JPH06288963A - Enzyme sensor plate - Google Patents

Abstract

PURPOSE:To intensify the adhesion between a substrate and enzyme-immobilized film so as to prevent the stripping off of the enzyme-immobilized film by forming an anchor film composed of a photosetting resin on an insulating film on the bottom of a pH sensitive film excluding the central part of the pH sensitive film and the enzyme-immobilized film on the anchor film. CONSTITUTION:A joined body of a sensor plate main body and bank body 6 is manufactured and a pH sensitive film 17 is formed at one window section 4a of each set by dropping the solution of a resin for pH sensitive films onto the periphery of the window section 4a and an exposed silver chloride layer 2C and drying the solution. Then, after an unhardened anchor film 18 is formed by applying a resin solution prepared by diluting a photosetting resin composed of epoxy acrylate with thinner to the internal surface of a circular hole 6a on the window 4a side and an insulating film 3 on the bottom of the hole 6a except the film 17 of a circular hole 6a and drying the solution, a resin solution containing enzyme is dropped into the hole 6a. After dropping, a hardened anchor film 18 and enzyme-immobilized film 19 are formed by immediately irradiating the film 18 and resin solution with ultraviolet rays. When this method is used, the stripping off of the film 19 by moisture, etc., can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a simple and easy-to-use enzyme sensor plate for use in an enzyme sensor for inspecting blood or the like, in which the adhesive strength of an enzyme immobilization membrane is improved.

[0002]

2. Description of the Related Art Several enzyme sensor plates have been proposed as disposable enzyme sensor plates for simple inspection. As one of them, the enzyme sensor plate previously proposed by the applicant of the present application, as shown in FIG. 2, includes a pair of a sample liquid measuring electrode 2a and a reference electrode 2b in which a copper electrode is plated with silver on a substrate 1. 5 sets are provided as a set, and as shown in FIG. 3, silver chloride layers 2c are further provided at the opposite ends of the electrodes of each set, and the circular portion and the electrodes of each set of FIG. The sensor plate body 5 is formed by covering the insulating film 3 except the ends, forming the windows 4a and 4b in the former, and forming the latter into external electrodes 5a and 5b, and further from the respective windows 4a and 4b of each set. A bank 6 made of a polyester film having five large round holes 6a and 6b as a pair is bonded to the sensor plate body 5. Then, as shown in FIG. 3, the electrode surface in one window portion 4a of each set is covered with a pH sensitive film 7 that covers the entire periphery including the peripheral edge of the window portion.
The enzyme-immobilized film 8 is provided by dropping a prepolymer liquid of a photocurable resin containing an enzyme into the round hole 6a on the side where the H-sensitive film is provided and polymerizing the solution. Such photocuring does not require high temperature and does not impair the activity of the enzyme.

When the enzyme sensor plate having such a structure is used, each set of round holes 6 in which a pair of enzyme immobilizing membranes are formed is used.
a, when the sample liquid is dropped so as to cover the round hole 6b where the silver chloride electrode is exposed, when glucose oxidase (GOD) is used as the enzyme and the sample liquid is blood, glucose in the blood Is oxidized by GOD to generate gluconic acid and hydrogen peroxide. Since gluconic acid has a carboxyl group (--COOH), it is acidic. As a result, when the reaction by the enzyme progresses, the aqueous solution in the enzyme-immobilized membrane 8 changes to acidic, and the pH change is sensed by the pH-sensitive membrane under the enzyme-immobilized membrane 8, and this is detected by the external electrodes 5a, 5b of the measuring device. It is detected and displayed by connecting the terminals. The above was for the BS (glucose) sensor, but BUN
When urease is used as an enzyme in the case of (urea) sensor, when urine is used as the sample liquid, urea is decomposed into ammonia and carbon dioxide by urease, and ammonia dissolves in water to form ammonium ion, which shows alkalinity. , This is detected and displayed in the same manner as above.

[0004]

However, in the above structure, the photocurable resin used for forming the enzyme-immobilized film 8 generally swells by absorbing water, and contracts when dried, so that the appearance dimension is small. It changes a lot. Therefore, the enzyme-fixing membrane 8 may be peeled off from the lower pH-sensitive membrane and the side wall of the bank. If peeled off, it will not function as an enzyme sensor and cannot be stored in a dry state. Further, since it is difficult to maintain the humidity control for storing in a wet state, long-term storage reliability becomes low. An object of the present invention is to provide a sensor plate in which an enzyme-immobilized membrane does not peel off regardless of humidity.

[0005]

In order to solve the above-mentioned problems, the present invention provides at least one pair of a sample liquid measuring electrode and a reference electrode on a substrate, and at least one pair of each pair of electrodes is provided. A sensor plate body in which opposite ends are covered with an insulating film that forms respective windows exposing the electrode surface, and a pH-sensitive film is provided on the electrode surface at the bottom of the window of the sample liquid measurement electrode, and each of these. Of the through hole on the side of the sample liquid measuring electrode and the p inside the through hole.
Provided is an enzyme sensor plate in which an anchor film containing a photocurable resin having an epoxy group is provided on the insulating film on the bottom surface of the H-sensitive film except at least the central portion, and an enzyme fixing film is provided on the anchor film. It is a thing.

[0006]

Since the enzyme immobilization layer is provided via the anchor film containing the resin having an epoxy group, the anchor film can improve the adhesiveness between the underlayer and the enzyme immobilization layer.

