JPH08240534A - Method for directly fixing reagent layer by torsional ultrasonic wave - Google Patents

Abstract

PURPOSE: To avoid chemical influences and physical obstacles owing to adhesives, and improve the quality of sample pieces and reduce costs, by overlapping a reagent layer of an extremely thin thermoplastic resin film with a base material and impressing a torsional ultrasonic vibration and an external force thereby uniting the same. CONSTITUTION: A reagent layer 2 with a reagent in an extremely thin thermoplastic resin film of a thickness of 10-50μm is overlapped arm a base material 1 of a thermoplastic resin (or a non-thermoplastic substance) as a supporting body, to which a torsional ultrasonic vibration of a frequency of 40KHz and a pressure of 60-80Kg/cm<2> are applied. After this state is maintained, e.g. for 0.2 second, the ultrasonic vibration is stopped while the pressure alone is impressed. This state is maintained for zero and several seconds. When the pressure is released thereafter, the melted resin of the reagent layer 2 and the resin of the base material 1 melted by the ultrasonic waves are united at circular fused points 3, so that, the reagent layer 2 and base material 1 are fixed. When the base material 1 is a non-thermoplastic substance, the melted resin of the reagent layer 2 invades small holes of the base material 1 thereby to be fixed.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a dry analytical tool (referred to as a test piece) for measuring a specific component in a liquid which is usually used in clinical examination fields such as urine analysis, serum analysis, whole blood analysis and immunoassay. In some cases), a reagent layer is immobilized on a base material that serves as a support.

[0002]

2. Description of the Related Art In the field of clinical examination, analysis of various components in body fluids such as blood, urine, saliva, and cerebrospinal fluid is an index for objectively knowing the effects of diagnosis and treatment of many diseases. .

A reagent has been developed in which a reagent is supplied as a test piece in a dry state, pre-preparation of a reagent such as a liquid reaction is completely unnecessary, a waste liquid is not generated, and a large amount of a small amount of sample can be measured. ing. This method is used as an immediate examination method in hospital emergency laboratories, night nurses' offices, and practitioners. This method is dry chemistry
is called.

In this dry chemistry technology,
The test strip generally consists of a reagent layer and a support. The reagent layer is made by impregnating and drying a reagent that reacts with various components in the sample in a porous matrix such as filter paper, or by coating a reagent and polymer binder kneaded with a solvent on a thin resin film and drying. Has been done.

Even without a support, the reagent layer can be cut into strips and used as it is, but an expensive reagent (eg, enzyme, substrate, color former, etc.) is used. Occasionally, it is uneconomical if such a strip shape is used and a large area is used, resulting in a great increase in cost.

[0006] Therefore, in consideration of the size of the luminous flux (spot diameter) in the reflectometer, the measurement accuracy, and the ease of handling in manufacturing and use, the size capable of visual color comparison is maintained. The reagent layer is used by cutting it into a square or a rectangle of 4 mm square to 10 mm square. The cut reagent layer is fixed to a base material that serves as a support or a handle with an adhesive (double-sided tape, glue, instant adhesive, etc.).

The most commonly used method for directly fixing the reagent layer to the base material is a double-sided tape fixing method. However, a polyacrylic resin is mainly used for the adhesive of the double-sided tape, and a polymerization initiator, a monomer, and a stabilizer, a plasticizer, a wetting agent are mixed in a considerable amount, and when contacting with the reagent layer, It may react with the reagent in the reagent layer to be colored or decompose the active ingredient, and thus it is necessary to carefully select the double-sided tape for each item of the reagent.

Further, in the processing step, the adhesive of the double-sided tape adheres to the processing machine and causes troubles, or the adhesive adheres to the surface of the reagent layer to cause a portion where the reagent and the sample do not react, resulting in uneven coloring. There was a problem of becoming.

A method of fixing with a hot melt (a thermoplastic resin that softens at 80 to 150 ° C.) is used as a method of solving the problem caused by the double-sided tape, but the temperature of the entire reagent layer is melted in order to melt the hot melt. For 10 seconds
It is necessary to raise the temperature to 0 to 110 ° C., and as a result, there is a risk of denaturing substances in the reagent layer (particularly proteins such as enzymes, antibodies and antigens). In addition, even in hot melt, plasticizers, stabilizers, etc. are mixed in as with double-sided tape,
These components had a considerable adverse effect on the reagents.

As a solution, Japanese Examined Patent Publication No. 53-6551 discloses a method in which a test piece is wrapped with a woven fabric or a web and the side thereof is heat-sealed with hot melt.
In Japanese Patent Publication No. 6-68488, a detection composition is prepared in which a thermoplastic resin is sandwiched between a reagent layer and a support, the laminate is cut by laser or ultrasonic waves, and fixed at a melted cut surface. A method is disclosed.

