JP6992164B2 - Detection device - Google Patents

Description

The present invention relates to a detection device that detects a substance contained in a gas sample.

A detection device for detecting a specific substance contained in a gas sample by detecting a decrease in coenzyme accompanying an enzymatic reaction is known.

As such a detection device, for example, it is possible to detect a substrate contained in a gas sample by utilizing the fact that NADH, which is a coenzyme, decreases with the reaction of a ketone such as acetone or a substrate such as nonenal. The biosensor system to be performed is disclosed in Patent Document 1. Specifically, the biosensor system of Patent Document 1 detects a decrease in the coenzyme by utilizing the fact that the coenzyme emits fluorescence when it is irradiated with a specific excitation light.

Japanese Unexamined Patent Publication No. 2016-220573

Here, the amount of fluorescence emitted by the coenzyme affects the detection accuracy. Therefore, in order to increase the amount of detectable fluorescence, it is conceivable to efficiently irradiate the coenzyme with the excitation light emitted from the light source and efficiently guide only the fluorescence emitted by the coenzyme to the detection unit. Therefore, in the biosensor system of Patent Document 1, an optical fiber probe is placed in the vicinity of the enzyme in which the concentration of the coenzyme changes due to the substrate, and the coenzyme is irradiated with excitation light through the optical fiber probe, and the coenzyme is coenzyme. Fluorescence emitted by is detected.

However, since the numerical aperture (NA) of the optical fiber is small, the utilization efficiency of the excitation light is significantly reduced when combined with the light source required for the configuration of the device and the lens having an appropriate numerical aperture, and the detection of fluorescence is detected. One of the challenges is that the efficiency will be low as well.

Further, when the detection device is mounted on a moving body such as an automobile, the mounting space is limited. Therefore, the detection device is required to be miniaturized by reducing the number of parts.

The present invention has been made in view of the above points, and is a detection device capable of improving the detection accuracy of a specific substance by improving the utilization efficiency of excitation light and fluorescence and reducing the size of the device. Is one of the issues to be provided.

The detection device according to claim 1 of the present application holds a gas flow path through which a gas sample flows, a solution containing a coenzyme that emits fluorescence when excited by excitation light before or after a catalytic reaction with the gas sample. A reaction section containing a holding section and an enzyme holding film holding an enzyme that catalyzes the catalytic reaction and arranged on one axis, and a reaction section provided in contact with the reaction section on the one axis. It is characterized by having a light guide member that forms a light guide path along the one axis, and a detection unit that detects the fluorescence that has passed through the light guide path.

It is sectional drawing which shows the structure of the detection apparatus which concerns on Example 1. FIG. It is an enlarged sectional view of the reaction part of FIG. It is explanatory drawing explaining the optical path of the excitation light of the detection apparatus which concerns on Example 1. FIG. It is explanatory drawing explaining the optical path of fluorescence of the detection apparatus which concerns on Example 1. FIG. It is sectional drawing which shows the structure of the detection apparatus which concerns on Example 2. FIG. It is explanatory drawing explaining the optical path of the excitation light of the detection apparatus which concerns on Example 2. FIG. It is sectional drawing which shows the structure of the detection apparatus which concerns on the modification of Example 2. FIG. It is sectional drawing which shows the structure of the detection apparatus which concerns on Example 3. FIG. It is sectional drawing which shows the structure of the detection apparatus which concerns on Example 4. FIG. It is explanatory drawing explaining the optical path of the excitation light of the detection apparatus which concerns on Example 4. FIG. It is explanatory drawing explaining the optical path of fluorescence of the detection apparatus which concerns on Example 4. FIG. It is sectional drawing which shows the structure of the detection apparatus which concerns on Example 5. FIG. It is sectional drawing which shows the structure of the detection apparatus which concerns on Example 6.

FIG. 1 shows a cross section of a biosensor 10 as a detection device according to an embodiment of the present invention along one axis AX.

In FIG. 1, the biosensor 10 as a detection device is a device that detects the fluorescence emitted by the coenzyme that binds to the apoenzyme and detects the substrate to be detected.

Specifically, the coenzyme used for detecting the substrate of the biosensor 10 is excited by the excitation light in one of the states before and after the reaction of the substrate and emits fluorescence. Therefore, the biosensor 10 detects the substrate by utilizing the fact that the amount of fluorescence emitted by the coenzyme changes due to the reaction of the substrate.

