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

Abstract

The invention relates to a carbamate pesticide residue rapid detection non-woven fabric and a preparation method thereof, the carbamate pesticide residue rapid detection non-woven fabric comprises an outer package, the outer package is internally provided with an enzyme-containing cloth, a water-soluble film, an indigo-containing cloth, a color-developing cloth, a flash-evaporation non-woven fabric and a warm paste, and the enzyme-containing cloth, the water-soluble film, the indigo-containing cloth, the color-developing cloth, the flash-evaporation non-woven fabric and the warm paste are stacked and connected from top to bottom. The preparation method comprises the following steps: dipping pure cotton spunlaced non-woven fabric in a cholinesterase gelatin solution, taking out and airing to obtain enzyme-containing fabric, dipping the pure cotton spunlaced non-woven fabric in an indophenol acetate solution, taking out and airing to obtain indigo-containing fabric, and drying to obtain the indigo-containing fabric. The enzyme-containing cloth, the water-soluble film, the indigo-containing cloth, the color-developing cloth, the flash-evaporation-method non-woven cloth and the warm paste are mutually connected and put into an outer package, and finally the interior of the outer package is vacuumized to obtain the quick-test non-woven cloth. The method is simple and convenient to operate, high in detection speed and high in detection result accuracy.

Description

Technical Field

[0001] The invention relates to a nonwoven fabric and a preparation method thereof, belonging to the field of functional nonwoven fabrics, and in particular to a nonwoven fabric for rapid detection of carbamate pesticide residues and a preparation method thereof. Background Art

[0002] At present, the detection of carbamate pesticide residues mainly relies on chromatography, spectroscopy and other detection methods. These technologies require expensive instruments and equipment, professional technical operations and complex sample pre-treatment processes, and have the disadvantages of high cost, complex operation, limited detection sites, and long detection time. In addition, in remote rural areas lacking health infrastructure, the amount of pesticides used on fruits and vegetables and other agricultural products is large and the number of times is high, and the abuse phenomenon is serious. Acute poisoning incidents caused by excessive pesticide residues occur frequently, so it is particularly important to develop rapid and instant detection technology for pesticide residues in fruits and vegetables and other agricultural products.

[0003] The invention patent application with application number 201610974422.8 and application date November 7, 2016 discloses a rapid test card for pesticide residues in agricultural products and a preparation method thereof, which includes an upper cover plate, a lower base plate, a test paper placement port, a connecting component, a sample addition hole, a test paper, a display sheet and a heating fiber cotton layer, and the upper cover plate and the lower base plate are connected by a connecting component. The patent application sets a temperature sensor for the heating fiber cotton layer, which can control the temperature at 37°C. When the temperature is at 37°C, the enzyme reaction speed is the fastest, which can improve the detection speed of the rapid test card. However, the device used in this application has a complex structure, which not only has a high production cost, but also requires more operations and a long detection time.

[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 of the pesticide residue detection products in the prior art, such as complicated operation and long detection time, and to provide a non-woven fabric for rapid detection of carbamate pesticide residues which is easy to operate and has a short detection time, and a preparation method thereof.

[0006] To achieve the above objectives, the technical solution of the present invention is: A nonwoven fabric for rapid detection of carbamate pesticide residues, the nonwoven fabric for rapid detection of carbamate pesticide residues comprising an outer package, the outer package containing enzyme-containing cloth, a water-soluble film, an indigo-containing cloth, a color-developing cloth, a flash-evaporation nonwoven fabric, and a warming patch, the enzyme-containing cloth being provided with a water-soluble film below, the bottom surface of the enzyme-containing cloth being connected to the top surface of the water-soluble film, the indigo-containing cloth and the color-developing cloth being provided below the water-soluble film, the water-soluble film being in contact with the indigo-containing cloth and the color-developing cloth, and the nonwoven fabric being provided with a flash-evaporation nonwoven fabric and a warming patch. The indigo-containing cloth and the color-developing cloth are arranged side by side in contact with each other. Below the indigo-containing cloth and the color-developing cloth is a flash-steamed non-woven fabric, and the top surface of the flash-steamed non-woven fabric is connected to the bottom surface of the indigo-containing cloth and the color-developing cloth. Below the flash-steamed non-woven fabric is a warming patch, and the warming patch is connected to the bottom surface of the flash-steamed non-woven fabric. The warming patch includes a non-woven fabric bag, and the non-woven fabric bag contains a mixture of reduced iron powder, activated carbon, inorganic salt and water.

