JPH06288962A - Magnesium ion sensor and sensor plate - Google Patents

Abstract

PURPOSE:To make magnesium ion sensitive films to properly sense magnesium ions without being affected by proteins by providing means which mask the proteins on the magnesium ion sensitive films. CONSTITUTION:A joined body of a multi-sensor plate main body 5 and bank body 9 is manufactured. On a sample liquid measuring electrode 2a side, magnesium ion sensitive electrodes 2a are constituted by forming a magnesium ion sensitive film 2d on the silver chloride layer 2c of the main body 5 with window sections 4a in between by dropping the solution of a resin for magnesium ion sensitive films into the narrow long holes 6a of the bank body 9 and drying the solution, similarly to a standard liquid measuring electrode side. Then the ion concentration of a sample liquid is measured by supplying the liquid to narrow long holes 6a through a flow passage and bringing the liquid into contact with a standard liquid at a liquid junction, and then, detecting a differential potential outputted to a measuring instrument. When a highly fat-soluble plasticizer is mixed with the solution of the resin and proteins in the liquid are masked with the plasticizer, the sensitive films 2 can detect proper sensitive values without being disturbed by the proteins.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnesium ion sensor plate for use in testing blood or the like, and more particularly to a disposable simple type magnesium ion sensor plate for masking proteins which interfere with the sensitivity of a magnesium ion sensitive membrane.

[0002]

2. Description of the Related Art Several magnesium ion sensor plates have been proposed as disposable magnesium sensor plates for simple inspection. As one of them, a differential multi-ion sensor previously proposed by the applicant of the present application is one in which a multi-sensor plate is connected to a measurement circuit to measure a large number of different ion concentrations at the same time. , As shown in FIG.
A pair of sample liquid measuring electrodes 2 in which a copper electrode formed by etching on a glass epoxy substrate 1 is electrolytically silver plated
a, 5 sets of reference electrodes 2b are provided as one set, and a silver chloride layer is provided on the silver-plated layers at the opposite ends of each electrode,
A sensor plate body 5 in which the circular portions on the silver chloride layer and the respective electrodes are covered with an insulating film 3 leaving the ends away from each other, the former circular portions serving as windows 4a and 4b, and the latter serving as external electrodes And a liquid junction part 7 for contacting the sample liquid and the reference liquid with the elongated holes 6a to 6e communicating with the windows 4a and 4b of each set and the tips of the two flow passages of the upper cell described later. (Attaching filter paper, etc.) and the electrodes 2a of each set
A bank 9 made of a polyester film having through holes 8a and 8b communicating with 2b is joined to the sensor plate body 5. Magnesium ions are formed by applying an ion-sensitive membrane solution containing an ion-sensitive substance such as a macrocyclic compound called ionophao or an ion-exchange resin to each of the elongated holes 6a to 6e of the dam body 9 and drying it to form an ion-sensitive film. In addition to 4 types, 5 types of different ion sensitive membranes will be provided. The sensor plate main body 5 and the bank body 9 are joined together to form a recess 10a in the lower cell 10 made of a transparent acrylic resin plate.
10b, and the upper cell 12 made of a transparent acrylic resin is bonded to the lower cell 10 with a double-sided adhesive tape to put the above bonded body inside. The upper cell 12 has a flow passage 1 formed by a concave groove communicating with the elongated holes 6a to 6e on the back surface of the transparent plate.
3, 14 are divided into two parts by partition walls, and a sample liquid introduction part 15 and a reference liquid introduction part 16 are provided at one end of each flow passage and air vent holes 17, 17, ... Are provided at the other end.
Further, terminal insertion holes 18a and 18b for inserting terminals of a measuring device (not shown) are provided corresponding to the exposed ends of the sample liquid measuring electrode 2a and the reference electrode 2b.

When the sensor plate having such a structure is used, when the sample solution and the reference solution are injected into the sample solution introduction section 15 and the reference solution introduction section 16 by a syringe or the like, the respective solutions are introduced into the flow passages 13 and 14. Is circulated, and the elongated holes 6a-
While being supplied to the ion-selective electrode in 6e, the sample liquid and the reference liquid come into contact with each other in the liquid junction 7. In this state, the terminal of the measuring instrument is inserted into the terminal insertion holes 18a, 18b and brought into contact with the respective external electrodes to measure the ionic components of the sample liquid, and magnesium ion is injected by one injection of the sample liquid and the reference liquid. The total concentration of five types of ions is measured.

