JP2011185698A - Chip structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a chip structure used in a surface plasmon enhanced fluorescent device, capable of being configured to eliminate the need for a lens, and preventing the lowering of an S/N value caused by the lowering of condensing efficiency regardless of low cost. <P>SOLUTION: In the chip structure used in the surface plasmon enhanced fluorescent device having a metal membrane receiving the irradiation with exciting light on one side to be enhanced in electric field, the reaction part formed on the other side of the metal membrane to excite a fluorescent substance by the enhanced electric field, and a substrate comprising a fluorescence pervious base material and having a flow channel for sending a liquid using the reaction part as a base by joining the surface having a flow channel groove formed thereto to the surface of the metal membrane, the cavity groove surrounding the periphery of the reaction part to upwardly extend is provided to the substrate centering the reaction part and fluorescence can be reflected from the boundary surface of the cavity groove and the substrate. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a chip structure used in a surface plasmon enhanced fluorescence measuring apparatus based on the principle of surface plasmon excitation enhanced fluorescence spectroscopy (SPFS).

  Conventionally, based on the principle of surface plasmon excitation enhanced fluorescence spectroscopy (SPFS), for example, detection of extremely small analytes in a living body has been performed. Surface plasmon excitation-enhanced fluorescence spectroscopy (SPFS) is a method in which a rough wave (surface plasmon) is generated on the surface of a metal thin film under the condition that the laser light (excitation light) irradiated from a light source attenuates total reflection (ATR) on the surface of the metal thin film. ) To increase the photon amount of the laser light (excitation light) emitted from the light source by several tens to several hundreds times (electric field enhancement effect of surface plasmons), thereby improving the efficiency of the fluorescent material near the metal thin film. It is a method for detecting an extremely small amount and / or an extremely low concentration of analyte by exciting well.

  In recent years, development of a surface plasmon enhanced fluorescence measuring apparatus based on the principle of such surface plasmon excitation enhanced fluorescence spectroscopy (SPFS) has been promoted, and the technical disclosure thereof has been made in, for example, Patent Document 1 and Patent Document 2. Yes.

  Such a surface plasmon enhanced fluorescence measuring apparatus 10 has a basic structure as shown in FIG. 8 and has a chip structure in which a metal thin film 102 is provided on the surface of a dielectric member 106 and a reaction portion 104 is provided on the surface thereof. 108 is provided.

  The chip structure 108 includes a light source 112 that is incident on the dielectric member 106 and irradiates the excitation light b1 toward the metal thin film 102 on the dielectric member 106 side. The light receiving means 116 for receiving the metal thin film total reflection light b2 totally reflected in (1) is provided.

  On the other hand, on the reaction part 104 side of the chip structure 108, a light detection means 120 for receiving the fluorescence b3 emitted from the fluorescent substance labeled with the analyte captured by the reaction part 104 is provided.

  In addition, between the reaction part 104 and the light detection means 120, the condensing member 122 for condensing the fluorescence b3 efficiently and the light contained other than the fluorescence b3 are removed, and only the necessary fluorescence is selected. A filter 124 is provided.

  In using the surface plasmon enhanced fluorescence measuring apparatus 10, a primary antibody that specifically binds to an antigen contained in an analyte such as DNA to be detected is immobilized in advance on the surface of the metal thin film 102. . An analyte and a secondary antibody that specifically binds to the analyte are sequentially sent to the reaction part 104 in contact with the metal thin film 102, and the secondary antibody is captured by the reaction part 104. The secondary antibody captured together with the analyte is labeled with a fluorescent substance.

  The excitation light b1 is irradiated into the dielectric member 106 from the light source 112 to the fluorescent label of the reaction unit 104, and the excitation light b1 is incident on the metal thin film 102 at a specific angle (resonance angle) θ1. In this way, a dense wave (surface plasmon) is generated. In addition, when a close-packed wave (surface plasmon) is generated on the metal thin film 102, the excitation light b1 and the electronic vibration in the metal thin film 102 are coupled, resulting in a phenomenon that the light amount of the metal thin film total reflection light b2 is reduced.