[0007] The mixture in the non-woven fabric bag is a paste, and the mass ratio of reduced iron powder, activated carbon, inorganic salt and water in the paste mixture is: reduced iron powder 61.5: activated carbon 16.5: inorganic salt 3.6: water 18.4.

[0008] The length and width of the non-woven fabric bag are both 3 cm, and the weight of the mixture in the non-woven fabric bag is 2.5-3 g.

[0009] The enzyme-containing cloth is a pure cotton spunlace nonwoven cloth carrying cholinesterase, the indigo-containing cloth is a pure cotton spunlace nonwoven cloth carrying indophenol acetate, and the color-developing cloth is a nonwoven cloth.

[0010] The amount of cholinesterase carried on the enzyme-containing cloth is 0.2-0.4 U / cm2, and the amount of indophenol acetate carried on the indigo-containing cloth is 0.3-0.6 mg / cm2.

[0011] The bottom surface of the enzyme-containing cloth is connected to the top surface of the water-soluble film, which means that the four sides of the enzyme-containing cloth are bonded 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.

[0012] The flash nonwoven fabric and the water-soluble film are both squares with a side length of 7-9 cm, the enzyme-containing fabric has a size of 2.4 cm×2.2 cm, the indigo-containing fabric has a size of 2 cm×2 cm, and the color-developing fabric has a size of 1.4 cm×2 cm.

[0013] The water-soluble film is any one of polyvinyl alcohol water-soluble film, polyvinyl pyrrolidone water-soluble film or hydroxypropyl methylcellulose water-soluble film, and the thickness of the water-soluble film is 40-60um.

[0014] A method for preparing a nonwoven fabric for rapid detection of carbamate pesticide residues, the method comprising the following steps: The first step is to add cholinesterase to a pH buffer solution and mix to obtain a cholinesterase solution; at the same time, add gelatin particles to another pH buffer solution and mix, then heat in a water bath until the gelatin particles are completely dissolved, and then cool to room temperature to obtain a gelatin solution; then add the cholinesterase solution to the gelatin solution and mix to obtain a cholinesterase gelatin solution, and then put a piece of pure cotton spunlace nonwoven fabric into the cholinesterase gelatin solution for impregnation and finishing until it is soaked, then take it out, and then dry it at room temperature to obtain the enzyme-containing fabric; Step 2: first dissolving indophenol acetate with ethanol to prepare an indophenol acetate solution, 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 then 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 indigo-containing cloth and the color-developing cloth side by side with the top surface of the flash-steamed non-woven fabric, the inner side of the indigo-containing cloth contacts the inner side of the color-developing cloth, 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, then connect the four sides of the enzyme-containing cloth with the top surface of the water-soluble film, then connect the warming patch with the bottom surface of the flash-steamed non-woven fabric, finally put the connected enzyme-containing cloth, water-soluble film, indigo-containing cloth, color-developing cloth, flash-steamed non-woven fabric, and warming patch into an outer package and seal it, then evacuate the inside of the outer package to obtain the non-woven fabric for rapid detection of carbamate pesticide residues.

[0015] In the first step, the mass percentage concentration of gelatin in the cholinesterase gelatin solution is 0.4%-0.8%, and the content of cholinesterase in the cholinesterase gelatin solution is 12-17U / ml. In the second step, the content of indophenol acetate in the indophenol acetate solution is 2-4mg / ml.

[0016] Compared with the prior art, the present invention has the following beneficial effects: 1. In the non-woven fabric for rapid detection of carbamate pesticide residues and the preparation method thereof of the present invention, the enzyme-containing fabric and the indigo-containing fabric both use pure cotton spunlace non-woven fabric as the base material. This is because the pure cotton spunlace non-woven fabric has good hydrophilicity and hygroscopicity. This property enables the enzyme-containing fabric and the indigo-containing fabric to quickly absorb the test liquid and facilitates the diffusion of the test liquid inside them. In addition, the enzyme-containing fabric is connected to the water-soluble film on four sides, and the part within the four sides of the enzyme-containing fabric is only in contact with the water-soluble film. This connection method can not only fix the enzyme-containing fabric on the water-soluble film, but also does not affect the smooth penetration of liquid in the longitudinal direction, thereby shortening the time for residual pesticides to flow to the indigo-containing fabric and the elimination time of the water-soluble film, thereby improving the speed of the test results. In addition, a heating pad is connected to the bottom surface of the flash nonwoven fabric. During the actual detection process, the heating pad can quickly heat up to 36-39°C, and the heating temperature can be stabilized in the range of 36-39°C until the end of the detection, which can ensure that the activity of cholinesterase is in the best state, so that cholinesterase and residual carbamate pesticides in the detection solution react fully and quickly. Therefore, the detection speed of the present invention is fast and the detection time is short.