[0004]

However, in the above structure, when a sample solution such as whole blood or serum is brought into contact with the magnesium ion-sensitive membrane in the measurement, it is contained in whole blood such as protein, serum, etc. Adsorption of various high molecular weight substances causes the sensitive value of the sensitive membrane to fluctuate and the differential potential of the detected value by the measuring instrument to fluctuate greatly, and the fluctuation varies depending on the type of sample liquid. Could not be measured accurately. An object of the present invention is to provide a magnesium ion sensor and a sensor plate having a magnesium ion sensitive membrane that is not affected by proteins such as blood.

[0005]

In order to solve the above problems, the present invention provides a sensor plate body having at least one pair of a sample liquid measuring electrode having a coating film of a magnesium ion sensitive film and a reference electrode. Provided is a magnesium ion sensor which is provided with a measuring circuit connected to the sensor plate body so as to measure magnesium ions in a sample liquid. The magnesium ion sensor is provided with masking means for masking proteins on the magnesium ion sensitive membrane. To do.

Further, a sample liquid is supplied to the sensor plate body in which at least one pair of a sample liquid measuring electrode having a coating film of a magnesium ion sensitive film and a reference electrode is provided on a substrate, and the sample liquid measuring electrode. A closed flow passage and a closed flow passage for supplying a reference liquid to the reference electrode are formed on the surface of the substrate, respectively, and an upper cell having a sample liquid introduction part and a reference liquid introduction part communicating with the respective flow passages. A masking means for masking proteins on the magnesium ion-sensitive membrane, which has at least a sample liquid provided in the sensor plate body and a liquid junction part for liquid junction with the reference liquid and the reference liquid. And a magnesium ion sensor plate. At this time, as the masking means, it is also preferable that the magnesium ion-sensitive film contains a highly lipophilic plasticizer and that a film containing a substance having a molecular sieving effect is provided on the magnesium ion-sensitive film.

In the present invention, the masking means for masking proteins is sensitive to the magnesium ion sensitive membrane without being interfered with by proteins coexisting with magnesium ions contained in the sample liquid, that is, proteins and lipoproteins. As described above, it means a means for allowing a substance that shields proteins to exist. The high fat-soluble plasticizer is a substance that dissolves proteins such as DOS (dioctyl sebacate) and D.
OA (dioctyl adipate) etc. are mentioned.

[0008]

[Function] Since the magnesium ion sensitive membrane is provided with a masking means for masking proteins, magnesium ions are sensitive to proteins even if they coexist.

[0009]

Embodiments of the present invention will now be described with reference to the drawings. In the figure, the same parts as those in the other figures represent the same parts. Example 1 A joined body of the multi-sensor plate body 5 and the bank 9 shown in FIG. 3 was prepared, and a magnesium ion-sensitive film resin solution having the following composition was dropped into the elongated holes 6a of the bank and dried to obtain magnesium. An ion sensitive film is formed and a magnesium ion sensitive electrode is formed. FIG. 1 shows a cross-sectional view around the electrode on the side for supplying the sample liquid. In the figure, 1 is a glass epoxy substrate, 2a is a sample liquid measuring electrode, 2c is a silver chloride layer, 3 is an insulating film, 4a is a window, 9 is a bank, 6a is an elongated hole, and 2d is a magnesium ion sensitive film. .

PVC (manufactured by Denki Kagaku Kogyo Co., Ltd.) 0.2 g (copolymer of vinyl chloride: vinyl alcohol: vinyl acetate = 91: 6: 3) NPPE (manufactured by Dojindo Co., Ltd.) 0.3 g (o-nitrophenylphenyl Ether) BBPA (manufactured by Fluka) (highly fat-soluble plasticizer) 0.1 g (bis (1-butylpentyl) adipate) ETH4030 (manufactured by Fluka) 2.5 mg (magnesium ionophore III) K-TCPB (manufactured by Dojindo Co., Ltd.) ) 0.5 mg (potassium tetrakisparachlorophenylborate) THF (tetrahydrofuran) 2 ml

Further, different ion sensitive film resin solutions are dropped into the other four elongated holes 6b to 6e in the same manner as above, and dried to form ion sensitive electrodes having the respective ion sensitive films formed thereon. To do.

Next, as in the case of FIG. 3, the joined body of the multi-sensor plate body 5 and the bank body 9 is fitted into the recesses 10a and 10b of the lower cell 10 made of a transparent acrylic resin plate, and the lower cell 10 The upper cell 12 made of a transparent acrylic resin is bonded with a double-sided adhesive tape, and the bonded body is incorporated. A control serum (manufactured by Wako Pure Chemical Industries, Ltd., human serum-derived, freeze-dried product) as a sample liquid is provided in each of the sample liquid injection unit 15 and the reference liquid injection unit 16 of the multi-sensor plate having such a structure, and the following composition as a reference liquid The liquid is injected by a syringe or the like, the respective liquids are circulated through the flow passages 13 and 14, and the respective liquids are supplied to the ion-sensitive electrodes in the elongated holes 6a to 6e, and both are contacted at the liquid junction 7. To be in a state in which electrical conduction can be achieved. Then, the terminals of the measuring device (not shown) are connected to the terminal insertion holes 18a, 1
In addition to magnesium ion in the sample liquid, four different ion concentrations were measured by inserting it into the electrode 8b and bringing it into contact with the electrode. Table 1 shows the results of measuring the fluctuation range of the differential potential output to the measuring device for magnesium ions.
It is the average of 20 samples.

