JPS6034061B2 - electrode device - Google Patents

Description

[Detailed Description of the Invention] This invention is used in cases where a sample solution is passed between electrodes to which a predetermined membrane, such as a fixed enzyme membrane, is attached, and a substance contained in the sample solution is quantified. This invention relates to an electrode device.

An example of this type of device is Japanese Patent Application Laid-Open No. 52-85077.
The one shown in the publication is known.

This electrode device includes an anode located at the center and cathodes surrounding the anode at required intervals, and these electrodes are buried in a support made of an insulator with their surfaces exposed. . The surface of the support member including the surfaces of the anode and cathode is formed into a convex curved surface. On the other hand, there is a membrane positioning member formed with a concave curved surface that matches the convex curved surface, and both of these curved surfaces are close to each other and face each other.
A membrane with characteristics depending on the type of measurement is sandwiched between both curved surfaces. A groove is formed in the concave curved surface of the membrane positioning member, and the sample liquid is subjected to predetermined measurements, detection, etc. while flowing through the space created by the groove and the membrane. . By the way, in this type of electrode mounting, it is necessary for the membrane to be in close contact with the electrode surface in order to improve measurement accuracy and stability.

For this purpose, in the above-described electrode device, a circle ring having an inner diameter equal to the outer diameter of the membrane positioning member is attached around the membrane. When setting up this electrode device, the membrane with the O-ring attached was first placed on the convex curved surface of the support member, and then the membrane positioning member was placed so that its concave curved surface faced the convex curved surface. Insert it into the ○ ring. Then, the concave curved surface stretches the membrane onto the convex curved surface, so
The membrane will be in tight contact with the convex curved surface. However, with this device, the structure of the membrane is special because it is necessary to attach the ○ ring to the membrane.The membrane positioning member is inserted into the ○ ring and the membrane is stretched, so this operation requires nerves and lower back pain. There are problems such as the need for skill to apply the product closely without covering it. The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide an electrode device that does not require the use of a specially structured membrane, is easy to assemble, and allows the membrane to be brought into close contact with the electrode. The electrode device according to the present invention is suitably used when attaching an immobilized enzyme membrane to the electrode and quantifying sucrose, glucose, uric acid, etc. in a sample solution.

For example, when measuring the concentration of glucose, the following enzymatic reaction is used. Glucose 10.

2 Glucose Oxidase Gluconic Acid Jusei 02 A membrane on which glucose oxidase is immobilized is used as the enzyme membrane, and as electrodes, the anode is composed of platinum and the cathode is composed of silver. Hydrogen peroxide measurement polarographic electrodes are used.

Between the anode and cathode, there is a voltage of 0.0, which corresponds to the polarization voltage of hydrogen peroxide.
A voltage of about 6 (V) is applied. Then, the concentration of glucose is measured based on the measurement history of the amount of hydrogen peroxide (day 202) produced in the above equation. Embodiments of the present invention will be described in detail below with reference to the drawings.

In FIG. 1, a hole 2 is formed in a base 1, and a mounting cylinder 3 is fixed to the lower surface of the base 1 around this hole 2 by a fixing member 4.

The hole 5a in the upper half of the mounting cylinder 3 has a slightly smaller diameter, and the hole 5b in the lower half has a larger diameter than this. Further, on the peripheral wall of the lower half of the mounting cylinder 3, elongated positioning notches 6 are formed at positions facing each other across the center and extending upward by a required length from the lower end. Furthermore, the mounting cylinder 3
An annular groove is formed in the inner surface of the peripheral wall facing the small diameter hole 5a and the step between the small diameter hole 5a and the large hole 5b.
8 is inserted. The membrane supporting portion 10 is housed in the large diameter hole 5b of the mounting cylinder 3, and its cross section is circular and consists of a small diameter portion in the upper half and a large diameter portion in the lower half.