  The light receiving means 116 and the light source 112 can be paired and rotated around the irradiation area of the metal thin film 102 to change the incident angle to the metal thin film 102. If the incident angle is changed and a point where the signal of the metal thin film total reflection light b2 received by the light receiving means 116 at that time changes (the amount of light decreases) is found, a resonance angle θ1 at which a dense wave (surface plasmon) occurs is obtained. be able to.

  Then, due to the phenomenon of generating the rough wave (surface plasmon), the fluorescent material in the reaction portion 104 on the metal thin film 102 is efficiently excited, and thereby the amount of fluorescent b3 emitted from the fluorescent material is increased.

  The increased fluorescence b3 is received by the light detection means 120 through the light collecting member 122 and the filter 124, so that an extremely small amount and / or extremely low concentration of the analyte can be detected.

  Thus, the surface plasmon enhanced fluorescence measurement device 10 is a high-sensitivity measurement sensor that enables observation of minute molecular activities, particularly between biomolecules.

Japanese Patent No. 3294605 JP 2008-102117 A

  However, in the conventional surface plasmon enhanced fluorescence apparatus 10 as described above, the enhanced fluorescence b3 is detected by the light detection means 120 using the light collecting member 122. A lens is usually used for such a light collecting member 122, but the lens is very expensive and focusing is very difficult.

  Further, in order to efficiently collect the fluorescence emitted from the fluorescent material in the reaction unit 104, it is desirable that the light collecting member 122 be close to the reaction unit 104. However, the chip structure 108 and the light collecting member 122 are different from each other. Since it is composed of parts, there is a limit naturally, and the condensing member 122 arranged at a distant position cannot secure sufficient condensing efficiency, and also has a problem that the value of S / N becomes low. It was a thing.

  In view of such a problem, the present invention makes it possible to make the lens an unnecessary configuration, and in spite of low cost, the light collection efficiency does not decrease and the S / N value does not decrease. It aims at providing the chip structure used for a fluorescence device.

  The above object is achieved by the invention described below.

1. A chip structure used in a surface plasmon enhanced fluorescence measuring device,
A metal thin film whose electric field is enhanced by irradiating one surface with excitation light;
A reaction part formed on the other surface side of the metal thin film, the reaction part exciting the fluorescent substance by the enhanced electric field;
And a substrate on which a flow path for sending liquid is formed with the reaction part as a bottom surface by joining the surface on which the channel groove is formed to the surface of the metal thin film. ,
The substrate is provided with a hollow groove extending around the periphery of the reaction portion and extending upward, and the fluorescence can be reflected at a boundary surface between the hollow groove and the substrate. Chip structure.

  2. 2. The chip structure according to 1 above, wherein the shape of the substrate surrounded by the hollow groove is a columnar shape or a truncated cone shape extending upward.

  3. 3. The chip structure according to 1 or 2, wherein the hollow groove does not penetrate the flow path.

  4). 4. The chip structure according to any one of 1 to 3, wherein a member made of another base material having a lower refractive index than the base material is inserted into the hollow groove.

  5. 5. The chip structure according to claim 1, wherein the base is a transparent resin, and the base is manufactured by molding.

6). A chip structure used in a surface plasmon enhanced fluorescence measuring device,
A metal thin film whose electric field is enhanced by irradiating one surface with excitation light;
A reaction part formed on the other surface side of the metal thin film, the reaction part exciting the fluorescent substance by the enhanced electric field;
And a substrate on which a flow path for sending liquid is formed with the reaction part as a bottom surface by joining the surface on which the channel groove is formed to the surface of the metal thin film. ,
The base body is provided with a hollow groove above the reaction part,
A cylindrical structure or a truncated cone-shaped condensing rod is inserted into the hollow groove, and the chip structure is capable of reflecting the fluorescence by a side wall of the condensing rod.

  7). 7. The chip structure according to 6, wherein the condensing rod is an optical fiber.