The method of wrapping the reagent layer in nylon mesh and heat-sealing both sides solves the above two problems, but the nylon mesh is slightly loosened by the impact during transportation, and as a result, the reagent layer is loosened. There was a risk that it would slip or come off. Further, this processing method has an economical drawback that it is complicated and very expensive.

The technique disclosed in Japanese Examined Patent Publication No. 6-68488 is a method for producing a dry multi-layer analytical tool without using an adhesive. It is of a type that is used after it is placed, and since a margin is cut off with a laser or ultrasonic waves, a wasteful part is generated. Further, a machine for generating a laser or an ultrasonic wave having a high output capable of cutting out a substance is required, and such a machine is usually expensive.

Further, in particular, when fixing a glass fiber filter paper chemically bound with an antibody, antigen, avidin, biotin, etc. used for analysis of a trace component utilizing an immunoreaction (so-called dry immunoassay) to a base material, a double-sided tape In addition to the above-mentioned problems, the use of a hot melt or hot melt has a problem that non-reacted components or substances affecting the reaction in the sample are non-specifically adsorbed on the glass fiber filter paper, resulting in a large error.

The above problems are caused by placing a non-thermoplastic or thermoplastic resin reagent layer in contact with a thermoplastic resin base substrate and applying vibration and pressure by ultrasonic waves from the outside to cause friction. By generating heat and melting the surface of the base material in contact with the reagent layer, one of the melted surface material is impregnated into the inside of the other, or the other surface material is also melted. This can be solved by directly adhering the surface material to the surface material by adhering them to each other and then stopping the vibration by ultrasonic waves to lower the temperature. Hereinafter, this method may be referred to as ultrasonic fusion.

Since the heat generated at this time is instantaneously generated on the surface of the layer and immediately cooled, the reagent in the reagent layer is rarely denatured. Further, since the base material base which is the support and the reagent layer are directly fixed, there is no blank portion to be cut off, which is an economical method. Since the vibration of ultrasonic waves is directly transmitted to the reagent layer, the ultrasonic oscillator can be a relatively inexpensive type.

[0016]

When the reagent layer consists of a thin thermoplastic film coated with a reagent, these films generally have a thickness of 50 μm to 150 μm. In addition, thinner (about 20 μm) ultrathin films are also used in some cases. However, it has been found that when the film to be the reagent layer is extremely thin as described above, the ultrasonic wave does not pass through the film and the vibration energy is not concentrated on the surface, so that the above-mentioned ultrasonic fusion cannot be achieved.

[0017]

The inventors of the present invention have found that the above problems can be solved by using "torsion ultrasonic waves" with respect to ultrasonic waves that cause friction, and have completed the present invention. It was That is, the present invention includes the following steps in a method of directly fixing a reagent layer made of an ultrathin thermoplastic resin film coated with a reagent onto a base substrate that serves as a support. A step of arranging the reagent layer on the base substrate so as to be in contact therewith, and melting the surface of the reagent layer in contact with the base substrate by applying vibration from torsional ultrasonic waves and external pressure. The process of integrating the surface of the melted reagent layer and the surface of the base material by applying pressure. The process of releasing torsional ultrasonic vibration and pressure.

The concept of "torsional ultrasonic wave" used in the present invention is characterized in that it is "ultrasonic wave having lateral vibration", and in contrast to the commonly used ultrasonic wave is longitudinal vibration. Concept. As an image of this "torsion ultrasonic wave", you should think of the scene in which a cup with a perfect circular shape is pressed down on the surface with the shape of the mouth lying down and twisted without moving the perfect circle. The edge of the cup is the horn of the ultrasonic oscillator, and the twisting motion corresponds to lateral vibration.

The normal longitudinal vibration ultrasonic wave cannot melt the ultra-thin thermoplastic film, but the transverse vibration ultrasonic wave "torsion ultrasonic wave" transmits vibration energy to the surface of the ultra-thin film. Therefore, the ultrathin film can be melted. That is, the ultrathin film can be fused onto the base substrate, and a test piece using the ultrathin film as a reagent layer can be prepared.

The method of applying the reagents onto the thermoplastic film may be a method generally used in this field. That is, reagents kneaded with a polymer binder and the like in a solvent are applied onto a film by a coater.

The base material to be the support has a plate shape, but the material may be a thermoplastic resin or a non-thermoplastic material. Examples of thermoplastic resins include
Examples thereof include polyethylene terephthalate, polycarbonate, polypropylene, polyethylene, polystyrene, polycarbonate, polyvinyl acetate, polyvinyl chloride, cellulose ether and the like. Examples of non-thermoplastic substances are paper, wood, glass fiber, metal cloth, non-woven fabric (membrane filter, uniaxially stretched porous film, biaxially stretched porous film, radiation irradiated porous film), sintered body, porous A ceramic sheet or the like can be used, but it is preferable to have fine holes.