Composition of Reference Solution NaCl 140 mM (mmol) KCl 4 mM Calcium chloride dihydrate CaCl ₂ .2H ₂ O 1 mM Magnesium chloride hexahydrate MgCl ₂ .6H ₂ O 1 mM Tris-HCl 10 mM

The reason why the differential potential width is small is that BBPA contained in the magnesium ion sensitive membrane 2d masks serum proteins, so that the sensitive substance (ETH4030) sensitive to magnesium ions is affected by the presence of proteins. This is because the magnesium ion is not interfered with by the protein and the response value is correctly detected by the measurement circuit.

Example 2 In Example 1, as shown in FIG. 2, Cl was substituted for BBPA in the composition of the resin solution for the magnesium ion sensitive membrane.
--P (chloroparaffin (Fluka)) 0.2 g
A magnesium ion-sensitive film 2f which has been conventionally used is provided by using the same resin solution for magnesium ion-sensitive film except that 0.2 g of NPPE is used instead of 0.3 g, and a molecular sieving effect is provided thereon. A dialysis membrane (cellophane membrane) was attached to provide a protective film 2g, and otherwise the same as in Example 1 to prepare a multi-sensor plate. Table 1 shows the results of the same measurement as in Example 1.

Example 3 In Example 2, instead of using a dialysis membrane, a hydrophilic photopolymerization curable resin solution having a molecular sieving effect by forming a lattice structure of about 100 Å (for example, ENT-1000 manufactured by Kansai Paint Co., Ltd.). Was dropped on the magnesium ion sensitive film, and a multi-sensor plate was prepared in the same manner except that it was cured by ultraviolet rays to form a protective film, and the measurement results of the multi-sensor plate were the same as in Example 1 and the results are shown in Table 1.

Comparative Example A multi-sensor plate was prepared in the same manner as in Example 2 except that the protective film was not provided, and the results of the same measurement as in Example 1 are shown in Table 1. In the table, -100 mV indicates that the fluctuation range is not constant in the range near 100 mV.

[0018]

[Table 1]

[0019]

According to the present invention, the magnesium ion-sensitive membrane is provided with a masking means for masking proteins, so that the magnesium ion-sensitive membrane affects the presence of proteins even when the sample liquid contains proteins. It is possible to suppress fluctuations in the differential potential of the output that is sensitive to magnesium ions and is detected by the measurement circuit without being affected by the above.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view of a multi-sensor plate of an embodiment to which a magnesium ion sensor plate of the present invention is applied.

FIG. 2 is a partial cross-sectional view of a multi-sensor plate of another embodiment.

FIG. 3 is an exploded perspective view of a multi-sensor plate.

[Explanation of symbols]

 2a Sample liquid measuring electrode 2b Reference electrode 2d, 2f Magnesium ion sensitive film 2g Protective film 5 Multi-sensor plate body 7 Liquid junction 13, 14 Flow path

Claims (4)

[Claims] 1. A sensor plate main body having at least one pair of a sample liquid measuring electrode having a coating film of a magnesium ion sensitive film and a reference electrode is provided, and a measuring circuit is connected to the sensor plate main body to connect the sample liquid. A magnesium ion sensor capable of measuring magnesium ions, wherein the magnesium ion sensitive membrane is provided with masking means for masking proteins. 2. A sensor plate body in which at least one pair of a sample liquid measuring electrode having a coating film of a magnesium ion sensitive film and a reference electrode is provided on a substrate, and a sample liquid is supplied to the sample liquid measuring electrode. A closed flow passage and a closed flow passage for supplying a reference liquid to the reference electrode are formed on the surface of the substrate, respectively, and an upper cell having a sample liquid introduction part and a reference liquid introduction part communicating with the respective flow passages. A masking means for masking proteins on the magnesium ion-sensitive membrane, which has at least a sample liquid provided in the sensor plate body and a liquid junction part for liquid junction with the reference liquid and the reference liquid. Magnesium ion sensor plate. 3. The masking means is to add a highly lipophilic plasticizer to the magnesium ion sensitive film.
The magnesium ion sensor plate described. 4. The magnesium ion sensor plate according to claim 2, wherein the masking means has a film containing a substance having a molecular sieving effect on the magnesium ion sensitive film.