8). A chip structure used in a surface plasmon enhanced fluorescence measuring device,
A metal thin film whose electric field is enhanced by irradiating one surface with excitation light;
A reaction part formed on the other surface side of the metal thin film, the reaction part exciting the fluorescent substance by the enhanced electric field;
And a substrate on which a flow path for sending liquid is formed with the reaction part as a bottom surface by joining the surface on which the channel groove is formed to the surface of the metal thin film. ,
The base body is provided with a hollow groove above the reaction part,
A chip structure, wherein the surface of the substrate facing the hollow groove is mirror-finished.

  Provided chip structure for use in a surface plasmon-enhanced fluorescent device that allows a lens to have an unnecessary configuration and does not lower the light collection efficiency and reduce the S / N value despite the low cost. It becomes possible to do.

It is the schematic of the surface plasmon enhanced fluorescence measuring apparatus using a microchip liquid feeding system. 2A is a cross-sectional view around the microchip 14, and FIG. 2B is a top view of a part thereof. FIG. 4 is a schematic diagram showing a configuration of a chip structure 108. It is a schematic diagram which shows the structure of the chip structure 108 in 2nd Embodiment. It is a schematic diagram which shows the structure of the chip structure 108 in 3rd Embodiment. It is a schematic diagram which shows the structure of the chip structure 108 in 4th Embodiment. It is a schematic diagram which shows the structure of the chip structure 108 in 5th Embodiment. It is the schematic of the conventional surface plasmon enhanced fluorescence measuring apparatus.

  Although the present invention will be described based on an embodiment, the present invention is not limited to the embodiment.

  1 and 2 are schematic views of a surface plasmon enhanced fluorescence measuring apparatus using the microchip liquid feeding system according to the embodiment.

  Surface plasmon-enhanced fluorescence measurement device accurately detects the fluorescence generated by the excited fluorescent material by irradiating a metal thin film with excitation light to generate a rough wave (surface plasmon), and it is extremely accurate even if the detection sensitivity is increased. It is possible to detect fluorescence.

[Surface Plasmon Enhanced Fluorescence Measurement Apparatus 10 and Specimen Detection Method]
As shown in FIG. 1, the surface plasmon enhanced fluorescence measuring apparatus 10 of the present invention includes a chip structure 108 having a metal thin film 102, a reaction portion 104 formed on the surface of the metal thin film 102, and a base 142. ing. A dielectric member 106 is formed on one surface side of the metal thin film 102, and the reaction portion 104 is formed on the other surface side of the metal thin film 102.

  A resin is used as the base material used for the base. Examples of the resin include good moldability (transferability and releasability), high transparency, and low autofluorescence with respect to ultraviolet rays and visible light, but are not particularly limited. Absent. For example, polycarbonate, polymethyl methacrylate, polystyrene, polyacrylonitrile, polyvinyl chloride, polyethylene terephthalate, nylon 6, nylon 66, polyvinyl acetate, polyvinylidene chloride, polypropylene, polyisoprene, polyethylene, polydimethylsiloxane, cyclic polyolefin, etc. Used.

  Further, from the viewpoint of high refractive index, polycarbonate is more preferable.

  A channel groove is formed on one surface of the substrate 142, and the surface on which the channel groove is formed is bonded to the surface of the metal thin film 102 by applying an adhesive or heating and pressing for a predetermined time. As a result, the flow path 143 for feeding the liquid with the reaction unit 104 as the bottom surface is formed. The base body 142 is provided with a hollow groove h1 surrounding the reaction portion 104 and extending upward. Details of the hollow groove h1 will be described with reference to FIG. In addition, as a method for forming the base 142, injection molding using a mold is preferable from the viewpoint of cost.

  The chip structure 108 further includes a light source 112 that is incident on the dielectric member 106 and irradiates the excitation light b1 toward the metal thin film 102 on the dielectric member 106 side, and is further irradiated from the light source 112 to the metal thin film 102. Light receiving means 116 for receiving the totally reflected metal thin film totally reflected light b2 is provided.

  Here, the excitation light b1 emitted from the light source 112 is preferably laser light, and a gas laser or solid-state laser having a wavelength of 200 to 1000 nm and a semiconductor laser having a wavelength of 385 to 800 nm are preferable.

  On the other hand, on the reaction part 104 side of the chip structure 108, a light detection means 120 for receiving the fluorescence b3 generated in the reaction part 104 is provided.