For example, as shown in Chemical formula 1, when NADH (reduced nicotinamide adenine dinucleotide) is used as a coenzyme, the enzyme S-ADH catalyzes the reaction in which the substrate acetone is reduced to 2-propanol. do. At this time, NADH, which is a coenzyme, is oxidized to NAD + (oxidized nicotinamide adenine dinucleotide) by an enzymatic reaction.

Here, NADH receives excitation light of a predetermined wavelength and emits fluorescence, but does not emit fluorescence even if NAD + receives excitation light of the same wavelength. Therefore, the fluorescence intensity detected before and after this reaction varies.

The biosensor 10 of the present invention is a device for measuring the concentration of a substrate by measuring the amount of fluorescence emitted by this NADH.

In FIG. 1, the light source LT is a light emitting device that emits excitation light. The light source LT is, for example, an ultraviolet light emitting diode that emits ultraviolet light having a peak wavelength of 340 nm as excitation light. The light emitting device is not limited to the ultraviolet light emitting diode, and for example, an ultraviolet laser diode, a mercury lamp, or the like can be used.

On one axis AX, an excitation optical optical system 20 which is an optical system for the excitation light emitted from the light source LT is provided. The excitation optical optical system 20 collects the excitation light toward one axis AX. One axis AX is the same axis as the optical axis of the excitation light in this embodiment.

The excitation optical optical system 20 is a collimating lens 21 that makes the excitation light parallel, and a ball lens 22 that is a condensing lens that collects the excitation light made parallel by the collimating lens 21 toward one axis AX. including. The excitation optical optical system 20 is configured to have at least a numerical aperture higher than the numerical aperture of the optical fiber.

Since the ball lens 22 has a short focal length among the condenser lenses, the configuration of the biosensor 10 can be made smaller. Further, the ball lens 22 has a large numerical aperture (NA) among the condenser lenses, and can capture more excitation light.

An excitation light bandpass filter EF that transmits the wavelength of the excitation light is provided between the ball lens 22 and the collimating lens 21. The band transmitted by the excitation light bandpass filter EF is a band including the wavelength of the excitation light excited by the coenzyme. In this example, NADH is used as a coenzyme. NADH absorbs ultraviolet rays of 340 nm and emits fluorescence. Therefore, the range of wavelengths transmitted by the excitation light bandpass filter EF is set to 330 to 350 nm.

A flow cell 30 is provided in the AX on one axis. The flow cell 30 functions as a reaction unit on which the enzymatic reaction shown in Chemical formula 1 is carried out. The flow cell 30 has a gas flow path 31 through which a gas sample containing a substrate flows, a solution flow path 32 as a solution holding portion for holding a solution containing a coenzyme, and an enzyme holding film 33 for holding an enzyme. Here, the solution flow path 32 may have a structure such as a tube through which a solution containing a coenzyme flows, or may have a structure such as a closed container in which the solution does not flow. good.

The substrate contains either a ketone group or an aldehyde group. As the coenzyme, one that is excited by excitation light and emits fluorescence in one of the states before and after the reaction of the substrate is used. Examples of such coenzymes include NADH, NADPH (reduced nicotinamide adenine dinucleotide phosphate) and the like. The chemical structure of the coenzyme changes reversibly between the two states before and after the reaction of the substrate.

When NADH or NADPH is used as the coenzyme, for example, alanine dehydrogenase, alcohol dehydrogenase, aldehyde dehydrogenase, isocitrate dehydrogenase, uridine-5'-diphospho-glucose dehydrogenase, galactose dehydrogenase. Elementary enzyme, formic acid dehydrogenase, glyceraldehyde-3-phosphate dehydrogenase, glycerol dehydrogenase, glycerol-3-phosphate dehydrogenase, glucose dehydrogenase, glucose-6-phosphate dehydrogenase, Glutamic acid dehydrogenase, cholesterol dehydrogenase, sarcosine dehydrogenase, sorbitol dehydrogenase, carbonate dehydrogenase, lactic acid dehydrogenase, 3-hydroxybutyric acid dehydrogenase, pyruvate dehydrogenase, fructose dehydrogenase, 6 -Phosphogluconic acid dehydrogenase, formaldehyde dehydrogenase, mannitol dehydrogenase, malic acid dehydrogenase, leucine dehydrogenase and the like can be mentioned, and in particular, ketone (NADH or NADPH is used as an electron donor). Enzymes that reduce acetone, 2-butanone, 2-pentanone, etc.) or aldehydes (nonenal, ethyl vinylketone, etc.), more specifically, secondary alcohol dehydrogenase (S-ADH) (secondary alcohol dehydrogenase). (secondary alcohol dehydrogenase) EC: 1.1.1.x), enone reductase (ER1) (enone reductase type 1, ER1) and the like can be used.

