Fluorescence detection device

Abstract

Provided is a fluorescence detection device having improved fluorescence detection sensitivity. The fluorescence detection device comprises a light source that irradiates a sample with circularly polarized excitation light, a sample holding part that holds the sample, a cholesteric liquid crystal layer that transmits fluorescence emitted by the sample due to the excitation light and reflects the excitation light, and a sensor that detects fluorescence transmitted through the cholesteric liquid crystal layer.

Description

Technical Field

[0001] The present disclosure relates to a fluorescence detection device.

Background Art

[0002] Patent Document 1 has an optical system having a dichroic mirror and detects fluorescence reflected from a sample. Further, Patent Document 2 provides a substrate capable of reproducibly adhering and holding a trace amount of a specific substance at a high density in a minute region.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] In Patent Document 1, a dichroic mirror is not required, and in Patent Document 2, further excitation light removal performance is required in the concave portion on the surface of the substrate that holds the liquid sample.

[0005] An object of the present disclosure is to provide a fluorescence detection device with improved fluorescence detection sensitivity.

Means for Solving the Problems

[0006] A fluorescence detection device according to an aspect of the present disclosure includes a light source that irradiates a sample with excitation light in a circularly polarized state, a sample holding unit that holds the sample, a cholesteric liquid crystal layer that transmits fluorescence emitted by the sample due to the excitation light and reflects the excitation light, and a sensor that detects the fluorescence transmitted through the cholesteric liquid crystal layer.

Brief Description of the Drawings

[0007]

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BEST MODE FOR CARRYING OUT THE INVENTION

[0008] Embodiments for implementing the present disclosure will be described in detail with reference to the drawings. The present disclosure is not limited by the content described in the following embodiments. Further, the components described below include those that can be easily assumed by those skilled in the art and substantially identical ones. Furthermore, the components described below can be combined as appropriate. Note that the disclosure is merely an example, and for those that can be easily conceived by those skilled in the art with appropriate modifications while maintaining the gist of the present disclosure, they are naturally included in the scope of the present disclosure. Also, for the purpose of making the description clearer, the drawings may schematically represent the width, thickness, shape, etc. of each part compared to the actual aspect, but this is merely an example and does not limit the interpretation of the present disclosure. Also, in the present disclosure and each figure, the same reference numerals may be given to the same elements as those described above for the previously shown figures, and detailed descriptions may be omitted as appropriate.

[0009] In the present embodiment and the claims, when expressing the aspect of arranging another structure on a certain structure, when simply described as "on", unless otherwise specified, it includes both the case of arranging another structure directly on a certain structure in contact with it and the case of arranging another structure above a certain structure via yet another structure.

[0010] (Embodiment 1) FIG. 1 is a schematic diagram showing a fluorescence detection device according to Embodiment 1. FIG. 2 is a cross-sectional view schematically explaining the cholesteric liquid crystal layer of Embodiment 1. FIG. 3 is a plan view schematically explaining the first layer and the seventh layer of the cholesteric liquid crystal layer of Embodiment 1. FIG. 4 is a plan view schematically explaining the second layer of the cholesteric liquid crystal layer of Embodiment 1. FIG. 5 is a plan view schematically explaining the third layer of the cholesteric liquid crystal layer of Embodiment 1. FIG. 6 is a plan view schematically explaining the fourth layer of the cholesteric liquid crystal layer of Embodiment 1. FIG. 7 is a plan view schematically explaining the fifth layer of the cholesteric liquid crystal layer of Embodiment 1. FIG. 8 is a plan view schematically explaining the sixth layer of the cholesteric liquid crystal layer of Embodiment 1. As shown in FIG. 1, the fluorescence detection device 1 includes a light source 60, a cholesteric liquid crystal layer 10, a light-transmissive substrate 20, a sample holding portion 30, a resin layer 40, and a sensor 50 in a space shielded from the outside.

[0011] When the fluorescence detection device 1 irradiates the sample 31 with excitation light L11 having a predetermined wavelength, the substances in the sample 31 are excited to emit fluorescence L13 having spectral characteristics with a peak wavelength slightly shifted from the wavelength of the excitation light. The fluorescence detection device 1 can observe the intensity of this fluorescence L13 and the emission intensity distribution of the fluorescence L13.

[0012] The resin layer 40 is an optically transparent resin and includes a first resin layer 41 and a second resin layer 42. The first resin layer 41 is disposed on the cholesteric liquid crystal layer 10. The second resin layer 42 is disposed under the cholesteric liquid crystal layer 10. The resin layer 40 is integrally formed with the cholesteric liquid crystal layer 10.

[0013] The light-transmissive substrate 20 is an insulating base material, and for example, glass is used. The light-transmissive substrate 20 is disposed under the second resin layer 42.