  As the light detection means 120, it is preferable to use an ultrasensitive photomultiplier tube or a CCD image sensor capable of multipoint measurement.

  And between the reaction part 104 of the chip structure 108 and the light detection means 120, a light collecting member 122 for efficiently collecting light, and transmission of light having a wavelength different from the fluorescence b3 in the light. A filter 124 formed so as to reduce and selectively transmit the fluorescence b3 is provided.

In this embodiment, the light collecting member 122 can be omitted by causing the base body 142 provided with the hollow groove h1 to bear a part of its function. As a result, the cost of the entire surface plasmon enhanced fluorescence measuring apparatus can be reduced. Further, in the configuration in which the light collecting member 122 is provided, the light collecting efficiency is improved and the S / N value does not decrease.
As the condensing member 122, any condensing system may be used as long as it aims at efficiently condensing the fluorescent signal on the light detection means 120. As a simple condensing system, a commercially available objective lens used in a microscope or the like may be used. The magnification of the objective lens is preferably 10 to 100 times.

  On the other hand, as the filter 124, an optical filter, a cut filter, or the like can be used. Examples of the optical filter include a neutral density (ND) filter and a diaphragm lens. Furthermore, the cut filter includes external light (illumination light outside the device), excitation light (excitation light transmission component), stray light (excitation light scattering component in various places), and plasmon scattering light (excitation light originated from plasmon A filter that removes various types of noise light such as scattered light generated by the influence of structures or deposits on the surface of the excitation sensor) and autofluorescence of the enzyme fluorescent substrate, such as an interference filter and a color filter.

In the analyte detection method using such a surface plasmon enhanced fluorescence measuring apparatus 10, a SAM film (Self-Assembled Monolayer: a primary antibody is bound on the surface of the metal thin film 102 on the side in contact with the reaction unit 104. (Also referred to as “self-assembled monolayer”) or a polymer material film. The primary antibody is bound to one surface of the SAM film or the polymer material film, and the other surface of the SAM film or the polymer material film is directly or indirectly fixed to the surface of the metal thin film 102. Examples of the SAM film include a film formed of a substituted aliphatic thiol such as HOOC- (CH ₂ ) ₁₁ —SH, and examples of the polymer material include polyethylene glycol (hereinafter referred to as “PEG”) and MPC polymer. Is mentioned. This may be prepared at the time of use, or a substrate on which these are bonded in advance may be used. Alternatively, a polymer having a reactive group for the primary antibody (or a functional group that can be converted into a reactive group) may be directly immobilized on the substrate, and the primary antibody may be immobilized thereon. When an antibody or a polymer is bound using various reactive groups, an amidation condensation reaction through succinimidylation, an addition reaction through maleimidation, or the like is common.

  A solution containing an analyte antigen as a target substance (hereinafter also referred to as a specimen solution) and a reagent solution containing a secondary antibody are sent to the reaction section 104 configured as described above. The antigen can be captured by the immobilized primary antibody. In contrast, the captured antigen is labeled by the action of a reagent solution containing a secondary antibody labeled with a fluorescent substance. The primary antibody may be allowed to act after the antigen and the secondary antibody have been reacted in advance.

  In order to detect the analyte labeled with the fluorescent substance, the reaction member 104 where the analyte is captured is irradiated with the excitation light b1 from the light source 112 to the dielectric member 106, and the excitation light b1 is applied to the metal thin film 102. By entering the metal thin film 102 at a specific incident angle (resonance angle θ1), a dense wave (surface plasmon) is generated on the metal thin film 102.

  Note that when a close-packed wave (surface plasmon) is generated on the metal thin film 102, the excitation light b1 and the electronic vibration in the metal thin film 102 are coupled, and the signal of the metal thin film total reflection light b2 changes (the amount of light decreases). Therefore, it is only necessary to find a point where the signal of the metal thin film total reflection light b2 received by the light receiving means 116 changes (the amount of light decreases).