[0007]

Embodiments of the present invention will now be described with reference to the drawings. In the figure, the same reference numerals as those in the other figures represent the same components. Example 1 A joined body of the sensor plate body 5 and the bank body 6 (the material of which is polyethylene terephthalate) shown in FIG. 2 was prepared, and then, as shown in FIG. The pH-sensitive film 17 is formed by dropping the resin solution for pH-sensitive film shown in 1) on the periphery of the window 4a and the exposed silver chloride layer 2c and drying. K-TCPB (ion sensitive substance) 0.25 g (potassium tetrakisparachlorophenylborate) PVC (binder) 0.2 g (copolymer of 91% vinyl chloride, 6% vinyl alcohol, 3% vinyl acetate) DOA (dioctyl adipate ( Plasticizer)) 0.35 ml TDA (tridodecylamine) 2.5 mg THF (solvent) 3 ml

Next, a photocurable resin made of epoxy acrylate (UVR-150G-R60, Taiyo Ink Co., Ltd.)
Resin solution diluted 1: 1 with thinner on the inner wall of the round hole 6a on the side of the window 4a and on the bottom insulating layer 3 excluding the pH sensitive film 17 (hatched portion of concentric circles in FIG. 1). And dried to form an uncured anchor film.

Then, a resin solution containing an enzyme having the following composition is dropped into the round hole 6a. ENTG-2000 (prepolymer of photocurable resin manufactured by Kansai Paint Co., Ltd.) 0.5 g Enzyme solution (50 mg / ml) 0.25 ml Photopolymerization initiator 25 μl The above-mentioned ENTG-2000 is represented by the following structural formula. In the formula, m = 34, n = 45, a / b = 2/8

[0010]

[Chemical 1]

Immediately after dropping, irradiation is performed with an ultraviolet irradiation device (BEL KET manufactured by Kansai Paint Co., Ltd.) for 3 minutes to form a cured anchor film 18 and enzyme fixing film 19. After irradiation, the enzyme-immobilized membrane was conditioned with a 30 mM phosphate buffer solution (pH 7.4) for 30 minutes, washed with pure water, and naturally dried overnight. In this way, an enzyme sensor plate was obtained, 100 sheets were prepared, and the number of peeled enzyme-immobilized membranes was visually counted. The results are shown in Table 1.

Example 2 In Example 1, except that the levee was changed from polyethylene terephthalate to VHB (a double-sided tape manufactured by Sumitomo 3M, in which an acrylic adhesive was applied to both sides of an acrylic foam substrate). Similarly, 1 enzyme plate
00 sheets were produced, and the number of peeled enzyme-immobilized membranes was visually counted in the same manner. The results are shown in Table 1.

Comparative Example 100 enzyme sensor plates were prepared in the same manner as in Example 1 except that the anchor film 18 was not provided, and the number of peeled enzyme-immobilized films was counted visually. The results are shown in Table 1.

[0014]

[Table 1]

In the above example, both the anchor film and the enzyme-immobilized film were made of a photocurable resin, and the latter uncured layer was superposed on the former uncured layer and then photocured. Both are bonded by a chemical bond, and the former is hardened in a state of being adhered to the substrate, and after hardening the former, when forming the uncured layer of the latter and hardening it, the former peels due to shrinkage during the hardening of the latter. However, if the anchor layer is flexible, both can be cured separately. Further, it is possible to use the other photo-curable resin having an epoxy group, and these can be used alone or in combination, and can also be used in combination with other systems of photo-curable resins, other resins, and additives. Other photocurable resins having an epoxy group include # 2768 and # 2797 manufactured by San Nopco Co., Ltd., and photocurable resins of other systems include urethane acrylic type # 3080 manufactured by ThreeBond Co., Ltd. .

[0016]

EFFECTS OF THE INVENTION According to the present invention, since the enzyme immobilization film is adhered via the anchor film containing the photocurable resin having an epoxy group, the adhesive force can be improved and the enzyme immobilization film can be applied to the enzyme immobilization film. It is possible to prevent the peeling even when a material having a great influence of humidity is used.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view of an enzyme sensor plate according to an embodiment of the present invention.

FIG. 2 is an exploded perspective view of an enzyme sensor plate mainly as proposed in the previous application.

FIG. 3 is a partial cross-sectional view thereof.

[Explanation of symbols]

 2a Sample liquid measuring electrode 2b Reference liquid measuring electrode 5 Sensor plate body 6 Levee body 17 pH sensitive film 18 Anchor film 19 Enzyme fixing film

Claims (1)

[Claims] 1. A sample liquid measuring electrode and a reference electrode are paired and at least one set is provided on a substrate, and respective window portions where the electrode surface is exposed are formed at at least opposite ends of each pair of electrodes. A sensor plate body that is covered with an insulating film and has a pH sensitive film on the electrode surface at the bottom of the window of the sample liquid measurement electrode, and a through hole that is larger than the window part corresponding to each of these window parts. The side wall of the through hole on the side of the sample liquid measuring electrode and the p inside the through hole are joined with the bank body.
An enzyme sensor plate in which an anchor film containing a photocurable resin having an epoxy group is provided on the insulating film on the bottom surface of the H-sensitive film except at least the central portion, and an enzyme fixing film is provided on the anchor film.