[0014] The cholesteric liquid crystal layer 10 has a liquid crystal layer 16 formed thereon via an alignment film 15 on the second resin layer 42. The alignment film 15 is made of polyimide or the like and is subjected to rubbing treatment or photo-alignment treatment. Cholesteric liquid crystal means that in one plane, elongated liquid crystal molecules are arranged with their long axes aligned, and as they proceed in a direction perpendicular to the plane of the second resin layer 42, the liquid crystal molecules LC turn in a spiral shape. Specifically, as shown in FIG. 2, the first layer LC1, the second layer LC2, the third layer LC3, the fourth layer LC4, the fifth layer LC5, the sixth layer LC6, and the seventh layer LC7 shown in FIGS. 3 to 8 have the liquid crystal molecules LC turning. Every half of the pitch p of the spiral, the long axes of the liquid crystal molecules LC are aligned. Therefore, as shown in FIG. 3, the long axis directions of the liquid crystal molecules LC in the first layer LC1 and the long axis directions of the liquid crystal molecules LC in the seventh layer LC7 are in the same direction. Here, the thickness when the liquid crystal molecules LC of the cholesteric liquid crystal layer 10 make one rotation is called the pitch p of the spiral.

[0015] FIG. 9 is an explanatory diagram for explaining the relationship between the excitation light and the reflected light. The cholesteric liquid crystal layer 10 reflects light of a predetermined wavelength having circular polarization in the same rotation direction as the rotation direction of the spiral. As shown in FIG. 9, the excitation light L11 incident on the cholesteric liquid crystal layer 10 is reflected according to the same conditions as the Bragg's law shown in the following formula (1).

[0016]

Number

[0017] The sample holding part 30 includes a light-shielding resin substrate 70 having a first surface 73 and a second surface 74 on the side opposite to the first surface 73 and on the side of the cholesteric liquid crystal layer 10, and a through hole 32 penetrating from the first surface 73 to the second surface 74. The opening surface 740 of the through hole 32 on the second surface 74 is blocked by the upper surface 410 of the first resin layer 41. The inside of the through hole 32 is filled with an aqueous solution, and the sample 31 is accommodated. The sample holding part 30 is located on the upper surface 410 of the first resin layer 41 and is integrally formed with the first resin layer 41.

[0018] The light source 60 includes a light emitter 61, a polarizing plate 62, and a quarter-wave plate 63. The light emitter 61 is a light-emitting element that oscillates and emits predetermined excitation light. The polarizing plate 62 polarizes the light from the light emitter 61 into a linearly polarized state. The quarter-wave plate 63 converts the light from the polarizing plate 62 into excitation light L11 in a circularly polarized state.

[0019] The sensor 50 is a charge-coupled device (CCD) and is an imaging circuit. The sensor 50 is embedded in the center of the second resin layer 42. The sensor 50 can detect the intensity of fluorescence and the emission intensity distribution of fluorescence.

[0020] As shown in FIG. 9, according to Bragg's law, the excitation light L11 incident from the light source 60 is selectively reflected to obtain reflected light L12. For example, when a plurality of liquid crystal molecules in the cholesteric liquid crystal layer 10 are swirling clockwise, the light in the right-circularly polarized state having a wavelength corresponding to the pitch p in the excitation light L11 is reflected to obtain the reflected light L12. On the other hand, when a plurality of liquid crystal molecules in the cholesteric liquid crystal layer 10 are swirling counterclockwise, the light in the left-circularly polarized state having a wavelength corresponding to the pitch p in the excitation light L11 is reflected to obtain the reflected light L12.

[0021] FIG. 10 is a schematic diagram showing an example of the arrangement of through holes. FIG. 11 is a schematic diagram showing the shape of the through holes. As shown in FIG. 10, a plurality of through holes 32 are formed in a single resin substrate 70. The plurality of through holes 32 are provided, for example, 25 in the longitudinal direction Am and 50 in the transverse direction An on a single resin substrate 70, for a total of 1250, and are arranged at equal intervals from each other. As shown in FIG. 11, for example, one side 32a of the opening surface 730 of the through hole 32 on the first surface 73 is a square with a side length of 650 μm, and the other side 32b is also 650 μm. Also, for example, one side 32c of the opening surface 740 of the through hole 32 on the second surface 74 is a square with a side length of 350 μm, and the other side 32d is also 350 μm. For example, the depth 32h of the through hole 32 is 150 μm.

[0022] The cholesteric liquid crystal layer 10 is manufactured by selecting a liquid crystal material and a chiral agent according to the wavelength of the excitation light L11.

[0023] FIG. 12 is a graph showing the emission spectrum of the inorganic LED. As shown in FIG. 12, when the light source 60 is, for example, an inorganic LED (Light Emitting Diode), since the wavelength range is about 100 nm, the wavelength range of the reflected light of the cholesteric liquid crystal layer 10 needs to be at least 50 nm or more.

[0024] Note that it is more desirable that the wavelength range of the reflected light of the cholesteric liquid crystal layer 10 is 100 nm or more.

