer 2 made of a resin using a photolithography technique. A resin over clad layer 3 is formed to sandwich and enclose the core layer 1. Further, another portion of the upper surface of the core layer 1 is exposed at a position away from the opening 3a for the detection unit 4 in the overcladding layer 3 in the optical path (optical axis of the core layer 1: x-axis) direction. An opening 3b is provided, and a light source 5 described later is formed in the opening 3b.

  A light receiving element 6 described later is disposed on the outer (lower) surface of the undercladding layer 2 adjacent to the detection unit 4, and the detection member 4 (vertical hole 41) is removed by removing the seal member 10. By irradiating the sample injected or filled with the light emitted from the light source 5 (excitation light) through the core layer 1, the sample is emitted in a direction perpendicular to the optical axis (x-axis) of the excitation light. Fluorescence can be measured.

  As described above, the feature of the optical waveguide type chemical sensor in the present embodiment is that the detection unit 4 formed by the opening 3a of the over clad layer 3 communicates with the opening 3a and the "4" That is, a “three-dimensional structure that increases the surface area” is formed. As a specific example of the “three-dimensional structure for increasing the surface area”, in the optical waveguide type chemical sensor of the present embodiment, the exposed surface (opening 3a) of the core layer 1 extends to the under cladding layer 2 as shown in FIG. A plurality of vertical holes 41, 41, ... are provided.

  Each of FIGS. 3A to 3E is a shape example of a three-dimensional structure (hole structure, groove structure) that increases the surface area formed in the detection unit 4 of the optical waveguide type chemical sensor in the first embodiment. FIG. In addition, in each figure of FIG. 3, in order to make it easy to see the shape of the three-dimensional structure which increases these surface areas, illustration of the sealing member 10 which covers the detection part 4 is abbreviate | omitted.

  Each vertical hole 41 of the detection unit 4 has a simple vertical hole shape when viewed from the sensor side surface (y-axis direction) as shown in FIG. 1, but when viewed from the upper surface (z-axis direction), As shown in 3 (a) to (e), various shapes can be used. For example, as shown in FIG. 3A, these vertical holes 41A may be a “groove-like structure” that is continuous in a direction (y-axis direction) perpendicular to the optical axis (x-axis) direction of the core layer 1. As shown in FIG. 3B, the vertical wall surface of each vertical hole 41B may be formed in a corrugated shape in order to further increase the surface area of the groove-like structure.

  3A and 3B, the vertical holes 41A and 41B constituting these groove-like structures reach the surface of the under cladding layer 2 from the upper surface (exposed surface) of the detection unit 4. However, these vertical holes 41A and 41B may be formed to such a depth as to leave a part of the core layer 1 at the bottom.

  Further, when these vertical holes 41 are “hole-shaped structures” in which intermittent hole rows are formed in a direction (y-axis direction) orthogonal to the optical axis direction of the core layer 1, for example, FIG. ) Or a columnar vertical hole 41D having a circular cross section as shown in FIG. 3D, or a prismatic vertical hole 41D having a polygonal cross section as shown in FIG. Furthermore, when the hole-like structure by the intermittent vertical holes 41 forms a matrix, the measurement light is uniformly irradiated to each of the vertical holes 41E as shown in FIG. In addition, the phases of the adjacent vertical holes 41E with respect to the optical axis (x axis) may be staggered for each hole row (staggered lattice).

  As with the above-mentioned “groove-like structure”, each of the vertical holes 41C, D, E constituting these hole-like structures may be formed to a depth that leaves a part of the core layer 1 at the bottom. Good. Further, only one of the groove-like structure and the hole-like structure of the detection unit 4 may be formed, or these may be used together to form the detection unit 4 at the same time. Furthermore, the shape and depth of each of the vertical holes 41 (including 41A to 41E) can be freely set in a range that does not penetrate the under cladding layer 2 toward the light receiving element 6 according to the target sample. Can do.

  Further, as in the modification of the first embodiment shown in FIG. 4, the detection unit 4 may have a single large hole shape. However, the shape of the detection unit 4 requires a larger amount of sample than the above-described optical waveguide type chemical sensor having a hole-like structure or a groove-like structure.

