CN100520373C - Quick detection paper card for pesticide residue in vegetable and preparation method therof - Google Patents

Abstract

The invention provides a vegetable pesticide residue rapid detection paper card and its preparation method. The rapid detection paper card of the present invention uses acetylcholinesterase enzyme tablets extracted from human serum, which can detect organophosphorus and carbamate pesticides. The sensitivity reaches 0.001-1.2mg/kg, which is a highly sensitive enzyme source. The present invention is also an enzyme source with good thermal stability, especially after adding stabilizer gelatin or trehalose to the enzyme liquid, it can be used at about 90°C , Enzyme activity can be maintained for 7-8 hours. The rapid test paper card prepared by the present invention can detect common pesticides on vegetables, and the operation is simple and fast. It can clearly determine whether the residual pesticides on edible vegetables exceed the standard without the help of a residual pesticide detector, and only 12 minute. With low cost, it is not only suitable for home testing, but also brings great convenience to market supervision, rapid screening and monitoring of field vegetables, health and epidemic prevention stations, agricultural plant inspection stations and other units for the detection of vegetable pesticide residues.

Description

Vegetable pesticide residue rapid test paper card and preparation method thereof

technical field

The invention belongs to the analysis of pesticide residues, in particular, the invention relates to a rapid detection paper card for pesticide residues in vegetables and a preparation method thereof

Background technique

my country is a large agricultural country, with abundant crops. In addition to food crops, oil crops, fiber crops, sugar crops, melons and fruits, and medicinal tobacco, there are also large areas of fruits, vegetables, pastures, and forests. Therefore, China is also a big country in the application of pesticides. The invention and use of pesticides have undoubtedly greatly improved agricultural productivity, but the annual spraying of chemical pesticides to prevent and control pests and diseases is still an indispensable and necessary measure. With the improvement of people's quality of life, the demand for safe, nutritious, and pollution-free vegetables and fruits is becoming stronger and stronger. At present, the amount of pesticides on fruits and vegetables is large, the number of times is large, and the abuse phenomenon is serious. Therefore, acute poisoning incidents caused by excessive pesticide residues are repeated. In some cases, pesticide residues can also accumulate in the human body to cause chronic poisoning, and even cause: three causes (teratogenic, carcinogenic, and mutagenic). In addition, reports of my country's agricultural products being rejected by foreign countries due to excessive pesticide residues are not uncommon. Therefore, in modern agricultural production, how to quickly detect pesticide residues has become an urgent need for food safety and people's dietary hygiene.

The detection of pesticide residues on fruits and vegetables has already been institutionalized in many countries. At present, immunoassay, supercritical fluid extraction and supercritical fluid chromatography, capillary zone electrophoresis and other technologies are used abroad to detect pesticide residues in fruits and vegetables. The accuracy of these separation testing techniques and high precision. However, it needs to be equipped with expensive instruments and equipment, which takes a long time and costs a lot; moreover, the production of commercial vegetables in many western countries is concentrated, and the local pesticide residue inspection units have plenty of time to carry out inspections. However, the production of fruits and vegetables in our country is relatively scattered, and they can be sold immediately after harvesting. It is impossible to analyze a large number of sampled samples with gas chromatography and other analytical instruments. Ready-to-sell on-site rapid test. In recent years, scientists in our country have also done a lot of research work from different angles, trying to find cholinesterase with high detection sensitivity for organophosphorus and carbamate pesticides. At present, the cholinesterase extracted from marine organisms, animal serum, and housefly is widely used. After several years of research, Beijing Agricultural College and Beijing Institute of Analytical Instruments have developed a pesticide residue rapid detector and the key used earlier. Reagent—high activity enzyme, the detection process is roughly 1, sampling 2, extraction 3, cultivation 4, color development 5, instrument measurement. Vegetables No. 3, 2001 "Comparative Test of Fast Detection Methods for Pesticide Residues in Fruits and Vegetables" disclosed cholinesterase with high sensitivity to the detection of organophosphorus and carbamate pesticides. ——Add phosphate buffer solution and sonicate for 2-3 minutes——Add a drop of sample extract to the white tablet position of the quick test card—Stay at room temperature for about 3 minutes—Reflect the pesticide residue rapid tester at 40°C for 10 minutes, and directly observe the color change with the naked eye (at the same time A blank sample was measured as a control). The detection sensitivity and detection reproducibility are shown in the table below

Detection sensitivity

It can be seen from the above table: Methamidophos 1.2mg/kg, can be detected by the quick test card; Dichlorvos 0.1mg/kg, can be detected by the quick test card; Dimethoate 2.0mg/kg, can be detected by the quick test card; Cypermethrin 30mg/kg, can be detected by the quick test card. However, this quick test card must be equipped with a pesticide residue quick tester to detect it, and this quick test card can only detect organophosphorus pesticides.

