JPH03245049A - Liquid-sample analyzing disk - Google Patents

Abstract

PURPOSE:To achieve automation and high accuracy in analysis for an object which does not have optical features against a background by providing electrodes which are arranged in the expanding part of a liquid sample at a specified interval and measure the electric characteristics in the expanding part. CONSTITUTION:Expanding parts 2 of a liquid sample are provided on a disk substrate. Electrodes 31a-31b, 32a-32b and 33a-33b for measuring the electric characteristics in the expanding part 2 are arranged it the expanding part 2 at a specified interval. At first, a constant AC voltage is applied between two electrodes, and the current is monitored. Then, a liquid sample is dropped on an analyzing disk 1. Then, the disk 1 is rotated, and the sample is spread. Thus the sample is supplied on the expanding part 2. After the expansion, the change in potential difference and the like at every divided electrodes 31a-31b, 32a-32b and 33a-33b are measured, and analysis is performed. Since the electrodes are provided on the analyzing disk, the analysis based on the electric property of the sample whose optical analysis cannot be performed beforehand can be conducted.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an analytical disk used for analyzing a liquid sample, for example, quantifying a specific component in a liquid sample, and in particular for analyzing a target that cannot be detected by optical methods. This invention relates to a liquid sample analysis disk that can be used to measure objects.

[Prior Art] A liquid sample such as serum is analyzed to detect various substances, e.g.
BACKGROUND OF THE INVENTION Measuring the presence and/or concentration of hormones, vitamins, lipids, enzymes, nitrogen-containing substances, sugars, antigenic substances, etc. is becoming increasingly important from the perspective of early detection of various diseases.

Therefore, in recent years, there has been a strong desire to analyze liquid samples with high precision and efficiency, and several proposals have been made in response to this demand.

As a result of extensive research from this perspective, the inventors of the present invention have applied a preconditioning reagent onto the disk, and allowed the reaction between the liquid sample and the reagent to occur on the disk. After discovering that liquid samples could be analyzed with high precision and efficiency through measurements, he completed the invention of a method for analyzing liquid samples using a disk, and disclosed this in Japanese Patent Application No. 1-92367 and other documents. ing.

In these analytical methods, reaction phenomena are mainly measured and analyzed using optical measuring means. for example,
Using laser light, it is possible to focus the detection light on a minute spot, making it possible to process multi-component signals using the normal laser disc method, and also to process minute amounts of multi-component systems that change from moment to moment. Analysis can be performed in real time.

Furthermore, depending on the object to be analyzed, analysis is performed not only by laser light but also by optical means using other light sources.

[Problems to be Solved by the Invention] However, in the above-mentioned analysis method using the conventional optical measurement means, there is a possibility that there is a problem between the analyte in the sample and the background of the sample developing solution or disk substrate. Optical measurements cannot be made unless there is some difference in optical properties such as reflectance, refractive index, absorption of light at a specific wavelength, fluorescence intensity, or optical rotation.

Therefore, in the past, it has not been possible to analyze objects that have no optical characteristics relative to the background using analysis methods that utilize optical measurement means.

On the other hand, in Japanese Patent Publication No. 51-502419, an electrode capable of measuring electrical characteristics is provided in a capillary cell cavity, a sample is supplied into the capillary cell cavity, and analysis based on the electrical characteristics of the sample is performed. Analytical devices have been proposed to enable this. The analytical device has also been shown to be capable of performing optical measurements if necessary.

However, the analytical device proposed in Japanese Patent Publication No. 61-502419 has multiple cavities on a sheet and supplies the sample into the cavities using capillary action. It has been difficult to automate sample development and improve analysis accuracy.

The present invention has been made in view of the above-mentioned problems.
The purpose of the present invention is to provide a liquid sample analysis disk capable of automatically and accurately analyzing an object whose optical characteristics are not influenced by the background.

[Means for Solving the Problems] In order to achieve the two objectives, the liquid sample analysis disk of the present invention has a liquid sample development area on a disk substrate and a measurement area for electrical characteristics in this development area. The electrodes are arranged in the expanded portion with a predetermined gap.

[Example] Hereinafter, an example of the liquid sample analysis disk of the present invention will be described in detail with reference to the drawings.

FIGS. 1(a) and 1(b) show a plan view (electrodes in other sections are omitted) and a partial sectional view of a liquid sample analysis disk according to a first embodiment of the present invention.

The analysis disk shown in these drawings has a disk substrate l.
A developed part 2 is formed on the upper surface of the , and three sets of electrodes 31a-31b are provided in this developed part 2.

