JP6638343B2 - Sensor chip and optical sample detection system equipped with the sensor chip - Google Patents

Description

  The present invention relates to a surface plasmon resonance apparatus that applies a surface plasmon resonance (SPR) phenomenon, and a surface plasmon excitation based on the principle of surface plasmon-excited fluorescence spectroscopy (SPFS). The present invention relates to a sensor chip used in an enhanced fluorescence measurement device and the like, and an optical sample detection system provided with the sensor chip.

2. Description of the Related Art Conventionally, in the case of detecting a very small substance, various specimen detection apparatuses that can detect such a substance by applying a physical phenomenon of the substance have been used.
As one of such specimen detection devices, a phenomenon of obtaining high light output by resonating electrons and light in a fine region such as a nanometer level (Surface Plasmon Resonance (SPR) phenomenon) is applied. For example, a surface plasmon resonance device (hereinafter, referred to as an “SPR device”) configured to detect minute analytes in a living body may be used.

  Also, based on the principle of Surface Plasmon-field enhanced Fluorescence Spectroscopy (SPFS) that applies the surface plasmon resonance (SPR) phenomenon, analyte detection can be performed with higher sensitivity than an SPR device. The surface plasmon excitation enhanced fluorescence spectrometer (hereinafter, referred to as “SPFS device”) is one of such sample detectors.

  This surface plasmon excitation enhanced fluorescence spectroscopy (SPFS) uses surface plasmon light on the surface of a metal thin film under the condition that excitation light such as laser light emitted from a light source is attenuated by the total reflection (ATR) on the surface of the metal thin film. By generating (compression waves), the light density of the excitation light emitted from the light source is increased to several tens to several hundreds of times, and an electric field enhancing effect of surface plasmon light is obtained.

FIG. 7 is a schematic configuration diagram for explaining the configuration of the conventional SPFS system 100. FIG. 8 is a schematic top view of the sensor chip 114 shown in FIG. The sensor chip 114 is placed on the SPFS device 101, and the detection of a very small substance is detected with high sensitivity.
The SPFS device 101 includes a sensor chip loading unit 116 on which the sensor chip 114 is mounted, a light projecting unit 122, a light collecting member 117, a wavelength selection function member 119, a light detecting unit 120, and the like.

  The conventional SPFS system 100 includes a prism-shaped dielectric member 102 having a substantially trapezoidal vertical cross section, a metal film 104 formed on a horizontal upper surface 102a of the dielectric member 102, and a metal film 104 formed on the upper surface of the metal film 104. And a sensor chip 114 including a flow path forming member 110 and a flow path cover member 112 for forming a flow path 108 so as to surround the reaction layer 106. As shown in FIG. 7, the sensor chip 114 is mounted on the upper surface of the sensor chip mounting section 116 of the SPFS apparatus 101 via the reagent well 45.

The reaction layer 106 of the sensor chip 114 has a solid phase film for capturing an analyte labeled with a fluorescent substance. In the reaction layer 106, the analyte can be fixed on the metal film 104 by sending the sample liquid containing the analyte to the flow path 108.
Further, only the fluorescent light 118 is selected above the sensor chip 114 in order to measure the intensity of the fluorescent light 118 emitted by the fluorescent substance excited by the surface plasmon light (compression wave) generated on the metal film 104. The wavelength selection function member 119 and the light detection means 120 formed as described above are provided.

  In the case of the SPFS device, the fluorescent light 118 detected by the light receiving unit 130 is light correlated with the amount of the analyte substance. Here, the light receiving unit 130 includes a light detection unit 120, a wavelength selection function member 119, and a light collection member 117.

  As shown in FIG. 7, a light projecting unit 122 is disposed on one side (incident surface 102 b) below the dielectric member 102, and light is emitted from the light source of the light projecting unit 122. Excitation light 124 enters the incident surface 102b of the dielectric member 102 from below the outside of the dielectric member 102, and irradiates the metal film 104 formed on the upper surface 102a of the dielectric member 102 via the dielectric member 102. Is done.

  In the conventional SPFS system 100 configured as described above, by irradiating the excitation light 124 from the light source of the light projecting unit 122 toward the metal film 104, surface plasmon light (compression waves) is generated on the surface of the metal film 104. The fluorescent substance that labels the analyte is excited by the surface plasmon light (compression waves), and the fluorescent light 118 emits light. The fluorescent light 118 is detected by the light detecting means 120 via the light collecting member 117 and the wavelength selecting function member 119, and the amount of the analyte is calculated based on the amount of the fluorescent light 118.