[0025] FIG. 13 is a schematic diagram showing the fluorescence detection device according to Comparative Example 1. The fluorescence detection device 1a of Comparative Example 1 shown in FIG. 13 does not have a cholesteric liquid crystal layer 10 as compared with the fluorescence detection device 1 shown in FIG. 1.

[0026] When the fluorescence detection device 1a of Comparative Example 1 irradiates the sample 31 with excitation light L21 having a predetermined wavelength, the substances in the sample are excited and emit fluorescence having a spectral characteristic with a peak wavelength slightly shifted from the wavelength of the excitation light. In the fluorescence detection device 1a, the fluorescence L22 including the noise of the excitation light reaches the sensor 50.

[0027] In contrast, in the fluorescence detection device 1 of Embodiment 1, the cholesteric liquid crystal layer 10 selectively reflects the excitation light L11 as the reflected light L12.

[0028] As described above, the fluorescence detection device 1 of Embodiment 1 includes a light source 60 that irradiates the sample 31 with excitation light L11 in a circularly polarized state, a cholesteric liquid crystal layer 10 that transmits the fluorescence L13 emitted by the sample 31 due to the excitation light L11 and reflects the excitation light L11, and a sensor 50 that detects the fluorescence L13 transmitted through the cholesteric liquid crystal layer 10. Thereby, the excitation light L11 can be selectively reflected as the reflected light L12, and the excitation light L11 reaching the sensor 50 is suppressed. As a result, the detection sensitivity of the fluorescence L13 detected by the sensor 50 is improved.

[0029] (Embodiment 2) FIG. 14 is a schematic diagram showing a fluorescence detection device according to Embodiment 2. In the following description, the same components as those described in the above-described embodiments are denoted by the same reference numerals, and redundant descriptions are omitted.

[0030] The fluorescence detection device 1A includes a light source 60, a cholesteric liquid crystal layer 10, a light-transmissive substrate 20, a sample holding portion 30, a resin layer 40, and a sensor 50 in a space shielded from the outside.

[0031] When the angle formed by the second surface 74 and the side wall 75 of the through-hole 32 is 45° or more, when the excitation light L11 of the light source 60 is refracted by the side wall 75, the direction of the circularly polarized state of the reflected light L12 is reversed, and the reflected light L12 is likely to be incident on the sensor 50. Since the direction in which the liquid crystal molecules LC of the cholesteric liquid crystal layer 10 turn is opposite to the direction of the circularly polarized state of the reflected light L12, the cholesteric liquid crystal layer 10 cannot reflect the reflected light L12, and there is a possibility that the fluorescence L22 including the noise of the excitation light L11 reaches the sensor 50.

[0032] Therefore, as shown in FIG. 14, the area of the opening surface 730 is larger than the opening area of the opening surface 740, and is tapered, and the angle formed by the second surface 74 and the side wall 75 is 45° or less.

[0033] As a result, the fluorescence detection device 1A can reflect the excitation light L11 as the reflected light L14 and suppress the excitation light L11 from entering the sensor 50.

[0034] (Embodiment 3) FIG. 15 is a schematic diagram showing a fluorescence detection device according to Embodiment 3. In the following description, the same components as those described in the above-described embodiments are denoted by the same reference numerals, and redundant descriptions are omitted.

[0035] The fluorescence detection device 1B includes a light source 60, a cholesteric liquid crystal layer 10, a light-transmissive substrate 20, a sample holding portion 30, a resin layer 40, and a sensor 50 in a space shielded from the outside. Specifically, the cholesteric liquid crystal layer 10 of Embodiment 3 has liquid crystal molecules LC that spiral, and includes a first liquid crystal layer 11 and a second liquid crystal layer 12 having a direction of rotation different from that of the liquid crystal molecules LC of the first liquid crystal layer 11. The first liquid crystal layer 11 has left-handed liquid crystal molecules LC and is formed on the second liquid crystal layer 12. The second liquid crystal layer 12 has right-handed liquid crystal molecules LC and is formed on the alignment film 15. Note that the cholesteric liquid crystal layer 10 may include three or more liquid crystal layers having directions of rotation different from that of the liquid crystal molecules.

[0036] In the fluorescence detection device 1A of Embodiment 2, by setting the angle formed by the second surface 74 and the side wall 75 to 45° or less, the excitation light L11 can be reflected as the reflected light L14, and the excitation light L11 can be suppressed from entering the sensor 50. On the other hand, in the fluorescence detection device 1B of Embodiment 3, even when the angle formed by the second surface 74 and the side wall 75 is 45° or more, the reflected light L14 can be suppressed from entering the sensor 50.

