JP5637266B2 - Surface plasmon enhanced fluorescence sensor and light collecting member used in surface plasmon enhanced fluorescence sensor - Google Patents

Description

  The present invention relates to a surface plasmon enhanced fluorescence sensor based on the principle of surface plasmon excitation enhanced fluorescence spectroscopy (SPFS) and a light collecting member used in the surface plasmon enhanced fluorescence sensor.

  Conventionally, for example, detection of minute analytes in a living body has been performed based on the principle of surface plasmon excitation enhanced fluorescence spectroscopy (SPFS).

  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, surface plasmon enhanced fluorescence sensors based on the principle of surface plasmon excitation enhanced fluorescence spectroscopy (SPFS) have been developed. For example, Patent Literature 1 and Patent Literature 2 disclose the technology thereof. .

  Such a surface plasmon enhanced fluorescence sensor 100 has a basic structure as shown in FIG. 6 and is first formed of a metal thin film 102, a reaction layer 104 formed on one side surface of the metal thin film 102, and the other side surface. A chip structure 108 having a dielectric member 106.

  The chip structure 108 includes a light source 112 that is incident on the dielectric member 106 and irradiates the excitation light 110 toward the metal thin film 102 on the dielectric member 106 side. The light receiving means 116 for receiving the metal thin film reflected light 114 reflected by the light is provided.

  On the other hand, on the reaction layer 104 side of the chip structure 108, a light detection means 120 that receives fluorescence 118 emitted from a fluorescent substance labeled with the analyte captured by the reaction layer 104 is provided.

  In addition, between the reaction layer 104 and the light detection means 120, the condensing member 122 for condensing the fluorescence 118 efficiently and the light contained other than the fluorescence 118 are removed, and only the necessary fluorescence is selected. A wavelength selection function member 124 is provided.

  When the surface plasmon enhanced fluorescence sensor 100 is used, the reaction layer 104 in which the analyte labeled with the fluorescent material is captured in advance is formed on the metal thin film 102, and in this state, the dielectric member from the light source 112 is formed. When the excitation light 110 is irradiated into the inside 106 and the excitation light 110 is incident on the metal thin film 102 at a specific angle (resonance angle) 134, coarse waves (surface plasmons) are generated on the metal thin film 102.

  In addition, when a close-packed wave (surface plasmon) is generated on the metal thin film 102, the excitation light 110 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 reflected light 114 is reduced.

  For this reason, if the point where the signal of the metal thin film reflected light 114 received by the light receiving means 116 changes (the amount of light decreases) is found, the resonance angle 134 at which rough waves (surface plasmons) are generated can be obtained.

  Then, due to the phenomenon of generating the rough wave (surface plasmon), the fluorescent material of the reaction layer 104 on the metal thin film 102 is efficiently excited, and thereby the light amount of the fluorescence 118 emitted from the fluorescent material is increased.

  By receiving the increased fluorescence 118 by the light detection means 120 via the light collecting member 122 and the wavelength selection function member 124, it becomes possible to detect an extremely small amount and / or extremely low concentration of the analyte. ing.

  Thus, the surface plasmon enhanced fluorescence sensor 100 is a high-sensitivity measurement sensor that enables observation of minute molecular activities, particularly between biomolecules.

Japanese Patent No. 3294605 JP 2006-208069 A

  However, in the conventional surface plasmon enhanced fluorescence sensor 100 as described above, the enhanced fluorescence 118 is detected by the light detection means 120 using both the light collecting member 122 and the wavelength selection function member 124. Therefore, the space between the reaction layer 104 and the light detection means 120 is widened, which may cause a problem that the condensing efficiency of the fluorescence 118 is lowered and the S / N value is lowered.

  In addition, a lens is usually used for the light collecting member 122, but the lens is very expensive, and there are some cases where focusing is very difficult.

  In addition, the lens cannot secure sufficient light condensing efficiency, and the S / N value is low.