  The analyte contained in the sample is, for example, a nucleic acid (DNA, RNA, polynucleotide, oligonucleotide, PNA (peptide nucleic acid), which may be single-stranded or double-stranded, or a nucleoside). , Nucleotides and their modified molecules), proteins (polypeptides, oligopeptides, etc.), amino acids (including modified amino acids), carbohydrates (oligosaccharides, polysaccharides, sugar chains, etc.), lipids, or modified molecules thereof, Examples thereof include a complex, and specific examples thereof include a carcinoembryonic antigen such as AFP (α-fetoprotein), a tumor marker, a signal transmitting substance, a hormone, and the like, and are not particularly limited.

  Note that, as shown in FIG. 8, a sample inlet 108a and a sample outlet 108b are formed in the channel cover member 112. A cylindrical sample inlet member 92 is provided upright above the sample inlet 108a, and a cylindrical liquid reservoir member 94 having an internal space for liquid mixing is provided above the sample outlet 108b. Has been established.

  In such SPFS measurement, since the light quantity of the fluorescent light 118 is about ten orders of magnitude lower than the light quantity of the excitation light 124, even if the excitation light 124 is slightly incident on the light detection means 120, the S / N is deteriorated, and the detection accuracy is reduced. Therefore, it is important to reduce stray light.

The excitation light 124 enters from the incident surface 102b of the dielectric member 102, is reflected by the metal film 104, and exits from the exit surface 102c of the dielectric member 102.
However, part of the excitation light 124 is reflected on the emission surface 102c of the dielectric member 102, and there is emission surface reflected light 124b emitted from the incident surface 102b of the dielectric member 102.

  When the outgoing surface reflected light 124b is incident on the flow path cover member 112 and is reflected by the side surface 112a of the flow path cover member 112, the light becomes light guided inside the flow path cover member 112 by total reflection as indicated by an arrow. If the exit surface reflected light 124b is present in the measurement area S of the light detection unit 120, the exit surface reflected light 124b excites the flow path cover member 112 to generate autofluorescence. Autofluorescence in the lid member 112 is also detected, which leads to deterioration of S / N. Further, not only the autofluorescence, but also the scattered light in which the emission surface reflected light 124b is scattered in the measurement region S of the flow path cover member 112 is detected, which leads to deterioration of S / N. Further, not only the reflected light 124b on the emission surface, but also the diffracted light, stray light, and excitation light of the light emitted from the light projecting unit 122 located below irradiates the inside of the device such as the sensor chip mounting unit 116 and the light scattered by the flow path. When the light enters the lid member 112, light is generated in which some light is guided by total reflection as shown by an arrow, which leads to deterioration of S / N.

  The emission surface reflected light 124b has a reflectivity of the dielectric member 102 of about 4% (a reflectivity of an interface of a normal optical member), and light guided by total reflection in the flow path cover member 112 is substantially equal to the light. Since the reflectance is 100%, an amount of autofluorescence that is equal to or larger than the fluorescence 118 is generated, and can be said to be stray light to be removed.

Various techniques have been proposed to reduce such stray light.
For example, in Patent Document 1, as shown in FIG. 9, a light absorbing portion 46 that absorbs the reflected light 21 reflected from the metal film 12 of the excitation light 20 incident toward the dielectric member 16a is formed by a dielectric material. It is provided in the optical path of the body member 16a.

  Further, in Patent Document 2, as shown in FIG. 10, an excitation light cut filter (wavelength filter) 60 is provided on the upper surface of the upper lid 11b to remove scattered light and reflected light inside the sensor chip 10. The excitation light L is cut. However, even with such a structure, the fluorescent wavelength passes, so that stray light due to autofluorescence remains.

JP 2014-167479 A JP 2012-202911 A

  In view of such circumstances, for example, the present invention is used in an optical sample detection system such as a SPFS system, and the lateral length of a flow path portion cover member placed so as to cover an upper portion of a reaction layer is reduced. In a sensor chip set to be longer than the length of the dielectric member in the horizontal direction, part of the scattered light or reflected light that has entered the flow passage cover member flows through the side surface shape of the flow passage cover member. A sensor chip that can quantitatively measure analytes with high precision and high sensitivity by greatly reducing stray light by preventing light reaching the measurement area by guiding light inside the roadside member by total internal reflection. And an optical sample detection system provided with the sensor chip.

