JPH0355893Y2 - - Google Patents

Description

[Detailed description of the invention] <Industrial application field> The present invention presses a pair of electrodes into the small holes of the flow cell channel through an immobilized membrane, and measures the concentration of components in the solution in the flow cell channel. This invention relates to an electrochemical sensor for quantitative detection. The immobilized membranes used in these electrochemical sensors include membranes on which enzymes, microorganisms, antibodies, tissues, etc. are immobilized, and the electrodes used are electrochemical measurement electrodes that can detect with these immobilized membranes. For example, by using an oxygen electrode, a peroxide electrode, a PH electrode, etc. as an electrode brought into contact with an immobilized membrane on which glucose oxidase is immobilized, the glucose concentration in a solution can be detected in any case. Therefore, this electrochemical sensor can be widely used in clinical tests, component concentration tests in foods, component tests in waterways and sewage systems for measuring industrial pollution, and the like.

<Prior art> Conventional electrochemical sensors can be manufactured by attaching a thin and flexible immobilized film to the detection part of the electrochemical measurement electrode using an O-ring or the like, depending on the measurement purpose. Common. The sensor is used by immersing it in a certain amount of the solution to be tested or by placing it in the flow path of a flow cell.

In the case of these electrochemical sensors, if the immobilized membrane loses its activity or is damaged when used for a long time, only the immobilized membrane is replaced. Therefore, the structure must be such that this replacement is easy and that the thin immobilization membrane is not damaged during manufacturing and assembly.

<Problems to be solved by the present invention> However, in the case of the conventional structure, attaching a thin film with the above-mentioned properties to the surface of the minute detection part of the measurement electrode is difficult, not only during manufacturing and assembly, but also during immobilization. Care and skill are also required when replacing membranes. or,
When an electrochemical sensor equipped with an immobilized membrane is pushed or screwed into a certain point in the flow path of a flow cell, not only is it time-consuming to manufacture, assemble, disassemble, and reassemble, but there is a risk that the immobilized membrane may be damaged during assembly. be. In addition, there is a risk that the lead wire disposed between the lead portion of the measurement electrode body and the signal processing circuit may be twisted as the electrode rotates. Therefore, it is necessary to work with the lead wires removed, which makes the work even more troublesome.

Therefore, the present invention was devised in view of the above disadvantages, and instead of attaching a small, thin, and weak immobilization membrane to the electrode sample section, the immobilization membrane is placed in the small hole of the flow channel of the flow cell. To provide a flow cell-type electrochemical sensor with extremely simple operation, in which a measurement electrode body can be attached to and detached from a flow cell with one touch without damaging an immobilization membrane by pressing an electrode specimen part. With the goal.

<Means for Solving the Problem> In order to achieve the above object, the flow cell integrated electrochemical sensor of the present invention includes: a) a rod-shaped electrode body whose tip detection portion is formed with a curved surface; b) the electrode from one end surface. an electrode case in which a body tip detection part protrudes, a lead part of the electrode body is led out at the other end, and an outer peripheral locking part is provided on the outer peripheral surface near one end; c. a base having a flow cell channel therein; a recess that has a curved bottom that is substantially equal to the tip detection portion of the electrode body, has a small hole connected to the flow cell flow path in the bottom, and receives the tip detection portion; and the electrode case that is formed continuously with the recess. It has a cylindrical space inside that receives one end, and the inner peripheral wall forming the cylindrical space engages directly or indirectly with the outer peripheral locking part of the electrode case to restrict rotation of the electrode case. a flow cell comprising a hollow cylindrical portion protruding from the base with an inner peripheral locking portion and an outer peripheral locking portion on the outer peripheral wall; d) having a space portion into which the other end of the electrode case is placed; An inner circumferential locking portion is provided on the inner surface of the electrode case receiving side end portion, and the inner circumferential locking portion is removably fitted and locked with the outer circumferential locking portion of the hollow cylindrical portion, and this inner circumferential locking portion is connected to the outer circumferential locking portion. an electrode holder fixed to the outer circumferential wall of the hollow cylindrical portion by being fitted and locked to the electrode holder; e. a spring means housed in the electrode holder and pressing the electrode case toward the flow cell; The tip detection section of the electrode body is arranged in the recess of the flow cell with an immobilization film interposed therebetween.