  The present invention has been made in view of such a current situation, and the condensing efficiency does not decrease, the S / N value does not decrease, and the space between the reaction layer and the light detection means is widened. It is an object of the present invention to provide a suppressed surface plasmon enhanced fluorescence sensor and a light collecting member used for the surface plasmon enhanced fluorescence sensor.

  Another object of the present invention is to provide a surface plasmon-enhanced fluorescent sensor and a condensing member used for the surface plasmon-enhanced fluorescent sensor that do not require focusing as in the case of a lens, and that reduce manufacturing costs.

The present invention was invented to solve the problems in the prior art as described above,
The light collecting member of the present invention is
By irradiating one side surface of the metal thin film with excitation light and enhancing the electric field on the metal thin film, the fluorescent material in the reaction layer formed on the other side surface of the metal thin film is excited, thereby enhancing the fluorescence. A condensing member used in a surface plasmon-enhanced fluorescence sensor that is detected by a light detection means,
The condensing member is
Between the reaction layer and the light detection means,
Consists of a total reflection functional member that collects the excited fluorescence and causes the fluorescence to reach the light detection means under total reflection conditions,
The total reflection functional member has a columnar cylindrical main body,
The upper surface of the cylindrical body portion is configured to face the light detection means, and the lower surface is configured to face the reaction layer.
On the lower surface of the cylindrical main body,
A wavelength selection function member that removes unnecessary light other than the fluorescence is disposed,
The wavelength selection functional member is
It is arranged only in the central part on the lower surface side of the cylindrical main body.

  In this way, if the light collecting member is composed of a total reflection functional member, the fluorescence generated in the reaction layer can be reliably detected by the light detection means. Accurate fluorescence detection is possible.

  In addition, the total reflection functional member collects the fluorescent light and causes the fluorescent light to reach the light detection means under the total reflection condition. Therefore, there is no need for focusing unlike a lens, and the light detection means, the reaction layer, Can be narrowed.

  Furthermore, the function of the conventional wavelength selection function member can be given to the total reflection function member, and in that case, the function of the conventional wavelength selection function member and the light collecting member can be made only by the total reflection function member. Therefore, the distance between the light detection means and the reaction layer can be further narrowed.

In addition, if the light collecting member has the cylindrical body portion in this way, the fluorescence generated in the reaction layer is incident from the lower surface of the cylindrical body portion and totally reflected in the cylindrical body portion, and further, the upper surface of the cylindrical body portion. By emitting more, this fluorescence can be detected by the light detection means.
Furthermore, if a wavelength selection function member that removes unnecessary light other than fluorescence is disposed on the lower surface of the cylindrical main body, it is possible to reduce detection of stray light other than fluorescence by the light detection means. Ultrahigh-precision fluorescence detection can be performed.
In addition, if the wavelength selection function member is disposed only in the central portion on the lower surface side of the cylindrical main body, for example, the wavelength of auto-fluorescence generated from the dielectric member due to excitation light irradiation or propagation light generated at the time of plasmon generation However, it is possible to reliably remove light of different types or specific wavelengths. For this reason, it is possible to perform ultra-high accuracy fluorescence detection.
Furthermore, if the wavelength selection function member is in the central portion on the lower surface side, it is possible to remove the light other than the fluorescence generated in the reaction layer by focusing on the autofluorescence of the dielectric member below the metal thin film.

Further, the light collecting member used in the surface plasmon enhanced fluorescence sensor of the present invention is:
The cylindrical body portion is a solid cylindrical shape.

  Thus, if the column main body is a solid columnar shape, it is relatively easy to achieve the total reflection condition.

  In addition, since the condensing member of the present invention as described above is specialized only to make it possible to reliably detect the fluorescence by the light detection means, there is no need for focusing as in the conventional lens, and it is simple. Because of the structure, manufacturing costs can be reduced.

Further, the light collecting member used in the surface plasmon enhanced fluorescence sensor of the present invention is:
The wavelength selection function member is further disposed on the upper surface of the cylindrical body part,
The wavelength selection functional member is:
It is characterized in that the wavelength of the light to be removed is different between the upper surface side and the lower surface side.