The present invention has been invented to solve the problems in the prior art as described above, and in order to realize at least one of the above-described objects, a sensor chip reflecting one aspect of the present invention is ,
A metal film,
A dielectric member that is adjacent to one side of the metal film and has an incident surface on which excitation light is incident;
A reaction layer located on the other side of the metal film,
A plate-shaped flow channel cover member adjacent above the reaction layer, and a sensor chip comprising:
And the perpendicular of the entrance surface, and a perpendicular line of the metal Makutaira surface, and the vertical virtual cross section to the metal film plane,
The lateral length of the channel cover member is greater than the lateral length of the dielectric member,
The angle formed between the lower surface of the flow path cover member on the side of the dielectric member and the end face of the flow path cover member on the incident surface side of the lateral end faces is obtuse.

Further, the optical sample detection system according to the present invention,
The above sensor chip,
A light emitting unit for irradiating the excitation light,
A light-receiving unit that detects light correlated with the amount of analyte substance generated when the metal film is irradiated with the excitation light via the dielectric member, and detects the amount of analyte substance.

  According to the sensor chip of the present invention, by forming the angle of the rising portion of the flow path cover member at an obtuse angle, the light incident from the lower surface of the flow path cover member and reflecting the slope of the rising portion can be used as the flow path cover member. The light guided by total internal reflection can be completely eliminated, and the measurement sensitivity and measurement accuracy of the analyte can be improved.

FIG. 1 is a schematic diagram for explaining a configuration of an SPFS system including a sensor chip according to the present invention. FIG. 2A is a schematic perspective view of the sensor chip shown in FIG. FIG. 2B is a schematic top view of the sensor chip shown in FIG. FIG. 3 is a schematic sectional view showing another embodiment of the sensor chip according to the present invention. FIG. 4 is a schematic diagram showing an optical path of light when light enters the flow path cover member from below. FIG. 5 is a diagram in which the light incident angle from the lower surface of the flow path cover member and the light emission angle from the upper surface of the flow path cover member are plotted. FIG. 6 is a schematic top view when the optical sample detection system according to the present invention is viewed from above. FIG. 7 is a schematic diagram for explaining the configuration of a conventional SPFS system. FIG. 8 is a schematic top view of the sensor chip shown in FIG. FIG. 9 is a cross-sectional view of a conventional sensor chip disclosed in JP-A-2014-167479. FIG. 10 is a cross-sectional view of another conventional sensor chip disclosed in Japanese Patent Application Laid-Open No. 2012-202911.

Hereinafter, embodiments (examples) of the present invention will be described in more detail with reference to the drawings.
FIG. 1 is a schematic diagram schematically showing an outline of an SPFS system which is one embodiment of the optical sample detection system of the present invention.

  In the following description, “up” and “down” directions are defined in the state of FIG. That is, the light detecting means 44 in FIG. 1 is located above the dielectric member 34, and the light projecting unit 48 is located below the dielectric member 34.

  2A and 2B show the sensor chip 30 employed in the SPFS system 70 of FIG. As illustrated in FIG. 1, the sensor chip 30 of the SPFS system 70 according to the present embodiment includes a metal film 32, a dielectric member 34 adjacent to one side of the metal film 32, and a sensor member 30 positioned on the other side of the metal film 32. And a flow path cover member 38 that forms a flow path above the reaction layer 36. The sensor chip 30 is loaded into the chip loading section 116 of the SPFS device 68 via the reagent well 45 as in the case shown in FIG.

In this embodiment, the sensor chip 30 includes a reagent well 45 formed of a material having a property of transmitting the excitation light L1.
The reagent well 45 is, for example, a container that stores a sample liquid, a drug solution, and the like. The sensor chip 30 is loaded in a sensor chip loading hole 49 provided in the reagent well 45.
Further, the sensor chip 30 may be loaded in the chip loading section 116 such that the chip loading section 116 and the flow path cover member 38 are in contact with each other.

