WO2022048040A1

WO2022048040A1 - Electrically conductive carbon paste for blood glucose test paper, preparation method therefor, and blood glucose test paper

Info

Publication number: WO2022048040A1
Application number: PCT/CN2020/131017
Authority: WO
Inventors: 蔺洪振; 李付锦; 李麟阁; 程双; 王健
Original assignee: 苏州烯时代材料科技有限公司
Priority date: 2020-09-04
Filing date: 2020-11-24
Publication date: 2022-03-10
Also published as: CN112164489B; CN112164489A

Abstract

An electrically conductive carbon paste for blood glucose test paper, a preparation method therefor, and blood glucose test paper. The raw material formula of the electrically conductive carbon paste comprises the following components by mass percentage: 5-35% of graphene, 0.1-15% of electrically conductive carbon black, 0.001-1% of dispersant, 5-50% of oily resin, and 35-80% of solvent, the oily resin being an acrylate resin. The addition of graphene flakes and carbon black to a specific resin, in combination with the use of the dispersant, causes an electrode obtained after curing the prepared electrically conductive carbon paste to have good electrical conductivity and stable electrochemical performance, and achieves good wettability between electrode surfaces and an enzyme solution, such that a dried enzyme film has good adhesion to the electrode. The electrically conductive carbon paste is used for preparing electrodes of blood glucose test paper, and thus the electrodes have good and stable electrical conductivity, and surfaces of the electrodes have the characteristics of facilitating uniform distribution of biological enzymes such as glucose oxidase or glucose dehydrogenase, good adhesion, etc., solving problems of poor sensitivity and poor reliability of the existing blood glucose test paper in practical applications.

Description

Conductive carbon paste for blood sugar test paper and preparation method thereof, and blood sugar test paper

claim of priority

This application claims the priority of the Chinese Patent Application No. 202010919535.4 filed with the China Patent Office on September 4, 2020, the entire contents of which are incorporated herein by reference.

technical field

The invention belongs to the technical field of conductive carbon pulp for blood sugar test paper, and particularly relates to a conductive carbon pulp for blood sugar test paper and a preparation method thereof, and blood sugar test paper.

Background technique

Electrochemical detection method to measure blood glucose concentration is a common blood glucose concentration detection method. It detects the current signal generated during the reaction between enzymes and glucose in the electrode reaction area through blood glucose test strips, so as to reflect the blood glucose concentration. The output value of the current signal of the blood glucose test strip is proportional to the reaction area of the electrode reaction area, and the distribution area of the enzyme in the electrode reaction area directly determines the effective reaction area of the electrode reaction area. The wettability of the electrode surface has a crucial impact on the distribution of enzymes in the electrode reaction area, thus affecting the reliability and sensitivity of blood glucose detection results. In addition, the conductivity and performance stability of the electrodes will also affect the reliability and sensitivity of blood glucose detection.

At present, most of the blood glucose test strip electrodes made of conductive carbon pulp have shortcomings such as poor wettability between the electrode surface and enzyme, poor conductivity and unstable performance of the electrode, resulting in low sensitivity and poor reliability of blood glucose detection. To this end, people have also taken some technical means to improve the performance of the conductive carbon paste.

For example, Chinese invention patent CN104569093A discloses a carbon slurry for electrochemical detection test strip and its preparation method, and an electrochemical detection test strip and its preparation method. 17.0% conductive carbon black, 4.5-7.5% polyester resin, 0.2-5.0% surfactant and 45.0-69.8% solvent. The thin film electrode prepared by using the carbon paddle has good wettability with the enzyme, but the conductivity and performance stability of the thin film electrode are not involved, and the test sensitivity of the prepared electrochemical detection test strip is not significantly improved.