[0017] 2. In the nonwoven fabric for rapid detection of carbamate pesticide residues and the preparation method thereof of the present invention, in actual use, it is only necessary to first slightly wet the agricultural products such as fruits and vegetables to be tested, and then use the side of the nonwoven fabric exposed as the enzyme-containing cloth to gently wipe the wet parts of the agricultural products, and then place the nonwoven fabric horizontally aside. The residual carbamate pesticides on the agricultural products will react with the cholinesterase in the enzyme-containing cloth, and then judge whether the residual pesticides exceed the standard based on the color display on the color-developing cloth. The whole process does not require multiple manual operations, only a wipe is needed, and the result can be waited for, and the test can be performed with one wipe. Therefore, the present invention not only has a short detection time, but also is extremely easy to operate.

[0018] 3. In the nonwoven fabric for rapid detection of carbamate pesticide residues and the preparation method of the present invention, the cholinesterase solution and the gelatin solution are prepared by mixing with a pH buffer solution. This is because the buffer solution can effectively adjust the pH value in the solution, so that the pH value of the mixed solution is maintained within a range that is most favorable for enzyme activity, and the inhibition or destruction of enzyme activity by an overly acidic or overly alkaline environment is avoided. The buffer solution can also reduce the effects of environmental factors such as temperature and humidity on enzyme activity, thereby improving the stability of the enzyme and the accuracy of the final test results. In addition, the color-developing cloth is arranged side by side in contact with the indigo-containing cloth, so that the blue indophenol generated by the reaction is accumulated on the color-developing cloth through capillary action, which can not only prevent the remaining cholinesterase from falling on the part outside the indigo-containing cloth and affecting the detection effect, but also enable the color development results to be observed outside the reaction area. Therefore, the test results of the present invention are highly accurate.

[0019] 4. In the nonwoven fabric for rapid detection of carbamate pesticide residues and the preparation method thereof of the present invention, a flash nonwoven fabric is used as a base, because the flash nonwoven fabric has a good water repellent effect and can prevent the detection liquid from seeping out. In addition, the flash nonwoven fabric is composed of ultra-fine and continuous high-density polyethylene filament fibers, has a unique three-dimensional dense structure, and the high-density polyethylene itself also has high strength and toughness, so the flash nonwoven fabric has good tensile strength, thereby providing the required mechanical strength for detection. Therefore, the present invention can not only effectively avoid the threat of detection liquid seepage to the detection personnel, but also has a certain mechanical strength, which can ensure the smooth progress of the detection.

[0020] 5. In the nonwoven fabric for rapid detection of carbamate pesticide residues and the preparation method thereof, the reason why the nonwoven fabric can detect whether there are carbamate pesticide residues on agricultural products is that the hydroxyl group of serine in the active center of cholinesterase in the enzyme-containing cloth can undergo carbamylation reaction with carbamate pesticides, thereby causing cholinesterase to lose the ability to catalyze the hydrolysis of indophenol acetate. In addition, after the water-soluble film contacts the detection liquid, it will dissolve by itself, and the remaining cholinesterase can contact and catalyze the hydrolysis of indophenol acetate in the indigo-containing cloth into blue indophenol. Subsequently, the blue indophenol generated by the reaction accumulates on the color-developing cloth by capillary action, and then the color change of the color-developing cloth is observed. 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, and if it is sky blue, it means that there is no carbamate pesticide residue. This detection principle enables the present invention to detect a variety of carbamate pesticides, such as common carbamate pesticides such as carbaryl, carbofuran, methomyl, and chlorpyrifos. Therefore, the present invention has a wide range of applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the overall structure 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 schematic diagram of the relative structure of the four sides of the enzyme-containing cloth in the present invention.

[0024] Figure 4 It is a production flow chart of the present invention.