  If the wavelength selection function member is provided so that the wavelengths of light to be removed are different in this way, for example, the wavelengths such as autofluorescence generated from the dielectric member due to excitation light irradiation and propagation light generated at the time of plasmon generation are different. Two or more specific wavelengths of light can be reliably removed. For this reason, it is possible to perform ultra-high accuracy fluorescence detection.

Further, the light collecting member used in the surface plasmon enhanced fluorescence sensor of the present invention is:
The wavelength selection function member disposed on the upper surface of the cylindrical body part is:
It is arranged on the entire upper surface of the cylindrical main body.

  If the wavelength selection function member is disposed on the entire upper surface of the cylindrical body in this way, only the fluorescence to be detected can be selectively taken out and detected by the light detection means, so that it has an extremely high accuracy. Fluorescence detection can be performed.

Further, the surface plasmon enhanced fluorescence sensor of the present invention,
The light collecting member according to any one of the above is provided.
Thus, if it is a surface plasmon intensification fluorescence sensor which arrange | positions the above-mentioned condensing member, since the condensing member has the structure which is excellent, it can perform a fluorescence detection with super high precision.

Further, the surface plasmon enhanced fluorescence sensor of the present invention,
The distance between the upper end portion of the total reflection functional member and the end portion of the light detection means is 5 mm or less.

  By setting such an interval, it is possible to suppress as much as possible that the fluorescence totally reflected in the light collecting member is scattered outside between the light detection means and the total reflection functional member. Accurate fluorescence detection can be performed.

Further, the surface plasmon enhanced fluorescence sensor of the present invention,
The distance between the lower end portion of the total reflection functional member and the end portion of the reaction layer is within 5 mm.

  By setting such an interval, it is possible to suppress the fluorescence generated in the reaction layer from scattering between the reaction layer and the total reflection functional member as much as possible. It can be performed.

  According to the present invention, since the condensing member has the unique configuration as described above, the condensing efficiency does not decrease and the S / N value does not decrease as in the conventional case, and the reaction layer and the light It is possible to provide a surface plasmon-enhanced fluorescence sensor that suppresses the space between the detecting means and the light condensing member used in the surface plasmon-enhanced fluorescence sensor.

  Further, it is possible to provide a surface plasmon-enhanced fluorescent sensor and a condensing member used for a surface plasmon-enhanced fluorescent sensor that do not require focusing unlike a lens and that can be manufactured at a reduced cost.

FIG. 1 is a schematic view of a surface plasmon enhanced fluorescence sensor of the present invention. FIG. 2 is a schematic view for explaining a first embodiment of a light collecting member used in the surface plasmon enhanced fluorescence sensor of the present invention. 3A is a top view and a cross-sectional view taken along line AA of the solid cylindrical light-collecting member, and FIG. 3B is a top view and a cross-sectional view taken along line BB of the hollow cylindrical light-collecting member. FIG. 4 is a schematic diagram illustrating a second embodiment of the light collecting member used in the surface plasmon enhanced fluorescence sensor according to the present invention, in which a concave shape is provided on the upper and lower surfaces of the light collecting member. . FIG. 5 is a schematic diagram illustrating a third embodiment of the light collecting member used in the surface plasmon enhanced fluorescence sensor of the present invention, in which a wavelength selection function member is provided on the upper and lower surfaces of the light collecting member. It is. FIG. 6 is a schematic view of a conventional surface plasmon enhanced fluorescence sensor.

  Hereinafter, embodiments of the present invention will be described in more detail based on the drawings. FIG. 1 is a schematic diagram of a surface plasmon enhanced fluorescence sensor of the present invention, FIG. 2 is a schematic diagram for explaining a first embodiment of a light collecting member used in the surface plasmon enhanced fluorescence sensor of the present invention, and FIG. (A) is a top view and AA sectional view of a solid cylindrical condensing member, and FIG. 3 (b) is a top view and BB sectional view of a hollow cylindrical condensing member.

