Non-woven fabric for rapidly detecting organophosphorus pesticide residues and preparation method of non-woven fabric

Abstract

A non-woven fabric for rapidly detecting organophosphorus pesticide residues comprises an enzyme-containing fabric, a water-soluble film, an indigo-containing fabric, a color-developing fabric and a flash-evaporation non-woven fabric, the enzyme-containing fabric and the indigo-containing fabric are respectively pure-cotton spunlace non-woven fabrics carrying cholinesterase and indophenol acetate, the color-developing fabric is a non-woven fabric, and the flash-evaporation non-woven fabric is a non-woven fabric. The top surface of the flash-evaporation-method non-woven fabric is connected with the bottom surfaces of the indigo-containing fabric and the color-developing fabric which are arranged side by side, the parts, except the indigo-containing fabric and the color-developing fabric, on the flash-evaporation-method non-woven fabric are connected with the four edges of the water-soluble film, and the top surface of the water-soluble film is connected with the bottom surface of the enzyme-containing fabric. The preparation method comprises the following steps: firstly, putting pure cotton spunlaced non-woven fabric into a cholinesterase gelatin solution for dipping and airing to obtain enzyme-containing cloth, then putting the pure cotton spunlaced non-woven fabric into an indophenol acetate solution for airing to obtain indigo-containing cloth, and finally compounding the cloth together according to a connecting structure between the cloth and the cloth to obtain the quick-test non-woven fabric. According to the design, the simplicity and the convenience are better, and the detection time is shorter.

Description

Technical Field

[0001] The invention relates to a pesticide residue detection technology, belongs to the field of functional non-woven fabrics, and particularly relates to a non-woven fabric for rapid detection of organophosphorus pesticide residues and a preparation method thereof. Background Art

[0002] my country is a large agricultural country with a rich variety of crops. The use of pesticides has greatly increased the yield of crops. Organophosphorus pesticides are one of the main types of pesticides currently used in my country, and are also the main source of excessive pesticide residues and pesticide poisoning accidents. Organophosphorus pesticide residues in the environment can enter the human body through the digestive tract, respiratory tract and skin mucosa, causing harm to the human body. Excessive pesticide residues can directly endanger the human nervous system and important organs such as the liver and kidneys. At the same time, residual pesticides accumulate in the human body. When they exceed a certain amount, they can cause some chronic diseases, such as muscle numbness, cough, diarrhea, etc., and even induce vascular diseases, diabetes and cancer. Therefore, it is particularly important to monitor organophosphorus pesticide residues in agricultural products, especially rapid detection.

[0003] The utility model patent application with application number 202222618978.7 and application date October 7, 2022 discloses a test strip for detecting pesticide residues in tea, including a test strip card, in which a reaction test strip and a colorimetric test strip are embedded in sequence, and a water-soluble isolation membrane is arranged between the reaction test strip and the colorimetric test strip; an elastic pad is arranged on the side of the colorimetric test strip facing away from the reaction test strip. Although this design can avoid manual pressing during the detection process, it requires the tea leaves to be added to water and then crushed and filtered to obtain a tissue extract, which is cumbersome and not simple enough to operate.

[0004] The information disclosed in this background technology section is only intended to increase the understanding of the overall background of the application, and should not be regarded as acknowledging or suggesting in any form that the information constitutes the prior art already known to ordinary technicians in this field. Summary of the invention

[0005] The purpose of the present invention is to overcome the defects and problems of poor simplicity in the prior art and to provide a non-woven fabric for rapid detection of organophosphorus pesticide residues with better simplicity and a preparation method.

[0006] To achieve the above objectives, the technical solution of the present invention is: a non-woven fabric for rapid detection of organophosphorus pesticide residues, the non-woven fabric for rapid detection comprises enzyme-containing fabric, water-soluble film, indigo-containing fabric, color-developing fabric, and flash-steamed non-woven fabric; the enzyme-containing fabric is a pure cotton spunlace non-woven fabric carrying cholinesterase, the indigo-containing fabric is a pure cotton spunlace non-woven fabric carrying indophenol acetate, and the color-developing fabric is a non-woven fabric; The top surface of the flash-steamed nonwoven fabric is connected to the bottom surface of the indigo-containing fabric and the color-developing fabric, the indigo-containing fabric and the color-developing fabric are arranged side by side, the inner side edge of the indigo-containing fabric is in contact with the inner side edge of the color-developing fabric, the portion of the flash-steamed nonwoven fabric outside the indigo-containing fabric and the color-developing fabric is connected to the four sides of the water-soluble film, the indigo-containing fabric and the color-developing fabric are sandwiched between the water-soluble film and the flash-steamed nonwoven fabric, and the top surface of the water-soluble film is connected to the bottom surface of the enzyme-containing fabric.