<Function> The flow cell-integrated electrochemical sensor of the present invention with the above configuration is provided directly between the outer peripheral wall of the electrode case holding the electrode body and the inner peripheral wall of the hollow cylindrical part of the flow cell that receives a part of the electrode case. Alternatively, a locking portion that indirectly engages to restrict rotation of the electrode case is provided. Since the tip detection part of the electrode body is pressed into the small hole of the flow channel of the flow cell through the immobilization membrane while this rotation is restricted, torsional stress on the immobilization membrane during assembly can be eliminated, and the Damage to the chemical film can be prevented.

Further, locking portions are provided between the outer circumferential wall of the hollow cylindrical portion of the flow cell and the inner circumferential wall of the electrode holder, each of which is removably fitted and locked to each other. Since one-touch attachment/detachment is performed between the locking portions, assembly during manufacturing and reassembly during disassembly can be simplified.

<Example> Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 is a partially longitudinal sectional view in the axial direction showing a first embodiment of the flow cell integrated electrochemical sensor of the present invention, and FIG. 2 is a partially exploded longitudinal sectional view of FIG. 1.

In the figure, a sensor 1 includes an electrode case 5 holding an electrode body 4 and a ring-shaped packing 6 in a space formed by a flow cell 2 and an electrode holder 3.
It has a structure incorporating a fixed membrane 7, a sliding cylinder 8, a coil spring 9, etc.

The electrode body 4 is a rod-shaped electrode case 5 made of acrylic resin.
It is stored as an insert molded inside.
The detection portion 10 of the electrode body 4 protrudes from one end surface of the electrode case 5, and a lead portion (not shown) is led out from the other end of the electrode case 5 via a lead wire 11. A connector 12 is attached to the end of this lead wire 11, and the electrode body 4 is connected to a measuring instrument via this connector 12. Further, the detection section 10 is formed of a pair of measurement electrodes 10A and 10B that are insulated from each other by a glass tube 40 (see FIG. 5), and their tip surfaces are curved. These measurement electrodes 10A, 10B
Depending on the purpose of the sensor 1, an oxygen electrode, a hydrogen peroxide electrode, a PH electrode, etc. are used.

The electrode case 5 has a flange 5A formed in the middle part over the entire circumference, and a pin-shaped outer periphery between the flange 5A and one end from which the detection part 10 of the electrode body 4 protrudes. A locking portion 5B is integrally provided.

The flow cell 2 is formed by integrally forming a base 13 having a flow cell channel 2A and a hollow cylindrical portion 14 protruding from the base 13 using acrylic resin. A fixed connecting pipe 15 connected to the flow cell channel 2A is insert-molded in the base 13. The fixed connection pipe 15 protruding from this base 13 has
A pipe 16 for supplying the subject is connected. or,
On the outer circumferential wall of the hollow cylindrical portion 14, outwardly protruding pin-shaped outer circumferential engaging portions 17, 17 are provided, respectively, at positions displaced by approximately 180°. Further, inside the hollow cylindrical part 14, there is a recess 1 for receiving the detection part 10 of the electrode body 4.
8 and this concave portion 18 are formed continuously to form the electrode case 5.
A cylindrical space 19 is formed to receive one end of the cylindrical space. The bottom surface 18A of the recess 18 is formed with a curved surface approximately equal to the curvature of the tip surface of the detection section 10 of the electrode body 4, and a small hole 20 communicating with the flow cell channel 2A is formed in the bottom surface 18A. There is. The inner diameter of the cylindrical space 19 is approximately equal to the outer circumferential diameter of the electrode case 5. Further, when one end of the electrode case 5 is inserted into the cylindrical space 19, the outer circumferential locking portion 5B of the electrode case 5 is fitted onto the inner wall surface, and the outer circumferential locking portion 5B is released. A groove-shaped inner peripheral locking portion 21 is provided. The groove of the inner circumferential locking portion 21 is formed in a straight line so as to have an insertion port on the open end surface and extend toward the inner part.