[0037] As shown in FIG. 15, in the fluorescence detection device 1B of Embodiment 3, a second liquid crystal layer 12 having liquid crystal molecules LC that rotate in a direction different from the direction in which the liquid crystal molecules LC of the first liquid crystal layer 11 rotate is laminated on the first liquid crystal layer 11. When the excitation light L11 reaches the first liquid crystal layer 11 without hitting the side wall 75 from the light source 60, the first liquid crystal layer 11 reflects the excitation light L11. As shown in FIG. 15, when the angle formed by the second surface 74 and the side wall 75 is 45° or more, the excitation light L11 incident from the position of the light source 60A is refracted by the side wall 75, and when the reflected light L14 reflected by the side wall 75 is incident toward the cholesteric liquid crystal layer 10, the first liquid crystal layer 11 cannot reflect the reflected light L14 of the light source 60A. This is because the direction in which the liquid crystal molecules LC of the first liquid crystal layer 11 rotate is opposite to the direction of the circularly polarized state of the reflected light L12.

[0038] Then, the reflected light L14 reaches the second liquid crystal layer 12. Since the direction in which the liquid crystal molecules LC of the second liquid crystal layer 12 rotate is the same as the direction of the circularly polarized state of the reflected light L12, the second liquid crystal layer 12 can reflect the reflected light L14 as the reflected light L15.

[0039] (Embodiment 4) FIG. 16 is a schematic diagram showing a fluorescence detection device according to Embodiment 4. FIG. 17 is an explanatory diagram showing the wavelength characteristics of the reflected excitation light for each number of twist pitches of liquid crystal molecules. FIG. 18 is an explanatory diagram showing the relationship between the wavelength characteristics of the excitation light reflected when the incident angle to the cholesteric liquid crystal layer is 0° and the wavelength characteristics of the excitation light reflected when the incident angle to the cholesteric liquid crystal layer is 30°. FIG. 19 is an explanatory diagram showing the relationship between the resolution of the cholesteric liquid crystal layer with respect to the excitation light and the incident angle of the excitation light to the cholesteric liquid crystal layer. FIG. 20 is an explanatory diagram showing the relationship between the reflectance of the excitation light with respect to the number of twist pitches when the incident angle to the cholesteric liquid crystal layer is 30° and the reflectance of the excitation light with respect to the number of twist pitches when the incident angle to the cholesteric liquid crystal layer is 0°. In the following description, the same components as those described in the above-described embodiments are denoted by the same reference numerals, and redundant descriptions are omitted.

[0040] The fluorescence detection device 1C includes a light source 60, a cholesteric liquid crystal layer 10, a light-transmitting substrate 20, a sample holding unit 30, a resin layer 40, and a sensor 50 in a space shielded from the outside light.

[0041] The number of pitches of the helix included in the thickness of the cholesteric liquid crystal layer 10 is referred to as the number of pitches. As shown in FIG. 17, when the number of pitches is 5 pitches or less, the reflectance of the cholesteric liquid crystal layer 10 tends to decrease.

[0042] Therefore, in order to maintain the reflectance of the cholesteric liquid crystal layer 10 at 100% as much as possible, the number of pitches is preferably 5 pitches or more, and more desirably 10 pitches or more.

[0043] Note that the smaller the film thickness of the cholesteric liquid crystal layer 10, the lower the reflectance. Therefore, a size of 4 μm or 5 μm is preferable.

[0044] As shown in FIG. 18, when the incident angle (hereinafter referred to as the incident angle) of the excitation light L11 with respect to the surface of the cholesteric liquid crystal layer 10 is 30° compared to the case where the incident angle is 0°, the central wavelength of the cholesteric liquid crystal layer 10 is shifted.

[0045] Therefore, when the incident angle is 30° or more, there is a possibility that the fluorescence L22 including the noise of the excitation light L11 reaches the sensor 50.

[0046] Further, as shown in FIG. 19, as the incident angle increases, the resolution of the cholesteric liquid crystal layer 10 with respect to the excitation light L11 tends to decrease.

[0047] Therefore, as shown in FIG. 16, in the fluorescence detection device 1B according to the fourth embodiment, even if the position is shifted to the position of the light source 60B rotated in the direction R from the position of the light source 60, by setting the incident angle to 30° or less, the reflectance of the excitation light L11 and the resolution with respect to the excitation light L11 can be maintained.

[0048] Also, in order to maintain the shift of the central wavelength and the resolution with respect to the excitation light L11 even when the incident angle changes, the incident angle is preferably 30° or less. As shown in Fig. 19, when the incident angle is 20°, the resolution can be maintained at 100% compared with the case of 30°, so it is more desirable that the incident angle is 20° or less.

[0049] Also, as shown in Figs. 17 and 20, when the incident angle is 0° and the number of pitches exceeds 5 and is 10 or more, even if the number of pitches increases, the reflectance of the cholesteric liquid crystal layer 10 can be maintained at 100%. Similarly, as shown in Fig. 20, when the incident angle is 30° and the number of pitches exceeds 5 and is 10 or more, even if the number of pitches increases, the reflectance of the cholesteric liquid crystal layer 10 can be maintained at 93%. However, as shown in Fig. 20, when the incident angle is 30° and the number of pitches is less than 10 pitches, the reflectance of the cholesteric liquid crystal layer 10 decreases. Therefore, in order to suppress the decrease in the reflectance of the cholesteric liquid crystal layer 10 even when the incident angle changes, the incident angle is preferably 30° or less, and the number of pitches is preferably 10 pitches or more.