[0007] The water-soluble film is any one of a polyvinyl alcohol water-soluble film, a polyvinyl pyrrolidone water-soluble film or a hydroxypropyl methylcellulose water-soluble film.

[0008] The top surface of the water-soluble film is connected to the bottom surface of the enzyme-containing cloth, which means that the four sides of the enzyme-containing cloth are connected to the top surface of the water-soluble film, and the connection width of the edge of the enzyme-containing cloth located directly above the junction of the indigo-containing cloth and the color-developing cloth is greater than the connection width of the other edges of the enzyme-containing cloth and the water-soluble film.

[0009] The amount of cholinesterase carried on the enzyme-containing cloth is 0.3-0.5 U / cm2, and the amount of indophenol acetate carried on the indigo-containing cloth is 0.4-0.7 mg / cm2.

[0010] The thickness of the water-soluble film is 50-70 um.

[0011] The enzyme-containing cloth also includes gelatin, which is wrapped on the surface of cotton fibers in the pure cotton spunlace nonwoven fabric to form a film, on which cholinesterase is physically adsorbed; In the indigo-containing fabric, indophenol acetate is physically adsorbed on cotton fibers in the pure cotton spunlace nonwoven fabric.

[0012] A method for preparing the above-mentioned nonwoven fabric for rapid detection of organophosphorus pesticide residues, the preparation method comprising the following steps: The first step is to first add cholinesterase to a pH buffer to obtain a cholinesterase solution, and at the same time, add gelatin to another pH buffer to obtain a gelatin solution, and then mix the cholinesterase solution and the gelatin solution to obtain a cholinesterase gelatin solution, wherein the mass percentage concentration of gelatin in the cholinesterase gelatin solution is 0.4%-0.8%, and the content of cholinesterase is 15-20U / ml, and then a piece of pure cotton spunlace nonwoven fabric is placed in the cholinesterase gelatin solution for impregnation and finishing until it is soaked, then taken out, and then dried at room temperature to obtain the enzyme-containing fabric; Step 2: first dissolving indophenol acetate with ethanol to prepare an indophenol acetate solution, wherein the content of indophenol acetate in the solution is 2-5 mg / ml, and then placing a piece of pure cotton spunlace nonwoven fabric into the indophenol acetate solution for impregnation and finishing until it is soaked, then taking it out and drying it at room temperature to obtain the indigo-containing fabric; The third step: first cut the enzyme-containing cloth and indigo-containing cloth, then connect the bottom surfaces of the enzyme-containing cloth and the color-developing cloth side by side with the top surface of the flash-steamed non-woven fabric, the inner side edge of the indigo-containing cloth contacts the inner side edge of the color-developing cloth, and then connect the four sides of the water-soluble film with the remaining parts on the top surface of the flash-steamed non-woven fabric, so that the indigo-containing cloth and the color-developing cloth are sandwiched between the water-soluble film and the flash-steamed non-woven fabric, and then connect the four sides of the enzyme-containing cloth with the top surface of the water-soluble film to obtain the rapid-test non-woven fabric.

[0013] In the first step, adding gelatin to the pH buffer to obtain a gelatin solution means: first adding gelatin particles to the pH buffer, then heating the resultant in a water bath until the gelatin particles are completely dissolved, and then cooling to room temperature to obtain a gelatin solution.

[0014] In the first step, the pH value of the pH buffer is 7-8.

[0015] In the first step, the pH value of the pH buffer is 7.5, and the preparation process of the pH buffer is as follows: first weigh disodium hydrogen phosphate and anhydrous potassium dihydrogen phosphate, and then dissolve them together with distilled water to obtain a pH buffer with a pH value of 7.5; The dosage ratio of disodium hydrogen phosphate, anhydrous potassium dihydrogen phosphate and distilled water is 15.0 g: 1.59 g: 500 mL.