The electrode holder 3 includes a cylindrical member 31 made of acrylic resin, and a disc-shaped end cover 32 also made of acrylic resin attached to the rear end surface of this cylindrical member 31.
It consists of. This end cover 32 has a fitting projecting wall 32A projecting in a ring shape from one end surface near its outer periphery.
The fitting projecting wall 32A is fitted into the rear end opening of the cylindrical member 31 to be attached. Also, end cover 3
An opening 32B through which the rear end of the electrode case 5 escapes is provided at the center of the electrode case 2. The cylindrical member 31 has an inner circumferential wall surface on the front end opening side of the hollow cylindrical portion 1 of the flow cell 2.
The small diameter portion 33 has an inner diameter approximately equal to the outer diameter dimension of No. 4. This small diameter portion 33 has an opening on the center side, the depth of which is approximately equal to the amount of protrusion of the outer periphery locking portion 17 formed in the hollow cylindrical portion 14, and the width of the opening on the outside of the outer periphery locking portion 17. It has an inner periphery locking portion 22 formed of a ring-shaped groove that is approximately equal in diameter. or,
This inner peripheral locking part 22 has a receiving opening on the open end surface, and a notch 23 formed in a groove shape along the center of the receiving opening.
It is formed by connecting. This notch 23 is approximately
Each is formed at a position displaced by 180°, and the flow cell
Each is formed at a position displaced by 80°, and the flow cell 2
When attaching the hollow cylindrical part 14 to the hollow cylindrical part 14,
The outer circumferential locking portion 17 is released and guided to the inner circumferential locking portion 22.

The sliding cylinder 8 is made of acrylic resin and has a cylindrical shape, and has a flange 8A that is approximately equal to the inner diameter of the electrode holder 3 at one end thereof. The sliding cylinder 8 receives and holds the other end of the electrode case 5 received in the electrode holder 3 with its inner circumferential wall and flange 8A.

The coil spring 9 is installed in the electrode holder 3 so as to cover the outer periphery of the sliding cylinder 8. One end thereof is in contact with the flange 8A of the sliding cylinder 8, and the other end is in contact with the inner surface of the end cover 32 and is placed in a compressed state, so that the electrode case 5 is always pressed toward the flow cell 2 side. A spring means is formed together with the sliding cylinder 8.

The ring-shaped packing 6 is made of silicone rubber or the like, has an outer diameter equal to the outer diameter of the electrode case 5, and an inner diameter equal to the outer diameter of the detection part 10 of the electrode body 4. It is attached to the outer periphery of the electrode case 5 and is positioned opposite to one end surface of the electrode case 5.

In the sensor 1 formed in this manner, when the electrode body 4 is attached to the flow cell 2, a desired immobilization film 7 is prepared as a single item. This immobilized film 7, like the aforementioned measurement electrodes 10A and 10B,
Depending on the purpose of the sensor 1, an oxygen membrane, a microbial membrane, an antibody membrane, a tissue membrane, etc. are used. The immobilization membrane 7 prepared as a single item is first dropped into the hollow cylindrical portion 14 of the flow cell 2 so as to cover the recess 18 . Next, the electrode case 5 holding the electrode body 4 is
from the detection unit 10 side of the electrode body 4, the electrode case 5
The outer periphery locking part 5B is inserted in a state corresponding to the inner periphery locking part 21 in the hollow cylindrical part 14. By inserting the electrode case 5, the immobilization membrane 7 is pressed against the bottom surface 18A of the recess 18 at the tip of the detection part 10 of the electrode body 4, and the small hole 20 is closed with the immobilization membrane 7. In this state, the outer circumferential locking portion 5B of the electrode case 5 and the inner circumferential locking portion of the hollow cylindrical portion 14 are engaged with each other, so rotational displacement of the electrode case 5 is reliably prevented. is in a state of being

In this state, the rear part of the electrode case 5 is housed in the electrode holder 3 via the sliding cylinder 8 from the rear of the electrode case 5, where the lead wire 11 has already passed through the inside of the electrode holder 3. In this state, the notch 23 of the electrode holder 3 is
7, press the electrode holder 3 toward the flow cell 2 side. At this time, the coil spring 9 receives a biasing force, but is pressed against this biasing force so that the outer circumferential locking portion 17 corresponds to the inner circumferential locking portion 22. In this state, when the electrode holder 3 is rotated by a predetermined angle, the protrusion of the outer peripheral locking part 17 is engaged with the groove of the inner peripheral locking part 22, and the electrode holder 3 is fixed to the hollow cylindrical part 14 of the flow cell 2 with one touch. The state shown in FIG. 1 is reached. In this state, the biasing force of the coil spring 9 applies a suitable pressure force between the outer peripheral locking part 17 and the inner peripheral locking part 22, and the play between the hollow cylindrical part 14 and the electrode holder 3 is removed. ing.
Moreover, the electrode case 5 is always urged toward the flow cell 2 by the urging force of the coil spring 9, and the detection part 10 of the electrode body 4 is in a state in which the immobilization film 7 is pressed against the bottom surface 18A of the recess. .