32a-32b and 33a-33b are provided.

Here, the disk substrate l has a disk shape, and convex portions 5 are formed radially from the center on the plane of the substrate. As a result, a plurality of concave expanded portions 2 are formed in the circumferential direction of the disk substrate 1. The size (radius), thickness, etc. of the disk substrate l are appropriately selected depending on the purpose and mode of analysis.

Examples of the material forming the disk substrate 1 include plastic materials such as polycarbonate, polymethyl methacrylate, polystyrene, polyvinyl chloride, polyvinyl acetate, polyurethane, and epoxy resin, and glass. Is it possible to use any non-conductive (conductive) material? If you are also performing the optical analysis described below,
Is it necessary to use a transparent material?

A shaft hole 6 is provided in the center of the disk substrate 1 for inserting the disk into the rotation shaft of the rotary chiffle, and the disk is mounted on a rotary table through the shaft hole 6 and rotated.

The developing portion 2 is a portion filled with a liquid sample and expanded, and is formed in a concave shape on the substrate plane of the disk substrate l. This expanded portion 2 is usually molded at the same time as injection molding or injection compression molding the disk substrate l.

Three sets of electrodes 31, 32, and 33 are arranged in the radial direction within the expanded portion 2, with a and b serving as one set, respectively, at predetermined intervals. Of these three sets of electrodes, electrodes 31 and 32 form signal terminals on the periphery of the disk substrate l via lead portions,
Further, the electrode 33 is used as a signal terminal at the end thereof. These signal terminals are connected to an electric signal supply device (not shown) via a slip link 10 or the like (see FIGS. 1(v) and (b)).

The number and arrangement pattern of these '7tL poles are the subject of analysis.

It may be changed as appropriate depending on the aspect etc.

The electrodes 31, 32, 33 are arranged on the disk substrate 1h,
It is formed by depositing a metal-only conductive material by f-steps such as sputter linking, plating, and screen printing.

Here, the conductive materials include gold, silver, flI4. Examples include metals such as platinum and its compounds, and non-metals such as graphite, and vehicles containing particles of these particles are also included.

The conductive material may also contain a sensitizing component to make the pole sensitive to a particular analyte. Sensitizing components include, for example, calcium diisooctylphenyl phosphate (for calcium-sensitive electrodes), halinomycin (for potassium-sensitive electrodes), tridodecylamine (for hydrogen ion-sensitive electrodes), silver chloride, silver bromide or silver iodide. particles (for halide-sensitive electrodes), silver sulfide particles (for sulfide-sensitive electrodes), and mixtures of silver sulfide and silver sulfide particles (for sulfide- and copper-sensitive electrodes).

In addition, in 1 [2 (a), an example is shown in which the electrodes 31, 32, 33 are provided only in one expanded portion 2, or an arbitrary number of electrodes 31, 32, 33 are provided in each expanded portion 2 divided in the circumferential direction. Of course, it is possible to provide electrodes of.

Furthermore, as shown in FIG. 1(C), it is also possible to guide one or both of the electrodes of the - group to the lower part of the substrate through the through hole 7 provided in the disk substrate l, and make them contact with the slip link IO here. It is. Furthermore, the extraction of the IT signal is
You can also do this from the top of the disc.

Next, a second embodiment of the present invention will be described.

FIG. 2 is a sectional view showing a liquid sample analysis disk according to a second embodiment of the present invention.

The analysis disk shown in the figure has a structure in which a first electrode 3a, a spreading layer 2, and a second electrode 3b are sequentially laminated on a disk substrate l.

Here, the disk substrate l is a flat plate in the form of a circular plate, and its material is the same as that of the first embodiment described above and a rotating material.

The liquid sample spreading layer 2 is formed of a material such as alumina, silica, or nonwoven fabric, and is used to spread the sample by centrifugal force after injecting the sample with an injection means such as a dispenser. Examples of the method for forming the spread layer 2 include coating using a roll coater/spin coater, drawing method using an ink jet, and the like.

The developing layer 2 may be hollow, and in this case, the components in the sample are separated and fractionated by centrifugal force according to the difference in specific gravity. Further, the developing layer 2 may contain or be coated with enzymes, dye molecules, antigens, antibodies, buffer salts, and other reagents suitable for analysis.

The first and second electrodes 3a, 3b are constructed using the same materials, methods, etc. as the electrodes in the first embodiment,
They are provided so as to sandwich the development layer 2 therebetween.