[0016] 1. In the non-woven fabric for rapid detection of organophosphorus pesticide residues and the preparation method of the present invention, the rapid detection non-woven fabric comprises enzyme-containing fabric, water-soluble film, indigo-containing fabric, color-developing fabric, and flash-evaporation non-woven fabric, wherein the enzyme-containing fabric is a pure cotton spunlace non-woven fabric carrying cholinesterase, the indigo-containing fabric is a pure cotton spunlace non-woven fabric carrying indophenol acetate (the indigo-containing fabric is initially red), and the color-developing fabric is a non-woven fabric. The indigo-containing fabric and the color-developing fabric are arranged side by side on the top surface of the flash-evaporation non-woven fabric. At the same time, the indigo-containing fabric and the color-developing fabric are sandwiched between the water-soluble film and the flash-evaporation non-woven fabric. The top surface of the water-soluble film is connected to the bottom surface of the enzyme-containing fabric. When used, the agricultural products such as fruits and vegetables to be tested are first lightly wetted with clean water, and then the side of the rapid detection non-woven fabric exposed as the enzyme-containing fabric is used to gently wipe the wet part of the agricultural product, and then the rapid detection non-woven fabric is horizontally stretched upward. Place (the enzyme cloth is at the top), and then react at room temperature. During the reaction, the wiped liquid will quickly penetrate the rapid-test nonwoven fabric in the longitudinal direction. On the one hand, the residual organophosphorus pesticide reacts with the active center of cholinesterase, the hydroxyl group of serine, to form phosphorylated cholinesterase, thereby causing it to lose the ability to catalyze the hydrolysis of indophenol acetate. On the other hand, the water-soluble film will dissolve after contacting water to ensure that the remaining cholinesterase can contact and catalyze the hydrolysis of indophenol acetate into blue indophenol. Subsequently, the blue indophenol generated by the reaction accumulates on the color-developing cloth by capillary action. Then observe the color change of the color-developing cloth. If there is no blue, it means that the pesticide residue is high. If it is light blue, it means that the pesticide residue is relatively low. If it is sky blue, it means that it does not contain organophosphorus pesticide residues. The advantages of this design are as follows: First point: When operating this rapid testing nonwoven fabric, not only does it not require the help of a residual pesticide detector, it can clearly determine whether the residual pesticides on agricultural products exceed the standard, and it does not require multiple manual operations, such as folding, etc. It only needs to be wiped and the results can be waited for. It is very convenient to test with one wipe; Second point: The entire reaction time after horizontal placement is 6-7 minutes, which is shorter than the existing technology; Third point: Enzyme-containing cloth and indigo-containing cloth both use pure cotton spunlace nonwoven fabric as the base material, and pure cotton spunlace nonwoven fabric has good hydrophilicity and hygroscopicity. This property enables enzyme-containing cloth and indigo-containing cloth to quickly absorb liquid and facilitate the diffusion of liquid inside, making the test results faster; Fourth point: Use flash-steamed nonwovens as the base, which has a good water-repellent effect and can prevent the test fluid from contacting the skin and protect the testers. In addition, it can provide the required strength for the test; Fifth point: The pesticides tested in this design include common pesticides such as methamidophos, parathion, isocarbophos, omethoate, dichlorvos, trichlorfon, dimethoate, and carbaryl, which have a wide range of applications; Therefore, the present invention is not only simpler and more convenient, but also has a shorter detection time and a greater mechanical strength and a wider application range.

[0017] 2. In the nonwoven fabric for rapid detection of organophosphorus pesticide residues and the preparation method of the present invention, the top surface of the flash nonwoven fabric is connected to the bottom surface of the indigo-containing fabric and the color-developing fabric, the indigo-containing fabric and the color-developing fabric are arranged side by side, the inner side edge of the indigo-containing fabric is in contact with the inner side edge of the color-developing fabric, the portion of the flash nonwoven fabric outside the indigo-containing fabric and the color-developing fabric is connected to the four sides of the water-soluble film, the indigo-containing fabric and the color-developing fabric are sandwiched between the water-soluble film and the flash nonwoven fabric, and the top surface of the water-soluble film is connected to the bottom surface of the enzyme-containing fabric. The advantages of the application include: First point: the enzyme-containing cloth and the water-soluble film are connected edge to edge, while the water-soluble film and the indigo-containing cloth are in contact with each other, rather than connected (even if connected, it is preferably connected edge to edge, rather than surface to surface), to ensure smooth liquid penetration in the vertical direction, thereby shortening the time for residual pesticides to flow to the indigo-containing cloth and the elimination time of the water-soluble film, thereby improving the detection speed; Second point: The color developing cloth is placed side by side with the indigo containing cloth, so that the blue indophenol generated by the reaction can be accumulated on the color developing cloth through capillary action. This can not only prevent the remaining cholinesterase from falling on the part outside the indigo containing cloth and affecting the detection effect, but also make it possible to observe the color development results outside the reaction area, which is clearer. Therefore, the present invention not only has a faster retrieval speed but also has a higher accuracy rate.

