JP2007178338A - Detection cell and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a detection cell having a long working length with which light is transmitted through a liquid sample, and shielding an excessive beam unnecessary for detection, and a manufacturing method of the detection cell for manufacturing the detection cell highly accurately. <P>SOLUTION: An approximately linear detection passage 12 is formed on a substrate 11, and a sample introduction passage 13 for introducing the liquid sample is formed on one end of the detection passage 12, and a sample discharge passage for discharging the liquid sample is formed on the other end, respectively on positions except in the linear direction of the detection passage 12. A pinhole formation groove 16 for entrance/exit of a beam is formed on the substrate side face 15 in the linear direction of the detection passage 12, and an upper plate 17 is laminated on the upper surface of the substrate 11, and the substrate side face 15 on which the pinhole formation groove 16 is formed is covered with a shielding film 18 excepting the pinhole formation groove 16. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a detection cell for forming a flow path on a transparent substrate and measuring the absorbance and the like of a liquid sample flowing in the flow path, and a method for manufacturing the same.

  There is a detection cell used for measuring the absorbance of a liquid sample using light in the visible region or ultraviolet region and analyzing the components in the liquid sample. In recent years, detection cells have been miniaturized in order to reduce the amount of liquid sample introduced into the detection cells. The detection cell is installed in a part of an analyzer such as capillary electrophoresis or liquid chromatography, and measures the absorbance by irradiating a small amount of liquid sample with light. A general analyzer using a detection cell is shown in FIG.

  As shown in FIG. 5, the analysis device 50 includes a detection cell 51, a light source 52 that emits light to the detection cell 51, and a light receiving element 53 that receives light transmitted through the detection cell 51. The detection cell 51 includes a detection channel 55 for allowing a liquid sample to flow through a transparent substrate (or block) 54 and transmitting light to the liquid sample, and a sample inlet / outlet channel for introducing and discharging the sample to and from the detection channel 55. 56 is formed. In the analyzer 50, the light emitted from the light source 52 passes through the liquid sample in the detection cell 51, is received by the light receiving element 53, and the absorbance of the liquid sample is measured.

  In addition, there is an analyzer that uses a detection cell in which a detection chamber is formed instead of a detection channel, introduces a liquid sample into the detection chamber using a micropipette or the like, and statically measures the absorbance of the liquid sample.

  In recent years, miniaturization of detection cells has progressed, and there is a movement to manufacture a detection flow path (or detection chamber) of a detection cell using a semiconductor microfabrication process instead of machining. If a semiconductor microfabrication process is used, a detection channel (detection chamber) can be produced with a size of several microns to several tens of microns.

JP 2000-121547 A

  In these detection cells, it is desirable that almost all of the light guided to the light receiving element 53 passes through the liquid sample. This is because the light beam received by the light receiving element 53 without passing through the liquid sample takes a constant value regardless of the type of the liquid sample and causes detection sensitivity to be weakened as background noise. In order to increase the detection sensitivity, such extra light must be shielded.

  For example, in the detector cell shown in Patent Document 1, in order to measure the absorbance of light incident in a direction perpendicular to the flow direction of the analysis flow path, it is parallel to the analysis flow path and perpendicular to the light beam. A method has been proposed in which a light shielding film is provided on one surface to increase detection sensitivity.

  However, apart from such a detection cell, as shown in FIG. 6, the light beam is incident in parallel with the flow path direction (the direction in which the liquid sample flows), and the path (action length) passing through the liquid sample is lengthened. Therefore, a detection cell 60 that increases the detection sensitivity of the detection cell is required. In the detection cell 60 having such a structure, it is not easy to align the pinhole through which light from the light shielding film passes and the detection flow path 55 with high accuracy.

  In view of the above, an object of the present invention is to solve the above-mentioned problems, to increase the working length of light passing through a liquid sample, and to block an extra light beam unnecessary for detection, and to increase the detection cell. An object of the present invention is to provide a manufacturing method of a detection cell manufactured with high accuracy.

  In order to achieve the above object, the invention of claim 1 introduces a liquid sample into a detection channel formed on a transparent substrate, transmits light in the ultraviolet region and visible region, and absorbs the absorbance. In a detection cell for measuring and analyzing a component of a liquid sample, the substrate, a substantially linear detection channel formed on the substrate, and one end of the detection channel are connected to the detection channel. A sample introduction channel that introduces a liquid sample into the detection channel formed at a position other than the linear direction, and a detection flow that is connected to the other end of the detection channel and formed at a position other than the linear direction of the detection channel. A sample discharge channel for discharging a liquid sample in the path, a pinhole forming groove for entering and exiting the light beam formed on the side surface of the substrate in the linear direction of the detection channel, an upper plate joined to the upper surface of the substrate, The side surface of the substrate on which the pinhole forming groove is formed is A detection cell and a light shielding film covering except groove.