[0025] Figure 5 It is a schematic diagram of the principle of the pesticide used in the present invention to inhibit cholinesterase. 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 carbamate pesticide residues, the nonwoven fabric for rapid detection of carbamate pesticide residues comprises an outer package, the outer package contains enzyme-containing cloth, water-soluble film, indigo-containing cloth, color-developing cloth, flash-evaporation nonwoven fabric, and a warming patch, the enzyme-containing cloth is provided with a water-soluble film below, the bottom surface of the enzyme-containing cloth is connected to the top surface of the water-soluble film, the indigo-containing cloth and the color-developing cloth are provided below the water-soluble film, the water-soluble film is in contact with the indigo-containing cloth and the color-developing cloth, The indigo-containing cloth and the color-developing cloth are arranged side by side in contact with each other; below the indigo-containing cloth and the color-developing cloth is a flash-steamed nonwoven fabric; the top surface of the flash-steamed nonwoven fabric is connected to the bottom surfaces of the indigo-containing cloth and the color-developing cloth; below the flash-steamed nonwoven fabric is a warming patch; the warming patch is connected to the bottom surface of the flash-steamed nonwoven fabric; the warming patch includes a non-woven fabric bag; the non-woven fabric bag contains a mixture of reduced iron powder, activated carbon, inorganic salt and water.

[0028] The mixture in the non-woven fabric bag is a paste, and the mass ratio of reduced iron powder, activated carbon, inorganic salt and water in the paste mixture is: reduced iron powder 61.5: activated carbon 16.5: inorganic salt 3.6: water 18.4.

[0029] The length and width of the non-woven fabric bag are both 3 cm, and the weight of the mixture in the non-woven fabric bag is 2.5-3 g.

[0030] The enzyme-containing cloth is a pure cotton spunlace nonwoven cloth carrying cholinesterase, the indigo-containing cloth is a pure cotton spunlace nonwoven cloth carrying indophenol acetate, and the color-developing cloth is a nonwoven cloth.

[0031] The amount of cholinesterase carried on the enzyme-containing cloth is 0.2-0.4 U / cm2, and the amount of indophenol acetate carried on the indigo-containing cloth is 0.3-0.6 mg / cm2.

[0032] The bottom surface of the enzyme-containing cloth is connected to the top surface of the water-soluble film, which means that the four sides of the enzyme-containing cloth are bonded 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.

[0033] The flash nonwoven fabric and the water-soluble film are both squares with a side length of 7-9 cm, the enzyme-containing fabric has a size of 2.4 cm×2.2 cm, the indigo-containing fabric has a size of 2 cm×2 cm, and the color-developing fabric has a size of 1.4 cm×2 cm.

[0034] The water-soluble film is any one of polyvinyl alcohol water-soluble film, polyvinyl pyrrolidone water-soluble film or hydroxypropyl methylcellulose water-soluble film, and the thickness of the water-soluble film is 40-60um.

[0035] A method for preparing a nonwoven fabric for rapid detection of carbamate pesticide residues, the method comprising the following steps: The first step is to add cholinesterase to a pH buffer solution and mix to obtain a cholinesterase solution; at the same time, add gelatin particles to another pH buffer solution and mix, then heat in a water bath until the gelatin particles are completely dissolved, and then cool to room temperature to obtain a gelatin solution; then add the cholinesterase solution to the gelatin solution and mix to obtain a cholinesterase gelatin solution, and then put a piece of pure cotton spunlace nonwoven fabric into the cholinesterase gelatin solution for impregnation and finishing until it is soaked, then take it out, and then dry it at room temperature to obtain the enzyme-containing fabric; Step 2: first dissolving indophenol acetate with ethanol to prepare an indophenol acetate solution, 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 then 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 indigo-containing cloth and the color-developing cloth side by side with the top surface of the flash-steamed non-woven fabric, the inner side of the indigo-containing cloth contacts the inner side of the color-developing cloth, 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, then connect the four sides of the enzyme-containing cloth with the top surface of the water-soluble film, then connect the warming patch with the bottom surface of the flash-steamed non-woven fabric, finally put the connected enzyme-containing cloth, water-soluble film, indigo-containing cloth, color-developing cloth, flash-steamed non-woven fabric, and warming patch into an outer package and seal it, then evacuate the inside of the outer package to obtain the non-woven fabric for rapid detection of carbamate pesticide residues.