[0018] 3. In the nonwoven fabric for rapid detection of organophosphorus pesticide residues and the preparation method of the present invention, when making the enzyme-containing fabric, it is necessary to first make a cholinesterase solution and a gelatin solution, specifically, a pH buffer is mixed with cholinesterase to obtain a cholinesterase solution, and at the same time, another pH buffer is mixed with gelatin to obtain a gelatin solution. The pH buffer is used. The advantages of this design are: the buffer can effectively adjust the pH value in the solution to keep it within a range that is most favorable for enzyme activity, avoiding the inhibition or destruction of enzyme activity by an overly acidic or overly alkaline environment. In addition, the buffer can also reduce the influence of environmental factors such as temperature and humidity on enzyme activity, thereby improving the stability of the enzyme and the accuracy of the test results. Therefore, the present invention can ensure the activity of the enzyme and the detection accuracy is high.

[0019] 4. In the nonwoven fabric for rapid detection of organophosphorus pesticide residues and the preparation method of the present invention, when mixing the cholinesterase solution and the gelatin solution, it is preferred that the gelatin solution is cooled to room temperature before mixing with the cholinesterase solution. The reason is that the gelatin particles need to be heated to dissolve in order to obtain the gelatin solution, and the storage conditions of cholinesterase are relatively harsh, usually needing to be stored at low temperatures. If the cholinesterase is placed at high temperatures, it will be inactivated. For this reason, the present invention preferably cools the gelatin solution to room temperature before mixing with the cholinesterase solution to ensure that after the cholinesterase is fixed in the gelatin, the activity of the cholinesterase can still be ensured, thereby significantly improving the stability of the enzyme, extending its shelf life, enhancing its catalytic activity, and thus ensuring the accuracy of the detection of this design. Therefore, the present invention can ensure the activity of cholinesterase to improve the accuracy of the detection.

[0020] 5. In the nonwoven fabric for rapid detection of organophosphorus pesticide residues and the preparation method of the present invention, the enzyme-containing fabric and the indigo-containing fabric are both made of pure cotton spunlace nonwoven fabric. The advantages of this design include: First point: Pure cotton spunlace nonwoven fabrics are preferably degreased to remove impurities such as fat and wax in the cotton during the degreasing process, making the cotton fiber surface cleaner and smoother, and water can more easily penetrate into the fiber, thereby increasing the water absorption of the cotton fiber and increasing the diffusion rate of the test liquid in the cloth, thereby speeding up the detection of pesticide residues; Second point: Cotton fiber contains a large number of polar groups (such as hydroxyl groups) in its chemical structure. These groups can form hydrogen bonds with water molecules, thus giving cotton fiber good hydrophilicity and hygroscopicity, thereby increasing the reaction speed of the test solution after entering the product; The third point: Spunlace nonwoven fabric is a material composed of a porous structure formed by three-dimensional random arrangement of fibers. It has a large specific surface area and more capillary channels, which are conducive to the adsorption and transmission of water molecules. Moreover, due to the large number of gaps and channels between fibers, water molecules can quickly diffuse into the interior of the fiber web, thereby improving the overall moisture absorption performance and facilitating the reaction speed. Therefore, the present invention not only has strong hydrophilicity and hygroscopicity, but also can improve the reaction speed after the detection liquid enters the product, which is conducive to shortening the detection time. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a structural schematic diagram of the present invention.

[0022] Figure 2 It is a schematic diagram of the relative positions of the enzyme-containing cloth, the indigo-containing cloth and the color-developing cloth in the present invention.

[0023] Figure 3 It is a production flow chart of the present invention.

[0024] Figure 4It is a schematic diagram of the principle of the organophosphorus pesticides involved in the present invention inhibiting cholinesterase.

[0025] Figure 5 It is a schematic diagram of the relative structure of the four sides of the enzyme-containing cloth in the present invention. DETAILED DESCRIPTION

[0026] The present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0027] See also Figure 1 — Figure 5 , a nonwoven fabric for rapid detection of organophosphorus pesticide residues, the nonwoven fabric for rapid detection comprises enzyme-containing fabric, water-soluble film, indigo-containing fabric, color-developing fabric, and flash-steamed nonwoven fabric; the enzyme-containing fabric is a pure cotton spunlace nonwoven fabric carrying cholinesterase, the indigo-containing fabric is a pure cotton spunlace nonwoven fabric carrying indophenol acetate, and the color-developing fabric is a nonwoven fabric; The top surface of the flash-steamed nonwoven fabric is connected to the bottom surface of the indigo-containing fabric and the color-developing fabric, the indigo-containing fabric and the color-developing fabric are arranged side by side, the inner side edge of the indigo-containing fabric is in contact with the inner side edge of the color-developing fabric, the portion of the flash-steamed nonwoven fabric outside the indigo-containing fabric and the color-developing fabric is connected to the four sides of the water-soluble film, the indigo-containing fabric and the color-developing fabric are sandwiched between the water-soluble film and the flash-steamed nonwoven fabric, and the top surface of the water-soluble film is connected to the bottom surface of the enzyme-containing fabric.