  The invention according to claim 2 is the detection cell according to claim 1, wherein the depth of the detection channel is 100 μm or less.

  The invention according to claim 3 is the detection cell according to claim 1 or 2, wherein the substrate is made of quartz glass.

  A fourth aspect of the present invention is the detection cell according to any one of the first to third aspects, wherein the light shielding film is formed of Si, Ta, Cr, Al, or W.

  The invention of claim 5 introduces a liquid sample into a detection channel formed on a transparent substrate, irradiates the liquid sample with light in the ultraviolet region or visible region, and measures the absorbance to analyze the component of the liquid sample. In the method of manufacturing a detection cell, a substantially linear detection channel, a sample introduction channel connected to one end of the detection channel, and a liquid sample connected to the other end are connected to the substrate. A sample discharge channel for discharging the light and a pinhole forming groove for entering and exiting the light beam located in a linear direction of the detection channel are simultaneously formed using a semiconductor micromachining process, and an upper plate is formed on the upper surface of the substrate. Were cut so that the pinhole forming groove was exposed on the side surface of the substrate, a light shielding film was formed from above the upper plate, and the pinhole forming groove was exposed. The substrate side is shielded except for the pinhole groove. It is a manufacturing method for detecting cells, wherein the covering with film.

  The invention according to claim 6 is the method for manufacturing a detection cell according to claim 5, wherein the light shielding film is formed by sputtering.

  A seventh aspect of the present invention is the detection cell manufacturing method according to the fifth or sixth aspect, wherein the semiconductor microfabrication process is a process using a photolithography method and reactive ion etching.

  The invention according to claim 8 is the method of manufacturing a detection cell according to any one of claims 5 to 7, wherein the substrate is formed of quartz glass.

  The invention of claim 9 is the method of manufacturing a detection cell according to any one of claims 5 to 8, wherein the light shielding film is formed of Si, Ta, Cr, Al or W.

  According to the present invention, it is possible to increase the detection sensitivity by increasing the working length and shielding extra light rays that are not necessary for detection.

  Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 shows a preferred embodiment of a detection cell according to the present invention, FIG. 1 (a) is a plan view, and FIG. 1 (b) is a view taken along line 1B-1B in FIG. 1 (a).

  As shown in FIGS. 1 (a) and 1 (b), the detection cell 10 of the present embodiment has a substantially linear detection channel 12 formed on a substrate 11, and one end of the detection channel 12 is formed. A sample introduction channel 13 for introducing the liquid sample and a sample discharge channel 14 for discharging the liquid sample at the other end are formed at positions other than the linear direction of the detection channel 12. A pinhole forming groove 16 for entering and exiting a light beam is formed on the substrate side surface 15 in the linear direction of the detection flow path 12, and an upper plate 17 is joined to the upper surface of the substrate 11 to form a pinhole 20. Further, the substrate side surface 15 on which the pinhole forming groove 16 is formed is covered with a light shielding film 18 except for the pinhole forming groove 16.

  In the detection cell 10 of the present embodiment, the sample introduction flow path 13 and the sample discharge flow path 14 are respectively connected to both ends of the linear detection flow path 12 at right angles to the detection flow path 12. The sample discharge channel 14 is formed facing the same substrate side surface 19. Although not shown, the sample introduction channel 13 and the sample discharge channel 14 are connected to capillaries and the like for introducing and discharging a liquid sample, respectively.

  The substrate 11 is made of a transparent material that transmits light in the ultraviolet region and visible region used for component analysis. In this embodiment, quartz glass having excellent characteristics in light transmittance and chemical stability is used. Formed. By forming the substrate 11 with quartz glass, it is possible to reduce the loss in the substrate 11 of the light transmitted through the detection flow path 12. In the present embodiment, the substrate 11 is formed of quartz glass, and the upper plate 17 to be bonded to the substrate 11 is also formed of quartz glass.