There is also the use of graphene and conductive carbon black to improve the conductivity of the conductive carbon paste, such as a graphene flexible film and its preparation method disclosed in Chinese patent CN108495385A, and the raw material formula of the slurry used in the flexible film includes polyurethane. 60-88.45 parts of resin, 0.5-10 parts of graphene or graphene composite, 1-15 parts of carbon-based conductive filler, 2-10 parts of dispersant, 0.5 part of auxiliary agent and solvent. The slurry improves the conductive network structure inside the polymer matrix and has excellent electrical conductivity. However, the slurry is developed for heating materials. From the perspective of its formulation and selected resin, it is not suitable for the conduction of blood glucose test strips. carbon paste.

In a word, most of the current blood glucose test strip electrodes made of conductive carbon pulp have shortcomings such as poor wettability between the electrode surface and the enzyme, poor conductivity and unstable performance of the electrode, which seriously affect the sensitivity and reliability of blood glucose detection.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide an improved conductive carbon paste for blood sugar test paper and a preparation method thereof in order to overcome the deficiencies of the prior art. The conductive carbon paste has good electrical conductivity and stability, and the electrode surface obtained after curing and molding The wettability with the enzyme solution is good, and the adhesion of the dried enzyme film on the electrode is good.

The present invention also provides a blood sugar test paper.

To achieve the above object, the technical scheme adopted in the present invention is:

A conductive carbon slurry for blood sugar test paper, in terms of mass percentage, the raw material formula of the conductive carbon slurry includes the following components:

The oil-based resin is an acrylate resin.

Further, in terms of mass percentage, the raw material formulation of the conductive carbon paste includes the following components:

According to some implementation aspects of the present invention, the particle size of the conductive carbon black is 14-300 nm.

According to some implementation aspects of the present invention, the graphene is a graphene sheet with 1 to 8 layers.

According to some implementation aspects of the present invention, the acrylic resin is an oily acrylic resin with a solid content of 65-100%. Preferably, the acrylic resin is an oily acrylic resin with a solid content of 70-100%. Such as NDG6113, NDG6728 from Canada Nengda Chemical and CFT2371 from Weifang Fuller New Materials Co., Ltd.

According to some implementation aspects of the present invention, the dispersant is a combination of one or more of lysine, polyacrylamide, and polyvinylpyrrolidone.

According to some implementation aspects of the present invention, the solvent is a combination of one or more of N-methylpyrrolidone, diethylene glycol ethyl ether acetate, and ethylene glycol butyl ether.

The present invention adopts another technical scheme: a preparation method of the above-mentioned conductive carbon slurry for blood sugar test paper, the preparation method comprises the following steps:

(1) According to the formula, graphene, conductive carbon black, dispersant and solvent are mixed, and then ground;

(2) adding oleoresin to the slurry obtained in step (1), stirring, and then grinding to a particle size of less than 10 μm;

(3) defoaming the slurry obtained in step (2) to prepare conductive carbon slurry.

According to some implementation aspects of the present invention, in step (1), the grinding uses zirconia beads with a particle size of 0.3-0.5 mm, and the grinding time is 30-50 min. Grinding graphene, conductive carbon black and dispersant can effectively improve dispersibility and conductivity.

According to some implementation aspects of the present invention, in step (3), the volume ratio of defoaming to bubbles is less than or equal to 0.1%.

According to some embodiments of the present invention, the defoaming is performed under a vacuum degree of 0.1±0.05 MPa, and the defoaming time is 30-60 seconds.

Controlling the particle size and bubble residue of the slurry can effectively improve the stability of the conductive carbon slurry. Too much particle size will affect the conductivity of the slurry, and too many bubbles will affect the uniformity of film formation.

Yet another technical solution adopted by the present invention is a blood glucose test paper, comprising a base material and an electrode layer formed on the base material, and the electrode layer is coated on the base material with the above-mentioned conductive carbon paste solidified.

Further, the base material is PET, PVC, PP or PC.

Further, the curing is baked at 100-140°C.

Further, the coating is carried out by printing.