[0028] The water-soluble film is any one of a polyvinyl alcohol water-soluble film, a polyvinyl pyrrolidone water-soluble film or a hydroxypropyl methylcellulose water-soluble film.

[0029] The top surface of the water-soluble film is connected to the bottom surface of the enzyme-containing cloth, which means that the four sides of the enzyme-containing cloth are connected to the top surface of the water-soluble film, and the connection width of the edge of the enzyme-containing cloth located directly above the junction of the indigo-containing cloth and the color-developing cloth is greater than the connection width of the other edges of the enzyme-containing cloth and the water-soluble film.

[0030] The amount of cholinesterase carried on the enzyme-containing cloth is 0.3-0.5 U / cm2, and the amount of indophenol acetate carried on the indigo-containing cloth is 0.4-0.7 mg / cm2.

[0031] The thickness of the water-soluble film is 50-70 um.

[0032] The enzyme-containing cloth also includes gelatin, which is wrapped on the surface of cotton fibers in the pure cotton spunlace nonwoven fabric to form a film, on which cholinesterase is physically adsorbed; In the indigo-containing fabric, indophenol acetate is physically adsorbed on cotton fibers in the pure cotton spunlace nonwoven fabric.

[0033] A method for preparing the above-mentioned nonwoven fabric for rapid detection of organophosphorus pesticide residues, the preparation method comprising the following steps: The first step is to first add cholinesterase to a pH buffer to obtain a cholinesterase solution, and at the same time, add gelatin to another pH buffer to obtain a gelatin solution, and then mix the cholinesterase solution and the gelatin solution to obtain a cholinesterase gelatin solution, wherein the mass percentage concentration of gelatin in the cholinesterase gelatin solution is 0.4%-0.8%, and the content of cholinesterase is 15-20U / ml, and then a piece of pure cotton spunlace nonwoven fabric is placed in the cholinesterase gelatin solution for impregnation and finishing until it is soaked, then taken out, and then dried at room temperature to obtain the enzyme-containing fabric; Step 2: first dissolving indophenol acetate with ethanol to prepare an indophenol acetate solution, wherein the content of indophenol acetate in the solution is 2-5 mg / ml, and then placing a piece of pure cotton spunlace nonwoven fabric into the indophenol acetate solution for impregnation and finishing until it is soaked, then taking it out and drying it at room temperature to obtain the indigo-containing fabric; The third step: first cut the enzyme-containing cloth and indigo-containing cloth, then connect the bottom surfaces of the enzyme-containing cloth and the color-developing cloth side by side with the top surface of the flash-steamed non-woven fabric, the inner side edge of the indigo-containing cloth contacts the inner side edge of the color-developing cloth, and then connect the four sides of the water-soluble film with the remaining parts on the top surface of the flash-steamed non-woven fabric, so that the indigo-containing cloth and the color-developing cloth are sandwiched between the water-soluble film and the flash-steamed non-woven fabric, and then connect the four sides of the enzyme-containing cloth with the top surface of the water-soluble film to obtain the rapid-test non-woven fabric.

[0034] In the first step, adding gelatin to the pH buffer to obtain a gelatin solution means: first adding gelatin particles to the pH buffer, then heating the resultant in a water bath until the gelatin particles are completely dissolved, and then cooling to room temperature to obtain a gelatin solution.

[0035] In the first step, the pH value of the pH buffer is 7-8.

[0036] In the first step, the pH value of the pH buffer is 7.5, and the preparation process of the pH buffer is as follows: first weigh disodium hydrogen phosphate and anhydrous potassium dihydrogen phosphate, and then dissolve them together with distilled water to obtain a pH buffer with a pH value of 7.5; The dosage ratio of the disodium hydrogen phosphate, anhydrous potassium dihydrogen phosphate and distilled water is 15.0 g:1.59 g:500 mL.

[0037] The supplementary technical features of the present invention are as follows: The color-developing cloth in the present invention is limited to non-woven cloth. The reason is that non-woven cloth is a cloth directly laid from fiber to fiber. At this time, the parallel laying process can make the fibers in the non-woven cloth oriented, increase the horizontal diffusion path of the liquid in the fiber web, and make the blue indophenol generated by the reaction more easily accumulate on the color-developing cloth due to capillary action, thereby accelerating the color change speed on the color-developing cloth and increasing the detection speed. It is further preferred that the color-developing cloth is a pure cotton spunlace non-woven cloth.