Then, in order to replace the immobilized membrane 7, the electrode holder 3 is rotated to the position where the notch 23 corresponds to the outer peripheral locking part 17 of the hollow cylindrical part 14, and the electrode can be replaced with one touch in the same way as when assembling. The holder 3 can be removed and replaced.

In addition, in the above embodiment, each of the inner circumferential locking portions 5
B, 22 are grooves, and the outer periphery locking parts 21, 17 are pins that are locked in these grooves, but this has the opposite configuration, that is, the inner periphery locking parts 5B, 22 are pins,
The outer circumferential locking portions 21 and 17 may be configured as grooves.

7 to 10 are diagrams showing a second embodiment of the flow cell integrated electrochemical sensor of the present invention. FIG. 7 is a partially sectional view along the axial direction, and FIG. 8 is a partially exploded sectional view along the axial direction.

Incidentally, in FIGS. 7 to 10, members designated by the same reference numerals as in FIGS. 1 to 6 are the same members having the same functions, and therefore, repeated explanation thereof will be omitted. This second embodiment differs from the first embodiment shown in FIGS. 1 to 6 in which the immobilization membrane 7 is attached and detached into the hollow cylindrical portion 14 by the immobilization membrane alone. On the other hand, the immobilization membrane 7 is made into a unit in order to further facilitate attachment and detachment.

As shown in an exploded view in FIG.
1, with the immobilization membrane 7 larger than this one end surface in contact with the inner cylindrical member 7.
An outer cylindrical member 72 made of acrylic resin is prepared to be placed over the outer periphery of the cylinder. And the inner cylindrical member 71
When covering the outer cylindrical member 72 with the outer cylindrical member 72, the part of the immobilization film 7 that protrudes outward from one end surface of the inner cylindrical member 71 is wrapped around the outer peripheral surface of the inner cylindrical member 71. In this way, the immobilization membrane 7 is formed into a unit by the inner cylindrical member 71 and the outer cylindrical member 72.

The inner diameter of the inner cylindrical member 71 of the unit fixing membrane 70 is approximately equal to the outer diameter of the electrode case 5, and the inner circumference is formed with a groove for receiving and locking the outer circumferential locking portion 5B of the electrode case 5. A locking portion 21' is provided. The outer diameter of the outer cylindrical member 72 is approximately equal to the inner diameter of the cylindrical space 19 of the hollow cylindrical portion 14, and the outer cylindrical member 72 has a pin-shaped outer periphery that is fitted and locked in the inner periphery locking portion 21 of the hollow cylindrical portion 14. A locking portion 5B' is formed on the outer peripheral surface.

Therefore, when assembling the sensor 1, this unit fixing membrane 70 first connects the outer periphery locking portion 5B' of the outer cylindrical member 72 to the inner periphery locking portion 21 of the hollow cylindrical portion 14.
It is dropped into the cylindrical space 19 in correspondence with the cylindrical space 19.

The immobilization membrane 7 is now placed in a state where it properly covers the recess 18 within the hollow cylindrical portion 14. Further, the unit fixing membrane 70 is in a state in which rotation within the cylindrical space 19 is prevented by engagement between the outer circumferential locking portion 5B' and the inner circumferential locking portion 21. Next, the electrode case 5 holding the electrode body 4 is attached to the outer circumferential locking portion 5 of the electrode case 5.
Insert the electrode body 4 from the detection part 10 side with B corresponding to the inner peripheral locking part 21' of the inner cylindrical member 71. By inserting the electrode case 5, the immobilization membrane 7 is pressed against the bottom surface 18A of the recess 18 at the tip of the detection part 10 of the electrode body 4, and the immobilization membrane 7 is pressed against the bottom surface 18A of the recess 18.
It becomes a closed form of 0. In this state, the outer circumferential locking portion 5B of the electrode case 5 and the inner circumferential locking portion 21' of the inner cylindrical member 71 are engaged with each other.
That is, the outer periphery locking portion 5B of the electrode case 5 connects to the hollow cylindrical portion 14 through the fitting between the inner cylindrical member 7 and the outer cylindrical member 72 that sandwich the margin of the immobilization membrane 7.
Since the electrode case 5 is indirectly engaged with the inner peripheral locking portion 21 of the electrode case 5, rotation of the electrode case 5 is prevented.