  Further, as shown in FIGS. 2A and 2B, a sample liquid containing an analyte is supplied to the reaction layer 36 at both ends in the longitudinal direction of the flow path cover member 38 of the sensor chip 30. A sample inlet 55 and a sample outlet 57 are formed. In the present embodiment, a cylindrical sample inlet member 58 is provided upright above the sample inlet 55, and a liquid reservoir member 59 having a space for sample mixing is provided above the sample outlet 57. It is erected.

The sample liquid used here is a solution prepared using a sample, for example, a process of mixing a sample and a reagent to bind a fluorescent substance to an analyte contained in the sample. Things.
Examples of such a sample include blood, serum, plasma, urine, nasal fluid, saliva, stool, body cavity fluid (cerebrospinal fluid, ascites, pleural effusion, etc.).

  In the sensor member 30 according to the present embodiment, the sample inlet member 58 connected to the sample inlet 55 and the liquid reservoir member 59 connected to the sample outlet 57 are separate from the channel cover member 38. The body is formed. The sample inlet member 58 and the liquid reservoir member 59 formed separately are integrated with the flow path cover member 38 in a later step.

  Therefore, in the present embodiment, for example, even when the flow path cover member 38 is injection-molded, the flow path cover member 38 has a gradient of the sample injection port member 58 and the liquid storage member 59 from the mold. It is possible to set its own shape without regard to this.

  For example, as in the other embodiment shown in FIG. 3, a shape in which the draft of the sample injection member 58 and the liquid reservoir member 59 from the mold is different from the shape of the flow path cover member 38 is also set. Is possible. When the gradients inside the sample injection member 58 and the liquid storage member 59 are made conical as shown in FIG. 3, the injection and discharge can be easily performed without liquid remaining. Further, the sample injection member 58 and the liquid storage member 59 may be integrally formed.

In the embodiment shown in FIGS. 2A and 2B and the embodiment shown in FIG. 3, an example in which a liquid reservoir 59 for mixing is provided at the other end of the channel cover member 38 is shown. However, the present invention is not limited to this. For example, a sensor chip that circulates and sends the sample liquid to one side by connecting the sample inlet 55 and the sample outlet 57 by a circulating liquid sending unit such as a pump. Is also applicable.
The channel cover member 38 is formed of a resin having a good light transmission property, such as PMMA (polymethyl methacrylate resin).

  In addition, the reaction layer 36, as in the case of the conventional example shown in FIGS. 7 and 8, allows the analyte liquid containing the analyte to flow through the channel 33 through the sample inlet 55 shown in FIGS. 2A and 2B, for example. Can be fixed to the metal film 32.

  2A and 2B and the embodiment shown in FIG. 3 show a configuration in which the sample liquid is introduced into the reaction layer 36 by sending the sample liquid to the flow path 33. The present invention is not limited to this. The present invention is also applicable to a configuration in which a well portion is provided as the reaction layer 36 and the sample liquid is retained in the well portion.

  On the other hand, as shown in FIG. 1, a light projecting unit 48 for irradiating the metal film 32 with the excitation light L1 is disposed below the sensor chip 30 of the SPFS system 70. Further, a light receiving unit 71 is disposed above the sensor chip 30.

  The light receiving unit 71 includes a stop 73, a wavelength selection function member 43, a light collecting member 52, a light detection unit 44, and the like. The diaphragm 73 may be integrated with the wavelength selecting function member 43, the light collecting member 52, and the light detecting means 44. Alternatively, the diaphragm 73 may be integrated with a member (not shown) that holds the wavelength selection function member 43, the light condensing member 52, and the light detection unit 44.

  In the sensor chip 30, one lower side surface of the dielectric member 34 forms an incident surface 34a on which the excitation light L1 from the light projecting unit 48 enters, and the other lower side surface of the dielectric member 34 is formed of a metal film. An emission surface 34b from which the light reflected by the light 32 is emitted is formed.

  The material of the dielectric member 34 is formed of a material that is optically transparent at least to the excitation light L1. Further, in order to provide the sensor chip 30 which is inexpensive and has excellent handleability, it is formed from a resin material by injection molding.

  Examples of the resin material forming the dielectric member 34 include polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate; polyolefins such as polyethylene (PE) and polypropylene (PP); cyclic olefin copolymer (COC); Polycyclic olefins such as olefin polymer (COP), vinyl resins such as polyvinyl chloride and polyvinylidene chloride, polystyrene, polyetheretherketone (PEEK), polysulfone (PSF), polyethersulfone (PES), polycarbonate ( PC), polyamide, polyimide, acrylic resin, triacetyl cellulose (TAC), or the like.