[0038] In the flash nonwoven fabric, indigo-containing fabric, color-developing fabric, water-soluble film, and flash nonwoven fabric of the present invention, the connection method between the fabrics is preferably bonding, and the bonding material used is further preferably hot melt adhesive or solvent-based adhesive (phenolic resin adhesive, epoxy resin adhesive, etc.), wherein the hot melt adhesive is solid at room temperature and melts into a viscous liquid when heated to a certain temperature. After being coated and wetted on the adherend, it is pressed and cooled to room temperature. The adhesive completes the bonding within a few seconds and will not affect the morphological properties of the polyvinyl alcohol water-soluble film.

[0039] The reason why the amount of indophenol acetate carried on the indigo-containing cloth in the present invention is limited to 0.4-0.7 mg / cm2 is that indophenol acetate is hydrolyzed into blue indophenol by the catalytic action of cholinesterase. Therefore, if the content of indophenol acetate is low, less indophenol is generated, and the color development is insufficient, which affects the judgment. If the content of indophenol acetate is high, even if all the cholinesterase in the top layer of spunlace cloth is used to catalyze the indophenol acetate, there will still be some left, which will cause waste.

[0040] The reason why the amount of cholinesterase carried on the enzyme-containing cloth in the present invention is limited to 0.3-0.5U / cm2 is that if it is lower than this range, even if there is only a little pesticide, it will react completely with the enzyme, and ultimately the result is that the pesticide residue content is too high, which is contrary to the facts. If it is higher than this range, even if there are a lot of pesticides, after the enzyme has reacted, there will still be enzyme left to catalyze the hydrolysis of indophenol acetate, and ultimately the result is that the pesticide residue content is too low, which is also contrary to the facts.

[0041] The reason why the mass percentage concentration of gelatin in the present invention is limited to 0.4%-0.8% is that if the gelatin concentration is too low, the immobilization effect is poor, and the enzyme will diffuse with the penetration of the sample liquid, resulting in uneven color development. If the gelatin concentration is too high, the sample liquid is not easy to penetrate therein and cannot completely infiltrate the enzyme, resulting in inaccurate color development.

[0042] Embodiment 1: See also Figure 1 — Figure 5, a nonwoven fabric for rapid detection of organophosphorus pesticide residues, the nonwoven fabric comprising enzyme-containing fabric, water-soluble film, indigo-containing fabric, color-developing fabric, and flash-evaporation nonwoven fabric; the enzyme-containing fabric is a pure cotton spunlace nonwoven fabric carrying cholinesterase, the indigo-containing fabric is a pure cotton spunlace nonwoven fabric carrying indophenol acetate, and the color-developing fabric is a nonwoven fabric; the top surface of the flash-evaporation nonwoven fabric is connected to the bottom surfaces of the indigo-containing fabric and the color-developing fabric, the indigo-containing fabric and the color-developing fabric are arranged side by side, the inner side edge of the indigo-containing fabric is in contact with the inner side edge of the color-developing fabric (preferably, the inner side edge of the indigo-containing fabric is overlapped on the top of the inner side edge of the color-developing fabric), the portion of the flash-evaporation nonwoven fabric outside the indigo-containing fabric and the color-developing fabric is connected to the four sides of the water-soluble film, the indigo-containing fabric and the color-developing fabric are sandwiched between the water-soluble film and the flash-evaporation nonwoven fabric, and the top surface of the water-soluble film is connected to the bottom surface of the enzyme-containing fabric. Preferably, the water-soluble film is any one of a polyvinyl alcohol water-soluble film, a polyvinyl pyrrolidone water-soluble film or a hydroxypropyl methylcellulose water-soluble film.

[0043] A method for preparing the above-mentioned nonwoven fabric for rapid detection of organophosphorus pesticide residues, the preparation method comprising the following steps: The first step is to first add cholinesterase to a pH buffer to obtain a cholinesterase solution, and at the same time, add gelatin to another pH buffer to obtain a gelatin solution, and then mix the cholinesterase solution and the gelatin solution to obtain a cholinesterase gelatin solution, wherein the mass percentage concentration of gelatin in the cholinesterase gelatin solution is 0.4%-0.8%, and the content of cholinesterase is 15-20U / ml, and then a piece of pure cotton spunlace nonwoven fabric is placed in the cholinesterase gelatin solution for impregnation and finishing until it is soaked, then taken out, and then dried at room temperature to obtain the enzyme-containing fabric; Step 2: first dissolving indophenol acetate with ethanol to prepare an indophenol acetate solution, wherein the content of indophenol acetate in the solution is 2-5 mg / ml, and then placing a piece of pure cotton spunlace nonwoven fabric into the indophenol acetate solution for impregnation and finishing until it is soaked, then taking it out and drying it at room temperature to obtain the indigo-containing fabric; The third step: first cut the enzyme-containing cloth and indigo-containing cloth, then connect the bottom surfaces of the enzyme-containing cloth and the color-developing cloth side by side with the top surface of the flash-steamed non-woven fabric, the inner side edge of the indigo-containing cloth contacts the inner side edge of the color-developing cloth, and then connect the four sides of the water-soluble film with the remaining parts on the top surface of the flash-steamed non-woven fabric, so that the indigo-containing cloth and the color-developing cloth are sandwiched between the water-soluble film and the flash-steamed non-woven fabric, and then connect the four sides of the enzyme-containing cloth with the top surface of the water-soluble film to obtain the rapid-test non-woven fabric.