Contents of the invention

The object of the present invention is to provide an enzyme source with high sensitivity and good thermal stability for rapid detection of organophosphorus and carbamate pesticide residues, and a technology for preserving the enzyme at normal temperature.

Another object of the present invention is to provide a quick-testing paper card for simple and rapid detection of pesticide residues and a preparation method thereof.

The first aspect of the present invention provides an enzyme source with high sensitivity and good thermostability. Acetylcholinesterase (hereinafter referred to as the enzyme) extracted from different animals has considerable differences in detection sensitivity to various highly toxic and banned pesticides. Some cholinesterases respond to very small amounts of pesticides, while some choline Esterase has no response to poisonous doses of pesticides, (the sensitivity of cholinesterase to pesticide detection is generally expressed as an inhibition rate%) in animals such as horse serum, human serum, bovine liver, bee head, housefly head, etc. Several animal bodies such as organs or serum are used as materials, and the high-sensitivity enzyme source-acetylcholinesterase is extracted and screened according to conventional methods. Through experimental screening, the enzyme extracted from human serum of the present invention has a significantly higher inhibition rate than the enzyme extracted from horse serum and the enzyme extracted from housefly brain in the prior art, and is a highly sensitive enzyme source. The highly sensitive enzyme provided by the present invention, Acetylcholinesterase extracted from human serum. With the enzyme preparation of the present invention, the minimum detection limit results of various pesticides are shown in Table 1.

Table 1 human serum enzyme preparation of the present invention has the minimum detection limit of various pesticides

Pesticide Chinese name English common name toxicity Minimum detection limit mg/kg Methamidophos methamidophos High toxicity 0.8 Omethoate omethoote High toxicity 1.2 trichlorfon trichlorphon High toxicity 0.25 Dichlorvos dichlorovos poisoned 0.10 Kebowei carbofuran High toxicity 0.001 Methomyl methomyl High toxicity 0.08 Carbaryl carboryl High toxicity 0.08

Results of the present invention are compared with the results of "Comparative Test of Quick Detection Methods for Pesticide Residues in Fruits and Vegetables" as follows:

Methamidophos: the minimum detection limit of the prior art is 1.2mg/kg; the minimum detection limit of the present invention is 0.8mg/kg

Dichlorvos: the minimum detection limit of the existing technology is 0.1mg/kg; the minimum detection limit of the present invention is 0.1mg/kg

Dimethoate: The minimum detection limit of the existing technology is 2.0mg/kg; the minimum detection limit of the present invention is 1.2mg/kg.

Trichlorfon: The minimum detection limit of the present invention is 0.25mg/kg.

Carbofuran: The minimum detection limit of the present invention is 0.001mg/kg.

Methomyl: The minimum detection limit of the present invention is 0.08mg/kg.

Carbaryl: The minimum detection limit of the present invention is 0.08mg/kg.

As can be seen from the table, the sensitivity of the enzyme preparation of the present invention is significantly higher than that of the prior art. Moreover, the quick test card in the prior art can only detect organophosphorus pesticides, but the present invention can detect not only organophosphorus pesticides but also carbamate pesticides. Sensitivity of 0.001 ~ 1.2mg/kg. The positive effects of the present invention are further described.

The high-sensitivity human serum enzyme powder screened out by the present invention is diluted into 0.5-1.5 units of enzyme liquid with pH8.0 and 0.1M phosphate buffer respectively, and then 0.5-1.% gelatin or 0.5-1.0% gelatin or 0.5-1. % trehalose was mixed, and a drop of enzyme solution (about 30 μl) was dropped on a qualitative filter paper with a diameter of 1.0 cm, and dried at room temperature to make an enzyme tablet. The enzyme slices were placed in a constant temperature and humidity chamber (adjustable temperature) for processing, and then the thermal stability of the enzyme was tested. The results are shown in Table 2.