[0036] In the first step, the mass percentage concentration of gelatin in the cholinesterase gelatin solution is 0.4%-0.8%, and the content of cholinesterase in the cholinesterase gelatin solution is 12-17U / ml. In the second step, the content of indophenol acetate in the indophenol acetate solution is 2-4mg / ml.

[0037] The supplementary technical features of the present invention are as follows: The function of the warm patch in the present invention is that because the binding of carbamate pesticides to cholinesterase is reversible, its inhibitory effect can be quickly restored under certain conditions, which will affect the test results and cause misjudgment. Therefore, the present invention uses a warm patch, which heats to 36-39°C when detecting pesticide residues, so that the activity of cholinesterase is in the best state, thereby providing a guarantee for the full and rapid reaction of carbamate pesticide residues with cholinesterase.

[0038] The pure cotton spunlace nonwoven fabrics in the present invention are preferably first degreased to remove impurities such as fat and wax in the cotton, so that the surface of the cotton fiber becomes cleaner and smoother, and water can more easily penetrate into the interior of the fiber, thereby increasing the water absorption of the cotton fiber. Secondly, the chemical structure of cotton fiber contains a large number of polar groups (such as hydroxyl groups), which can form hydrogen bonds with water molecules, thereby giving the cotton fiber good hydrophilicity and hygroscopicity. Thirdly, the spunlace nonwoven fabric is a material composed of a porous structure formed by a three-dimensional random arrangement of fibers, with a large surface area and more capillary channels, which is conducive to the adsorption and transmission of water molecules. Moreover, due to the presence of a large number of gaps and channels between the fibers, water molecules can quickly diffuse into the interior of the fiber web, thereby improving the overall hygroscopicity and facilitating the shortening of the detection time.

[0039] The heating pad in the present invention preferably includes a non-woven bag, and the inner side of the non-woven bag has a waterproof breathable film, and the waterproof breathable film wraps the paste mixture composed of reduced iron powder, activated carbon, inorganic salt, and water. Each sample in the paste mixture plays an indispensable role in the heating pad. The oxygen in the air passes through the non-woven bag and contacts the iron powder. Under the catalysis of water and inorganic salts (such as sodium chloride), the iron powder undergoes an oxidation reaction to generate ferric oxide (Fe2O3). This oxidation reaction is an exothermic reaction, so a large amount of heat is released, causing the heating pad to heat up. Activated carbon mainly plays an adsorption role in the heating pad, and can absorb the moisture generated during the heating process, thereby maintaining the dryness of the heating pad. Inorganic salts are mainly used as catalysts in the heating pad to promote the oxidation reaction of iron powder, accelerate the heating rate, and thus accelerate the detection rate of carbamate pesticide residues. Water is an indispensable component in the heating reaction of the heating pad. As a reaction medium, it works together with iron powder and inorganic salts to promote the occurrence and progress of the oxidation reaction. The size of the heating patch is preferably 3×3cm 2 .

[0040] In the present invention, when mixing the cholinesterase solution and the gelatin solution, it is preferred that the gelatin solution is first cooled to room temperature and then mixed 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, and usually need 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 and then mixes it 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, and enhancing its catalytic activity, thereby ensuring the accuracy of the test results of this product.

[0041] The reason why the color-developing cloth is preferably limited to nonwoven cloth in the present invention is that: nonwoven cloth is fiber-to-cloth, and at this time, the parallel web laying process can make the fibers in the nonwoven 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 by 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 pure cotton spunlace nonwoven cloth.

[0042] In the present invention, the enzyme-containing cloth, water-soluble film, indigo-containing cloth, color-developing cloth, flash-evaporated nonwoven fabric, and heating pad are preferably connected to each other by bonding, and the bonding material used is 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, and the adhesive completes the bonding within a few seconds, and will not affect the morphological properties of the polyvinyl alcohol water-soluble film.

[0043] The reason why the amount of cholinesterase carried on the enzyme-containing cloth is preferably limited to 0.2-0.4U / cm2 in the present invention 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.

[0044] The reason why the amount of indophenol acetate carried on the indigo-containing cloth is preferably limited to 0.3-0.6 mg / cm2 in the present invention 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.

[0045] The reason why the mass percentage concentration of gelatin is preferably limited to 0.4%-0.8% in the present invention 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.