On the upper surface of the dielectric member 34, a flow path forming member 50 made of an acrylic pressure-sensitive adhesive sheet having a flow path groove punched out is disposed. The thickness of such an acrylic pressure-sensitive adhesive sheet is not particularly limited, but is preferably about 0.1 mm.
By reacting such a flow path forming member 50 on the upper surface of the dielectric member 34, the reaction layer 36 in which the test solution is stored is formed.

Hereinafter, the flow path cover member 38 which is a characteristic requirement of the present embodiment will be described in detail.
In the present embodiment, when the excitation light L1 is emitted from the light source of the light emitting unit 48 toward the metal film 32 at an incident angle θ, the perpendicular of the incident surface 34a of the dielectric member 34 on which the excitation light L1 is incident and the metal The virtual cross section where the perpendicular to the film plane intersects is defined as "virtual cross section 40". The imaginary cross section 40 is a cross section in a plane direction indicated by hatching on the flow path cover member 38 in FIG.

  In the present embodiment, the lateral length D of the flow path cover member 38 is set to be longer than the length E of the dielectric member 34 in the same direction.

  Further, in the present embodiment, the angle X1 between the lower surface 38a of the flow path cover member 38 on the dielectric member 34 side and the end face 38c on the incident surface side of the lateral end faces of the flow path cover member 38 is formed at an obtuse angle. Have been.

That is, the angle X1 of the lower surface rising portion X located on the incident surface 34a side of the flow path cover member 38 is formed to be an obtuse angle. The range of the angle X1 is preferably, for example, 90 ° <X1 <150 °. If the angle is 90 °, a draft angle for molding cannot be ensured. If the angle is less than 90 °, light that guides the inside of the flow path cover member 38 exists, and the S / N deteriorates. Further, when the angle is more than 150 °, there is a problem that the flow path cover member 38 is chipped and a problem that the sensor chip becomes large. If the angle X1 is set in the above range, no matter what angle the light enters the lower surface 38a of the flow path cover member 38 at the rising portion X of the flow path cover member 38, the flow path cover member There is no light that reflects the side surface 38c of the rising portion X of 38 and guides the inside of the flow path cover member 38 by total internal reflection. Therefore, not only the light reflected from the back surface of the dielectric member 34 toward the rising portion X of the flow path cover member 38 but also the diffracted light, the stray light, and the excitation light L1 generated from the light projecting unit 48 Even when the light irradiates the inside of the device and scatters the light, even if the light is incident on the lower surface 38a of the flow path cover member 38 at any angle, it reflects the side surface 38c of the rising portion X of the flow path cover member 38 and reflects the light. There is no light that guides the inside of the device 38 by total internal reflection.
For this reason, light is not guided inside the flow path cover member 38 by total reflection, and analyte detection can be performed with high accuracy.

  In addition, since light that does not guide the flow path cover member 38 is emitted from the upper surface 38b of the flow path cover material 38, if a light shielding member 47 or the like is arranged in advance outside the measurement region S, light detection described later will be performed. Unnecessary light can be prevented from entering the means 44. Thus, the SPFS device 70 can detect an analyte with high accuracy and high sensitivity by using the fluorescence generated when the excitation light is irradiated as light correlated with the amount of the analyte substance.

Here, the measurement area S is a measurement range in the flow path 33 and the flow path cover member 38 that can be measured by the light detection means 44 (when there is a lens for guiding light to the light detection means 44, a lens (Measureable range of the light receiving unit including the light receiving unit, that is, the visual field range of the light receiving unit)
Here, when the light travels from the medium 1 having the refractive index n1 to the medium 0 having the refractive index n0 (<n1), when the incident angle of the light incident on the interface between the medium 1 and the medium 0 is θi [°], When the conditional expression is satisfied, total reflection occurs in the medium 1.
sinθi> n0 / n1

The following is an example of the channel cover member 38.
As shown in FIG. 4, the refractive index of the flow path cover member 38 is 1.5, the medium above the upper surface 38 b of the flow path cover member 38 and the medium below the lower surface 38 a are air, The light incident angle on the lower surface 38a of the flow path cover member 38 and the flow path lid when the angle between the lower surface 38a and the side surface 38c is 95 ° and 91 °, and when the angle is 89 ° and 85 ° as a comparative example. FIG. 5 is a diagram in which the light emission angle from the upper surface 38b of the member 38 is plotted. When the light emission angle is 0 °, the inside of the flow path cover member 38 is guided by total reflection.
In FIG. 4, θ0 is the light incident angle, θ1 is the light emission angle, and X1 is the inclination angle of the flow path cover member 38.

