JPS6224141A - Chemical substance detector - Google Patents

Abstract

PURPOSE:To enable simultaneous measurement of two chemical substance to be effected quickly and accurately, by providing electrodes for detecting two chemical material in the same cell. CONSTITUTION:This chemical material detector has a spacer 1 placed between substrates 2 and 3, a hole 1a is provided at the center of the spacer 1 and a hole 2a on both sides of the substrate 2 to connect a passage 4 of a solution to be measured. An opposed electrode 2b of an electrode or the like is fixed on the inner side of the substrate 2. An electrode 3a for detecting glucose is fixed on the inner side of the substrate 3 while an electrode 3b for detecting uric acid is fixed. The electrode 3a has a physiologically active substance such as enzyme, for example, glucosidase immobilized on the electrode body and so arranged to turn inward. The opposed electrode 2b is common to the electrodes 3a and 3b. The space formed with upper and lower faces of the hole 1a of the spacer as covered with the substrates 2 and 3 serves as a path 5 to allow a solution to be measured to flow and both ends thereof are con nected to the respective holes 2a and 2a. In this manner, the spacer 1 and the substrates 2 and 3 compose a flowcell with a sensor section.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a chemical substance detector capable of simultaneously measuring two types of chemical substances, such as simultaneous determination of uric acid and glucose in blood.

[Background technology]

Some clinical analyzers currently on the market can measure 32 analysis items at a speed of 300 test breaks per hour. However, these devices are expensive and are only used in a few large hospitals.Recently, small devices that can only measure glucose for diabetic patients are becoming popular.

However, diabetic patients often have other diseases, such as kidney disease or heart disease. For this reason, there is a need for a compact and popular measuring device that can easily measure not only glucose but also other substances simultaneously.

[Purpose of the invention]

In view of the current situation, this invention provides two methods using simple steps.
The purpose of the present invention is to provide a small-sized chemical substance detector that can accurately measure different types of substances to be measured simultaneously.

[Disclosure of the invention]

In order to achieve such an object, the present invention includes two detection electrodes in the same cell so that two types of substances to be measured in a solution to be measured can be measured simultaneously, and a detection electrode for both detection substances. The gist is a chemical substance detector in which the electrodes also include one common counter electrode.

Hereinafter, the present invention will be explained in detail based on drawings showing embodiments thereof.

1 and 2 represent a first embodiment of a chemical substance detector according to the present invention. In this chemical substance detector A, a spacer l made of a soft material or the like is sandwiched between substrates 2 and 3. A horizontally long hole 1a is provided in the center of the spacer 1. One hole 2a is provided on each side of the substrate 2 to serve as an inlet/outlet for a solution to be measured. A flow path 4 for a solution to be measured is connected to the hole 2a. On the inner surface of the board 2,
A counter electrode 2b such as an Ag-AgC1 electrode is fixed. On the inner surface of the substrate 3, a working electrode 3a for glucose detection is fixed, and a working electrode 3b for uric acid detection is also fixed. The working electrode 3a for glucose detection has an enzyme such as glucose oxidase or a physiologically active substance such as a microorganism fixed to an electrode body made of platinum or the like, and the surface on which the physiologically active substance is fixed faces inward. It is installed. The counter electrode 2b is a common counter electrode for both working electrodes 3a and 3b. The space created by covering the upper and lower surfaces of the hole 1a of the spacer with the substrate 2.3 becomes a passage 5 through which the solution to be measured flows, and both ends of this passage 5 are connected to the holes 2a and 2a of the substrate 2, respectively. has been done. In this way,
Spacer 1. The substrate 2.3 constitutes a flow cell equipped with a sensor section. In the figure, 6 is a conducting wire made of a carbon rod.

FIG. 3 shows a second embodiment of the chemical substance detector according to the present invention. As shown in the figure, this chemical substance detector A'
As in the first embodiment, spacer 1. The substrates 2 and 3 form a flow cell. Holes 2a of this board 2,'
The channels 4', 4' for the solution to be measured are connected to la. The portions of the channels 4', 4' connected to the holes 2a', 2a' are pipes 4 made of a conductive material such as platinum.
1.41, and this pipe 41.41 serves as a counter electrode to the two working electrodes 3a and 3b fixed to the inner surface of the substrate 3, as in the first embodiment. An Ag-AgCl electrode is fixed to the inner surface of the substrate 2 as a reference electrode 2b'. In this way, even if the two working electrodes 3a and 3b are provided very close to each other, no electrical interaction occurs with each other, so that the detector can be miniaturized. In the figure, 61 is a conducting wire.