[0046] Embodiment 1: See also Figure 1 — Figure 5A nonwoven fabric for rapid detection of carbamate pesticide residues, the nonwoven fabric comprising an outer package, which is a conventional small plastic bag that is sealed and vacuumed inside, and contains enzyme-containing cloth, water-soluble film, indigo-containing cloth, color-developing cloth, flash-steamed nonwoven fabric, and a warming patch. The enzyme-containing cloth is a pure cotton spunlace nonwoven fabric carrying cholinesterase, the indigo-containing cloth is a pure cotton spunlace nonwoven fabric carrying indophenol acetate, and the color-developing cloth 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, the top surface of the water-soluble film is connected to the bottom surface of the enzyme-containing fabric, and the warming patch is connected to the bottom surface of the flash-steamed nonwoven fabric.

[0047] A method for preparing a nonwoven fabric for rapid detection of carbamate pesticide residues, the 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 particles to another pH buffer, mix and then heat in a water bath until the gelatin particles are completely dissolved, and then cool to room temperature to obtain a gelatin solution; 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 12-17U / 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 cloth; Step 2: first dissolving indophenol acetate with ethanol to prepare an indophenol acetate solution, wherein the content of indophenol acetate in the solution is 2-4 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 of the indigo-containing cloth contacts the inner side of the color-developing cloth, 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, then connect the four sides of the enzyme-containing cloth with the top surface of the water-soluble film, and then connect the warming patch with the bottom surface of the flash-steamed non-woven fabric, finally put the connected enzyme-containing cloth, water-soluble film, indigo-containing cloth, color-developing cloth, flash-steamed non-woven fabric, and warming patch into an outer package and seal it, and then evacuate the inside of the outer package to obtain the non-woven fabric for rapid detection of carbamate pesticide residues.

[0048] Embodiment 2: The basic content is the same as that of Example 1, except that: Preferably, the four sides of the enzyme-containing cloth are connected to the top surface of the water-soluble film by bonding, and the bonding material is hot melt adhesive. The portion within the four sides of the enzyme-containing cloth is only in contact with the water-soluble film. Figure 2 , 3 As shown, the connection width of the edge on the enzyme-containing cloth located just above the junction of the indigo-containing cloth and the color-developing cloth is greater than the connection width between the other edges on the enzyme-containing cloth and the water-soluble film. The reason why this edge is located just above the junction of the indigo-containing cloth and the color-developing cloth is that the largest connection width can play a blocking effect after the wiped liquid contacts the enzyme-containing cloth, so as to prevent the liquid from crossing the enzyme-containing cloth and directly falling on the water-soluble film, and then falling on the color-developing cloth and outside the indigo-containing cloth, affecting the accuracy of the detection.

[0049] Embodiment 3: The basic content is the same as that of Example 1, except that: The preferred water-soluble film is any one of polyvinyl alcohol water-soluble film, polyvinyl pyrrolidone water-soluble film or hydroxypropyl methylcellulose water-soluble film. The preferred thickness of the water-soluble film is 40-60um. 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, resulting in a lower pesticide residue content and an inaccurate result; if the thickness is higher than this range, the detection time is increased in vain.

[0050] 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 0.2-0.4 U / cm2, and the amount of indophenol acetate carried on the indigo-containing cloth is 0.3-0.6 mg / cm2. More preferably, the amount of cholinesterase carried on the enzyme-containing cloth is 0.30 U / cm2, and the amount of indophenol acetate carried on the indigo-containing cloth is 0.45 mg / cm2.

[0051] 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 carbamate pesticide residues, characterized in that: The nonwoven fabric for rapid detection of carbamate pesticide residues includes an outer package, which contains enzyme-containing cloth, water-soluble film, indigo-containing cloth, color-developing cloth, flash-evaporation nonwoven fabric, and a warming patch. The enzyme-containing cloth is provided with a water-soluble film below, and the bottom surface of the enzyme-containing cloth is connected to the top surface of the water-soluble film. The water-soluble film is provided with indigo-containing cloth and color-developing cloth below, and the water-soluble film is in contact with the indigo-containing cloth and color-developing cloth. The indigo-containing cloth and color-developing cloth are in contact with each other and arranged side by side. The indigo-containing cloth and color-developing cloth are provided with a flash-evaporation nonwoven fabric below, and the top surface of the flash-evaporation nonwoven fabric is connected to the bottom surface of the indigo-containing cloth and color-developing cloth. The flash-evaporation nonwoven fabric is provided with a warming patch below, and the warming patch is connected to the bottom surface of the flash-evaporation nonwoven fabric. The warming patch includes a nonwoven fabric pouch, and the nonwoven fabric pouch contains a mixture of reduced iron powder, activated carbon, inorganic salt and water.