  In the surface plasmon enhanced fluorescence sensor and the surface plasmon enhanced fluorescence sensor of the present invention, the light collection efficiency does not decrease and the S / N value does not decrease, and there is no gap between the reaction layer and the light detection means. It is possible to reduce the manufacturing cost by suppressing the widening, further eliminating the need for focusing.

<Surface plasmon enhanced fluorescence sensor 10>
As shown in FIG. 1, the surface plasmon enhanced fluorescence sensor 10 of the present invention includes a metal thin film 12, a reaction layer 14 formed on one side surface of the metal thin film 12, and a dielectric member 16 formed on the other side surface. And a chip structure 18 having the following.

  The chip structure 18 includes a light source 22 that is incident on the dielectric member 16 and irradiates the excitation light 20 toward the metal thin film 12 on the dielectric member 16 side. A light receiving means 26 for receiving the metal thin film reflected light 24 reflected by the light is provided.

  The excitation light 20 emitted from the light source 22 is preferably a laser beam, 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 suitable. .

  On the other hand, on the reaction layer 14 side of the chip structure 18, a light detection means 30 that receives the fluorescence 28 generated in the reaction layer 14 is provided. As the light detection means 30, it is preferable to use an ultra-sensitive photomultiplier tube or a CCD image sensor capable of multipoint measurement.

  In the surface plasmon enhanced fluorescence sensor 10 of the present invention, a light collecting member 32 having a total reflection functional member 34 is disposed between the reaction layer 14 of the chip structure 18 and the light detection means 30.

  Such a condensing member 32 is configured to condense the fluorescent light 28 and cause the fluorescent light 28 to reach the light detection means 30 under total reflection conditions. In use of such a surface plasmon enhanced fluorescence sensor 10, for example, a reaction layer 14 in which an analyte labeled with a fluorescent substance is captured is provided on the metal thin film 12. The body member 16 is irradiated with the excitation light 20, and the excitation light 20 is incident on the metal thin film 12 at a specific angle (resonance angle 44), so that a dense wave (surface plasmon) is generated on the metal thin film 12. can do.

  Note that when a close-packed wave (surface plasmon) is generated on the metal thin film 12, the excitation light 20 and the electronic vibration in the metal thin film 12 are coupled, and the signal of the metal thin film reflected light 24 changes (the amount of light decreases). Therefore, it is only necessary to find a point where the signal of the metal thin film reflected light 24 received by the light receiving means 26 changes (the amount of light decreases).

  Then, due to this rough wave (surface plasmon), the fluorescent material of the reaction layer 14 on the metal thin film 12 is efficiently excited, thereby increasing the light quantity of the fluorescent light 28 emitted from the fluorescent material. By collecting by the light detection means 30 via 32, an extremely small amount and / or extremely low concentration of the analyte can be detected.

  The metal thin film 12 of the chip structure 18 is preferably made of at least one metal selected from the group consisting of gold, silver, aluminum, copper, and platinum, more preferably gold, It consists of a metal alloy.

  Such a metal is suitable for the metal thin film 12 because it is stable against oxidation and the electric field enhancement due to the dense wave (surface plasmon) increases. Examples of the method for forming the metal thin film 12 include sputtering, vapor deposition (resistance heating vapor deposition, electron beam vapor deposition, etc.), electrolytic plating, electroless plating, and the like. Among 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 12 is in the range of gold: 5 to 500 nm, silver: 5 to 500 nm, aluminum: 5 to 500 nm, copper: 5 to 500 nm, platinum: 5 to 500 nm, and alloys thereof: 5 to 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 12 is within the above range, close-packed waves (surface plasmons) are easily generated, which is preferable. Moreover, if it is the metal thin film 12 which has such thickness, a magnitude | size (length x width) will not be specifically limited.

  On the other hand, the reaction layer 14 contains a sample in which a fluorescent substance is bound to an analyte, and examples of such a sample include blood, serum, plasma, urine, nasal fluid, saliva, stool, and body cavity. Fluid (spinal fluid, ascites, pleural effusion, etc.).