From this state, by attaching the electrode holder 3 in the same manner as described in the first embodiment, it is possible to attach and detach it with a single touch.

Incidentally, even in the above embodiment, the inner peripheral locking portion 21,
Although 21' is a groove and the outer peripheral locking parts 5B and 5B' are pins, the configuration may be reversed.

<Effects of the invention> As explained above, the present invention integrates a flow cell, an immobilization membrane, and a measurement electrode body, and the tiny, thin, and weak immobilization membrane can be easily crimped onto the electrode specimen part, and the flow cell It is an electrochemical sensor that can quantitatively measure the concentration of a sample by touching it through a small hole that communicates with a flow path.

Furthermore, when assembling the sensor, the rotation of the electrode case holding the electrode body that presses the immobilization membrane is restricted, so no torsional stress is applied to the immobilization membrane, thereby preventing damage to the immobilization membrane. be able to. Further, since a locking means that can be attached and detached in one-touch between the flow cell and the electrode holder is provided, attachment at the time of manufacturing and reattachment at the time of disassembly becomes easy.

[Brief explanation of the drawing]

1 to 6 show a first embodiment of the flow cell integrated electrochemical sensor of the present invention,
Figure 1 is a partial longitudinal cross-sectional view in the axial direction, and Figure 2 is the
A partially exploded longitudinal cross-sectional view of the figure, Figure 3 is A- in Figure 1.
A'-line arrow plan view, Figure 4 is a cross-sectional view of the B-B' line of Figure 3, and Figure 5 is the electrode body and electrode case seen from the C-C' line of Figure 2. , FIG. 6 is a sectional view taken along line D-D' in FIG. 2, and FIGS. 7 to 10 show a second embodiment of the present invention. The figure is a partially longitudinal sectional view in the axial direction, FIG. 8 is a partially exploded sectional view in the axial direction, FIG. 9 is an exploded view of the unit immobilization membrane shown in FIG.
FIG. 0 is a plan view of the unit immobilization membrane viewed from the direction of arrow E-E' in FIG. DESCRIPTION OF SYMBOLS 1... Sensor, 2... Flow cell, 2A... Flow cell channel, 3... Electrode holder, 4... Electrode body, 5... Electrode case, 7... Immobilization membrane, 8... Sliding cylinder which constitutes a spring means with a coil spring, 9... Coil spring constituting a spring means together with the sliding cylinder, 10... Detection section, 14... Hollow cylindrical section, 18... Concave section, 18A... Curved bottom section, 19... Cylindrical space section, 20
...Small hole, 5B, 5B', 17...Outer periphery locking part, 21,
21', 22...Inner circumferential locking portion.

Claims (1)

[Claims for Utility Model Registration] a. A rod-shaped electrode body whose tip detection portion is formed with a curved surface; b. The tip detection portion of the electrode body protrudes from one end surface, and a lead portion of the electrode body is led out from the other end. an electrode case having an outer circumferential locking portion on the outer circumferential surface near one end; c. a base having a flow cell channel therein; and a curved bottom portion substantially equal to the tip detection portion of the electrode body; a recess that has a small hole connected to the channel and receives the tip detection section; and an inner circumferential wall that has a cylindrical space that is formed continuously with the recess and that receives one end of the electrode case, and that forms the cylindrical space. An inner peripheral locking part is provided on the outer peripheral wall of the electrode case to restrict rotation of the electrode case by directly or indirectly engaging with the outer peripheral locking part of the electrode case, and an outer peripheral locking part is provided on the outer peripheral wall of the base. a flow cell consisting of a hollow cylindrical part protruding from a base; d having a space part for receiving the other end of the electrode case, and having an inner surface of the electrode case receiving end thereof attached to and detachable from the outer circumferential locking part of the hollow cylindrical part; an electrode holder provided with an inner peripheral locking part that can be fitted and locked to each other, the inner peripheral locking part being fitted and locked to the outer peripheral locking part, and fixed to the outer peripheral wall of the hollow cylindrical part; e a spring means housed in the electrode holder and pressing the electrode case toward the flow cell;
A flow cell-type electrochemical sensor, comprising: a front end detection portion of the electrode body disposed within the recess of the flow cell with an immobilization membrane interposed therebetween.