Table 2 Heat Stability Test of Enzyme Tablets

time (min) temperature °C Enzyme Activity Mark+ 0 84 +++ 30 70 +++ 60 95 +++ 90 90 +++ 120 88 +++ 150 90 +++ 180 88 +++ 240 90 +++ 300 92 +++ 360 90 +++ 420 90 +++ 480 90 ++

The above test results show that: the enzyme screened by the present invention shows through experiments that the enzyme activity can be kept for 5-6 hours under the condition of about 90° C. 1. When mixed with trehalose, the human serum enzyme activity of the present invention can be maintained for 7-8 hours under the condition of about 90° C., which solves the preservation technology of the enzyme at normal temperature. The invention is an enzyme source with good thermal stability, which solves the problem that the current domestic and foreign enzyme systems can only be stored for several hours at normal temperature, and further illustrates the positive effect of the invention.

The second aspect of the present invention provides optimal enzyme concentration, dilutes the human serum enzyme of the present invention to 0.5, 0.75, 1, 1.25, 1.5 different units with pH8.0, 0.1M phosphate buffer, and the concentration of methamidophos pesticide is 5mg /kg, by experimental comparison, the preferred concentration is 0.5 units, and the more optimal concentration is 0.75 units.

The third aspect of the present invention provides optimum substrate concentration, and 100ml distilled water is added in 0.0448g potassium ferricyanide (red blood salt) and 0.0715g potassium ferrocyanide (yellow blood salt) mixed salt to make mixed solution ( PH5.5), first drop one drop (30μl) of the mixture on three pieces of filter paper, then add one drop (about 30μl) of indole acetate 180mg/10ml acetone, indole acetate 270mg/10ml acetone, Indole acetate 360mg/10ml acetone on 3 pieces of filter paper, react with enzyme after drying, the preferred substrate concentration is 270mg/10ml, the best substrate concentration is 180mg/10ml.

The fourth aspect of our invention provides the best action time between human serum enzymes and pesticides of the present invention. The enzyme tablet containing human serum enzyme solution is immersed in methamidophos solution, and after taking it out, it reacts with the substrate for 2, 5, 10, and 15 minutes respectively. Minutes, the preferred action time is 5 minutes, and the best action time is 8 minutes.

The fifth aspect of the present invention provides a method for preparing and using a quick test card. Extract the acetylcholinesterase in human serum according to the conventional method, freeze-dry to be enzyme powder, dilute the freeze-dried human serum enzyme powder of the present invention with PH8, 0.1M phosphate buffer, add auxiliary agent 0.5～1.0% gelatin in the enzyme solution Or 0.5-1.0% trehalose, drop the prepared enzyme solution onto the qualitative filter paper to make an enzyme tablet, place it at room temperature and dry it for use; add the prepared potassium ferricyanide and potassium ferrocyanide dropwise on the qualitative filter paper The mixed solution is then added dropwise with a prepared indole acetate 180mg-360/10ml acetone solution to make a substrate sheet and place it to dry at room temperature for later use. Add a drop (30μl) of pesticide or vegetable juice to the enzyme tablet, wet it for 30 seconds, and let it stand at room temperature for 8 minutes, or put the enzyme tablet in a pesticide solution or vegetable juice containing a certain concentration, and soak it for 30 seconds, and the enzyme tablet Take it out, let it rest at room temperature for 8 minutes, put the substrate on the enzyme sheet, pinch it tightly with your hands for 3 minutes, uncover the enzyme sheet, and observe the color development.

In order to further illustrate the positive effect of the present invention, the sensitivity results of the rapid detection paper card prepared by the present invention to detect 8 kinds of pesticides are shown in Table 3.

Table 3 Quick test card of the present invention detects sensitivity to 8 kinds of pesticides

Pesticide name Detection limit (mg/kg) ADI (mg/kg) Oral LD₅₀ in male rats (mg/kg) Methamidophos 5.0^* 4^* 20～30 trichlorfon 5.0 10 560 Dichlorvos 1.0 4 56～80 Omethoate 5.0 10 320～380 methyl parathion 1.0 20 9～25 carbofuran 0.2 10 8～14 Methomyl 0.5 30 17～24 Carbaryl 0.5 10 246～283

As can be seen from Table 3, the quick-test paper card of the present invention does not need to rely on instruments, and the detection limits of commonly used pesticides on vegetables are all in the scope of 0.2～5mg/kg, which are all in the range of World Health Organization (WHO), World Food and Agriculture Organization (FAO). ) is below the allowable intake (ADI) of pesticides per person per kilogram of body weight per day, so samples that are negative according to the quick test card will not cause acute harm to the human body. For the prevention of pesticide poisoning, it is prohibited The entry of poisonous vegetables into the market will play a supervisory role.