  In this manner, by making the angle X1 between the lower surface 38a of the flow path cover member 38 and the end face 38c on the incident surface side an obtuse angle, the light inside the flow path cover member 38 is totally reflected and guided to reach the measurement area S. Since the reaching light can be blocked, the autofluorescence of the channel cover member 38 can be reduced, and the analyte can be quantitatively measured with high accuracy and high sensitivity.

  In this embodiment, the lower surface 38a of the flow path cover member 38 on the dielectric member 34 side and the other of the pair of lateral end faces of the flow path cover member 38 which are located on the opposite side to the end face 38c on the incident surface 34a side. Is formed at an obtuse angle with the end face 38d. That is, the angle Y1 of the lower surface rising portion Y located on the emission surface 34b side of the dielectric member 34 is formed at an obtuse angle. It is preferable that the range of the angle Y1 is, for example, 90 ° <Y1 <150 ° as in the case of X1.

  If the angle Y1 of the rising portion Y is set in such a range, the excitation light L4 that has passed through the emission surface 34b is reflected or scattered in the device section and entered near the rising portion Y of the channel cover member 38. In this case, even if light is incident on the lower surface 38a of the flow path cover member 38 at any angle, the incident light does not guide the inside of the flow path cover member by total reflection, so that high accuracy and high sensitivity can be achieved. The analyte can be quantitatively detected.

  In addition, since light that does not guide the flow path cover member 38 is emitted from the upper surface 38b of the flow path cover member 38, if a light shielding member 47 or the like is disposed in advance outside the measurement region S, light detection described later will be performed. Unnecessary light can be prevented from entering the means 44, and the analyte can be detected with high sensitivity and high accuracy.

  Further, in the sensor chip 30 of the present embodiment, the end surfaces 38c and 38d of the flow path cover member 38 are formed as smooth surfaces, respectively. As described above, if the end surfaces 38c and 38d are formed as smooth surfaces, irregular reflection does not occur, so that it is possible to effectively prevent light from being reflected in a direction in which light is guided in the flow path cover member 33. .

  Here, the excitation light L1 emitted from the light projecting unit 48 is preferably a laser light, and an LD laser having a wavelength of 200 to 900 nm and 0.001 to 1,000 mW, or a semiconductor laser having a wavelength of 230 to 800 nm and 0.01 to 100 mW. Is preferred. Further, since generation of surface plasmons has a light incident angle dependency on the metal film 32, it is preferable that the excitation light L1 is a collimated light.

  On the other hand, the light detecting means 44 provided above the sensor chip 30 receives the fluorescence 60 generated in the reaction layer 36, and the light detecting means 44 includes an ultra-high-sensitivity photomultiplier or It is preferable to use a CCD image sensor capable of multipoint measurement. Further, a photodiode or an avalanche photodiode may be used.

  Further, between the channel cover member 38 and the light detecting means 44, a light collecting member 52 for efficiently collecting light, and a wavelength selecting function for transmitting only the fluorescent light 60 in the supplied light. Members and the like are provided.

  As the light-collecting member 52, any light-collecting optical system may be used as long as the light-collecting member 52 aims to efficiently collect the fluorescent signal on the light detecting means 44. As a simple condensing optical system, a commercially available objective lens and eyepiece used in a microscope or the like may be diverted. The magnification of the objective lens is preferably 10 to 100 times. The light collecting member may be a single lens or may be composed of a plurality of lenses. A condensing optical system in which two aspherical collimating lenses are arranged in tandem may be used. At this time, by disposing the wavelength selection function member 43 between the lenses, the substantially collimated excitation light and fluorescence enter the wavelength selection function member 43, so that the wavelength selection function member having high incident angle dependency is used. Even if used, the excitation light can be efficiently cut and the fluorescence can be transmitted.