  And the method of forming the detection part 4 which has these groove-like structure or hole-like structure is not specifically limited, However, When forming the core layer 1 using the lithography method, it draws in the mask pattern beforehand. It can be created simultaneously with the formation of the optical waveguide. When forming by post-processing, fine processing by etching, laser, or the like may be used depending on the material of the core layer 1.

  Furthermore, as the optical waveguide used in the present embodiment, a polymer-based optical waveguide that is lightweight and easy to finely process using photolithography is preferable. Examples of the material for forming the clad layers 2 and 3 include epoxy resin, polyimide resin, acrylic resin, photopolymerizable resin, and photosensitive resin. Among these, an epoxy resin is preferable from the viewpoint of transparency, heat resistance, and moisture resistance, and a mixed resin of a fluorein type epoxy resin and an alicyclic epoxy resin is particularly preferable.

  Moreover, as a forming material of the core layer 1, usually, a photopolymerizable resin made of an epoxy resin, a polyimide resin, an acrylic resin or the like can be mentioned, and among them, from the viewpoint of satisfying all of transparency, heat resistance, and moisture resistance. A mixed resin of a fluorein epoxy resin and an oxetane compound can be preferably used.

  Next, another feature of the optical waveguide type chemical sensor according to the present embodiment, which is a light emitting means (light source 5) and a light receiving means (light receiving element 6), will be described.

  As described above, the light source 5 is spaced apart from the detection unit 4 in the over clad layer 3 in the optical path (optical axis: x-axis) direction separately from the opening 3 a for the detection unit 4. It is disposed in the opening 3b provided at the position, and is configured integrally with the optical waveguide structure. As a light emitting element of the light source 5, a light emitting diode such as an LED (Light Emitting Diode) or an OLED (Organic Light Emitting Diode), a laser diode or a VCSEL (Vertical Cavity Surface Emitting Laser) or the like is a vertical cavity surface emitting laser. It can be used suitably.

  In particular, since the OLED can be formed in contact with the core layer 1 in the opening 3b of the over clad layer 3 provided for the light source 5, alignment of the light emitting element is unnecessary (alignment-free). This is preferable.

  Further, the light receiving element 6 is disposed on the outer (lower side in the drawing) surface of the under cladding layer 2 adjacent to the detection unit 4, and from the sample disposed in the “structure for increasing the surface area” of the detection unit 4. The fluorescent light emitted in the direction orthogonal to the optical axis (x-axis) of the excitation light is positioned at a position where it can be measured efficiently. As the type of the light receiving element 6, an inorganic or organic photodiode or the like is used.

  In particular, the organic photodiode can be formed in contact with the under-cladding layer 2 and is therefore preferable because alignment of the light receiving element is unnecessary (alignment free).

  With the above configuration, the optical waveguide type chemical sensor in the present embodiment can measure the fluorescence intensity or the fluorescence spectrum emitted from the target sample efficiently, with high sensitivity and high accuracy, even with a small number of samples.

  Further, since the light guide type chemical sensor is provided integrally with the light source 5 and the light receiving element 6 so as to come into contact with the light guide structure, the entire apparatus can be configured compactly. There is no need to adjust the optical system on both the light emitting side and the light receiving side. Therefore, the optical waveguide type chemical sensor according to the present embodiment has high generality, and measurement can be performed under various environments as long as a power supply device that supplies the device is prepared.

Next, a second embodiment of the present invention will be described.
FIG. 5 is a schematic cross-sectional view in the length (longitudinal) direction showing the configuration of the optical waveguide type chemical sensor according to the second embodiment of the present invention. The side view (end face) of the optical waveguide type chemical sensor according to this embodiment viewed from the X direction is the same as FIG. 2 of the first embodiment, and the “three-dimensional structure for increasing the surface area” formed on the detection unit 4. The example of the shape is also the same as the respective drawings in FIG. 3 of the first embodiment, and the illustration thereof is omitted. Moreover, the same code | symbol is attached | subjected to the structural member which has the same function as 1st Embodiment, and the detailed description is abbreviate | omitted.