  Then, due to this dense wave (surface plasmon), the fluorescent material generated in the reaction portion 104 on the metal thin film 102 is efficiently excited, thereby increasing the amount of fluorescent b3 emitted from the fluorescent material, and condensing this fluorescent b3. By receiving light by the light detection means 120 through the member 122 and the filter 124, an extremely small amount and / or extremely low concentration of the analyte can be detected.

  The metal thin film 102 is preferably made of at least one metal selected from the group consisting of gold, silver, aluminum, copper, and platinum, more preferably gold, and an alloy of these metals. That is.

  Such a metal is suitable for the metal thin film 102 because it is stable against oxidation and the electric field enhancement due to dense waves (surface plasmons) increases.

  Examples of a method for forming the metal thin film 102 include sputtering, vapor deposition (resistance heating vapor deposition, electron beam vapor deposition, etc.), electrolytic plating, electroless plating, and the like. Of these, the sputtering method and the vapor deposition method are preferable because the thin film formation conditions can be easily adjusted.

  Further, the thickness of the metal thin film 102 is in the range of gold: 5-500 nm, silver: 5-500 nm, aluminum: 5-500 nm, copper: 5-500 nm, platinum: 5-500 nm, and alloys thereof: 5-500 nm. It is preferable to be within.

  From the viewpoint of the electric field enhancement effect, within the range of gold: 20-70 nm, silver: 20-70 nm, aluminum: 10-50 nm, copper: 20-70 nm, platinum: 20-70 nm, and alloys thereof: 10-70 nm More preferably.

  If the thickness of the metal thin film 102 is within the above range, it is easy to generate close-packed waves (surface plasmons). Moreover, as long as the metal thin film 102 has such a thickness, the size (length × width) is not particularly limited.

In addition, as the dielectric member 106, for example, a high refractive index 60 degree prism can be used. As the material, various optically transparent inorganic substances, natural polymers, and synthetic polymers can be used. From the viewpoint of chemical stability, production stability, and optical transparency, silicon dioxide (SiO ₂ ) or titanium dioxide ( TiO ₂ ) is preferably included.

  Furthermore, such a surface plasmon enhanced fluorescence measurement apparatus 10 adjusts the optimum angle (resonance angle θ1) of surface plasmon resonance by the excitation light b1 irradiated from the light source 112 to the metal thin film 102, so that an angle variable unit (not shown). Z).

  Here, the angle variable unit (not shown) is controlled by the control unit 13, and in the “resonance angle scanning process”, the light receiving means 116 and the light source 116 are used to determine the total reflection attenuation (ATR) condition by the servo motor of the angle variable unit. 112 is synchronized with the irradiation region, and the angle can be changed within a range of 45 to 85 °. The resolution is preferably 0.01 ° or more.

  2A is a cross-sectional view around the microchip 14, and FIG. 2B is a top view of a part thereof. A reaction unit 104 is provided in the flow path 143. An opening 144a is provided at one end of the flow path 143, and an opening 144b is provided at the other end. A connection portion 145 is provided on the opening 144a side.

  The pipette 150 can be connected to the connection unit 145. The connection portion 145 is made of an elastic material and functions as a seal member when the pipette 150 is loaded. A liquid reservoir 151 is provided at the tip of the opening 144b on the other end side. A fine air hole (not shown) is provided in the upper part of the liquid reservoir 151.

  The thickness (the length in the Z direction) in the vicinity of the base 142 where the hollow groove h1 is provided is preferably 2 to 5 mm, but may be thicker than this. The width (Y direction length) of the flow path 143 is 1 mm to 3 mm, the height (Z direction) is 50 μm to 500 μm, the width of the reaction unit 104 is equal to the width of the flow path 143, and the length (X direction) is Although it is 1 mm-3 mm, it is not necessarily limited and may extend over the whole region of the flow path 143 longer than it. The sizes of the openings 144 a and 144 b at both ends of the flow path 143 are φ1 mm to φ3 mm, which is equivalent to the width of the flow path 143. The tip of the pipette 150 has substantially the same shape as the opening 144a, and the root portion has a cylindrical shape with a shaft diameter larger than this. The liquid reservoir 151 has a cross-sectional shape larger than that of the opening 144b in the flow path direction. For example, the liquid reservoir 151 has a rectangular column shape with a cross section of 2 to 4 mm square.