A light guide member 40 is provided in contact with the flow cell 30 on one axis AX. The light guide member 40 is formed in a columnar shape in this embodiment. The light guide member 40 may have a shape other than a columnar shape, and may be, for example, a columnar shape having a non-planar end face, a polygonal columnar shape, or a truncated cone shape.

The light guide member 40 is made of the same material such as glass having a uniform refractive index. The light guide member 40 is not limited to the same material such as glass having a uniform refractive index, and may be composed of two materials, a core and a clad, which have different refractive indexes from each other, for example. Further, the light guide member 40 may be made of a material having little absorption with respect to the measured fluorescence wavelength, for example, having an absorption coefficient of 0.1 or less. The light guide member 40 has a light guide path 41 formed along one axis AX.

On one axial AX, a fluorescence optical system 50, which is an optical system for fluorescence emitted from the light guide member 40, is provided. The fluorescence optical system 50 collects the fluorescence emitted from the light guide member 40 toward one axis AX.

The fluorescent optical system 50 includes a collimated lens 51 that makes the fluorescence parallel light, and a condenser lens 52 that collects the fluorescence made into parallel light by the collimated lens 51 on one axis AX.

A fluorescence bandpass filter FF that transmits a band including a wavelength of fluorescence is provided between the condenser lens 52 and the collimating lens 51. The wavelength of fluorescence emitted by the excitation of NADH, which is a coenzyme, is 450 to 510 nm, more specifically, around 491 nm. Therefore, in this embodiment, the wavelength range transmitted by the fluorescent bandpass filter FF is 440 to 510 nm.

On one axis AX, a detection unit 60 for detecting fluorescence that has passed through the fluorescence optical system 50 is provided. The detection unit 60 includes a photomultiplier tube, a photodiode detector, and a spectrophotometer including these, and detects the concentration of the substrate in the gas sample based on the amount of fluorescent light detected or the spectral characteristics.

The case C is formed in a tubular shape that covers the periphery of each of the light source LT, the excitation optical optical system, the flow cell 30, the light guide member 40, the fluorescent optical system, and the detection unit 60. That is, the case C houses each of the light source LT, the excitation optical optical system 20, the flow cell 30, the light guide member 40, the fluorescent optical system 50, and the detection unit 60. Therefore, the case C is configured to prevent outside light from entering the inside of the case C.

In the case C, two through holes HA provided so as to penetrate the case C in a direction perpendicular to one axis AX are formed. By inserting the gas flow path 31 through the two through holes HA, the gas flow path 31 can be mounted on one axis AX. That is, the two through holes HA function as a first mounting portion on which the gas flow path 31 can be mounted on one axis AX.

The case C is formed with two through holes HB provided so as to penetrate the case C in a direction perpendicular to one axis AX. By inserting the solution flow path 32 having a tubular structure into the two through holes HB, the solution flow path 32 can be mounted on one axis AX. That is, the two through holes HB function as a second mounting portion on which the solution flow path 32 can be mounted on one axis AX.

The case C is formed with a protruding portion P formed so as to approach the inner walls facing each other in the direction perpendicular to one axis AX. The protrusion P is formed along the circumferential direction of the inner wall of the case C. Further, the protruding portion P is formed between the through hole HA and the through hole HB on one axis AX. By fitting the enzyme-retaining membrane 33 into the protrusion P, the enzyme-retaining membrane 33 is mounted on one axis AX. That is, the protruding portion P functions as a third mounting portion on which the enzyme holding membrane 33 can be mounted on one axis AX.

In this way, the gas flow path 31, the liquid flow path 32, and the enzyme holding membrane 33 are each removable to the case C. At least one of the gas flow path 31, the liquid flow path 32, and the enzyme holding membrane 33 may be detachable, and the rest may be fixed to the case C.