[0044] Embodiment 2: The basic content is the same as that of Example 1, except that: See also Figure 2, the top surface of the water-soluble film is connected to the bottom surface of the enzyme-containing cloth means that: the four sides of the enzyme-containing cloth are connected to the top surface of the water-soluble film, and the connection width of the edge of the enzyme-containing cloth located directly above the junction of the indigo-containing cloth and the color-developing cloth is greater than the connection width of the other edges of the enzyme-containing cloth and the water-soluble film.

[0045] When applied, the four sides of the enzyme-containing cloth are connected to the water-soluble film, but among these four sides, there is one side with the largest connection width ( Figure 5 It is clearly visible that the width of the rightmost side is greater than that of the other sides). This side is located directly above the junction of the indigo-containing cloth and the color-developing cloth. The maximum connection width can block the wiped liquid after it comes into contact with the enzyme-containing cloth, so as to prevent the liquid from crossing the enzyme-containing cloth and falling directly on the water-soluble film, and then falling on the color-developing cloth, causing it to fall outside the indigo-containing cloth and affect the accuracy of the detection.

[0046] At the same time, in order to increase the speed of detection, it is preferred that both the indigo-containing cloth and the color-developing cloth are non-woven fabrics, and the fibers inside them are arranged in a horizontal directional structure, which is more conducive to increasing the horizontal diffusion rate of the blue indophenol generated by the reaction and can accumulate on the color-developing cloth faster.

[0047] Embodiment 3: The basic content is the same as that of Example 1, except that: The preferred thickness of the water-soluble film is 50-70um. When used, if the thickness is lower than this range, the pesticide residue detection solution and cholinesterase do not react fully, and the water-soluble film has dissolved, causing cholinesterase to react with the substrate indophenol acetate, making the tested pesticide residue content too small and the result inaccurate; if the thickness is higher than this range, the detection time is increased in vain.

[0048] Embodiment 4: The basic content is the same as that of Example 1, except that: Preferably, the amount of cholinesterase carried on the enzyme-containing cloth is 0.3-0.5 U / cm2, and the amount of indophenol acetate carried on the indigo-containing cloth is 0.4-0.7 mg / cm2. More preferably, the amount of cholinesterase carried on the enzyme-containing cloth is 0.40 U / cm2, and the amount of indophenol acetate carried on the indigo-containing cloth is 0.55 mg / cm2.

[0049] The above description is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiment. Any equivalent modifications or changes made by ordinary technicians in this field based on the contents disclosed by the present invention should be included in the protection scope recorded in the claims.

Claims

1. A nonwoven fabric for rapid detection of organophosphorus pesticide residues, characterized in that: The rapid test nonwoven fabric includes enzyme-containing fabric, water-soluble film, indigo-containing fabric, color-developing fabric, and flash-steamed nonwoven fabric; the enzyme-containing fabric is a pure cotton spunlace nonwoven fabric carrying cholinesterase, the indigo-containing fabric is a pure cotton spunlace nonwoven fabric carrying indophenol acetate, and the color-developing fabric is a nonwoven fabric; The top surface of the flash-steamed nonwoven fabric is connected to the bottom surface of the indigo-containing fabric and the color-developing fabric, the indigo-containing fabric and the color-developing fabric are arranged side by side, the inner side edge of the indigo-containing fabric is in contact with the inner side edge of the color-developing fabric, the portion of the flash-steamed nonwoven fabric outside the indigo-containing fabric and the color-developing fabric is connected to the four sides of the water-soluble film, the indigo-containing fabric and the color-developing fabric are sandwiched between the water-soluble film and the flash-steamed nonwoven fabric, and the top surface of the water-soluble film is connected to the bottom surface of the enzyme-containing fabric.