[0050] The fluorescence detection device 1C suppresses the shift of the central wavelength and the decrease in reflectance of the cholesteric liquid crystal layer 10, and the circular polarization resolution ability of the cholesteric liquid crystal layer 10 is increased.

[0051] (Embodiment 5) Fig. 21 is a schematic diagram showing a fluorescence detection device according to Embodiment 5. In the following description, the same components as those described in the above-described embodiments are denoted by the same reference numerals, and redundant descriptions are omitted.

[0052] The fluorescence detection device 1D includes a light source 60, a cholesteric liquid crystal layer 10, a light-transmitting substrate 20, a sample holding portion 30, a resin layer 40, a sensor 50, and a light-shielding layer 71 in a space shielded from the outside.

[0053] As shown in FIG. 21, the translucent substrate 20 has a first translucent substrate 21 and a second translucent substrate 22. The resin layer 40 is installed on the second translucent substrate 22. The sensor 50 is embedded in the center of the resin layer 40. The outer periphery of the upper surface 51 of the sensor 50 is surrounded by a light-shielding layer 71. 。The The first translucent substrate 21 is disposed on the cholesteric liquid crystal layer 10.

[0054] In the fluorescence detection devices 1, 1A, 1B, and 1C, the sample holding portion 30 is integrally formed with a first resin layer 41 provided on the cholesteric liquid crystal layer 10, and the opening surface 740 is covered by the upper surface 410 of the first resin layer 41.

[0055] On the other hand, in the fluorescence detection device 1D, the opening surface 740 is covered by the upper surface 210 of the first translucent substrate 21. Further, since the first translucent substrate 21 has higher solvent resistance than resin, the selected degree of freedom of the solvent entering the through hole 32 is increased.

[0056] In addition, the light-shielding layer 71 shields stray light incident on the sensor 50 and suppresses light scattering on the first translucent substrate 21, so that the detection accuracy of the sensor 50 is improved.

[0057] (Embodiment 6) FIG. 22 is a schematic diagram showing a fluorescence detection device according to Embodiment 6. In the following description, the same components as those described in the above-described embodiments are denoted by the same reference numerals, and redundant descriptions are omitted.

[0058] The fluorescence detection device 1E includes a light source 60, a cholesteric liquid crystal layer 10, a translucent substrate 20, a sample holding portion 30, a resin layer 40, and a sensor 50 in a space shielded from the outside.

[0059] As shown in FIG. 22, the resin layer 40 is installed on the light-transmissive substrate 20. The sensor 50 is embedded in the center of the resin layer 40. The upper surface 51 of the sensor 50 is exposed and is arranged to match the opening surface 740. The cholesteric liquid crystal layer 10 is arranged on the upper surface 51 of the sensor 50, and the liquid crystal layer 16 is formed on the resin layer 40 via the alignment film 15. The alignment film 15 covers the first surface 73 of the sample holding part 30, the side wall 75, and the upper surface 51 of the sensor 50.

[0060] Since the cholesteric liquid crystal layer 10 is formed inside the through hole 32 in the fluorescence detection device 1E, the manufacturing process of the fluorescence detection device can be simplified.

[0061] Also, in the fluorescence detection devices 1, 1A, 1B, and 1C, the excitation light L11 enters the cholesteric liquid crystal layer 10 through the first resin layer 41, respectively.

[0062] On the other hand, in the fluorescence detection device 1E, since the excitation light L11 directly enters the cholesteric liquid crystal layer 10 without passing through the resin layer, the noise of the excitation light L11 can be further suppressed, so that the detection accuracy of the sensor 50 is improved.

[0063] (Embodiment 7) FIG. 23 is a schematic diagram showing a fluorescence detection device according to Embodiment 7. In the following description, the same components as those described in the above embodiments are denoted by the same reference numerals, and redundant descriptions are omitted.

[0064] The fluorescence detection device 1F includes a light source 60, a cholesteric liquid crystal layer 10, a light-transmissive substrate 20, a sample holding part 30, a resin layer 40, and a sensor 50 in a space shielded from the outside.

[0065] The sample holding part 30 includes a light-shielding resin substrate 70 having a first surface 73 and a second surface 74 on the opposite side of the first surface 73 and on the side of the cholesteric liquid crystal layer 10, and a through hole 32 penetrating from the first surface 73 to the second surface 74.

[0066] As shown in FIG. 23, in a single resin substrate 70, a plurality of accommodating portions 300 for accommodating the sample 31 are respectively surrounded by the side wall 75 of the through hole 32 and arranged. The accommodating portion 300 is arranged on the cholesteric liquid crystal layer 10. The inside of the accommodating portion 300 is filled with an aqueous solution and the sample 31 is accommodated therein.