When the solution flow path 32 has a structure like a closed container, it is not necessary to provide the through hole HB. In this case, it is preferable to provide a groove G formed by being recessed outward from the inner wall of the case C. Further, the groove G may be formed along the circumferential direction of the inner wall of the case C. By fitting the solution flow path 32 in the shape of a closed container into the groove G, the solution flow path 32 can be mounted on one axis AX. In this case, the groove G functions as a second mounting portion on which the solution flow path 32 can be mounted on one axis AX.

FIG. 2 shows an enlarged cross section of the flow cell 30 along one axis AX. As shown in FIG. 2, on the light source LT side of the flow cell 30, a window W for transmitting excitation light is provided, and a gas flow path 31 through which a gas sample containing a substrate flows is provided. A through hole H1 that penetrates the gas flow path 31 and the outside is provided on the detection unit 60 side of the gas flow path 31.

A solution flow path 32 through which a solution containing a coenzyme flows is provided on the detection unit 60 side of the flow cell 30. The solution flow path 32 includes an upstream connection portion provided on the upstream side in the solution flow direction, a downstream connection portion provided on the downstream side in the solution flow direction, an upstream connection portion, and a downstream connection portion. It has a curved portion formed by being curved from the portion toward the light source LT side. A through hole H2 that penetrates the solution flow path 32 and the outside is provided on the gas flow path 31 side of the curved portion of the solution flow path 32.

The solution flowing through the solution flow path 32 contains a coenzyme and a buffer solution having a pH value in consideration of the enzyme and the optimum pH value of the coenzyme as components.

The enzyme holding membrane 33 for holding the enzyme is provided in contact with both the gas flow path 31 and the solution flow path 32 so as to close the through hole H1 of the gas flow path 31 and the through hole H2 of the solution flow path 32. ing. That is, the enzyme retention membrane 33 is a diaphragm in which the retained enzyme can come into contact with the solution in the solution flow path 32 and the gas sample in the gas flow path 31, and separates the solution flow path 32 and the gas flow path 31. ..

The enzyme-retaining membrane 33 has an enzyme immobilized on a carrier which is a membrane material. Examples of the carrier of the enzyme retention film 33 include polytetrafluoroethylene, polydimethylsiloxane, polypropylene, polyethylene, polymethylmethacrylate, polystyrene, polyvinylidene fluoride, nitrocellulose, cellulose and the like.

The flow cell 30 is formed by being recessed along one axis AX so as to face the light source LT side from the detection unit 60 side, and has a through hole H3 penetrating the solution flow path 32 and the outside. The through hole H3 has a small diameter portion having a size equivalent to the outer diameter of the light guide member 40, and an enlarged diameter portion formed by expanding the diameter from the small diameter portion toward the fluorescence optical system 50.

Therefore, by fitting the light guide member 40 to the small diameter portion, the light guide member 40 is held by the flow cell 30. In other words, the flow cell 30 functions as a holding member for holding the light guide member 40.

The flow cell 30 has a space SP between the side surface SS of the light guide member 40 extending along one axis AX and the wall portion of the enlarged diameter portion of the through hole H3. Assuming that the refractive index of the light guide member 40 is n ₁ and the refractive index of the space SP is n ₂ , the numerical aperture (NA) is given by the following equation.

Here, in order to maximize the numerical aperture (NA) under the condition that the refractive index n ₁ of the light guide member 40 is fixed, it is necessary to set n ₂ to 1, that is, the space SP to be air. Therefore, the numerical aperture (NA) of the light guide member 40 is maximized by forming an air layer around the side surface SS.

Here, the light guide path 41 of the light guide member 40 may be formed so as to reduce the amount of light guided by the excitation light. Specifically, the incident angle of the excitation light passing through the solution flow path 32 of the flow cell 30 with respect to at least a part of the light guide member 40 is from the maximum light receiving angle that can be totally reflected on the inner surface of the light guide path 41 of the light guide member 40. It is good to make it larger.

FIG. 3 shows an aspect of the excitation light emitted from the light source LT. In FIG. 3, the alternate long and short dash arrow indicates the excitation light LT1. The excitation light LT1 emitted from the light source LT is converted into parallel light by the collimating lens 21.