2. The nonwoven fabric for rapid detection of carbamate pesticide residues according to claim 1, characterized in that: The mixture in the non-woven fabric bag is a paste, and the mass ratio of reduced iron powder, activated carbon, inorganic salt and water in the paste mixture is: reduced iron powder 61.5: activated carbon 16.5: inorganic salt 3.6: water 18.

4.

3. A nonwoven fabric for rapid detection of carbamate pesticide residues according to claim 1 or 2, characterized in that: The length and width of the non-woven fabric bag are both 3 cm, and the weight of the mixture in the non-woven fabric bag is 2.5-3 g.

4. A nonwoven fabric for rapid detection of carbamate pesticide residues according to claim 1, 2 or 3, characterized in that: The enzyme-containing cloth is a pure cotton spunlace nonwoven cloth carrying cholinesterase, the indigo-containing cloth is a pure cotton spunlace nonwoven cloth carrying indophenol acetate, and the color-developing cloth is a nonwoven cloth.

5. The nonwoven fabric for rapid detection of carbamate pesticide residues according to claim 4, characterized in that: The amount of cholinesterase carried on the enzyme-containing cloth is 0.2-0.4 U / cm2, and the amount of indophenol acetate carried on the indigo-containing cloth is 0.3-0.6 mg / cm2.

6. A nonwoven fabric for rapid detection of carbamate pesticide residues according to claim 1, 2 or 3, characterized in that: The bottom surface of the enzyme-containing cloth is connected to the top surface of the water-soluble film, which means that the four sides of the enzyme-containing cloth are bonded 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.

7. A nonwoven fabric for rapid detection of carbamate pesticide residues according to claim 1, 2 or 3, characterized in that: The flash nonwoven fabric and the water-soluble film are both squares with a side length of 7-9 cm, the enzyme-containing fabric has a size of 2.4 cm×2.2 cm, the indigo-containing fabric has a size of 2 cm×2 cm, and the color-developing fabric has a size of 1.4 cm×2 cm.

8. The nonwoven fabric for rapid detection of carbamate pesticide residues according to claim 7, characterized in that: The water-soluble film is any one of polyvinyl alcohol water-soluble film, polyvinyl pyrrolidone water-soluble film or hydroxypropyl methylcellulose water-soluble film, and the thickness of the water-soluble film is 40-60 um.

9. A method for preparing a nonwoven fabric for rapid detection of carbamate pesticide residues according to claim 1, 2 or 3, characterized in that: The preparation method comprises the following steps: The first step is to add cholinesterase to a pH buffer solution and mix to obtain a cholinesterase solution; at the same time, add gelatin particles to another pH buffer solution and mix, then heat in a water bath until the gelatin particles are completely dissolved, and then cool to room temperature to obtain a gelatin solution; then add the cholinesterase solution to the gelatin solution and mix to obtain a cholinesterase gelatin solution, and then put a piece of pure cotton spunlace nonwoven fabric into the cholinesterase gelatin solution for impregnation and finishing until it is soaked, then take it out, and then dry it at room temperature to obtain the enzyme-containing fabric; Step 2: first dissolving indophenol acetate with ethanol to prepare an indophenol acetate solution, 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 then 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 indigo-containing cloth and the color-developing cloth side by side with the top surface of the flash-steamed non-woven fabric, the inner side of the indigo-containing cloth contacts the inner side of the color-developing cloth, 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, then connect the four sides of the enzyme-containing cloth with the top surface of the water-soluble film, then connect the warming patch with the bottom surface of the flash-steamed non-woven fabric, finally put the connected enzyme-containing cloth, water-soluble film, indigo-containing cloth, color-developing cloth, flash-steamed non-woven fabric, and warming patch into an outer package and seal it, then evacuate the inside of the outer package to obtain the non-woven fabric for rapid detection of carbamate pesticide residues.

10. The method for preparing a nonwoven fabric for rapid detection of carbamate pesticide residues according to claim 9, characterized in that: In the first step, the mass percentage concentration of gelatin in the cholinesterase gelatin solution is 0.4%-0.8%, and the content of cholinesterase in the cholinesterase gelatin solution is 12-17U / ml. In the second step, the content of indophenol acetate in the indophenol acetate solution is 2-4mg / ml.

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