Here, the arrangement pattern of the electrodes 3a and 3b on the disk substrate l is, for example, a radially arranged shape or a circumferentially arranged shape as shown in FIGS. 4(a) and 4(b). It's Toshide. Usually, electrodes having a layout pattern as shown in FIGS. 4(a) and 4(b) are used as the first or second electrodes, and these are laminated with the spread layer 2 in between.

For example, if the electrode shown in FIG. 4(a) is used as the first electrode 3a and the electrode shown in FIG. 4(b) is used as the second electrode 3b,
When these are combined, a disk as shown in FIG. 4(c) is obtained.

Note that the arrangement pattern must intersect at a portion corresponding to the analysis portion on the disk surface, as shown in FIG. 4(C).

Electrodes patterned in this way can be used to mask the non-electrode portions, to etch the non-electrode portions, etc.
It can be easily obtained by known techniques.

In addition, when using a sample that may corrode the electrode or a highly conductive liquid, an insulator (lnsu) is placed between the electrode 3 and the developing layer 2 as shown in No.
later) It is preferable to provide 4. This insulator 4 is made of a material such as ceramics, and is made by vapor deposition,
It is formed by methods such as sputtering and spin code.

Alternatively, the electrode may be covered with a resin thin film.

In the above embodiments, an example is shown in which the disk shape is a disk shape, but the shape of the disk is not limited to the disk shape.

[Function] First, the function of the liquid sample analysis disk according to the first embodiment described above will be explained.

First, a constant voltage alternating current is applied between two electrodes, and the current is monitored.

After dropping the liquid sample onto the analytical disk, the disk is rotated to develop the sample and supply the sample to the developing section 2.

After development, analysis is performed by measuring changes in potential difference between each divided electrode.

In addition, if the component to be analyzed has optical characteristics due to the application of an electric field, etc., qualitative and/or quantitative analysis may be performed by optical analysis means in addition to the above-mentioned electrical analysis means. .

For example, optical analysis using the Kerr effect, which exhibits birefringence in proportion to the intensity of the applied electric field, is possible.

In addition, for example, the promotion of chemical reactions, etc. in biochemical tests (a)
Alternatively, it is also possible to perform analysis by applying electrochemical action using electrodes (for simplification).

Next, the operation of the liquid sample analysis disk according to the second embodiment described above will be explained.

First, a constant voltage alternating current is applied between the two electrodes 3a and 3b, and the current is monitored.

After the liquid sample is injected into the developing layer 2 by an injection means such as a dispenser, the disk is rotated to spread the sample onto the developing layer 2 by centrifugal force.

After deployment, a combination of electrodes 3a and 3b is selected, and changes in impedance between the electrodes are measured using alternating current to perform qualitative/quantitative analysis of the components at each position. Usually, this is done by dividing the expanded portion for each electrode 3a.

In addition to the above-mentioned analysis by current measurement, measurement of electrical parameters such as capacitance and voltage by potential difference measurement,
Analysis may be performed. Furthermore, if the electrical characteristics of the component to be analyzed in the sample change over time, it is also possible to perform analysis while measuring this change over time.

[Effects of the Invention] As explained above, according to the analytical disk of the present invention, since the disk is provided with electrodes, analysis based on the electrical properties of the sample, which was previously impossible, is now possible. becomes.

In addition, since the disk method is adopted, it is possible to automate sample injection and expansion, and it is also possible to improve analysis accuracy.

Furthermore, since analysis can be performed by optical means while applying an electric field or the like, it becomes possible to perform analysis that was not possible with conventional optical means.

[Brief explanation of drawings]

FIG. 1(a) is a plan view showing a liquid sample analysis disk according to an embodiment of the present invention. FIG. 1(b) is a partial sectional view taken along line I--I in FIG. 1(a). FIG. 1(C) is a partial sectional view showing another mounting state of the electrode. FIG. 2 is a partial sectional view showing a liquid sample analysis disk according to another embodiment of the present invention. FIG. 3 is a partial sectional view showing a liquid sample analysis disk in which an insulator is provided between an electrode and a developing layer. FIGS. 4(a) and 4(b) are plan views showing specific examples of electrode arrangement patterns. FIG. 4(C) is a plan view of an analytical disk using the electrodes of FIGS. 4(a) and 4(b). l Disk board expansion section 3 (3a, 3b), 31a, 31b. 32b, 33a, 33b: Electric bridge 32a. Insulator convex part 1L applicant Idemitsu Petrochemical Co., Ltd.

Claims (1)

[Claims] 1. A liquid sample analysis disk comprising, on a disk substrate, a liquid sample development section and an electrode disposed at a predetermined gap in the development section for measuring electrical characteristics in the development section.