In the excitation light LT1 made into parallel light by the collimated lens 21, light having a wavelength other than a predetermined band is removed by the excitation light bandpass filter EF. The excitation light LT1 that has passed through the excitation light bandpass filter EF is focused by the ball lens 22 toward the solution flow path 32 of the flow cell 30.

The ball lens 22 has the shortest focal length among the biconvex lenses. Therefore, by using the ball lens 22 in the excitation optical optical system 20, the amount of excitation light LT1 incident at an incident angle larger than the maximum light receiving angle of the light guide path 41 can be increased. Here, the ball lens 22 has poor aberration but has a short focal length, which is advantageous for miniaturization of the biosensor 10. Therefore, by increasing the diameter of the light guide member 40, defocusing due to deterioration of the aberration of the ball lens 22 is allowed. That is, the ideal diameter of the light guide member 40 is the minimum diameter that allows the size of the light source LT and the lens aberration. Further, when the excitation light LT1 is used as the annular light and the diameter of the annular light incident on the ball lens 22 is increased, the aberration of the ball lens 22 can be reduced and the focal length can be further shortened. Therefore, it becomes easy to increase the amount of the excitation light LT1 incident beyond the maximum light receiving angle of the light guide path 41.

Further, the excitation optical optical system 20 including the ball lens 22 is configured with a numerical aperture larger than the numerical aperture of the light guide member 40. Therefore, the excitation light LT1 incident on the light guide path 41 at an acute angle with respect to one axis AX increases. That is, the amount of the excitation light LT1 incident on the light guide path 41 increases at an incident angle larger than the maximum light receiving angle of the light guide path 41. As a result, the amount of the excitation light LT1 transmitted to the outside without guiding the light guide member 40 increases.

Further, even when the optical system is not configured with a numerical aperture larger than the numerical aperture of the light guide member 40 as described above, as long as the excitation light LT1 shows an annular distribution, as described below, as described below. By arranging the collimating lens in the subsequent stage, the collimation of the excitation light LT1 (guide to the detection unit 60) can be suppressed.

Here, the excitation light LT1 that has passed through the flow cell 30 is incident on the light guide member 40 at various angles of incidence. At that time, the excitation light LT1 incident at an incident angle equal to or less than the maximum light receiving angle that can be totally reflected on the inner surface of the light guide path 41 has a constant distribution under the influence of the light source LT and the excitation optical optical system 20. The distribution of the excitation light LT1 is maintained also in the light guide path 41, and as a result, the shading of the excitation light LT1 occurs in the light guide path 41.

The collimating lens 51 is arranged so that the faint light of the excitation light LT1 is collimated in the collimating lens 51. That is, the collimating lens 51 is arranged so that the excitation light LT1 is defocused at the focal position of the collimating lens 51 in the light guide path 41. By arranging the collimating lens 51 in this way, many excitation lights L1 can be diffused without being collimated by the collimating lens 51.

The excitation light LT1 made into parallel light by the collimated lens 51 is reflected by the fluorescent bandpass filter FF.

FIG. 4 shows an aspect of fluorescence emitted from the flow cell 30. In FIG. 4, the alternate long and short dash arrow indicates fluorescent LT2. When the coenzyme receives the excitation light LT1, it emits a fluorescent LT2. The fluorescent LT 2 passes through the solution of the solution flow path 32 and is incident on the light guide path 41 of the light guide member 40. The fluorescent LT2 that has guided the light guide path 41 is emitted from the emission end of the light guide member 40 toward the collimating lens 51.

In the fluorescent LT2 collimated by the collimating lens 51, light having a wavelength other than a predetermined band is removed by the fluorescent bandpass filter FF. The fluorescent LT2 that has passed through the fluorescent bandpass filter FF is focused toward the detection unit 60 by a condenser lens.

As described above, according to the biosensor 10 which is the detection device of the present invention, the excitation light LT1 emitted from the light source LT is applied to the flow cell 30 without going through the optical fiber used in the conventional detection device. To. Therefore, since it is not necessary to configure the excitation optical optical system 20 according to the numerical aperture of the optical fiber, it is possible to configure the excitation optical optical system 20 with a numerical aperture higher than the numerical aperture of the optical fiber.