  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 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, Specific examples thereof include a complex, and may be a carcinoembryonic antigen such as AFP (α-fetoprotein), a tumor marker, a signal transduction substance, a hormone, and 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 28 by being irradiated with predetermined excitation light 20 or excited by using a field effect. The fluorescence 28 in this specification includes various types of light emission such as phosphorescence.

As the dielectric member 16, various optically transparent inorganic substances, natural polymers, and synthetic polymers can be used. From the viewpoint of chemical stability, manufacturing stability, and optical transparency, silicon dioxide (SiO 2 ₂ ) or titanium dioxide (TiO ₂ ).

  Further, such a surface plasmon enhanced fluorescence sensor 10 adjusts an optimum angle (resonance angle 44) of surface plasmon resonance by the excitation light 20 irradiated from the light source 22 to the metal thin film 12, and therefore an angle variable unit (not shown). ), A computer (not shown) for processing information input to the light receiving means 26 and / or the light detecting means 30 or the like.

  Here, the angle variable unit (not shown) synchronizes the light receiving means 26 and the light source 22 in order to obtain the total reflection attenuation (ATR) condition with a servo motor, and enables an angle change of 45 to 85 °, and the resolution. Is preferably 0.01 ° or more.

  As described above, the surface plasmon enhanced fluorescence sensor 10 of the present invention having such a configuration has a characteristic structure in the configuration of the light collecting member 32. Hereinafter, the light collecting member 32 will be described in detail.

<Condensing member 32>
The condensing member 32 used in the surface plasmon enhanced fluorescence sensor 10 of the present invention condenses the excited fluorescence 28 as shown in FIG. 2, and causes the fluorescence 28 to reach the light detection means 30 under total reflection conditions. The total reflection functional member 34 is configured as described above.

  The total reflection functional member 34 has a cylindrical main body 36, and the side facing the light detection means 30 is the upper surface 38, and the side facing the reaction layer 14 is the lower surface 40. The material of the total reflection functional member 34 may be any material as long as the fluorescence 28 can reach the light detection means 30 under the total reflection condition, but preferably glass or a transparent resin is used. Is preferred.

  In addition, it is preferable that the distance L1 of the space | interval of the upper surface 38 edge part of the total reflection functional member 34 and the edge part of the optical detection means 30 is less than 5 mm, More preferably, it is less than 2 mm.

  On the other hand, the distance L2 between the end portion of the lower surface 40 of the total reflection functional member 34 and the end portion of the reaction layer 14 is preferably within 5 mm, and more preferably within 2 mm.

  When the distance is as described above, the fluorescence 28 totally reflected in the light collecting member 32 is prevented from being scattered outside between the light detection means 30 and the total reflection functional member 34 as much as possible. In addition, since it is possible to suppress the fluorescence 28 generated in the reaction layer 14 from being scattered outside between the reaction layer 14 and the total reflection functional member 34 as much as possible, ultrahigh-precision fluorescence detection can be performed. It can be carried out.

  By the way, the condensing member 32 configured in this way has a cylindrical main body 36 with a solid cylindrical shape as shown in FIG. 3 (a) or as shown in FIG. 3 (b). It can be made into a hollow cylindrical shape.

  In addition, when the condensing member 32 is a solid cylindrical shape as shown in FIG. 3A, it is relatively easy to make the fluorescent light 28 satisfy the total reflection condition. Further, as shown in FIG. 3B, when the light collecting member 32 has a hollow cylindrical shape, the cylindrical inner wall surface or outer wall surface is, for example, a mirror surface layer (not shown), and the fluorescent light 28 is in a condition of total reflection. Can be.

  Thus, since the condensing member 32 used in the surface plasmon enhanced fluorescence sensor 10 of the present invention has the unique structure as described above, it is possible to detect the fluorescence 28 generated in the reaction layer 14 with extremely high accuracy. Can do.