  The detection flow path 12 was formed with a depth of 100 μm or less, and the depths of the sample introduction flow path 13, the sample discharge flow path 14, and the pinhole formation groove 16 were also equal to the detection flow path 12. The widths of the detection flow path 12, the sample introduction flow path 13, the sample discharge flow path 14, and the pinhole forming groove 16 were 100 μm or less. The length of the detection flow path 12 was 3 mm, and the length of the pinhole forming groove 16 was 300 μm. However, the length of the pinhole forming groove 16 is a distance from the substrate side surface 15. The length between the detection channel 12 and the pinhole forming groove 16 was 100 μm.

  Further, in the detection cell 10, in addition to the substrate side surface 15 on which the pinhole forming groove 16 is formed, the upper surface of the upper plate 17 and the side surface on which the pinhole forming groove 16 is not formed are also covered with the light shielding film 18. May be. In this embodiment, the light shielding film is formed using Si, but the material for forming the light shielding film 18 may be any material that has light shielding properties and can be formed by sputtering. For example, Ta, Cr , Al, W and the like.

  Next, the manufacturing method of the detection cell 10 is demonstrated based on FIGS.

  As shown in FIG. 2A, the detection channel 12, the sample introduction channel 13, the sample discharge channel 14 and the pinhole forming groove 16 are simultaneously formed on the substrate 11. These flow paths and grooves are formed using a semiconductor microfabrication process, specifically, using photolithography and reactive ion etching. Since the pinhole formation groove 16 and the detection flow path 12 are simultaneously formed by photolithography, the alignment accuracy between the pinhole formation groove 16 and the detection flow path 12 is a photomask drawing accuracy level, which is on the order of submicron. High-precision alignment is possible. FIG. 2A is a perspective view showing one step of the detection cell manufacturing process in an easy-to-understand manner. At this stage, the substrate 11 is not yet cut (side surfaces 15 and 19 are formed). 2), a flow path or the like is formed in the substrate 11a that is not cut as shown in the top view of FIG.

  As shown in FIG. 3A, the upper plate 17 is bonded to the substrate 11 on which the flow path and the like are formed by thermal bonding. The bonded substrate 11 and the upper plate 17 (bonded body 21) are cut by dicing so that the pinhole forming groove 16 is exposed, and the side surface 15 is formed. As in the case of FIG. 2, the joined body 21 after dicing is actually a joined body 21a on which the side surface 15 shown in FIG. 3B is formed.

  Next, the joined body 21 in which the pinhole forming groove 16 is exposed is disposed in the sputtering apparatus. At this time, the joined body 21 is disposed so that Si is deposited on the upper surface of the upper plate 17 (the upper surface of the upper plate 17 faces the Si target). As shown in FIGS. 4A and 4B, Si is formed on the bonded body 21 by sputtering to form the light shielding film 18. At this time, the light shielding film 18 is formed not only on the upper surface of the upper plate 17 but also on the side surfaces of the upper plate 17 and the substrate side surfaces 15 and 19 by sputtering. Sputtering wrap-around has a limitation on the wrap-around distance. If the length of the pinhole forming groove 16 is set to a predetermined length or more, a light-shielding film is formed at the deepest portion (surface farthest from the side surface 15) of the pinhole forming groove 16. Not filmed. Preferably, the length of the pinhole forming groove 16 is 300 μm or more. As a result, the light shielding film 18 is formed on the side surface 15 so as to transmit light only through the pinhole formed on the straight line of the detection flow path 15. Finally, the joined body on which the light shielding film 18 is formed is diced to a desired size, and the detection cell 10 is obtained.

  Next, the operation of the present embodiment will be described.

  The liquid sample is introduced from the sample introduction channel 13, passes through the detection channel 12, and is discharged from the sample discharge channel 14. Light from a light source (not shown) is incident from a pinhole 20 formed on the side surface 15 of the detection cell 10. Light incident from one pinhole 20 passes through the detection channel 12 and exits from the other pinhole 20. The light transmitted through the detection cell 10 is detected by a light receiving element (not shown), and the component and concentration of the liquid sample are measured from the absorbance (attenuation) of the light.

  In the detection cell 10, light is incident in the direction of the flow path of the detection flow path 12, so that the action length of the light passing through the liquid sample can be increased. The longer the action length, the greater the attenuation of light caused by the liquid sample, and the detection sensitivity can be increased.

  Further, since the substrate side surface 15 on which the pinhole forming groove 16 is formed is covered with the light shielding film 18 except for the pinhole forming groove 16, noise light imparted to the detected light beam can be blocked, and detection can be performed. Sensitivity can be increased.