As a result, the biosensor 10 has a high utilization efficiency of the excitation light LT1, and the amount of fluorescence emitted from the coenzyme increases, so that the detection accuracy of the specific substance can be improved. Further, since the biosensor 10 does not have an optical fiber, the number of parts can be reduced and the size of the device can be reduced.

Further, the biosensor 10 has a light guide member 40 provided in contact with the flow cell 30. As a result, a part of the excitation light LT1 incident on the light guide path 41 beyond the maximum light receiving angle of the light guide path 41 is transmitted through the light guide path 41 without guiding. Therefore, it is possible to reduce the amount of the excitation light LT1 detected by the detection unit 60, and it is possible to improve the detection accuracy.

The biosensor 10 according to the second embodiment will be described. The biosensor 10 according to the second embodiment is different from the biosensor 10 of the first embodiment in that it includes a light-shielding member for forming the radiation distribution of the excitation light LT1 emitted from the light source LT into an annular shape. The same configuration as that of the first embodiment will be omitted by assigning the same reference numerals to the same parts, and the same applies to the subsequent examples.

FIG. 5 shows a cross section along one axis AX of the biosensor 10 according to the second embodiment. As shown in FIG. 5, the excitation optical optical system 20 includes a light-shielding member 70 arranged on one axis AX and capable of light-shielding the excitation light LT1.

The light-shielding member 70 is formed in a disk shape, for example. The size of the light-shielding member 70 is preferably formed to be larger than the diameter of the light guide path 41 of the light guide member 40. By arranging the light-shielding member 70 thus formed on one axis AX, the excitation light LT1 traveling straight on one axis AX can be blocked.

FIG. 6 shows an aspect of the excitation light LT1 emitted from the light source LT in the biosensor 10 of the second embodiment. In FIG. 6, the alternate long and short dash arrow indicates the excitation light LT1. As shown in FIG. 6, many excitation lights LT1 are incident on the light guide path 41 at an angle larger than the total reflection angle. As a result, most of the excitation light LT1 passes through the light guide member 40 without guiding the light guide path 41.

Specifically, the excitation light LT1 that is not absorbed by the coenzyme (NADH) in the solution flow path 32 is incident on the light guide member 40. A part of the excitation light LT1 is incident on the axis AX at a wide angle, that is, at an incident angle larger than the maximum light receiving angle that can be totally reflected on the inner surface of the light guide path 41 of the light guide member 40. The excitation light LT1 incident at an incident angle larger than the maximum light receiving angle is transmitted from the side surface SS to the outside of the light guide member 40 without guiding the light guide path 41.

As described above, according to the biosensor 10 according to the present embodiment, the excitation light LT1 traveling straight on one axis AX can be blocked. Further, the incident angle of the excitation light LT1 incident on the light guide member 40 can be increased, and many excitation light LT1 can be prevented from being guided in the light guide path 41. As a result, the amount of the excitation light LT1 detected by the detection unit 60 can be reduced, and the detection accuracy can be improved.
[Modification example]
When the excitation optical optical system 20 includes a light-shielding member 70 as in this embodiment, the amount of the excitation light LT1 that guides the light guide path 41 can be reduced. Therefore, the biosensor 10 may be configured without providing the fluorescence optical system 50.

FIG. 7 shows the configuration of a modified example of the biosensor 10 according to this embodiment. As shown in FIG. 7, the biosensor 10 does not have the fluorescence optical system 50 and the fluorescence filter FF. By configuring the biosensor 10 in this way, it is possible to reduce the size of the biosensor 10.

The biosensor 10 according to the third embodiment will be described. The biosensor 10 according to the third embodiment is different from the biosensor 10 of the first and second embodiments in that the shape of the flow cell 30 is different.

FIG. 8 shows an enlarged cross section of the flow cell 30 along one axis AX of the biosensor 10 according to the third embodiment. As shown in FIG. 8, the light guide member 40 is formed so that the portion 34 in contact with the solution flow path 32 of the flow cell 30 is narrowed toward the fluorescence optical system 50. That is, the portion 34 of the light guide member 40 in contact with the solution flow path 32 of the flow cell 30 is inclined so as to have an angle with respect to one axis AX. Therefore, the excitation light LT1 irradiated to the portion 34 in contact with the solution flow path 32 of the flow cell 30 of the light guide member 40 is reflected toward the solution flow path 32 of the flow cell 30.