Based on the experimental results of the present invention, the sensitivity of human serum acetylcholinesterase is significantly higher than that of the enzyme preparations in the prior art. Sensitivity of 0.001 ~ 1.2mg/kg. Moreover, the human serum acetylcholinesterase of the present invention is an enzyme source with good thermal stability, and the enzyme activity can be maintained for 5-6 hours at about 90°C, and 0.5-1. % gelatin or 0.5-1.% trehalose is mixed, and the human serum enzyme activity of the present invention can be kept for 7-8 hours at about 90°C, which solves the problem that the current domestic and foreign enzyme systems can only be stored for several hours at room temperature , the rapid test paper card that prepares with human serum enzyme of the present invention does not need to rely on instrument, and the detection limit of commonly used pesticide on vegetables is all in the scope of 0.2～5mg/kg, all in the World Health Organization (WHO), the World Food and Agriculture Organization (FAO ) is below the allowable intake (ADI) of pesticides per person per kilogram of body weight per day. For the prevention of pesticide poisoning, prohibiting poisonous vegetables from entering the market will play a supervisory role. The invention has strong practicability, simple and fast operation, and only needs 12 minutes for one measurement. Low cost, is a product with broad market prospects

The present invention will be further described below in conjunction with specific examples. It should be understood that these examples are only used to illustrate the present invention rather than limit the scope of the present invention.

Embodiment 1, the screening of enzyme source

Using horse serum, human serum, bovine liver, bee head, housefly head and other animal organs or serum as materials, extract and screen the highly sensitive enzyme source-acetylcholinesterase according to conventional methods. Mash frozen horse serum, human serum, bovine liver, bee brain, and housefly brain respectively, add distilled water at a ratio of 1:9 (W/V), homogenate for 3 minutes, and centrifuge at 2000-3000r/min for 10 minutes , the supernatant was filtered through filter paper, freeze-dried, divided into equipment, and stored at -20°C. It was the enzyme source.

1) Reagent preparation:

Enzyme liquid preparation: Dilute freeze-dried horse serum enzyme powder, serum enzyme powder, bovine liver enzyme powder, bee brain enzyme powder, and housefly brain enzyme powder with PH8. .

Pesticide concentration: 0.8ppm for methamidophos and 0.002ppm for carbofuran.

Substrate: Thioacetylcholine iodide.

Chromogenic agent: dinitrobenzoic acid, the test concentration is 0.08mg.

2.) Instruments: CL-I Residual Pesticide Tester, Special Spectrophotometer 410nm.

With the help of a special spectrophotometer, the screening results of the above five acetylcholinesterases using the enzyme inhibition method are shown in Table 4.

Table 4 Comparison of sensitivity of five acetylcholinesterases to pesticides

As can be seen from Table 4, the cholinesterase extracted from various animal organs or serum is different in sensitivity to pesticides, and the enzyme extracted from human serum of the present invention is better than the enzyme extracted from horse serum of the prior art and the enzyme extracted from housefly brain. The inhibition rate of the enzyme is obviously high, which is a highly sensitive enzyme source.

Embodiment 2: the selection of enzyme concentration

1) Enzyme preparation: Dilute the freeze-dried human serum enzyme powder of the present invention with pH 8.0 and 0.1M phosphate buffer to 0.5, 0.75, 1.0, 1.25, and 1.5 units respectively. Add one drop (about 30 μl) onto a qualitative filter paper with a diameter of 1.0 cm to make an enzyme tablet.

2) Substrate: Mix 0.0448g potassium ferricyanide (red blood salt) and 0.0715g potassium ferrocyanide (yellow blood salt), add 100ml distilled water (PH5.5) after mixing, add one drop (about 30μl) in 30 μl of indole acetate 180 mg/10 ml acetone solution was added dropwise to a qualitative filter paper with a side of 1.0 cm ² to prepare a substrate sheet.

3) The concentration of methamidophos is 0.1 mg/μl.

4) Use distilled water for comparison

The results of the reaction of five kinds of enzyme concentration enzyme tablets with the pesticide methamidophos are shown in Table 3

Table 5 Comparison of the responses of five enzyme concentrations to methamidophos

^* +++ full control color (enzyme catalyzed normal hydrolysis of substrate, no pesticides) full blue

++ Partial color development (incomplete reaction between enzyme and substrate) Light blue

+ Poor color development (poor reaction between enzyme and substrate) Very light blue

—Full inhibition (enzymes are completely inhibited by pesticides) White

It can be seen from Table 5 that the 0.75 unit enzyme concentration is better than the control color, and it can be inhibited by 0.1 mg/μl methamidophos pesticide.