  Examples of the wavelength selection function member 43 include an interference filter such as a band-pass filter, a long-pass filter, and a dichroic mirror, and a color glass filter.

  Then, in the SPFS system 70, the excitation light L2 applied to the metal film 32 on the upper surface of the dielectric member 34 generates surface plasmon light (compression waves) on the surface of the metal film 32, so that the light projection unit 48 The light density of the excitation light L2 emitted from the light source is increased to several tens to several hundreds of times to obtain an electric field enhancement effect of surface plasmon light.

  Due to such an electric field enhancing effect, the ligand immobilized on the metal film 32 efficiently excites the fluorescent substance bonded (labeled) to the analyte captured near the surface of the metal film 32, and observes this fluorescence. Thereby, an extremely small amount and an extremely low concentration of the analyte are detected.

  In the sensor chip 30, of the excitation light L 1 incident on the metal film 32 from the light projecting unit 48, the incident surface reflected light reflected from the incident surface 34 a of the dielectric member 34 and the metal from the dielectric member 34 side Of the excitation light L1 emitted toward the film 32, the emission surface reflected light reflected by the metal film 32 and further reflected by the emission surface 34b may enter the flow path cover member 38, respectively. .

  However, of these lights, the light L3 incident on the rising portion X of the flow path cover member 38 is reflected so as to rise obliquely upward from the rising portion X, and is emitted to the outside of the flow path cover member 38. be able to.

  Further, in this embodiment, it is preferable that the light shielding member 42 is disposed integrally with the upper surface 38 b of the flow path cover member 38 outside the measurement region S in the flow path cover member 38. The light-shielding member 42 may be any member as long as it absorbs light. If such a light shielding member 42 is integrally provided on the upper surface 38a of the flow path cover member 38, it is possible to prevent stray light serving as noise from being emitted from outside the measurement region S toward the measurement region S. Can be.

  Further, in this embodiment, the end surfaces 38c and 38d of the flow path cover member 38 are formed to be smooth surfaces. Therefore, irregular reflection does not occur from the end surfaces 38 c and 38 d of the flow path cover member 38, so that it is possible to effectively prevent light from being reflected in a direction in which light is guided in the flow path cover member 38.

In the present embodiment, a portion of the upper surface 38b of the flow path cover member 38 that is located outside the measurement region S is a scattering surface.
That is, more specifically, as shown in FIG. 6, the upper surface 38 a of the flow path cover member 38 and at least a part of the intersection area where the outside of the measurement area S intersects the virtual cross section 40 are included. Ranges T, T are formed on the scattering surface. The range of the scattering surface need not be the entire surface of the upper surface 38a, but may be only a partial range to which unnecessary excitation light may be applied.

  Further, in the SPFS system 70 in which the sensor chip 30 is employed, between the sensor chip 30 and the light receiving unit 71, in order to prevent unnecessary light from being incident on the light detecting means 44 in the light receiving unit 71. The disposed shielding member 47 is disposed outside the measurement region S and is not integrated with the flow path cover member 38.

  In the SPFS system 70 in which the light shielding member 47 is provided at such a position, even if light is emitted from the outside of the measurement area S to the light receiving unit 71 in the flow path cover member 38, the stray light is generated. The light can be blocked by the light blocking member 47.

  As described above, according to the sensor chip 30 and the SPFS system 70 employing the sensor chip 30 according to the present embodiment, the light is reflected from the incident surface 34a of the dielectric member 34 or the output surface 34b of the dielectric member 34. Even if part of the light that has entered the rising portions X and Y in the flow path cover member 38, the light is directed obliquely upward without generating light that guides the inside of the flow path cover member 38 by total reflection. The light can be raised and reflected, and the light can be emitted to the outside of the flow path cover member 38. Therefore, it is possible to prevent the light or the fluorescence generated by the light from being detected as stray light by the light detection unit 44. Thus, the analyte can be measured with high accuracy and high sensitivity.

In the above embodiment, the sensor chip is applied to the SPFS system. However, the sensor chip of the present invention is not limited to the SPFS system, but can be applied to the SPR system.
In the SPR system, the light reflected by the metal film 32 is received by a light receiving unit disposed on the other side surface below the dielectric member 34.

  In the case of the SPR system, light reflected from the metal film 32 is light correlated with the amount of the analyte substance. Therefore, the light receiving unit does not have a wavelength selection function member, and the light detecting unit detects a wavelength equivalent to the excitation light L1 emitted from the light projecting unit.

