JPH0650931A - Solid-state ion sensor - Google Patents

Abstract

PURPOSE:To obtain a compact multi-ion sensor, which can be manufactured in large quantity at a low cost and has the high measuring accuracy, by covering a plate material made of conductive material with polyvinyl chloride, and forming an ion sensitive film on the surface of a slice piece, which is sliced in the vertical direction of a major axis. CONSTITUTION:Polyvinyl chloride 2 is formed so as to cover the surrounding part of a circular conductive plate material 1. The surface of the conductive material 1 is made to be chloride 4 by electrochemical treatment. A signal line 3 is connected to the surface at the opposite side of the chloride 4. Tetrahydrofuran or tetrohydrofuran, wherein ion-sensitive film material is dissolved, is dropped on the surface, on which the chloride 4 is formed. Thus, an ion sensitive film 5 is provided. Both the polyvinyl chloride 2 and the ion sensitive film 5 around the conductive plate material are dissolved into the tetrahydrofuran. Therefore, after the evapolation of the tetrahydrofuran, the unitary body is obtained, and the ion sensitive film 5 is strongly bonded to the conductive plate material 1 and the covering layer of the polychloride 2. Thus, the ion sensitive film 5 is not peeled away, and the stable potential can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ion sensor incorporated in a blood analyzer for medical use, and more
The present invention relates to a disposable, multi-ion sensor that integrates a plurality of items of sensors.

[0002]

2. Description of the Related Art A small potassium ion sensor manufactured by using a photolithography technique is disclosed in Sensors and Actuators, 11 (1987), pages 23 to 36 (Sensors and Actuators, 11 (1986)).
pp23-36). This sensor was manufactured by forming a conductive electrode such as a metal on a silicon chip and forming an ion sensitive film on the conductive electrode.

[0003]

However, in the prior art, the manufacturing process is complicated and a special device such as a semiconductor manufacturing device is required, so that it is difficult to reduce the cost. Further, since the conductive electrodes are minute, the ion-sensitive film forming method has a poor compatibility with the semiconductor manufacturing process and is difficult to be miniaturized and integrated. In addition, the adhesion between the ion-sensitive film and the conductive electrode is poor, and the sensor is unstable, resulting in poor measurement accuracy.

An object of the present invention is to provide a small multi-ion sensor which can be mass-produced at low cost and has high measurement accuracy.

[0005]

The above object is to coat a wire rod made of a conductive material with polyvinyl chloride, slice the coated wire rod in the direction perpendicular to the major axis, and form an ion-sensitive film on the surface of the sliced piece. In addition, the sliced piece on which the film is formed is placed on a substrate or a channel.

[0006]

According to the present invention, a series of manufacturing steps such as coating polyvinyl chloride on a wire rod, slicing the wire rod, forming an ion-sensitive film on the sliced piece, and setting it on a substrate or a flow channel in the production of an ion sensor are performed. It is possible to provide a low-priced sensor that can be automated, is suitable for mass production. Further, in the sensor of the present invention, since the periphery of the conductive electrode is coated with polyvinyl chloride, the ion-sensitive film-coated polyvinyl chloride firmly adheres, and the adhesiveness with the conductive electrode can be improved and stable. An ion sensor having excellent properties can be provided.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a first embodiment of the present invention. A circular conductive plate material 1 having a thickness of 0.5 mm and a diameter of 0.5 mm was coated with polyvinyl chloride 2 having a thickness of 0.2 mm. Conductive plate material 1
The surface of was converted into chloride by electrochemical treatment, and the signal line 3 was connected to the surface opposite to the surface.

FIG. 2 shows an ion-sensitive membrane 5 provided by dropping tetrahydrofuran or tetrahydrofuran in which an ion-sensitive membrane material is dissolved onto the surface on which chloride 4 is formed in the first embodiment. Is a cross-sectional view and (b) is a perspective view. Since both the polyvinyl chloride and the ion-sensitive film around the conductive plate material are dissolved in tetrahydrofuran, they become united after the volatilization of tetrahydrofuran, and the ion-sensitive film firmly adheres to the conductive plate material and the polyvinyl chloride coating layer. Therefore, the ion sensitive film is not peeled off, and a stable potential can be obtained.

FIG. 3 shows a third embodiment of the present invention.
(A) is a perspective view and (b) is a sectional view taken along the line AA 'in (a). Three sensor elements 6 shown in the second embodiment are integrated on a glass epoxy substrate 7. In order to firmly hold the sensor element 6 on the substrate and protect the back surface of the conductive plate material and the signal line from the sample solution, the concave portion 8 is provided in the substrate, the sensor element 6 is installed therein, and the epoxy resin 9 or the like is provided. It was fixed with an adhesive with excellent electrical insulation and water resistance. Further, the through hole 10 was formed in the recess for taking out the signal line from the back surface of the substrate.

FIG. 4 shows a fourth embodiment of the present invention. 9A is a perspective view, and FIG. 8B is a sectional view taken along line BB 'in FIG. A through hole 12 is provided in the vicinity of the center of a pair of surfaces of the polyvinyl chloride rectangular parallelepiped 11 and serves as a flow path through which the sample solution passes. A part of the side surface of the flow path is cut as shown in FIG. The sensor element 6 shown in the second embodiment is adhered to each hole 13 using tetrahydrofuran or tetrahydrofuran in which an ion sensitive membrane material is dissolved, and the holes are formed so that the ion sensitive membrane becomes a part of the inner surface of the flow channel. Close up. In order to suppress the temperature change in the rectangular parallelepiped 11 to be small, the rectangular parallelepiped 11 may be filled with a material having a large heat capacity such as silicone rubber.