  FIG. 2A shows a state where the pipette 150 is loaded. In addition, although the liquid reservoir 151 has shown the example fixed to the microchip 14, it is good also as a structure which can be removed similarly to the pipette 150. FIG. Note that the pipette 150 only needs to have a rigidity that does not deform with respect to a change in internal pressure due to driving of the pump 130 and hardly changes in volume. In this embodiment, polypropylene is used as the material. Further, it can be easily detached through the connecting portion 145, and the pipette 150 can be easily discarded together with the supplied specimen liquid.

  The pump 130 is a syringe pump, for example, and can discharge or suck a predetermined amount of liquid. A liquid such as a sample liquid stored in the pipette 150 is sent into the microchip 14 by the pump 130. In this way, the reagent solution containing the secondary antibody labeled with the fluorescent substance and the sample solution containing the analyte are sent to the flow path 143 by the pump 130.

  Examples of the specimen include blood, serum, plasma, urine, nasal fluid, saliva, stool, body cavity fluid (eg, cerebrospinal fluid, ascites, pleural effusion). The analyte contained in the sample is, for example, nucleic acid (DNA that may be single-stranded or double-stranded, RNA, polynucleotide, oligonucleotide, PNA (peptide nucleic acid), etc., or nucleoside, nucleotide And modified molecules thereof), proteins (polypeptides, oligopeptides, etc.), amino acids (including modified amino acids), carbohydrates (oligosaccharides, polysaccharides, sugar chains, etc.), lipids, or modified molecules and complexes thereof. Specifically, it may be a carcinoembryonic antigen such as AFP (α-fetoprotein), a tumor marker, a signaling substance, a hormone, or the like, and is not particularly limited.

  Furthermore, the fluorescent substance is not particularly limited as long as it is a substance that emits fluorescence b3 by being irradiated with predetermined excitation light b1 or excited by using a field effect. In addition, the fluorescence b3 as used in this specification includes various light emission, such as phosphorescence.

  FIG. 3 is a schematic diagram showing the configuration of the chip structure 108, which is a partially enlarged view of FIG. 3A is a top view, and FIG. 3B is a cross-sectional view taken along the line AA. As shown in these drawings, the hollow groove h1 is provided so as to surround the periphery of the reaction portion 104 and extends upward. More specifically, the hollow groove h1 is provided so as to surround a region where the fluorescent light b3 from the fluorescent material in the reaction unit 104 emits light. The region where the fluorescence b3 emits is a region where the secondary antibody labeled with the fluorescent substance is captured and the electric field is enhanced by irradiation with the excitation light b1. In the example shown in FIG. 3 (the same applies to FIGS. 4 to 7), since the region of the reaction portion 104 is narrower than the region where the electric field is enhanced, the region of the reaction portion 104 and the region where the fluorescence b3 emits coincide with each other. ing.

  The base 142 includes a central portion 142a, an outer peripheral portion 142c, and a bridging portion 142b that connects them. The outer peripheral wall a2 (boundary surface between the hollow groove and the base body) of the central portion 142a is substantially vertical, and the shape of the central portion 142a surrounded by the hollow groove h1 is a columnar shape.

  The base material of the base body 142 including the central portion 142a is made of a material having a high refractive index. Since the hollow groove h1 is a space (air), its refractive index is low (approximately 1.0). The fluorescence b3 emitted from the reaction unit 104 and entering the upper central portion 142a is totally reflected when it enters the outer peripheral wall a2 at an angle greater than the critical angle. The fluorescence b3 repeats total reflection and escapes from the upper surface a4. As described above, the central portion 142a of the base body 142 can function as a light collecting member, whereby the fluorescent light b3 emitted from the reaction portion 104 can be efficiently collected.