[0067] The resin layer 40 is installed on the light-transmitting substrate 20. The sensor 50 is embedded in the center of the resin layer 40. The upper surface 51 of the sensor 50 is exposed. sensor 50 is arranged for each housing portion 300. The cholesteric liquid crystal layer 10 is arranged on the upper surface 51 of the sensor 50, and a liquid crystal layer 16 is formed on the resin layer 40 via an alignment film 15. Outside the cholesteric liquid crystal layer 10 around is surrounded by the side wall 75. The sensors 50 are arranged adjacent to each other in the horizontal direction.

[0068] FIG. 24 is a schematic diagram showing a fluorescence detection device according to Comparative Example 2. The fluorescence detection device 1Fa of Comparative Example 2 shown in FIG. 24 has the cholesteric liquid crystal layer 10 together with the accommodating portion 300 distributed arranged not and the outside of the cholesteric liquid crystal layer 10 around is not surrounded by the resin substrate 70.

[0069] In order to sufficiently reflect the excitation light L11 from the light source 60, the film thickness of the cholesteric liquid crystal layer 10 needs to be thicker than the film thickness of the accommodating portion 300. However, in the form of the fluorescence detection device 1Fa of Comparative Example 2, among the sensors 50 adjacent to each other, the fluorescence L13 that should enter the other sensor 50 enters one sensor 50, causing so-called crosstalk CT that interferes with each other between the adjacent sensors 50, and the light reception sensitivity may decrease.

[0070] On the other hand, in the fluorescence detection device 1F of Embodiment 7, the cholesteric liquid crystal layer 10 is surrounded by the resin substrate 70 for each accommodating portion 300, and by blocking light between the cholesteric liquid crystal layers 10, it is possible to suppress the fluorescence L13 that should enter the other sensor 50 from entering one sensor 50.

[0071] (Embodiment 8) FIG. 25 is a schematic diagram showing a fluorescence detection device according to Embodiment 8. FIG. 26 is a schematic diagram showing another example of the fluorescence detection device according to Embodiment 8. In the following description, the same components as those described in the above-described embodiments are denoted by the same reference numerals, and redundant descriptions are omitted.

[0072] The fluorescence detection device 1G includes a light source 60, a cholesteric liquid crystal layer 10, a light-transmitting substrate 20, a sample holding portion 30, a resin layer 40, and a sensor 50 in a space shielded from the outside. The cholesteric liquid crystal layer 10 includes a first liquid crystal layer 11 and a second liquid crystal layer 12.

[0073] As shown in FIG. 25, the incident angle θ1 of the excitation light L11 with respect to the side wall 75 is incident at a critical angle of 45° at which the excitation light L11 does not critically enter the sensor 50 directly, so that the inside of the accommodating portion 300 is partitioned into an exposed exposure region AA and a non-exposed non-exposure region AB. The entire upper surface 110 where the fluorescence L13 enters the cholesteric liquid crystal layer 10 faces the non-exposure region AB.

[0074] The configuration of the fluorescence detection device 1G' shown in FIG. 26 is the same as that of the fluorescence detection device 1G. As shown in FIG. 26, the incident angle θ1 of the excitation light L11 with respect to the side wall 75 is incident at a critical angle of 45° or more, so that the inside of the accommodating portion 300 is partitioned into an exposure region AA and a non-exposure region AB. The entire upper surface 110 where the fluorescence L13 enters the cholesteric liquid crystal layer 10 faces the non-exposure region AB.

[0075] FIG. 27 is a schematic diagram showing a fluorescence detection device according to Comparative Example 3. The fluorescence detection device 1Ga of Comparative Example 3 shown in FIG. 27 has a part of the upper surface 110 exposed in the exposure region AA as compared with the fluorescence detection devices 1G and 1G' shown in FIGS. 25 and 26.

[0076] In the form of the fluorescence detection device 1Ga of Comparative Example 3, the incident angle θ1 of the excitation light L11 with respect to the side wall 75 is incident at an angle less than the critical angle of 45°, so that a part of the upper surface 110 where the fluorescence L13 is incident on the cholesteric liquid crystal layer 10 is exposed in the exposure region AA, and the amount of the excitation light L11 directly entering the sensor 50 increases.

[0077] On the other hand, in the fluorescence detection device 1G of Embodiment 8 shown in FIGS. 25 and 26, since the entire upper surface 110 faces the exposure region AA, the excitation light L11 can be made incident only on the sample 31, suppressing the excitation light L11 from directly entering the sensor 50, and reducing the amount of the excitation light L11 entering.

[0078] In the fluorescence detection device 1G (FIG. 25) and the fluorescence detection device 1G' (FIG. 26), a device in which the aspect ratio (length-to-width ratio) of the side wall 75 to the upper surface 110 is 1:1 is illustrated, and the critical angle of the incident angle θ1 is 45°. When the aspect ratio (length-to-width ratio) of the fluorescence detection device is different, the critical angle of the incident angle θ1 is appropriately changed according to the aspect ratio.