Due to the application of the above-mentioned technical solutions, the present invention has the following advantages compared with the prior art:

In the present invention, by adding graphene sheets and carbon black to a specific resin and using a dispersant, the electrode obtained after the prepared conductive carbon paste is cured has good conductivity and stable electrochemical performance, and the surface of the electrode and the enzyme solution are also stable. It has good wettability, and the dried enzyme film has good adhesion on the electrode.

The preparation method of the conductive carbon paste of the present invention has low requirements on equipment, simple process, easy operation and easy industrial production.

The conductive carbon slurry of the present invention is used to prepare electrodes for blood glucose test strips, the electrodes have good and stable electrical conductivity, and the surface of the electrodes has the characteristics that biological enzymes such as glucose oxidase or glucose dehydrogenase are easy to distribute evenly and have good adhesion, etc. The problems of poor sensitivity and poor reliability of the existing blood glucose test strips in practical applications are solved.

Description of drawings

Figure 1 is a schematic diagram of the relationship between the response current and the blood glucose concentration of the blood glucose test strips prepared by using the conductive carbon pulp of Examples 1 to 3 and Comparative Examples 1 to 3.

detailed description

The technical solutions of the present invention are described in detail below in conjunction with specific embodiments, so that those skilled in the art can better understand and implement the technical solutions of the present invention, but the present invention is not limited to the scope of the examples.

Example 1

The conductive carbon paste for blood sugar test paper provided in this embodiment, the raw material formula includes: graphene 9wt%, conductive carbon black 0.5wt%, oily acrylic resin 10.5wt%, polyacrylamide 0.01wt%, polyvinylpyrrolidone 0.09wt%, 19.9% by weight of N-methylpyrrolidone and 60% by weight of diethylene glycol ethyl ether acetate.

Among them, the oily acrylic resin was purchased from Canada Nengda Chemical, the model is NDG6113.

Thin-layer graphene with 1 to 8 layers of graphene is a self-made multi-layer graphene obtained by mechanical/chemical exfoliation of graphite.

The particle size of conductive carbon black is 30-40nm, brand TIMCAL, model SUPER P LI.

The conductive carbon paste is prepared by the following method:

(1) Graphene, conductive carbon black, polyvinylpyrrolidone, N-methylpyrrolidone, diethylene glycol ethyl ether acetate are mixed into a sand mill for grinding, and the diameter of the zirconia beads used for grinding is 0.3-0.5mm, and the rotational speed is controlled 2200 rpm, grinding for 45 minutes;

(2) adding the oily acrylic resin and the slurry obtained in step (1) into the mixer for stirring, the rotational speed is controlled to be 1000 rev/min, and stirred for 30 minutes;

(3) adding the slurry obtained in step (2) to a three-roll mill for grinding, grinding for 3-5 times, controlling the roll gap to be 10 μm, and grinding until the particle size of the slurry is below 10 μm.

(4) adding the slurry obtained in step (3) into a defoaming mixer for defoaming and stirring treatment, the time is controlled to be 60 seconds, the vacuum degree is controlled to be 0.1 MPa, the rotational speed is controlled to be 2000 rpm, and the defoaming is performed to the foam volume ratio less than 0.1%. After this process is completed, the conductive carbon paste used for blood glucose test strips is obtained.

Example 2

The conductive carbon paste for blood glucose test paper provided in this example, the raw material formulation of which is shown in Table 1, and the preparation method is the same as that of Example 1. Among them, oily acrylic resin was purchased from Canada Nengda Chemical, model NDG6728.

The dispersant is polyvinylpyrrolidone.

The solvent is diethylene glycol ethyl ether acetate.

Example 3

The conductive carbon slurry for blood glucose test paper provided by the present embodiment, its raw material formula is shown in Table 1, and the preparation method is the same as that in Example 1. Among them, the oily acrylic resin was purchased from Weifang Fuller New Material Co., Ltd., and the model is CFT2371.

The dispersant is polyacrylamide.

The solvent is ethylene glycol butyl ether.

