JPS6019491A - Determination device using biocatalyst electrode - Google Patents

Abstract

PURPOSE:To enable the determination of plural components in a sample at the same time, by connecting a cylinder containing a biocatalyst electrode and a counter electrode detachably to a tube in a manner to be able to pass the solvent passing through the tube. CONSTITUTION:The present apparatus is composed of the tube 2 to flow the solution containing the substance to be determined, and the biocatalyst electrodes 8, 10 and their counter electrodes 9, 11 contacting with the solvent passing through the tube 2. In the above apparatus, the cylinders 5, 6 containing the biocatalyst electrodes 8, 10 and the counter electrodes 9, 11 are connected detachably to the tube 2 in a manner to be able to pass the solvent passing through the tube 2. Consequently, plural components in a sample can be determined at the same time, the hazards of the damage of biocatalyst electrode can be reduced, and the handling of the electrode can be facilitated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a measuring device using a biocatalyst electrode that can measure a plurality of substances at once and that has less risk of damaging the biocatalyst electrode. BACKGROUND ART Conventionally, when measuring a specific substance in a solution using a physicochemical method, it is necessary to increase the purity of the substance, which requires separation and purification, which takes a long time. This has been a major obstacle to quantitative analysis. Furthermore, there are also problems such as the need for heating and pressurization during measurement, and the need for non-aqueous systems.

In this regard, biocatalysts have advantages such as being able to catalyze only a specific substrate (substrate specificity), allowing the reaction to occur at room temperature and under lightning pressure, and allowing the reaction to proceed quickly in an aqueous system. In recent years, a method has been developed in which biocatalysts such as enzymes are made water-insoluble and combined with an electrical device to selectively react with a substance to be measured in an aqueous solution, thereby capturing the content as electrical output (current, voltage). Ta.

In this measurement method using a biocatalyst, for the purpose of improving reaction efficiency, etc., a flow set measurement method involves continuously flowing a solvent into a tube and injecting a sample containing the substance to be measured into the tube. However, when measuring a specific substance in a solution, the conventional flow-type measuring device has a problem in that only one specific substance can be measured at a time. This is because in conventional measurement devices, one biocatalyst electrode is placed in a tube, and the type of biocatalyst electrode is changed depending on the type of specific substance to be measured. It is from. In addition, because the physical strength of the biocatalyst membrane is low, with conventional measurement devices, it is necessary to pay close attention when attaching the biocatalyst electrode to a holder etc. provided in the tube. The biocatalyst membrane is sometimes damaged by the application of some kind of force, making it extremely difficult to handle, as it often ceases to function as a biocatalyst electrode.

[Purpose of the invention]

This invention was made in view of the above circumstances, and has the following features:
It is an object of the present invention to provide a measuring device using a biocatalyst electrode that can measure a plurality of substances at the same time, has less risk of damaging the biocatalyst electrode, and is easy to handle.

[Disclosure of the invention]

In order to achieve the above objects, the present invention provides a measuring device comprising a tube through which a solution containing a substance to be measured flows, a biocatalyst electrode that comes into contact with the solution passing through the tube, and a counter electrode thereof. characterized in that a cylinder having a catalytic electrode and a counter electrode disposed therein is removably connected to the tube such that a solvent can be passed through the tube;
Its gist is a measurement device using biocatalytic electrodes.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 shows an embodiment of a measuring device using a biocatalyst electrode according to the present invention. As shown in the figure, this measuring device consists of a solvent reservoir 1. A tube 2. One end faces the solvent reservoir 1, and the middle part has a sample injection port 2a. Solvent 3 in solvent reservoir 1
A pump 4 and cylindrical bodies 5 and 6 are provided, respectively. The end of the tube 2 has a large diameter portion 2c. Cylindrical body 5
, 6 have large diameter portions 5a, 6a, respectively.
The remaining parts are the narrow diameter parts 5b and 6b, respectively.
By inserting the tip of the narrow diameter portion 5b of the tube 5 into the large diameter portion 2c of the tube 2, the tube 5 is removably connected to the tube 2, and the tip of the narrow diameter portion 6b of the tube 6 (tube side The cylindrical body 6 is removably connected to the cylindrical body 5 by inserting the connecting end) into the large diameter portion 5a of the cylindrical body 5. By inserting one end of the discharge pipe 7 into the large diameter portion 6a of the cylinder 6, the discharge pipe 7 is removably connected to the cylinder 6. A biocatalyst electrode 8 and its counter electrode 9 are arranged inside the cylinder 5, and a biocatalyst electrode 10 and its counter electrode 11 are also arranged inside the cylinder 6. Therefore, the cylinders 5 and 6 are a kind of cartridge, with biocatalyst electrodes 8 and 1o and counter electrodes 9 and 1o.
1 can contact the solvent passing through tube 2. Biocatalyst electrode 8 and counter electrode 9, and biocatalyst electrode 1o and counter electrode 11
12. is an electrical output measuring means such as a potentiostat.
13, respectively.

When performing measurements using this measuring device, as in the conventional case, when the solvent 3 in the solvent reservoir 1 is flowed into the pipe 2 using the pump 4,
This solvent flows from tube 2 into cylinders 5, 6 and is discharged from tube 7. In this state, a sample is injected from the injection port 2a using an injector (microsyringe) 14 or the like. Then, the solution containing the substance to be measured flows from the tube 2 to the cylinder 5.6, and the electrical output between the biocatalyst electrode and the counter electrode is measured by a measuring means 12.13 such as a potentiostat. Measure the content.