As shown in an enlarged view in FIG. 2, a recess 11 having a concavely curved surface 12 is formed in the center of the upper surface of the lumbar support member 10. This concave curved surface 12 is formed by the electrodes 27 and 2, as will become clear from what will be described later.
In order to improve the adhesion between the enzyme membrane 8 and the enzyme membrane 20, it is formed into a spherical shape. Further, the recess 11 has a vertical peripheral wall 13 having a small length at the upper end of its periphery. This vertical peripheral wall 1
3 is for increasing the tension of the enzyme membrane 20 when inserting the electrode into the recess 11. Membrane support member 1
An annular groove 14 is formed on the outer circumferential surface of the small portion of 0, and the peripheral green part of the enzyme membrane 20 attached to the upper end of the membrane support village 10 is pressed down by the ring 15 fitted in the annular groove 14. ing. Positioning pins 16 that protrude outward are provided on the outer peripheral surface of the large portion of the membrane support member 10 at positions facing each other across the center. ing. Further, in the recess 11 of the membrane support member 10, as shown in FIG. 3, a flow groove 17 is formed which passes through the center of the recess 11 and extends in a straight line in all directions. The space created by the groove 17 and the enzyme membrane 20 becomes a flow path for the sample liquid. Both ends of the flow groove 17 communicate with an inlet passage 17a and an outlet passage 17b formed within the membrane support member 10. An inlet pipe 18 and an outlet pipe 19 are connected to the inlet passage 17a and the outlet passage 17b, respectively. A female thread is formed on the inner peripheral surface of the lower end of the peripheral wall of the mounting cylinder 3.

The stop member 21 has a small diameter screw portion 21a and a large diameter knob portion 2.
1b, and has a through hole 22 in the center. A male thread is formed in the threaded portion 21a.
The threaded portion 21a of the stopper member 21 is fitted with a female thread of the mounting cylinder 3. The stopper member 21 pushes up the membrane support member 10 with its upper end surface, thereby fixing the membrane support member 10 within the large recess 5b of the mounting cylinder 3. On the other hand, a guide tube 25 is attached to the upper surface of the base 1 around the hole 2 by a fixing member 4.

An electrode support member 26 is housed within this guide tube 25. The electrode support member 26 is also made of an insulator, and includes an upper half portion with a larger diameter and a lower half portion with a smaller diameter portion.
At the lower end of the small diameter portion of the electrode support member 26, there is an anode 27 made of platinum in the center, and an annular cathode 28 made of silver arranged to surround this anode 27 at a required interval.
is buried. The lower surfaces of the anode 27 and the cathode 28 are exposed from the support member 26 and are continuous with the lower surface of the support member 26, and have a spherical convex curved surface 29 that matches the concave curved surface 12.
It has become. A connector 30 is embedded in the upper end of the electrode support member 26, a portion of which protrudes upward, and the support member 26 is attached to the mounting plate 31 via this connector 30. The mounting plate 31 is a disc and can slide up and down within the guide tube 25. A positioning pin 32 is fixed to the circumferential surface of the mounting plate 31 so as to protrude outward.
The positioning notch 33 is located in a positioning notch 33 that is elongated and extends upward by a required length from the lower end of the holder 5. The mounting plate 31 is provided with a conduit 34 extending upwardly from the connector 30. A lead wire 35 is connected to the anode 27 and the cathode 28, and this IJ wire 35 is inserted into a conduit 34 and connected to a lead wire 36 by a connector 30. An annular stopper piece 25a extending inward is integrally formed at the upper end of the guide tube 25, and a spring 37 is provided between the stopper piece 25a and the mounting plate 31. The spring 37 pushes the electrode support member 26 downward, brings the enzyme membrane 20 into close contact with the electrodes 27 and 28, and serves to prevent the state of contact from changing due to vibration or the like. Figure 4 shows the fixed enzyme membrane 2.
An example of a configuration of 0 is shown.