  According to the optical sample detection system according to the present invention, the sensor chip, the light projecting unit for irradiating the excitation light, and the amount of the analyte substance generated when the metal film is irradiated with the excitation light via the dielectric member. A light receiving unit that detects correlated light (fluorescence in the case of SPFS, light reflected from a metal film in the case of SPR) is provided, and the end surface of the sensor chip is formed at an obtuse angle, so that stray light is significantly reduced. As a result, it is possible to measure light correlated with the amount of the analyte substance with high accuracy and high sensitivity.

Reference Signs List 30 sensor chip 32 metal film 33 flow path 34 dielectric member 34a incident surface 34b emission surface 36 reaction layer 38 flow path cover member 38a lower surface 38b upper surface 38c side end surface 38d side end surface 40 virtual cross section 42 light shielding member 43 wavelength selection function member 44 light Detecting means 45 Reagent well 47 Light blocking member 48 Light emitting unit 50 Flow path forming member 52 Light collecting member 57 Sample outlet 58 Sample inlet member 59 Liquid reservoir member 60 Fluorescent 68 SPFS device 70 SPFS system 71 Light receiving unit 73 Aperture 101 SPFS device

Claims (10)

A metal film,
A dielectric member that is adjacent to one side of the metal film and has an incident surface on which excitation light is incident;
A reaction layer located on the other side of the metal film,
A plate-shaped flow channel cover member adjacent above the reaction layer, and a sensor chip comprising:
And the perpendicular of the entrance surface, and a perpendicular line of the metal Makutaira surface, and the vertical virtual cross section to the metal film plane,
The lateral length of the channel cover member is greater than the lateral length of the dielectric member,
A sensor chip, wherein an angle formed between a lower surface of the flow path cover member on the side of the dielectric member and an end face of the pair of lateral end faces of the flow path cover member on the incident surface side is obtuse. The dielectric member has an emission surface from which the metal film reflected light from which the excitation light is reflected by the metal film is emitted,
Of the excitation light emitted toward the metal film from the dielectric member side, incident surface reflected light reflected from the incident surface of the dielectric member,
Of the excitation light emitted toward the metal film from the dielectric member side, the emission surface reflected light reflected on the metal film and further reflected on the emission surface,
2. The sensor chip according to claim 1, wherein each of the sensor chips is incident on an end surface on the incident surface side of the flow path cover member. 3.   The lower surface of the flow path cover member on the dielectric member side, the angle between the other end face of the pair of lateral end faces of the flow path cover member opposite to the end face on the incident surface side, 3. The sensor chip according to claim 1, wherein the sensor chip is formed at an obtuse angle. The sensor chip according to any one of claims 1 to 3 , wherein a pair of end surfaces facing each other in the virtual cross section of the flow path cover member are smooth surfaces. The sensor according to any one of claims 1 to 4, wherein a light-shielding member is disposed outside the measurement region in the flow path cover member, and the light-shielding member is provided integrally with the flow path cover member. Chips. The sensor chip according to any one of claims 1 to 5, wherein a portion of the upper surface of the flow path cover member that is not opposed to the dielectric member and that is located outside the measurement region is a scattering surface.   The sensor chip according to claim 6, wherein a range including the upper surface of the flow path cover member and including at least a part of an intersection region where the outside of the measurement region intersects the virtual cross section is a scattering surface. A sample inlet and a sample outlet for supplying a sample liquid containing an analyte to the flow channel are formed in the channel cover member, and a sample inlet member stands on the sample inlet. A liquid storage member is provided upright on the sample outlet,
The sample injection port member and the liquid storage member are formed separately from the flow path cover member, and then integrated with the flow path cover member according to any one of claims 1 to 7. Sensor chip. A sensor chip according to any one of claims 1 to 8,
A light emitting unit for irradiating the excitation light,
Through said dielectric member and a light receiving unit for detecting light to correlate the analyte substance amount generated when irradiated with the excitation light, the analyte substance amount detecting an optical analyte detection on the metal film system. Between the sensor chip and the light receiving unit, a light blocking member is disposed outside the measurement region and outside a light path for causing light emitted from the measurement region to enter light detection means in the light receiving unit. An optical sample detection system according to claim 9.

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