Since this measuring device handles the biocatalyst electrode while it is placed inside the cylinder, there is very little risk of the biocatalyst electrode being damaged. Also, since there are two sets of biocatalyst electrodes and counter electrodes, if the two biocatalyst electrodes are of different types,
Two types of substances can be measured at once. Furthermore, by changing the arrangement of the cylinders, the order of measurement can be changed.

In the above embodiment, two cylindrical bodies are provided in which the biocatalyst electrode and its counter electrode are disposed, but three or more may be provided. This makes it possible to measure three or more types of substances at once. Further, in the embodiment described above, one set of a biocatalyst electrode and a counter electrode is arranged in the cylinder, but two or more sets may be arranged.

Next, a more specific example will be described.

(Example 1) In FIG. 1, the tube 2 is a silicon tube, the biocatalyst electrodes 8 and 10 are a glucose oxidase fixed electrode (enzyme electrode) and a glucose oxidase/inhertase fixed electrode (enzyme electrode), and an electrical output measuring means. 12
．． A potentiostat was used as No. 13 to serve as the measuring device of Example 1.

Using the measurement device of Example 1, a sample solution (measurement solution) containing equimolar amounts of glucose and sucrose (each contained at a concentration of 10'M) was measured. However, the flow rate of the solvent was 1++l/min, the injection amount of the sample solution was 5μβ, +0.7V was applied to the biocatalyst electrode, and the value of the current flowing between the biocatalyst electrode and the counter electrode was measured. The measurement results are shown in Figure 2.

In the figure, the solid line segment 15 indicates the current value flowing between the glucose oxidase fixed electrode and its counter electrode, and the broken line segment 16 indicates the current value flowing between the glucose oxidase/invertase fixed electrode and its counter electrode. It's raining value. Response time was approximately 10 seconds. Since glucose is converted to hydrogen peroxide at the glucose oxidase fixed electrode, the peak of the solid line 15 corresponds to the amount of glucose. On the other hand, since both glucose and sucrose are converted to hydrogen peroxide in the fixed electrode of glucose and glucose oxidase/inhertase, the dashed line 16 corresponds to the total amount of glucose and sucrose. Since the concentrations of glucose and sucrose in the sample solution are the same, the peak value of broken line 1G is approximately twice the peak value of solid line 15. solid line 1
The amount of glucose can be determined from the peak value of 5, and the amount of sucrose can be determined by subtracting the peak value of solid line 15 from the peak value of broken line 16. Therefore, this measuring device can measure two types of substances at once.

(Example 2) In FIG. 1, a uricase fixed electrode (enzyme electrode) and a glucose oxidase fixed electrode (enzyme electrode) were used as the biocatalyst electrode 8.10, and the rest was carried out in the same manner as in Example 1. This is a measuring device.

First, 5μβ of a sample solution containing uric acid at a concentration of 0.1mM was prepared.
was injected and the current value was measured. The measurement conditions are the same as those described in Example 1. The measurement results are shown in Figure 3. solid line 17
shows the current change between the uricase fixed electrode and its counter electrode, and the solid line 18 shows the current change between the glucose oxidase fixed electrode and its counter electrode.

Next, sample solution 5 containing glucose at a concentration of 1 m'M
The current value was measured by injecting p(l). The measurement results are shown in FIG.
Solid lines 20 represent the current changes between the glucose oxidase fixed electrode and its counter electrode. From Figure 3,
It can be seen from FIG. 4 that uric acid is not affected by the glucose oxidase fixed electrode, and glucose is not affected by the uricase fixed electrode.

Thereafter, 5 μl of a sample solution containing uric acid at a concentration of 0.1 mM and glucose at a concentration of 1 mM was injected, and the current value was measured. The measurement results are shown in Figure 5. A solid line 21 represents the current change between the uricase fixed electrode and its counter electrode, and a solid line 22 represents the current change between the glycose oxidase fixed electrode and its counter electrode. From FIG. 5, it can be seen that the amount of uric acid and the amount of glucose are clearly captured as the peak values of the current values.

〔Effect of the invention〕

Since the measuring device using the biocatalyst electrode according to the present invention is configured as described above, it is possible to measure multiple substances at once, there is less risk of damage to the biocatalyst electrode, and it can be handled easily. is easy.

[Brief explanation of the drawing]

FIG. 1 is a structural explanatory diagram of one embodiment of a measuring device using a biocatalyst electrode according to the present invention, and FIGS. 2 to 5 are graphs showing changes in current over time. 1... Solvent reservoir 2... Tube 2a... Inlet 4
...Pump 5,6...Cylinder 8,10...Biocatalyst electrode 9.11...Counter electrode patent attorney Takehiko Matsumoto Figure 1 Time: 10 seconds Figure 2 Time: 0 seconds 3 figure

Claims (2)

[Claims] (1) A measurement device that is equipped with a tube through which a solution containing a substance to be measured flows, and a biocatalyst electrode that contacts the solution passing through the tube and its counter electrode, the tube in which the biocatalyst electrode and the counter electrode are arranged. A measuring device using a biocatalytic electrode, characterized in that the body is removably connected to a tube such that a solvent can be passed through said tube. (2) The biocatalyst electrode according to claim 1, wherein one end of the cylindrical body is connectable to a tube, and the other end is connectable to a tube-side connecting end of another cylindrical body having the same structure. A measurement device using