  The lower end a1 of the hollow groove h1 does not penetrate the flow path 143, and the upper wall surface a3 constituting the flow path 143 is flat. As a result, the liquid flowing through the flow path 143 can be smoothly fed without adverse effects. Further, the outer peripheral portion 142c and the central portion 142a of the base body 142 are connected to the hollow groove h1 by a bridging portion 142b below, but the thickness (Z direction) of the bridging portion 142b is made as thin as possible as long as strength is allowed. It is preferable that the lower end part a1 of the hollow groove h1 is closer to the reaction part 104 because the fluorescent light b3 can be efficiently condensed. Further, in the configuration shown in FIG. 3, the hollow groove h1 is annular and the bridging portion 142b is provided only at the lower end. However, the present invention is not limited thereto, and the bridging portion 142b is provided in the hollow groove h1, and a part of the annular shape is cut off. It may be a configuration. Furthermore, although the central portion 142a has a cylindrical shape with a perfect cross section, it may have a cylindrical shape with an elliptical cross section.

  Further, the autofluorescence b301 from the dielectric member 106 by the excitation light b1 or visible light becomes noise and affects the S / N value. In this embodiment, such autofluorescence b301 is the inner peripheral wall a5 of the outer peripheral portion 142c. Since total reflection can be performed at the boundary surface between the outside of the hollow groove and the substrate, the influence can be reduced. Further, the outer wall and the inner wall surface (inner peripheral wall a5 and outer peripheral wall a2) of the hollow groove h1 do not need to be parallel, and in order to more efficiently totally reflect the autofluorescence b301 by the outer inner peripheral wall a5, the autofluorescence b301 The angle may be determined so that the angle of incidence on the inner peripheral wall a5 is more than the critical angle. Further, when the base body 142 is formed by injection molding, a draft taper of 2 to 5 ° may be formed on the outer and inner wall surfaces of the hollow groove h1 in order to improve transferability.

[Other Embodiments]
4 to 7 are schematic views showing the configuration of the chip structure 108 in the second to fifth embodiments, respectively. This corresponds to FIG. 3, and the description of the configuration common to FIG. The configuration other than that shown in FIG. 4 is the same as that shown in FIGS.

  In the chip structure 108 according to the second embodiment shown in FIG. 4, the shape of the central portion 142a surrounded by the hollow groove h1 is a truncated cone shape that extends upward. With such a configuration, the outer peripheral wall a2 of the central portion 142a has an inclination that spreads in a trumpet shape with respect to the surface on which the reaction portion 104 is formed. Therefore, the fluorescent light b3 is more parallel ( Since the light is totally reflected at an angle close to the normal direction to the surface of the reaction unit 104, the light collection efficiency is improved.

  In the chip structure 108 according to the third embodiment shown in FIG. 5, a member 147 is inserted into the hollow groove h1 with respect to the base body 142 shown in FIG. Since the member 147 is made of a base material having a lower refractive index than the base material of the base body 142, the fluorescent b3 irradiated to the inside of the central portion 142a of the base body 142 is similar to the configuration shown in FIG. Total reflection can be performed at the boundary between 147 and the central portion 142a. Then, by inserting the member 147, the rigidity strength of the entire base body 142 can be increased. PDMS (polydimethylsiloxane) is preferred as the low refractive index substrate.

  In the chip structure 108 according to the fourth embodiment shown in FIG. 6, a condensing rod 148 is inserted into the hollow groove h2, and the condensing rod 148 is used as a condensing member. The condensing rod 148 is an integrated structure made of glass or resin, and is a structure that takes in light from one side and guides it inside, and emits light from the other side.

  FIG. 6A is a diagram showing the base 142, and the cylindrical hollow groove h <b> 2 is provided on the upper side so as to cover the reaction unit 104. FIG. 6B is a view showing the chip structure 108 configured by using the base body 142 shown in FIG. 6A, in which a condensing rod 148 is inserted. The condensing rod shown in the figure is cylindrical and is made of a high refractive index base material, so that it collects from the reaction part 104 through the central part 142d of the base body 142 in the same way as the structure shown in FIG. The fluorescence b3 irradiated to the inside of the optical rod 148 can be totally reflected at the boundary between the condensing rod 148 and the outer space (cavity groove h2). The fluorescence b3 repeats total reflection and escapes from the upper surface a4. As described above, the condensing rod 148 can function as a condensing member, whereby the fluorescent b3 emitted from the reaction unit 104 can be efficiently condensed.