Comparative Example 1

For the conductive carbon paste provided in this comparative example, the raw material formulation of the conductive carbon paste is shown in Table 1, and the others are the same as those in Example 1. Among them, the resin adopts oily polyurethane resin, which was purchased from Dongguan Baojing Chemical Co., Ltd., model MR-917.

Comparative Example 2

For the conductive carbon paste provided in this comparative example, the raw material formulation of the conductive carbon paste is shown in Table 1, and the others are the same as those in Example 1. Among them, the resin adopts the polyester resin of SK company, model ES550.

Comparative Example 3

The conductive carbon paste provided in this comparative example was purchased from a certain brand of conductive carbon paste.

Table 1 is the raw material formulations of the conductive carbon pastes of Examples 1-3 and Comparative Examples 1-3 (in terms of mass percentage)

Performance test of the conductive carbon pastes of Examples 1-3 and Comparative Examples 1-3

1) Preparation of test samples: The conductive carbon pastes of Examples 1-3 and Comparative Examples 1-3 were respectively printed on a PET substrate by screen printing, and baked at 120° C. for 3 minutes to form an electrode film on the substrate. Floor.

2) The resistivity of the electrode film layer was measured by the four-probe method, and the resistivity was re-measured after being placed at room temperature for half a year.

3) Drop the enzyme paddle on the electrode film layer of the sample, and use a contact angle measuring instrument to test the contact angle of the enzyme slurry on the electrode surface. The average value is taken for 10 tests. A small contact angle indicates that the electrode film layer has a good effect on the enzyme paddle. The wettability is conducive to the uniform distribution of the enzyme slurry on the electrode film layer; rub it 10 times to observe whether the dried enzyme film is detached from the electrode, so as to judge the adhesion on the electrode.

The enzyme paddle used was a self-prepared 1‰ glucose oxidase aqueous solution, and the glucose oxidase used in the above was purchased from Aladdin, model G109029.

4) The prepared electrode samples were applied to the blood glucose test strips respectively, and the response current and blood glucose concentration curves of the blood glucose test strips were tested by the electrochemical workstation, as shown in Figure 1, so as to calculate the sensitivity of the blood glucose test strips.

After the blood glucose test paper samples prepared by using the conductive carbon slurries of Examples 1-3 and Comparative Examples 1-3 were detected by the above method, the results are shown in Table 2.

Table 2 shows the performance test results of the conductive carbon pastes of Examples 1-3 and Comparative Examples 1-3

As can be seen from Table 2:

(1) The resistivity of Example 1-3 is as low as 0.01Ω·cm, and the resistivity of Example 1-3 is lower than that of Comparative Example 1-3, indicating that the electrical conductivity of Example 1-3 is better excellent. After being placed at room temperature for half a year, the resistivity of Examples 1-3 changed little; the resistivity of Comparative Examples 1-3, after being placed at room temperature for half a year, would have a change of more than 20%. This shows that Examples 1-3 have stable and excellent electrical conductivity, which can effectively ensure the reliability of the test results of blood glucose test strips.

(2) The contact angles of Examples 1-3 and Comparative Example 2 are both relatively small, and the contact angles of Comparative Examples 1 and 3 are relatively large, indicating the surface wettability of the electrodes prepared in Examples 1-3 and Comparative Example 2 Well, the enzyme slurry is easy to distribute evenly thereon.

(3) In Example 1-3, after rubbing the enzyme film 10 times, the enzyme film did not fall off, and in Comparative Example 1-3, after rubbing the enzyme film 10 times, the enzyme film was detached to different degrees. This shows that the adhesion of the enzyme film on the electrodes prepared in Examples 1-3 is good.

(4) The sensitivity of the blood glucose test strips prepared in Examples 1-3 is 0.314-0.346 μA/mmol/L.

The above-mentioned embodiments are only intended to illustrate the technical concept and characteristics of the present invention, and the purpose thereof is to enable those who are familiar with the art to understand the content of the present invention and implement them accordingly, and cannot limit the protection scope of the present invention. All equivalent changes or modifications made according to the spirit of the present invention should be included within the protection scope of the present invention.