The enzyme membrane 20 is composed of three types of membranes. Membrane 20a
is a porous membrane with a pore diameter of about 300△, and is made of a polymer material (
For example, blood cells) are prevented from entering the electrode. membrane 20
b is a membrane on which the necessary enzymes are immobilized. The membrane 20c allows the generated hydrogen peroxide to pass through the electrode, and prevents interfering substances such as ascorbic acid and uric acid from diffusing into the electrode. The enzyme membrane 20 is attached with the membrane 20c as the electrode. In the above electrode device, the sample liquid is sent from the introduction tube 18 and passes through the introduction path 17a to the flow groove 17 and the enzyme membrane 2.
0 and is discharged from the outlet path 17b to the outlet pipe 19.

In the process of continuously circulating the sample liquid in this way, the anode 2
7. A required voltage is applied between the cathodes 28 and glucose concentration measurement and other measurements or detections are performed based on the amount of hydrogen peroxide produced as described above. This method of measuring by continuously flowing a sample solution through an electrode with an immobilized enzyme membrane allows for the miniaturization of the device, eliminates the need for reagents because the immobilized enzyme membrane can be used repeatedly, and improves the response rate. It has characteristics such as being fast.

FIG. 5 shows the procedure for assembling the electrode device.

First, the enzyme membrane 20 is placed on the membrane support member 10', the peripheral edge thereof is bent to align with the small portion, and the enzyme membrane 20 is fixed with the circle ring 15 without any slack. Electrode support member 26
The guide cylinder 25 is placed in advance with the electrodes 27 and 28 facing downward.
and is located inside the mounting cylinder 3. Electrode support member 2
6 is composed of a 4-diameter portion between the electrodes 27 and 28 and a large-diameter portion continuous to this, and there is a step 26a between the two portions, so this step 26a is connected to the small-diameter hole 5a of the mounting cylinder 3. It is supported by hanging around the periphery of the upper end, and is biased downward by a header 37. In such a state, the enzyme membrane 2
The membrane support member 10 with the screw 0 attached is inserted from below into the large flea hole 5b of the mounting cylinder 3, and the stopper village 21 is screwed into the mounting cylinder 3 to push the membrane support member 10 up. As the membrane support member 10 rises, the enzyme membrane 20 becomes a convex curved surface 29 formed by the electrode support member 26 and the electrodes 27 and 28.
The enzyme membrane 20 becomes more stretched due to the curved surface 29, and since the convex curved surface 29 and the concave curved surface 12 of the membrane support member 10 match each other, the enzyme membrane 20
Finally, it comes into close contact with the electrodes 27 and 28. Eventually, the electrode support member 26 is pushed up by the membrane support member 1,
The stepped portion 26a is in a state slightly lifted from the surrounding green portion of the small recess 5a of the mounting cylinder 3. ○ The ring 8 comes into close contact with the upper surface of the enzyme membrane 20 and presses the enzyme membrane 20. The pin 16 attached to the membrane support section 101 is in the notch 6 of the mounting cylinder 3, so turn the stopper member 21 to push up the membrane support section 10, and the membrane support section 10 will be pushed up. The enzyme membrane 20 does not rotate together with the stop member 21, and the enzyme membrane 20 is prevented from being wrinkled when the enzyme membrane 20 comes into contact with the convex curved surface 29. Note that even if the curvatures of the convex curved surface 29 of the electrode support member 26 and the concave curved surface 12 of the membrane support member 10 do not completely match and there is a slight difference, the enzyme membrane 20 can be fixed by applying grease or the like. It is possible to bring it into close contact with the electrodes 27 and 28. FIG. 6 shows a modification of the flow groove of the membrane support member.