As described above, according to the biosensor 10 according to the present embodiment, a part of the excitation light LT1 incident on the light guide member 40 can be reflected toward the solution flow path 32 of the flow cell 30, so that it is fluorescent. It is possible to improve the luminous efficiency of LT2.

In order to positively reflect the excitation light LT1 toward the solution flow path 32, a reflective member that reflects the excitation light LT1 may be installed at the portion 34 in contact with the solution flow path 32 of the flow cell 30. Further, in order to diffusely reflect the excitation light LT1, the portion of the flow cell 30 in contact with the solution flow path 32 may have an uneven surface.

The biosensor 10 according to the fourth embodiment will be described. The biosensor 10 according to the fourth embodiment is different from the biosensor 10 according to the first embodiment in that it does not have the excitation optical optical system 20.

FIG. 9 shows a cross section of the biosensor 10 according to the fourth embodiment along the axis AX.

As shown in FIG. 9, on one axis AX, a long pass filter LF that cuts a band including the wavelength of the excitation light LT1 is provided between the collimating lens 51 and the fluorescent bandpass filter FF.

FIG. 10 shows an embodiment of the excitation light LT1 emitted from the light source LT of the biosensor 10 according to the fourth embodiment. In FIG. 10, the alternate long and short dash arrow indicates the excitation light LT1. As shown in FIG. 10, the excitation light LT1 emitted from the light source LT passes through the flow cell 30 and is incident on the light guide member 40.

Here, the excitation light LT1 that exceeds the maximum light receiving angle of the light guide path 41 passes through the light guide path 41 without guiding. The excitation light LT1 guided through the light guide path 41 is collimated by the collimating lens 51 and attenuated by the long pass filter LF.

FIG. 11 shows an embodiment of the fluorescent LT2 emitted from the flow cell 30 of the biosensor 10 according to the fourth embodiment. In FIG. 11, the alternate long and short dash arrow indicates fluorescent LT2.

The fluorescent LT2 emitted in the solution flow path 32 of the flow cell 30 is guided in the light guide path 41 of the light guide member 40. The fluorescent LT2 emitted from the light guide member 40 is collimated by the collimating lens 51 and passes through the long pass filter LF and the fluorescent bandpass filter FF. The fluorescent LT2 that has passed through the fluorescent bandpass filter FF is focused toward the detection unit 60 through the condenser lens 52.

As described above, according to the biosensor 10 according to the present embodiment, since the excitation optical optical system 20 is not provided, it is possible to directly irradiate the solution flow path 32 with high-intensity excitation light. .. Therefore, the amount of light emitted from the fluorescent LT2 can be increased, and the number of parts of the device can be reduced, so that the device can be miniaturized.

The biosensor 10 according to the fifth embodiment will be described. The biosensor 10 according to the fifth embodiment is different from the biosensor 10 of the first to fourth embodiments in that the shape of the gas flow path 31 of the flow cell 30 is different.

FIG. 12 shows a cross section along one axis AX of the biosensor 10 according to the fifth embodiment. In FIG. 12, the excitation optical optical system 20 has a collimating lens 21, but does not have a ball lens 22.

The gas flow path 31 of the flow cell 30 has a lens portion 31a formed so as to have a curved surface that is convex toward the enzyme holding film 33 with one axis AX as the center.

The lens unit 31a collects the excitation light LT1 collimated by the collimated lens 21 toward the enzyme holding film 33. Therefore, according to the biosensor 10 according to the present embodiment, the ball lens 22 of the excitation optical optical system 20 becomes unnecessary. This reduces the number of parts of the device and makes it possible to reduce the size of the device.

The biosensor 10 according to the sixth embodiment will be described. The biosensor 10 according to the sixth embodiment is different from the biosensor 10 of the first to fifth embodiments in that the arrangement positions of the light source LT and the detection unit 60 are different.

That is, in Examples 1 to 4, the light source LT, the excitation optical optical system 20, the flow cell 30, the light guide member 40, the fluorescence optical system 50, and the detection unit 60 are arranged on one axis AX, but the light source LT. And at least one of the detection units 60 may not be arranged on one axis AX.