  The optical waveguide type chemical sensor according to the second embodiment differs from the first embodiment in that the width is intermittent in the depth direction (z-axis direction) of the detection unit 4 exposed by the opening 3a of the over clad layer 3. .., A three-dimensional structure that increases the surface area of the concavo-convex shape (corrugated shape) that changes with time, is formed. An optical path conversion structure (45 ° micromirror 7) for converting the optical path of the excitation light emitted from the light source 5 is formed in a predetermined region of the core layer 1 corresponding to the lower side (lower side in the drawing) of the light source 5. Has been.

  With the configuration described above, the optical waveguide type chemical sensor according to the present embodiment has a core layer that is further further than the optical waveguide type chemical sensor according to the first embodiment due to the vertical holes 42 whose width changes intermittently in the depth direction. The irradiation area (measurement target area) of the sample with respect to the excitation light irradiated through 1 increases, and the amount of the sample actually involved in the measurement (effective volume as a sensor) increases.

  In addition, the total reflection of the micromirror 7 formed below the light source 5 suppresses light leaking from the core layer 1 so that the sample can be directly irradiated with excitation light having a higher light quantity. Therefore, the optical waveguide type chemical sensor of this embodiment can measure the fluorescence with high sensitivity and high accuracy even with a small number of samples.

  In addition, the groove-like structure or the hole-like structure of the detection unit 4 may be formed in either one of them as in the first embodiment described above or may be formed in the detection unit 4 at the same time by using these together. May be. The shape and depth of each vertical hole 42 can be freely set in a range not penetrating the under cladding layer 2 to the light receiving element 6 side according to the target sample (see FIG. 3).

  In addition, the method for forming the detection unit 4 having each of the vertical holes 42 is not particularly limited, but the lithography method as in the first embodiment cannot be used. Therefore, depending on the material of the core layer 1, etching, laser, etc. It is sufficient to use the fine processing by.

  Furthermore, as a method of forming the micromirror 7, a method by lithography or laser processing may be used in addition to a general dicing method.

  Next, examples of the present invention will be described. However, the present invention is not limited to this embodiment.

  A film having an optical waveguide structure was produced as follows.

First, a clad layer forming material and a core layer forming material were prepared.
[Clad layer forming material]
Component A: 83 parts by weight of bisphenoxyethanol fluoreneglycidyl ether which is a fluorene derivative Component B: 3 ′, 4′-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate which is an alicyclic epoxy resin as a diluent (Daicel) 17 parts by weight of component C: 4,4′-bis [di (β-hydroxyethoxy) phenylsulfinio] phenyl sulfide-bis-hexafluoroantimonate 50% propionate carbonate solution (photoacid) Generating agent) 1 part by weight By mixing the above components A, B, and C, materials for forming the under cladding layer 2 and the over cladding layer 3 were prepared.

[Material for forming the core layer]
Component A: 50 parts by weight of bisphenoxyethanol fluorenediglycidyl ether as a fluorene derivative Component D: 50 parts by weight of bisphenol fluorenediglycidyl ether as a fluorene derivative Component C: 4,4′-bis [di (β-hydroxyethoxy) phenylsulfur Finio] 50% propionate carbonate solution of phenyl sulfide-bis-hexafluoroantimonate (photoacid generator) 1 part by weight The above components A, B and C were mixed to prepare a material for forming the core layer 1.

  Next, a clad layer and a core layer were formed using the above forming material, and a film-like optical waveguide was produced.

[Preparation of underclad layer]
On the glass plate, the “cladding layer forming material” was applied by spin coating (1000 rpm: 15 sec) to form a coating layer. Then, the entire surface of the coating layer is irradiated with ultraviolet rays (mixed line: accumulated light quantity 1000 mJ / cm ² ) using an ultra-high pressure mercury lamp, and then heated at 120 ° C. for 30 minutes to form an under cladding layer 2 having a thickness of 30 μm. did.