[0079] For example, when the aspect ratio (length-to-width ratio) of the fluorescence detection device is such that the size of the side wall 75: the size of the upper surface 110 = √3:1, the critical angle of the incident angle θ1 is 30°. When the incident angle θ1 is incident at an angle less than the critical angle of 30°, a part of the upper surface 110 where the fluorescence L13 is incident on the cholesteric liquid crystal layer 10 is exposed in the exposure region AA, and the amount of the excitation light L11 directly entering the sensor 50 increases.

[0080] On the other hand, when the incident angle θ1 is incident at a critical angle of 30° or more, since the entire upper surface 110 faces the exposure region AA, the excitation light L11 can be incident only on the sample 31, suppressing the direct entry of the excitation light L11 into the sensor 50 and reducing the amount of the excitation light L11 that enters.

[0081] (Embodiment 9) FIG. 28 is a schematic diagram showing a fluorescence detection device according to Embodiment 9. In the following description, the same components as those described in the above-described embodiments are denoted by the same reference numerals, and redundant descriptions are omitted.

[0082] In the fluorescence detection device 1H shown in FIG. 28, the upper surface 110 on which the cholesteric liquid crystal layer 10 faces the non-exposure region AB and the upper surface 51 of the sensor 50 are inclined with respect to the side wall 75 side so as to be parallel to the optical axis of the excitation light L11.

[0083] As a result, the distance until the excitation light L11 is reflected by the side wall 75 and enters the upper surface 51 where the light of the sensor 50 is incident becomes longer. Therefore, it is possible to further suppress the direct entry of the excitation light L11 into the sensor 50 compared to the fluorescence detection device 1G of Embodiment 8.

[0084] (Embodiment 10) FIG. 29 is a schematic diagram showing a fluorescence detection device according to Embodiment 10. FIG. 30 is a schematic diagram showing another example of the fluorescence detection device according to Embodiment 10. In the following description, the same components as those described in the above-described embodiments are denoted by the same reference numerals, and redundant descriptions are omitted.

[0085] The configuration of the fluorescence detection device 1I shown in FIG. 29 and the configuration of the fluorescence detection device 1I' shown in FIG. 30 are the same as those of the fluorescence detection device 1B. As shown in FIG. 29, when the incident angle θ1 of the excitation light L11 with respect to the side wall 75 is incident at a critical angle of 45°, the inside of the through hole 32 is partitioned into an exposure region AA and a non-exposure region AB. The entire opening surface 740 faces the non-exposure region AB.

[0086] In the fluorescence detection device 1I´ shown in FIG. 30, the incident angle θ1 of the excitation light L11 with respect to the side wall 75 is incident at a critical angle of 45° or more, so that the inside of the through hole 32 is partitioned into an exposed area AA and a non-exposed area AB. The entire surface of the opening surface 740 faces the non-exposed area AB.

[0087] FIG. 31 is a schematic diagram showing a fluorescence detection device according to Comparative Example 4. The fluorescence detection device 1Ia of Comparative Example 4 shown in FIG. 31 has a part of the opening surface 740 exposed to the exposed area AA as compared with the fluorescence detection devices 1I and 1I´ shown in FIGS. 29 and 30.

[0088] In the form of the fluorescence detection device 1 I a of Comparative Example 4, the incident angle θ1 of the excitation light L11 with respect to the side wall 75 is incident at an angle less than the critical angle of 45°, so that a part of the opening surface 740 is exposed to the exposed area AA, and the amount of the excitation light L11 directly entering the sensor 50 increases.

[0089] On the other hand, in the fluorescence detection device 1 I, 1I´ of Embodiment 10 shown in FIGS. 29 and 30, since the entire surface of the opening surface 740 faces the exposed area AA, the excitation light L11 can be made incident only on the sample 31, suppressing the excitation light L11 from directly entering the sensor 50 and reducing the amount of the excitation light L11 entering.

[0090] In the fluorescence detection device 1I (FIG. 29) and the fluorescence detection device 1I´ (FIG. 30), a device in which the aspect ratio (length-to-width ratio) of the side wall 75 and the opening surface 740 is 1:1 is illustrated, and the critical angle of the incident angle θ1 is 45°. When the aspect ratio (length-to-width ratio) of the fluorescence detection device is different, the critical angle of the incident angle θ1 is appropriately changed according to the aspect ratio.

[0091] For example, when the aspect ratio (length-to-width ratio) of the fluorescence detection device is such that the size of the side wall 75: the size of the opening surface 740 = √3:1, the critical angle of the incident angle θ1 is 30°. By making the incident angle θ1 less than the critical angle of 30°, a part of the opening surface 740 where the fluorescence L13 enters the cholesteric liquid crystal layer 10 is exposed to the exposure region AA, and the amount of the excitation light L11 directly entering the sensor 50 increases.