  According to the manufacturing method of the detection cell 10 of the present embodiment, since the pinhole forming groove 16 is formed together with the detection flow path 12 on the substrate side surface 15 in the linear direction of the detection flow path 12, The pinhole 20 for allowing the light beam to enter the detection flow path 12 can be formed with high precision alignment.

  In the present embodiment, the sample introduction flow path 13 and the sample discharge flow path 14 are formed facing the same side face 19, but the sample introduction flow path 13 and the sample discharge flow path 14 are formed to face the substrate side surfaces facing each other. Alternatively, it may be formed facing the substrate side surface 15 on which the pinhole forming groove 16 is formed. However, when it is formed facing the side surface 15 of the substrate, a part of the sample introduction channel 13 and the sample discharge channel 14 (channel inner wall in the vicinity of the side surface of the substrate) is formed with a light-shielding film. It is necessary to select an appropriate light-shielding film material. Further, the sample introduction channel 13 and the sample discharge channel 14 may not be connected to the detection channel 12 at a right angle, and a pinhole forming groove 16 is formed in the channel extension direction (linear direction) of the detection channel 12. If possible, the detection channel 12 may be connected in any way.

It is a figure which shows the detection cell of suitable embodiment which concerns on this invention, (a) is a top view, (b) is the 1B-1B arrow directional view of (a). It is a figure which shows 1 process of the manufacturing method of the detection cell of FIG. 1, (a) is a perspective view, (b) is a top view. It is a figure which shows 1 process of the manufacturing method of the detection cell of FIG. 1, (a) is a perspective view, (b) is a top view. It is a figure which shows 1 process of the manufacturing method of the detection cell of FIG. 1, (a) is a perspective view, (b) is a top view. It is the schematic which shows the general analyzer using a detection cell. It is the schematic which shows the other example of an analyzer.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Detection cell 11 Board | substrate 12 Detection flow path 13 Sample introduction flow path 14 Sample discharge flow path 16 Pinhole formation groove 17 Upper plate 18 Light shielding film

Claims (9)

In a detection cell for analyzing the components of a liquid sample by introducing a liquid sample into a detection channel formed on a transparent substrate, transmitting light in the ultraviolet or visible range to the liquid sample, and measuring the absorbance ,
The substrate, a substantially linear detection channel formed on the substrate, and one end of the detection channel connected to one end of the detection channel, formed at a position other than the linear direction of the detection channel, and introducing a liquid sample into the detection channel A sample introduction channel, a sample discharge channel connected to the other end of the detection channel and formed at a position other than the linear direction of the detection channel and discharging the liquid sample in the detection channel, and the detection flow Pinhole forming grooves for entering and exiting the light beam formed on the side surface of the substrate in the linear direction of the path, an upper plate joined to the top surface of the substrate, and forming the pinhole on the side surface of the substrate on which the pinhole forming groove is formed A detection cell comprising a light-shielding film covering except for the groove.   The detection cell according to claim 1, wherein the detection channel has a depth of 100 μm or less.   The detection cell according to claim 1, wherein the substrate is made of quartz glass.   The detection cell according to claim 1, wherein the light shielding film is formed of Si, Ta, Cr, Al, or W. Manufacture of a detection cell for component analysis of a liquid sample by introducing a liquid sample into a detection channel formed on a transparent substrate, irradiating the liquid sample with ultraviolet or visible light, and measuring the absorbance In the method
A substantially linear detection channel on the substrate; a sample introduction channel connected to one end of the detection channel to introduce a liquid sample; a sample discharge channel connected to the other end to discharge the liquid sample; A pinhole forming groove for entering and exiting the light beam located in the linear direction of the detection flow path is simultaneously formed using a semiconductor micromachining process, and an upper plate is joined to the upper surface of the substrate, and the joined substrate and The upper plate is cut so that the pinhole forming groove is exposed on the side surface of the substrate, and a light shielding film is formed from above the upper plate. A method for manufacturing a detection cell, wherein the detection cell is covered with a light shielding film.   The method of manufacturing a detection cell according to claim 5, wherein the light shielding film is formed by a sputtering method.   7. The detection cell manufacturing method according to claim 5, wherein the semiconductor microfabrication process is a process using a photolithography method and reactive ion etching.   The detection cell manufacturing method according to claim 5, wherein the substrate is made of quartz glass. The method of manufacturing a detection cell according to claim 5, wherein the light shielding film is formed of Si, Ta, Cr, Al, or W.

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