  Next, the condensing member 32 shown in FIG. 4 is a schematic view in the second embodiment of the present invention. The condensing member 32 shown in FIG. 4 has basically the same configuration as the condensing member 32 of the first embodiment shown in FIG. 2 and FIG. Detailed description thereof will be omitted.

  The light collecting member 32 shown in FIG. 4 is different from the first embodiment in that the upper surface 38 and the lower surface 40 of the total reflection functional member 34 are concave.

  Thus, if the lower surface 40 of the total reflection functional member 34 has a concave shape, the fluorescent light 28 generated in the reaction layer 14 can be efficiently collected by the concave shape portion 46 and taken into the cylindrical body portion 36. . Further, by making the upper surface 38 of the total reflection functional member 34 into a concave shape, it is possible to send the fluorescent light 28 totally reflected in the cylindrical main body portion 36 to the light detection means 30 in a state where it is condensed by the concave shape portion 48. is there.

  For this reason, the fluorescence 28 generated in the reaction layer 14 can be collected more efficiently, and ultrahigh-precision fluorescence detection can be performed.

  In FIG. 4, the concave-shaped portions 46 and 48 are provided on both sides of the upper surface 38 and the lower surface 40 of the total reflection functional member 34, but may be formed on only one of them, as appropriate. It is selectable. However, in order to efficiently collect the fluorescent light 28 generated in the reaction layer 14 and take it into the cylindrical main body 36, it is preferable to provide a concave-shaped portion 46 on the lower surface 40 of the total reflection functional member 34.

  Next, the condensing member 32 shown in FIG. 5 is a schematic view in the third embodiment of the present invention. The condensing member 32 shown in FIG. 5 has basically the same configuration as the condensing member 32 of the first embodiment shown in FIGS. 2 and 3, and therefore the same reference numerals are assigned to the same constituent members. Detailed description thereof will be omitted.

  The condensing member 32 shown in FIG. 5 is implemented in that wavelength selection function members 42 and 50 for removing unnecessary light other than the fluorescence 28 are disposed on the upper surface 38 and the lower surface 40 of the cylindrical main body 36. Different from Example 1.

  If the wavelength selection function members 42 and 50 are provided in this way, stray light other than the fluorescence 28 is not detected by the light detection means 30, and therefore ultra-high-precision fluorescence detection can be performed. .

  The wavelength selection function members 42 and 50 disposed on the upper surface 38 and the lower surface 40 of the cylindrical main body 36 are configured such that the wavelengths of light to be removed are different between the upper surface 38 side and the lower surface 40 side. It is preferable.

  Thus, if the wavelengths of light to be removed are different, light having a specific wavelength can be reliably removed.

  In FIG. 5, the wavelength selection function member 50 on the lower surface 40 side is provided only in a part (center portion) of the lower surface 40, but this is a range 52 of the fluorescence 28 emitted from the fluorescent material generated in the reaction layer 14. Is a hemispherical shape, of the light other than the fluorescence 28 generated in the reaction layer 14, the autofluorescence range 54 of the dielectric member 16 below the metal thin film 12 is rod-shaped. This is to remove the target.

  The wavelength selection function member 42 on the upper surface 38 side is provided on the entire upper surface 38, and here, the propagation light generated mainly when plasmons are generated is removed.

  In addition, as such wavelength selection function members 42 and 50, an optical filter, a cut filter, etc. can be used.

  Examples of the optical filter include a neutral density (ND) filter and a diaphragm lens. The cut filter includes external light (illumination light outside the device), excitation light (excitation light transmission component), stray light (excitation light scattering component at various points), and plasmon scattering light (excitation light originated from plasmon A filter that removes various types of noise light such as scattered light generated due to 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.

  If the wavelength selection function members 42 and 50 are provided in accordance with the generation location of light to be removed in this way, the fluorescence 28 is not removed more than necessary, and only the fluorescence 28 to be detected is selectively selected. Therefore, the light detection means 30 can detect the fluorescent light, so that it is possible to detect fluorescence with extremely high accuracy.