2. The nonwoven fabric for rapid detection of organophosphorus pesticide residues according to claim 1, characterized in that: The water-soluble film is any one of a polyvinyl alcohol water-soluble film, a polyvinyl pyrrolidone water-soluble film or a hydroxypropyl methylcellulose water-soluble film.

3. The nonwoven fabric for rapid detection of organophosphorus pesticide residues according to claim 1 or 2, characterized in that: The top surface of the water-soluble film is connected to the bottom surface of the enzyme-containing cloth, which means that the four sides of the enzyme-containing cloth are connected to the top surface of the water-soluble film, and the connection width of the edge of the enzyme-containing cloth located directly above the junction of the indigo-containing cloth and the color-developing cloth is greater than the connection width of the other edges of the enzyme-containing cloth and the water-soluble film.

4. The nonwoven fabric for rapid detection of organophosphorus pesticide residues according to claim 1 or 2, characterized in that: The amount of cholinesterase carried on the enzyme-containing cloth is 0.3-0.5 U / cm2, and the amount of indophenol acetate carried on the indigo-containing cloth is 0.4-0.7 mg / cm2.

5. The nonwoven fabric for rapid detection of organophosphorus pesticide residues according to claim 1 or 2, characterized in that: The thickness of the water-soluble film is 50-70 um.

6. The nonwoven fabric for rapid detection of organophosphorus pesticide residues according to claim 1 or 2, characterized in that: The enzyme-containing cloth also includes gelatin, which is wrapped on the surface of cotton fibers in the pure cotton spunlace nonwoven fabric to form a film, on which cholinesterase is physically adsorbed; In the indigo-containing fabric, indophenol acetate is physically adsorbed on cotton fibers in the pure cotton spunlace nonwoven fabric.

7. A method for preparing a nonwoven fabric for rapid detection of organophosphorus pesticide residues according to claim 1 or 2, characterized in that: The preparation method comprises the following steps: The first step is to first add cholinesterase to a pH buffer to obtain a cholinesterase solution, and at the same time, add gelatin to another pH buffer to obtain a gelatin solution, and then mix the cholinesterase solution and the gelatin solution to obtain a cholinesterase gelatin solution, wherein the mass percentage concentration of gelatin in the cholinesterase gelatin solution is 0.4%-0.8%, and the content of cholinesterase is 15-20U / ml, and then a piece of pure cotton spunlace nonwoven fabric is placed in the cholinesterase gelatin solution for impregnation and finishing until it is soaked, then taken out, and then dried at room temperature to obtain the enzyme-containing fabric; Step 2: first dissolving indophenol acetate with ethanol to prepare an indophenol acetate solution, wherein the content of indophenol acetate in the solution is 2-5 mg / ml, and then placing a piece of pure cotton spunlace nonwoven fabric into the indophenol acetate solution for impregnation and finishing until it is soaked, then taking it out and drying it at room temperature to obtain the indigo-containing fabric; The third step: first cut the enzyme-containing cloth and indigo-containing cloth, then connect the bottom surfaces of the enzyme-containing cloth and the color-developing cloth side by side with the top surface of the flash-steamed non-woven fabric, the inner side edge of the indigo-containing cloth contacts the inner side edge of the color-developing cloth, and then connect the four sides of the water-soluble film with the remaining parts on the top surface of the flash-steamed non-woven fabric, so that the indigo-containing cloth and the color-developing cloth are sandwiched between the water-soluble film and the flash-steamed non-woven fabric, and then connect the four sides of the enzyme-containing cloth with the top surface of the water-soluble film to obtain the rapid-test non-woven fabric.

8. The method for preparing a nonwoven fabric for rapid detection of organophosphorus pesticide residues according to claim 7, characterized in that: In the first step, adding gelatin to the pH buffer to obtain a gelatin solution means: first adding gelatin particles to the pH buffer, then heating the resultant in a water bath until the gelatin particles are completely dissolved, and then cooling to room temperature to obtain a gelatin solution.

9. The method for preparing a nonwoven fabric for rapid detection of organophosphorus pesticide residues according to claim 7, characterized in that: In the first step, the pH value of the pH buffer is 7-8.

10. The method for preparing a nonwoven fabric for rapid detection of organophosphorus pesticide residues according to claim 9, characterized in that: In the first step, the pH value of the pH buffer is 7.5, and the preparation process of the pH buffer is as follows: first weigh disodium hydrogen phosphate and anhydrous potassium dihydrogen phosphate, and then dissolve them together with distilled water to obtain a pH buffer with a pH value of 7.5; The dosage ratio of the disodium hydrogen phosphate, anhydrous potassium dihydrogen phosphate and distilled water is 15.0 g:1.59 g:500 mL.

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