When the support is a thermoplastic resin, the resin melted from the reagent layer and the resin from the support which is similarly melted by ultrasonic waves are integrally fixed. When the support is a non-thermoplastic material, the molten resin from the reagent layer digs into the fine pores of the support and is fixed by the so-called "tack effect".

The reagent layer and the base material base are arranged, and the frequency 40
Torsional ultrasonic vibration of kHz and pressure 60-80kg / cm
Multiply by ² . Keep this state for 0 commas for a few seconds, then
Stop ultrasonic vibration. In the state of pressure only, hold for 0 comma for a few seconds and then release the pressure. After this step, the reagent layer and the base material base are fixed.

[0024]

EXAMPLE An example of a method for producing a dry analytical tool (test piece) having a reagent layer fixed thereto by the method of the present invention will be described below with reference to the accompanying drawings. However, the present invention is not limited to the examples.

As an example, a test piece for detecting nitrite in urine was prepared with the following formulation. (Prescription) d-naphthylamine 1.0 g sulfanilamide 2.5 g trichloroacetic acid 3.0 g polyvinyl butyl acetal 20.0 g methanol 100 ml-thermoplastic resin plate (used as a support / base plate, base material in the figure) ... …………… 0.3 mm thick
PET film-Thermoplastic resin film (used as reagent layer, in the figure,
) ……………… 1 cm wide tape-shaped PET film
Thickness 20μm ・ Ultrasonic oscillator …………………… Made by Emerson Japan 90
0 series "947M" type

A coating solution was prepared based on the formulation shown in the table above, and the solution was applied onto a film with a coating machine to a wet thickness of 400 μm, and dried with hot air to form a reagent layer (reagent Layer). The obtained reagent layer is allowed to stand still on a base material, and torsional ultrasonic vibration with a frequency of 40 kHz and pressure 70 k are applied.
It was multiplied by g / cm ² . This state was maintained for 0.2 seconds, then the vibration was stopped, and the pressure was released after the pressure was maintained for another 0.2 seconds. At this time, the shape of the ultrasonic oscillating horn is a cylindrical shape having a concentric outer circle diameter of 6 mm and a concentric inner circle diameter of 4 mm, and the fusion state at this time is the center of the reagent layer Then, only the peripheral portion was fused and fixed in a circular shape. As for the size of the circle, as shown in FIG. 3, the diameter of the concentric outer circle is 6 mm and the diameter of the concentric inner circle is 4 mm. A test piece in the state shown in FIG. 1 completed as described above is 1 cm wide.
Then, the test piece shown in FIG. 2 was obtained.

When this test piece was applied to nitrite-containing urine, it showed a good red coloration depending on the nitrite content.

When the ultra-thin film as described above is used as the reagent layer, although fusion does not occur with normal ultrasonic waves, when torsional ultrasonic waves are used as described above, fusion occurs and the activity decreases. It was possible to create a test piece without the problem.

[0029]

According to the method of the present invention, since no pressure sensitive adhesive or adhesive (double-sided tape, hot melt, etc.) is used, there is no chemical influence due to these, and improvement in quality in performance can be expected. Further, since no pressure sensitive adhesive is used, there is no physical obstacle due to adhesion of glue or the like, and the cost can be reduced.
Since an inexpensive ultrasonic oscillating device is used, the equipment machine can be made simple and inexpensive in terms of production equipment, and the process is simplified, so that the manufacturing cost can be reduced. Furthermore, even when an ultra-thin film is used as the reagent layer so that energy concentration does not occur with normal ultrasonic waves,
The ultrasonic fusion can be reliably performed.

[Brief description of drawings]

FIG. 1 is a plan view and a front view of a test piece before cutting according to the present invention. FIG. 2 is a plan view of the test piece after being cut according to the present invention. FIG. 3 is an enlarged plan view of the tip portion of the test piece of FIG.

[Explanation of symbols]; Support (base material base); Reagent layer (thermoplastic ultra-thin film);

Claims (2)

[Claims] 1. A method for producing a dry analytical tool for measuring a specific component in a liquid, comprising: forming a reagent layer made of an ultrathin thermoplastic resin film coated with a reagent on a base substrate as a support. A method for fixing directly, which comprises the following steps. A step of arranging the reagent layer on the base substrate so as to be in contact therewith, and melting the surface of the reagent layer in contact with the base substrate by applying vibration from torsional ultrasonic waves and external pressure. The process of integrating the surface of the melted reagent layer and the surface of the base material by applying pressure. The process of releasing torsional ultrasonic vibration and pressure. 2. The ultrathin thermoplastic resin film has a thickness of 10
The method according to claim 1, wherein the method is μm to 50 μm.