[0092] On the other hand, when the incident angle θ1 is incident at an angle of 30° or more with respect to the critical angle, since the entire surface of the opening surface 740 faces the exposure region AA, the excitation light L11 can be made to enter only the sample 31, suppressing the excitation light L11 from directly entering the sensor 50 and reducing the amount of the excitation light L11 that enters.

[0093] As described above, the preferred embodiments of the present disclosure have been described, but the present disclosure is not limited to such embodiments. The content disclosed in the embodiments is merely an example, and various modifications are possible without departing from the spirit of the present disclosure. Appropriate modifications made without departing from the spirit of the present disclosure also naturally belong to the technical scope of the present disclosure. Without departing from the gist of each of the above-described embodiments and each modification example, at least one of various omissions, substitutions, and changes of components can be made.

Explanation of Reference Numerals

[0094] 1, 1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H, 1I, 1a, 1Fa, 1Ga, 1Ia Fluorescence detection device 10 Cholesteric liquid crystal layer 11 First liquid crystal layer 12 Second liquid crystal layer 16 Liquid crystal layer 20 Translucent substrate 30 Sample holding part 300 Accommodation part 31 Sample 32 Through hole 50 Sensor 60, 60A, 60B Light source 61 Light emitter 62 Polarizing plate 63 1 / 4 wavelength plate 70 Resin substrate 71 Light-shielding layer 73 First surface 74 Second surface 75 Side wall L11, L21 Excitation light L12 Reflected light L13, L22 Fluorescence LC Liquid crystal molecules AA Exposure area AB Non-exposure area CT Crosstalk

Claims

1. A light source that irradiates a sample with excitation light in a circularly polarized state, a sample holding unit that holds the sample, a cholesteric liquid crystal layer that transmits fluorescence emitted by the sample due to the excitation light and reflects the excitation light, a sensor that detects the fluorescence that has passed through the cholesteric liquid crystal layer, and a fluorescence detection device.

2. The light source includes a light emitter, a polarizing plate that converts the light of the light emitter into a linearly polarized state, and a quarter-wave plate that converts the linearly polarized light emitted from the polarizing plate into the excitation light in the circularly polarized state. The fluorescence detection device according to Claim 1.

3. The sample holding unit includes a light-shielding resin substrate having a first surface and a second surface on the opposite side of the first surface and on the cholesteric liquid crystal layer side, and a through hole that penetrates the resin substrate from the first surface to the second surface. The fluorescence detection device according to Claim 1 or 2.

4. The opening area of the through hole on the first surface is larger than the opening area of the through hole on the second surface, and the angle formed by the second surface and the side wall of the through hole surrounding the sample is 45° or less. The fluorescence detection device according to Claim 3.

5. The cholesteric liquid crystal layer has liquid crystal molecules that spiral, and includes a first liquid crystal layer and a second liquid crystal layer having liquid crystal molecules that spiral in a direction different from the direction in which the liquid crystal molecules of the first liquid crystal layer spiral. The fluorescence detection device according to Claim 3.

6. The angle at which the excitation light is incident on the surface of the cholesteric liquid crystal layer is 30° or less. The fluorescence detection device according to Claim 1.

7. a light-transmitting substrate on which the cholesteric liquid crystal layer is formed on the cholesteric liquid crystal layer, and a light-shielding layer having light-shielding properties that surrounds the outer periphery of the upper surface of the sensor. The fluorescence detection device according to Claim 1.

8. The cholesteric liquid crystal layer is located in the vicinity of the second surface of the through hole. The fluorescence detection device according to Claim 3.

9. The sample holding unit includes a light-shielding resin substrate having a first surface and a second surface on the opposite side of the first surface, and a through hole that penetrates the resin substrate from the first surface to the second surface. A plurality of accommodating portions that are surrounded by the side wall of the through hole and accommodate the sample are arranged. Each of the accommodating portions includes the cholesteric liquid crystal layer formed on the lower side of the accommodating portion. The sensor is disposed under the cholesteric liquid crystal layer. The cholesteric liquid crystal layer has an outer periphery surrounded by the side walls, The sensors are arranged adjacent to each other in the lateral direction, The fluorescence detection device according to claim 1 or 2.

10. The light from the light source is incident obliquely with respect to the side walls, The inside of the housing portion is partitioned into an exposed exposure region and a non-exposed non-exposure region, The entire surface of the surface on which the fluorescence is incident on the cholesteric liquid crystal layer faces the non-exposure region, The fluorescence detection device according to claim 9.

11. The surface of the cholesteric liquid crystal layer facing the non-exposure region and the upper surface of the sensor are inclined with respect to the side wall side, The fluorescence detection device according to claim 10.

12. The light from the light source is incident obliquely with respect to the side walls of the through hole, The inside of the through hole is partitioned into the exposure region and the non-exposure region, The opening surface of the through hole on the second surface faces the non-exposure region, The fluorescence detection device according to claim 10.

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