As shown in the third and fourth embodiments, by integrating a plurality of the second embodiments, it is possible to provide a low cost multi-ion sensor which is easy to use.

FIG. 5 shows an example of a method of manufacturing the sensor element of the present invention. A conductive wire 14 having a diameter of 0.5 mm is dipped in tetrahydrofuran in which polyvinyl chloride is dissolved, pulled up, and dried to form a polyvinyl chloride film on the surface. When the desired film thickness of polyvinyl chloride cannot be obtained, dipping and drying are repeated a predetermined number of times. Next, the conductive wire 15 coated with polyvinyl chloride is sliced to a thickness of 0.5 mm. In order to obtain good thickness reproducibility and flatness of the sliced surface, it is effective to slice using a dicing saw or the like used for cutting a silicon chip or the like. A signal extraction line is attached to one surface of the sliced piece, and an electrochemical treatment is performed in a potassium chloride aqueous solution with platinum as a counter electrode to form the chloride on the surface of the conductive plate material.
After that, the ion sensitive membrane is adhered to the chloride surface with tetrahydrofuran or the like.

FIG. 6 shows a measuring system for evaluating the present invention. In this measurement system, the solid-state ion sensor shown in the fourth embodiment of the present invention was evaluated.

The standard solution 16 and the standard solution 17 are introduced into the solid ion sensor 20 by the squeezing pump 19 through the switching valve 18 and discarded in the waste solution bottle 21. A sample such as blood is introduced into the flow path by the syringe 22. The potential difference between the reference electrode 23 provided downstream of the solid-state ion sensor and each ion sensor is measured by the amplifier 24 and recorded in the recorder 25.

FIG. 7 shows the correlation between the measurement results obtained by the solid ion sensor for measuring sodium and potassium ions of the present invention and the results obtained by the conventional sodium and potassium ion electrodes when a serum sample is used in the measurement system shown in FIG. . A film made of polyvinyl chloride, valinomycin and dioctyl adipate was used as the potassium ion sensitive film, and a film made of polyvinyl chloride, biscrown and dioctyl adipate was used as the sodium ion sensitive film. Correlation coefficients of both sodium and potassium were 0.99 or more, and good results were obtained.

As described above, since the solid-state sensor of the present invention is manufactured by a method suitable for mass production, it is inexpensive, and since the conductive electrode has a polyvinyl chloride coating film around it,
Excellent adhesion due to strong adhesion to the ion-sensitive membrane,
Highly accurate measurement can be performed.

[0017]

According to the present invention, since a solid-state ion sensor can be manufactured by a simple method suitable for mass production, an inexpensive sensor can be provided. Further, since the polyvinyl chloride coating film is provided around the conductive electrode, the adhesion with the ion-sensitive film is strong, so that the stability is excellent and highly accurate measurement can be performed.

[Brief description of drawings]

FIG. 1 is a perspective view of a solid-state ion sensor element according to a first embodiment of the present invention.

FIG. 2 is a vertical sectional view and a perspective view of a solid-state ion sensor element according to a second embodiment of the present invention.

FIG. 3 is a perspective view and a vertical sectional view of an integrated solid-state ion sensor according to a third embodiment of the present invention.

FIG. 4 is a perspective view and a vertical sectional view of an integrated solid-state ion sensor according to a fourth embodiment of the present invention.

FIG. 5 is an explanatory view showing an embodiment of a method for manufacturing a solid-state ion sensor element of the present invention.

FIG. 6 is a block diagram showing a measurement system for evaluating the solid-state ion sensor of the present invention.

FIG. 7 is a characteristic diagram showing the effect of the present invention.

[Explanation of symbols]

3 ... Signal line, 6 ... 2nd Example, 11 ... Polyvinyl chloride rectangular parallelepiped, 12 ... Through hole, 13 ... Hole.

Claims (6)

[Claims] 1. A solid-state ion sensor characterized in that a side surface of a conductive plate material is covered with polyvinyl chloride, and an ion sensitive film is provided on a surface composed of the conductive plate material and the polyvinyl chloride. 2. The solid-state ion sensor according to claim 1, wherein the one or more solid-state ion sensors are arranged on an insulating substrate, and the conductive plate member is provided with a signal extraction line. 3. The one or more solid ion sensors according to claim 1, wherein the wall surface of the flow path is made of an insulating material.
A solid-state ion sensor in which the ion-sensitive film is arranged so as to face the inside of a flow path, and a signal extraction line is provided on the conductive plate material. 4. The conductive plate material coated with polyvinyl chloride according to claim 1, wherein the surface of the conductive wire is coated with polyvinyl chloride dissolved in a volatile solvent, and the solvent is volatilized to form a polychlorinated material. A solid ion sensor manufactured by slicing a conductive wire with the polyvinyl chloride after forming a vinyl coating film. 5. The ion sensitive film according to claim 1, wherein:
Consists of a base material, a plasticizer, an ion-sensitive substance, or an additive, the base material is polyvinyl chloride or silicone rubber, and the plasticizer is dioctyl adipate (DOA), tri (2-ethylhexyl) trimellitate (TOTM), 3,3 ′,
4,4-benzophenone tetracarboxylic acid tetra-1-
Undecyl ester (BTCU), ion sensitive substance is valinomycin, [bis (12-crown-4) methyl]
Methyldodecylmalonic acid, quaternary ammonium salt, solid ion sensor prepared by uniformly dissolving it in a volatile solvent using potassium tetraphenylborate or sodium tetraphenylborate as an additive. 6. The conductive plate material according to claim 1, wherein the conductive plate material is silver,
A solid ion sensor made of gold, platinum or the above metals and their chlorides.