The endpoints of ranges and any values disclosed herein are not limited to the precise ranges or values, which are to be understood to encompass values proximate to those ranges or values. For ranges of values, the endpoints of each range, the endpoints of each range and the individual point values, and the individual point values can be combined with each other to yield one or more new ranges of values that Ranges should be considered as specifically disclosed herein.

Claims

A blood sugar test paper, comprising a base material and an electrode layer formed on the surface of the base material, the electrode layer is formed by coating the surface of the base material with conductive carbon paste and solidified, characterized in that, in terms of mass percentage, The raw material formulation of the conductive carbon paste includes the following components:

Wherein, the oil-based resin is an acrylate resin with a solid content of 70-100%;

The dispersant is a combination of one or more of lysine, polyacrylamide, and polyvinylpyrrolidone;

The solvent is a combination of one or more of N-methylpyrrolidone, diethylene glycol ethyl ether acetate, and ethylene glycol butyl ether;

The base material is PET, PVC, PP or PC.
The blood sugar test strip according to claim 1, wherein the oleoresin is one or more of NDG6113 of Canada Nengda Chemical, NDG6728 of Canada Nengda Chemical and CFT2371 of Weifang Fuller New Materials Co., Ltd.
A conductive carbon slurry for blood sugar test paper, characterized in that, in terms of mass percentage, the raw material formula of the conductive carbon slurry includes the following components:

The oil-based resin is an acrylate resin.
The conductive carbon slurry for blood sugar test paper according to claim 3, wherein, in terms of mass percentage, the raw material formula of the conductive carbon slurry comprises the following components:

5 . The conductive carbon paste for blood sugar test paper according to claim 4 , wherein the particle size of the conductive carbon black is 14-300 nm. 6 .
The conductive carbon paste for blood sugar test paper according to claim 5, wherein the particle size of the conductive carbon black is 30-40 nm.
The conductive carbon paste for blood glucose test paper according to claim 4, wherein the graphene is a graphene sheet with 1 to 8 layers.
The conductive carbon paste for blood sugar test paper according to claim 4, wherein the acrylic resin is an oily acrylic resin with a solid content of 65-100%.
The conductive carbon paste for blood glucose test paper according to claim 8, wherein the oleoresin is one of NDG6113 of Canada Nengda Chemical, NDG6728 of Canada Nengda Chemical and CFT2371 of Weifang Fuller New Materials Co., Ltd. or several.
The conductive carbon paste for blood glucose test paper according to claim 4, wherein the solvent is a combination of one or more of N-methylpyrrolidone, diethylene glycol ethyl ether acetate and ethylene glycol butyl ether .
A preparation method of the conductive carbon pulp for blood glucose test paper according to any one of claims 3 to 10, wherein the preparation method comprises the following steps:

(1) According to the formula, graphene, conductive carbon black, dispersant and solvent are mixed, and then ground;

(2) adding oleoresin to the slurry obtained in step (1), stirring, and then grinding to a particle size of less than 10 μm;

(3) defoaming the slurry obtained in step (2) to prepare conductive carbon slurry.
The method for preparing conductive carbon slurry for blood glucose test paper according to claim 11, wherein in step (1), zirconia beads with a particle size of 0.3-0.5 mm are used for the grinding, and the grinding time is 30-50 min; In step (3), the defoaming is performed until the volume ratio of bubbles is less than or equal to 0.1%.
A blood sugar test paper, comprising a base material and an electrode layer formed on the base material, characterized in that: the electrode layer is coated with the conductive carbon paste according to any one of claims 3 to 10 on the base material. formed by curing on the substrate.
The blood sugar test strip according to claim 13, wherein the base material is PET, PVC, PP or PC.
The blood sugar test strip according to claim 13, wherein the curing is baking at 100-140°C.