  In FIG. 5, the wavelength selection function member 50 disposed on the lower surface 40 side is illustrated as being provided at a position slightly inserted on the cylindrical body 36 side, but this is for convenience of explanation. For example, it may be disposed on the lower surface 40.

  The preferred embodiments of the surface plasmon enhanced fluorescence sensor 10 and the light collecting member 32 used therefor have been described above, but the present invention is not limited to the above embodiments.

  For example, the first to third embodiments of the present invention are appropriately combined, such as coating the wavelength-selective function member 42 shown in FIG. 5 on the concave shape portions 46 and 48 of the light collecting member 32 shown in FIG. However, various modifications can be made without departing from the object of the present invention.

DESCRIPTION OF SYMBOLS 10 Surface plasmon enhancement fluorescence sensor 12 Metal thin film 14 Reaction layer 16 Dielectric member 18 Chip structure 20 Excitation light 22 Light source 24 Metal thin film reflected light 26 Light receiving means 28 Fluorescence 30 Photodetection means 32 Condensing member 34 Total reflection functional member 36 Cylinder Main body 38 Upper surface 40 Lower surface 42 Wavelength selection functional member 44 Resonance angle 46 Concave surface portion 48 Concave surface portion 50 Wavelength selection functional member 52 Range of fluorescence emitted by fluorescent material generated in reaction layer 54 Autofluorescence range L1 Distance L2 Distance Distance of 100 Surface plasmon enhanced fluorescence sensor 102 Metal thin film 104 Reaction layer 106 Dielectric member 108 Chip structure 110 Excitation light 112 Light source 114 Metal thin film reflected light 116 Light receiving means 118 Fluorescence 120 Photodetection means 122 Condensing member 124 Wavelength selection function member 134 Resonance angle

Claims (7)

By irradiating one side surface of the metal thin film with excitation light and enhancing the electric field on the metal thin film, the fluorescent material in the reaction layer formed on the other side surface of the metal thin film is excited, thereby enhancing the fluorescence. A condensing member used in a surface plasmon-enhanced fluorescence sensor that is detected by a light detection means,
The condensing member is
Between the reaction layer and the light detection means,
Consists of a total reflection functional member that collects the excited fluorescence and causes the fluorescence to reach the light detection means under total reflection conditions,
The total reflection functional member has a columnar cylindrical main body,
The upper surface of the cylindrical body portion is configured to face the light detection means, and the lower surface is configured to face the reaction layer.
On the lower surface of the cylindrical main body,
A wavelength selection function member that removes unnecessary light other than the fluorescence is disposed,
The wavelength selection functional member is
A condensing member for use in a surface plasmon-enhanced fluorescent sensor, wherein the condensing member is disposed only in a central portion on a lower surface side of the cylindrical main body. The cylindrical body portion is
The condensing member used for the surface plasmon enhanced fluorescence sensor according to claim 1 , wherein the condensing member has a solid cylindrical shape. The wavelength selection function member is further disposed on the upper surface of the cylindrical body part,
The wavelength selection functional member is:
The condensing member used for the surface plasmon enhanced fluorescence sensor according to claim 1 or 2 , wherein the wavelength of the light to be removed is different between the upper surface side and the lower surface side. The wavelength selection function member disposed on the upper surface of the cylindrical body part is:
The condensing member used in the surface plasmon enhanced fluorescence sensor according to claim 3 , wherein the condensing member is disposed on the entire upper surface of the cylindrical main body. Surface plasmon enhanced fluorescence sensor, characterized in that formed by disposing the light collector according to any one of claims 1 to 4. 6. The surface plasmon enhanced fluorescence sensor according to claim 5 , wherein a distance between an upper end portion of the total reflection functional member and an end portion of the light detection means is within 5 mm. The surface plasmon enhanced fluorescence sensor according to claim 5 or 6 , wherein a distance between a lower surface end portion of the total reflection functional member and an end portion of the reaction layer is within 5 mm.

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