[Production of core layer]
The above “core layer forming material” is applied to the upper surface of the undercladding layer 2 by a spin coating method (1500 rpm: 15 sec) and heated on a hot plate at 70 ° C. for 5 minutes to volatilize the solvent. A resin layer for formation was formed. The coating thickness of the core layer 1 is adjusted so that the film thickness becomes 50 μm after the solvent volatilization process. Next, the core layer shape and the photomask having a predetermined opening pattern having the shape of the detection unit 4 having the same “groove-like structure for increasing the surface area” as in the first embodiment (FIG. 3A) are used. Exposure was performed by irradiating with ultraviolet rays (i-line: accumulated light quantity 2000 mJ / cm ^{2 on a} 365 nm basis) using a high-pressure mercury lamp. And after heating for 10 minutes on a 70 degreeC hotplate further and completing reaction, it developed by using the 10 weight% aqueous solution of (gamma) -butyrolactone, and the unexposed part was melt | dissolved and removed. Then, the heat drying process for 120 degreeC x 10 minutes was performed, and the core layer 1 on the said under clad layer 2 was formed.

[Preparation of overclad layer]
On the upper surface of the core layer 1 on the under cladding layer 2, the above “cladding layer forming material” is applied by spin coating (1500 rpm: 15 sec) so as to cover the core layer 1, and a hot plate at 70 ° C. The solvent was volatilized by heating for 5 minutes above, and a resin layer for forming an overclad layer was formed. Next, ultraviolet rays (cross-link: integrated light quantity) are used using a super high pressure mercury lamp through a photomask having a predetermined opening pattern having an overcladding layer layer shape, an opening 3a shape for the detector 4 and an opening 3b shape for the light source 5. The exposure was performed by irradiating 2000 mJ / cm ² ). And after heating for 10 minutes on a 80 degreeC hotplate further and completing reaction, it developed using the 10 weight% aqueous solution of (gamma) -butyrolactone, and the unexposed part was melt | dissolved and removed. Thereafter, a heat drying treatment at 120 ° C. for 15 minutes was performed to form an over clad layer 3 (film thickness: 20 μm) on the core layer 1.

  The film-type optical waveguide obtained above was peeled from the glass plate to form the light-emitting element and the light-receiving element 6 of the light source 5, and the optical waveguide-type chemical sensor of the present invention was produced.

[Light emitting element]
As the light emitting element of the light source 5, an OLED composed of a transparent positive electrode, an organic compound layer, a metal cathode, or the like is used.

  As the transparent positive electrode, one having a light transmittance of 70% or more in a visible light region of 400 to 700 nm, such as tin oxide, indium tin oxide (ITO), and indium zinc oxide is used.

  The organic compound layer may have a single-layer structure composed only of a light emitting layer, or a laminated structure having a hole injection layer, a hole transport layer, an electron injection layer, an electron transport layer, a charge blocking intermediate layer, and the like. Also good. In this example, in particular, Alq3 (aluminum quinolinol complex) was used as the light emitting material of the light emitting layer.

  The metal cathode is made of an alkali metal such as Li or K having an excellent electron injection property and a low work function, an alkaline earth metal such as Mg or Ca, or a material such as Al or Ag which is not easily oxidized and is stable. desirable. In this example, LiF / Al was used in a stacked manner.

  The light-emitting element (light source 5) of this example formed using the above materials emits green light having a peak near 525 nm. In addition, since the OLED of this embodiment is formed in the opening 3b of the over clad layer 3 provided for the light source 5, it is not necessary to perform alignment (alignment) again.

[Light receiving element]
An organic photodiode is used as the light receiving element 6. In addition, about the constituent material which comprises a photodetection layer, a formation method, and a film thickness, the thing similar to a conventionally well-known organic photodiode is used.

  The photodetection layer is composed only of an organic thin film, and as an example of the element, like the light emitting element, a transparent positive electrode such as indium tin oxide (ITO), an organic compound layer, and a metal cathode such as LiF / Al. The light detection layer can be raised. In this example, a layered layer of CuPc (copper phthalocyanine) and C60 (60 fullerene) was used as the organic compound layer.

  The light receiving element 6 of this embodiment formed using the above materials has a high sensitivity region in the vicinity of 550 to 700 nm. Further, the light receiving element 6 of the present embodiment can be made unnecessary (alignment free) by being formed on the outer surface of the under-cladding layer 2 adjacent to the detector 4.