Here, the circulation groove 41 has a depression 11 corresponding to the anode 27.
The cathode 28 is formed in a spiral shape, consisting of a slightly short groove extending in the opposite direction from the center thereof, and an occluded groove connected to this groove and having a diameter approximately equal to that of the annular cathode 28. As described above, the flow groove may have any shape as long as it has a portion facing the anode 27 and the cathode 28 and these portions are connected to each other. As explained in detail above, in the electrode device according to the present invention, a hollow groove for the ○ ring is formed on the outer circumferential surface of the membrane support member, and the membrane covers the concave curved surface formed on the membrane support member. has a bent peripheral edge and is fixed to the outer circumferential surface of the membrane support member by an iron ring fitted into the hollow groove.

Therefore, there is no need to use a special membrane with a circle attached thereto as in the conventional case. Also, simply align the convex curved surface of the electrode support member having an anode and a cathode, which has a convex curved surface that matches the concave curved surface, with the concave curved surface of the membrane support section to which the membrane is attached. It is easy to assemble. Furthermore, since the concave curved surface of the membrane support member and the convex curved surface of the electrode support member match each other, the membrane can be brought into close contact with the electrode. The membrane support member is formed with an iron groove for holding the membrane and a circulation groove for the sample liquid to flow through.The structure is simple because one member has two functions. ing.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a longitudinal sectional view of the whole, FIG. 2 is an enlarged sectional view of the membrane support member, FIG. 3 is a plan view of the membrane support member, and FIG. 4 is a cross-sectional view of the membrane support member. FIG. 5 is an enlarged sectional view showing the enzyme membrane, FIG. 5 is an assembled view showing the assembly procedure, and FIG. 6 is a plan view showing another example of the membrane support member. 3... Mounting cylinder body, 10... Membrane support member, 12... Concave curved surface, 14... Placing groove, 15...... 0 ring, 17, 41... Distribution groove, 20... Enzyme membrane, 21... Stopping member, 25...
...Guide tube, 26... Electrode support member, 2
7... Anode, 28... Cathode, 29...
...Convex curved surface, 37... Spring. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6

Claims (1)

[Scope of Claims] 1. A membrane support member having a concave curved surface, a flow groove formed in the curved surface, and a fitting mechanism for an O-ring formed on the outer circumferential surface, which covers the concave curved surface and has a bent peripheral edge. a membrane fixed to the outer peripheral surface of the membrane support member by an O-ring fitted into the fitting groove, and an anode and a cathode, including the surfaces of both electrodes and matching the concave curved surface. An electrode device comprising an electrode support member formed with a convex curved surface, the convex curved surface facing the concave curved surface and sandwiching the membrane, and the membrane being in close contact with both the electrodes. . 2. The electrode device according to claim 1, wherein either one of the membrane support member and the electrode support member is fixed, and the other is biased in the one direction by a spring. 3. The electrode device according to claim 1, comprising a mounting cylinder having a hole for housing the membrane support member, the membrane support member being housed in the housing hole and fixed by a stopper member. 4. Claim 1, further comprising a guide tube having a hole for accommodating the electrode support member, wherein the electrode support member is housed in the housing hole and is biased toward the membrane support member by a spring. Electrode device as described in section. 5. A guide tube having a hole for accommodating the electrode support member and a mounting tube having a hole for accommodating the membrane support member, the electrode support member being accommodated in the housing hole of the guide tube and attached to the membrane by a spring. The electrode device according to claim 1, wherein the electrode device is biased in the direction of the support member, and the membrane support member is housed and fixed in the storage hole of the mounting cylinder, and receives the biasing force of the spring. . 6 a mounting cylinder having a hole for accommodating the membrane support member;
a stop member for fixing the membrane support member, a female thread is formed on the inner surface of one end of the peripheral wall of the mounting cylinder, and a positioning notch is formed that extends slenderly in the axial direction from the one end; A male thread is formed on the outer peripheral surface, and the membrane support member has a positioning pin that fits into the positioning notch, and the membrane support member is housed in the storage hole, and the stopper member is screwed into the mounting cylinder. The electrode device according to claim 1, wherein the membrane support member is fixed by being fitted.