FIG. 13 shows a cross section along one axis AX of the biosensor 10 according to the sixth embodiment. As shown in FIG. 13, the light source LT and the detection unit 60 are arranged on the axis AX2 and the axis AX3 orthogonal to one axis AX, respectively. Further, the mirror MR1 and the mirror MR2 are arranged at positions where the axis AX2 and the axis AX3 intersect with one axis AX. That is, the excitation light LT1 emitted from the light source LT is reflected by the mirror MR1 so as to reach the excitation optical optical system 20. Further, the fluorescent LT2 that has passed through the fluorescent optical system 50 is reflected by the mirror MR2 so as to reach the detection unit 60.

In Examples 1 to 5, the excitation optical optical system 20 and the fluorescence optical system 50 are arranged on one axis AX, which is the same axis as the optical axis of the excitation light LT1. However, as described in this embodiment, the excitation optical optical system 20 and the fluorescence optical system 50 may not be arranged on one axis AX, which is the same axis as the optical axis of the excitation light LT1, and the excitation light may not be arranged. The optical axis of the LT1 and the optical axis of the fluorescent LT2 may be deviated from the axis AX within a range in which the fluorescent LT2 can reach the detection unit 60.

The equipment, the configuration of the apparatus, etc. in the above-described embodiment are merely examples, and can be appropriately selected or changed depending on the intended use and the like.

10 Biosensor 20 Excitation optical optical system 30 Flow cell 31 Gas flow path 32 Solution flow path 33 Enzyme holding film 40 Light guide member 41 Light guide path 50 Fluorescent optical system 60 Detection unit 70 Light-shielding member AX One axis

Claims (13)

It serves as a gas flow path through which the gas sample flows, a solution holding portion that holds a solution containing a coenzyme that emits fluorescence when excited by excitation light before or after the catalytic reaction with the gas sample, and a catalyst for the catalytic reaction. A reaction unit containing an enzyme-retaining membrane in which the enzyme is retained and arranged on one axis,
A light guide member provided on the one axis in contact with the reaction portion and forming a light guide path along the one axis.
A fluorescent optical system that collects the fluorescence that has passed through the light guide path, and
A detection unit that detects the fluorescence that has passed through the fluorescence optical system , and
Have ,
The fluorescence optical system is a detection device characterized in that the excitation light that has passed through the light guide path is defocused . The detection device according to claim 1 , wherein the fluorescence optical system includes a first collimating lens that makes the fluorescence that has passed through the light guide path parallel light. The detection device according to claim 2, wherein the fluorescence optical system includes a condenser lens that collects the fluorescence that has passed through the first collimating lens. The invention according to any one of claims 1 to 3 , further comprising an excitation optical optical system provided on the opposite side of the fluorescent optical system when viewed from the reaction unit and condensing the excitation light on the reaction unit. Detection device. In the excitation optical optical system, a second collimating lens arranged on the one axis and parallelizing the excitation light and the excitation light collimated by the second collimating lens are focused on the reaction unit. The detection device according to claim 4 , wherein the condensing lens is configured by the condenser lens. The detection device according to claim 4 or 5 , wherein the numerical aperture of the excitation optical optical system is larger than the numerical aperture of the light guide member. The detection device according to any one of claims 4 to 6, wherein the excitation optical optical system is arranged on the one axis and includes a light-shielding member capable of blocking the excitation light. The angle of incidence of at least a part of the excitation light that has passed through the reaction unit on the light guide member is configured to be larger than the maximum light receiving angle that can be totally reflected on the inner surface of the light guide path of the light guide member. The detection device according to any one of claims 1 to 7. The detection device according to any one of claims 1 to 8, wherein the light guide member has a space along a side surface extending in a direction along the one axis. It has a holding member that holds the light guide member so as to cover the periphery of the light guide member.
The detection device according to claim 9, wherein a space is provided between the holding member and the side surface of the light guide member. The detection device according to any one of claims 1 to 10 , wherein the light guide member is formed so that a portion in contact with the reaction portion is narrowed toward the fluorescent optical system. The detection device according to any one of claims 1 to 11 , wherein an optical filter that transmits a band including a wavelength of fluorescence is provided between the light guide member and the detection unit. The detection device according to any one of claims 1 to 12 , wherein at least one of the gas flow path, the solution holding portion, and the enzyme holding membrane is detachable from the detection device.

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