Of course, the chemical substance detector according to the present invention is not limited to the above embodiments. Even in the case of a combination of two working electrodes and a counter electrode as in the first embodiment, the counter electrode may be provided in a part of the flow path.

Furthermore, the cell is not limited to a complete flow set.

The chemical substance detector of the present invention is placed in a measuring device as shown in FIG. 4, for example. As shown in the figure, this measuring device is a flow set measuring device,
A solvent reservoir 8 into which a solvent 7 such as a buffer solution is placed. Pump 9.
It is provided with a sample injection port 10°, a chemical substance detector 11, and a receiver (waste liquid reservoir) 12 for the solvent 7, which are connected in order by a channel 4 through which the solvent 7 passes. A device 13 equipped with a constant voltage source and a (micro) ammeter is connected to the chemical substance detector 11.

Using this measuring device, for example, glucose and uric acid in blood are measured as follows.

Between the working electrode 3a and the counter electrode 2b for glucose detection.

and 0°5V between the working electrode 3b and counter electrode 2b for uric acid detection.
At the same time, the solvent 7 is caused to flow through the channel 4 at a constant speed by the pump 9. First, for sensitivity calibration, a 100μ/a glucose solution was poured into the injection port 10 by 10μ
When p is injected, the glucose sensing electrode 3a and the pipe 2b
A current change of Il occurs between the two, and this is recorded. Next, when 0 μl of 10 μl/dl of uric acid solution is injected through the injection port 10, I29. A current change of 12 u occurs between the uric acid detection electrode 3b and the pipe 2b, and this is recorded. Then, as an actual sample, serum was poured into the injection port 10 at 10μ! When injected, 1'19 is formed between the glucose sensing electrode 3a and the counter electrode 2b, and the uric acid sensing electrode 3b
A current change of I su occurs between and the counter electrode 2b. Using the measurement results of this standard solution and serum, the glucose concentration and uric acid concentration in serum can be determined by the following formula.

Glucose concentration (■ / d) Uric acid concentration (■ / d /d = (1,) The results of the analysis are shown in Table 1 together with the catalog values.

As shown in Table 1, in both Examples 1 and 2, the analytical values almost matched the catalog values using only a small sample of 10 μβ, which clearly shows the high precision of this chemical substance detector.

In the above embodiment, only the detector for simultaneous measurement of glucose and uric acid has been described, but of course, other detection electrodes may be used to detect other chemical substances. Also,
The type of electrode is not limited to the enzyme electrode on which a biocatalyst is immobilized as described above.

〔Effect of the invention〕

In the chemical substance detector of the present invention, two chemical substance detection electrodes are provided in the same cell as described above.
Two chemical substances can be measured simultaneously quickly and accurately.

[Brief explanation of the drawing]

FIG. 1 is an exploded perspective view of a first embodiment of a substance detector according to the present invention, FIG. 2 is a sectional view thereof, and FIG. 3 is a second embodiment of a substance detector according to the present invention. The sectional view and FIG. 4 are schematic illustrations of one embodiment of an analysis device using the substance detector according to the present invention. A, A', 11...Chemical substance detector 2b...Counter electrode 3a...Glucose detection electrode 3b...Uric acid detection electrode 4...Flow path agent Patent attorney Takehiko Matsumoto No. 7 Figure 2 Figure 3

Claims (5)

[Claims] (1) A chemical substance that is equipped with two detection electrodes in the same cell so that two types of substances to be measured in a solution can be measured simultaneously, and one counter electrode that is common to both detection electrodes. Detector. (2) The cell is a flow cell, a flow path for transporting the solution to be measured is connected to this flow cell, a part of this flow path is made of a conductive material, and this conductive material is the counter electrode of the detection electrode. A chemical substance detector according to claim 1, wherein: (3) A chemical substance detector according to claim 2, wherein a part of the flow path is made of a pipe made of platinum, which is a conductive material. (4) A chemical substance detector according to any one of claims 1 to 3, which includes a reference electrode within the cell. (5) The chemical substance detector according to any one of claims 1 to 4, wherein the two types of substances to be measured are glucose and uric acid.