  The result of having performed fluorescence measurement of glucose and glutamic acid using the thus configured optical waveguide chemical sensor is shown.

[Reaction mechanism of glucose]
Glucose advances the following reaction in the presence of glucose oxidase.
β-D-glucose + O ₂ + H ₂ O →
D-glucono-1,5-lactone + H ₂ O ₂
Further, the generated H ₂ O ₂ generates a fluorescent substance Resolfin by FluoroH ₂ O ₂ (Detection reagent) containing peroxidase.
2H ₂ O ₂ + Detection reagent (non-fluorescent) → Resolfin
This Resolfin emits fluorescence of 590 to 600 nm by excitation light of 530 to 571 nm.

[Reaction mechanism of glutamic acid]
L-glutamate advances the following reaction in the presence of L-glutamate oxidase.
L-Glutamic acid + O ₂ + H ₂ O →
D-ketoglutamic acid + NH ₃ + H ₂ O ₂
Further, the generated H ₂ O ₂ generates a fluorescent substance Resolfin by FluoroH ₂ O ₂ (Detection reagent) containing peroxidase.
2H ₂ O ₂ + Detection reagent (non-fluorescent) → Resolfin
This Resolfin emits fluorescence of 590 to 600 nm by excitation light of 530 to 571 nm.

  In the optical waveguide type chemical sensor of the present embodiment, green light (excitation light) having a peak near 525 nm emitted from the light source 5 propagates in the core layer 1 in the optical axis (x-axis) direction, and the detection unit The sample (reaction solution) arranged in the “structure for increasing the surface area” 4 is directly irradiated. At this time, the fluorescence emitted from the Resolfin contained in the sample is incident on the light receiving element 6 disposed in a direction (z-axis direction) orthogonal to the optical axis, and is converted into a direct current by photoelectric conversion. Then, by measuring and recording the increase / decrease and absolute value of each current value (voltage value) for each wavelength by a separately provided control unit (not shown), the above-described quantitative or qualitative analysis of glucose or glutamic acid can be performed. It was possible to carry out with high sensitivity and high accuracy.

  The optical waveguide type chemical sensor of the present invention can be used not only for quantitative or qualitative analysis of glucose or glutamic acid but also for quantitative or qualitative analysis of a substance that emits fluorescence directly or indirectly with a reagent or the like.

  The optical waveguide type chemical sensor of the present invention can be used for various purposes in inspections where many samples such as biological substances and environmental chemical substances are difficult to obtain. Moreover, the optical waveguide type chemical sensor of the present invention can be used not only for measurement in a laboratory but also for simple measurement or quick measurement at a production site, a medical site, a disaster site or the like.

DESCRIPTION OF SYMBOLS 1 Core layer 2 Under clad layer 3 Over clad layer 4 Detection part 41 Vertical hole 5 Light source 6 Light receiving element

Claims (4)

  An optical waveguide structure comprising a core layer having a long shape in the optical path direction and two clad layers sandwiching and encapsulating the core layer, a light emitting means, and a light receiving means. One clad layer includes the core layer An opening that exposes a part of the detection part as a detection part is provided, and the detection part has at least one of a hole-like structure and a groove-like structure for increasing the surface area of the detection part from the exposed surface of the core layer to the other. At least one of a hole-like structure and a groove-like structure formed in the detection part is provided for sample placement, and the light emitting means transmits the emitted light to the core layer. An optical waveguide type chemical sensor having a function of irradiating a sample arranged in the structure through the light receiving means, and the light receiving means has a function of measuring luminescence generated from the sample by the irradiation.   The light emitting means is disposed at a position away from the detection unit in the optical path direction and is in contact with the outer surface of any one of the cladding layers, or directly on the core layer instead of any one of the cladding layers. The optical waveguide type chemical sensor according to claim 1, wherein the optical waveguide type chemical sensor is formed so as to come into contact with each other.   The optical waveguide type chemical sensor according to claim 1 or 2, wherein the light receiving means is disposed on an outer surface of the other cladding layer adjacent to the detection unit.   The opening of said one clad layer is provided with a sealing member that seals the detection part before use and can be peeled off during use to expose the detection part. The optical waveguide type chemical sensor according to one item.

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