  Note that the condensing rod 148 may have a truncated cone shape that spreads upward as well as a cylindrical shape. Further, instead of the condensing rod 148, an optical fiber may be inserted into the hollow groove h2. The optical fiber is a glass fiber or a hollow optical fiber, and is preferable in that it can be bent flexibly as compared with a condensing rod. For example, since the detection light can be guided by the optical fiber to the sensor surface arranged in a complicated place, the degree of freedom in design is improved.

  In the chip structure 108 according to the fifth embodiment shown in FIG. 7, the surface of the base 142 facing the hollow groove h2 is a mirror surface a6 that has been subjected to mirror finishing. Mirror finish is to smooth the surface by polishing the surface or forming a metal thin film by sputtering or vapor deposition so that light is reflected.

  Similarly to the configuration shown in FIG. 3, the fluorescent light b3 that has passed through the central portion 142d of the base body 142 from the reaction portion 104 and passed through the upper hollow groove h2 can be totally reflected by the mirror surface a6. The fluorescence b3 repeats total reflection and escapes upward. As described above, the base body 142 provided with the mirror surface a6 can function as a light collecting member, whereby the fluorescent light b3 emitted from the reaction unit 104 can be efficiently collected.

DESCRIPTION OF SYMBOLS 10 Surface plasmon enhanced fluorescence measuring apparatus 102 Metal thin film 104 Reaction part 106 Dielectric member 108 Chip structure 112 Light source 116 Light receiving means 120 Photodetection means 122 Condensing member 124 Filter 142 Base 142a Central part 142b Bridging part 142c Outer peripheral part 142d Central part h1, h2 hollow groove a1 lower end a2 outer peripheral wall a3 upper wall surface a4 upper surface a5 inner peripheral wall a6 mirror surface

Claims (8)

A chip structure used in a surface plasmon enhanced fluorescence measuring device,
A metal thin film whose electric field is enhanced by irradiating one surface with excitation light;
A reaction part formed on the other surface side of the metal thin film, the reaction part exciting the fluorescent substance by the enhanced electric field;
And a substrate on which a flow path for sending liquid is formed with the reaction part as a bottom surface by joining the surface on which the channel groove is formed to the surface of the metal thin film. ,
The substrate is provided with a hollow groove extending around the periphery of the reaction portion and extending upward, and the fluorescence can be reflected at a boundary surface between the hollow groove and the substrate. Chip structure.   2. The chip structure according to claim 1, wherein the shape of the substrate surrounded by the hollow groove is a columnar shape or a truncated cone shape extending upward.   The chip structure according to claim 1, wherein the hollow groove does not penetrate the flow path.   The chip structure according to any one of claims 1 to 3, wherein a member made of another base material having a lower refractive index than the base material is inserted into the hollow groove.   The chip structure according to claim 1, wherein the base material is a transparent resin, and the base body is manufactured by molding. A chip structure used in a surface plasmon enhanced fluorescence measuring device,
A metal thin film whose electric field is enhanced by irradiating one surface with excitation light;
A reaction part formed on the other surface side of the metal thin film, the reaction part exciting the fluorescent substance by the enhanced electric field;
And a substrate on which a flow path for sending liquid is formed with the reaction part as a bottom surface by joining the surface on which the channel groove is formed to the surface of the metal thin film. ,
The base body is provided with a hollow groove above the reaction part,
A cylindrical structure or a truncated cone-shaped condensing rod is inserted into the hollow groove, and the chip structure is capable of reflecting the fluorescence by a side wall of the condensing rod.   The chip structure according to claim 6, wherein the condensing rod is an optical fiber. A chip structure used in a surface plasmon enhanced fluorescence measuring device,
A metal thin film whose electric field is enhanced by irradiating one surface with excitation light;
A reaction part formed on the other surface side of the metal thin film, the reaction part exciting the fluorescent substance by the enhanced electric field;
And a substrate on which a flow path for sending liquid is formed with the reaction part as a bottom surface by joining the surface on which the channel groove is formed to the surface of the metal thin film. ,
The base body is provided with a hollow groove above the reaction part,
A chip structure, wherein the surface of the substrate facing the hollow groove is mirror-finished.

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