Embodiment 3: the selection of optimal substrate concentration

1) Preparation of substrate sheet: Mix 0.0448g potassium ferricyanide (red blood salt) and 0.0715g potassium ferrocyanide (yellow blood salt) into 100ml distilled water, take a drop of the mixture (about 30μl pH5.5) first Add dropwise on 3 pieces of ^qualitative filter paper with a side length of 1.0cm2, and then add one drop (about 30μl) of indole acetate 180mg/10ml acetone solution, indole acetate 270mg/10ml acetone solution, indole ethyl acetate Ester 360mg/10ml acetone solution on 3 pieces of qualitative filter paper, dry at room temperature for use as a substrate sheet.

2) Preparation of enzyme tablets: Dilute the frozen enzyme powder extracted from the serum with pH 8.0 and 0.1M phosphate buffer to 0.5 and 0.75 units respectively. Add it dropwise on a qualitative filter paper with a diameter of 1.0 cm to make an enzyme tablet.

The results of reacting 0.5 units and 0.75 units of enzyme tablets with substrate tablets (indole acetate 180mg/10ml acetone, indole acetate 270mg/10ml acetone, indole acetate 360mg/10ml acetone) are shown in Table 6 .

Table 6.3 Color comparison between substrate concentration and enzyme reaction

++++ full blue (enzyme and substrate react well), good color development (within 50 seconds);

+++ full blue (enzyme reacts well with substrate), slow color development (more than 50 seconds;)

++ Uneven color development (spotted), fast color development (within 50 seconds);

+ Uneven color development (spotty), Slow color development (more than 50 seconds).

As can be seen from Table 4, 0.75 unit enzyme concentration, indole acetate 180mg/10ml acetone substrate concentration, full blue (enzyme and substrate react well) good color development, fast color development, 0.5 unit enzyme concentration, indole Indole acetate 180mg/10ml acetone substrate concentration, full blue (enzyme and substrate react well) color development is slightly slower, so indole acetate 180/10ml acetone is the optimal concentration.

Embodiment 4: the selection of enzyme and pesticide optimal time of action

The enzyme sheet (0.75 unit) that the human serum enzyme preparation of the present invention is made is immersed in the 5mg/kg methamidophos aqueous solution, about 30 seconds, takes out and stands for 8 minutes, then stacks 2 respectively with the substrate sheet described in embodiment 3 , 5, 10, and 15 minutes, observe the color development of the enzyme tablet, and distinguish whether it is inhibited or not. The results are shown in Table 5.

Table 7 Comparison of enzymes and pesticides acting at different times

+ (pesticides do not inhibit enzymes) full blue; - (pesticides inhibit enzymes) inhibition color

It can be seen from Table 7. The optimal time for enzyme and pesticide action is 8 minutes.

Embodiment 5: Preparation and use of quick test card

1. Preparation of quick test card

a) Enzyme extraction: use human serum as material, add distilled water at a ratio of 1:9 (W/V), homogenate for 3 minutes, centrifuge at 2000-3000r/min for 10 minutes, filter the supernatant through filter paper, and freeze-dry , aliquoted for use, and stored at -20C. It is the enzyme source.

b) Preparation of enzyme tablets: Dilute the acetylcholinesterase freeze-dried enzyme powder extracted from human serum with pH 8.0 and 0.1M phosphate buffer solution to form 0.75 units of enzyme liquid, add 1% gelatin to the enzyme liquid and mix, and prepare The good enzyme solution was added dropwise on a qualitative filter paper with a diameter of 1.0 cm, and left to dry at room temperature for use.

c) Preparation of substrate sheet: Mix 0.0448g potassium ferricyanide (red blood salt) and 0.0715g potassium ferrocyanide (yellow blood salt), add 100ml distilled water, take potassium ferricyanide and potassium ferrocyanide One drop of the mixed solution (about 30μl PH5.5) was first dropped on a qualitative filter paper with a side length of ^1.0cm2 , then 180mg of indole acetate was mixed with 10ml of acetone solution, and then 30μl of indole acetate acetone solution was added dropwise on qualitative filter paper, and then let it dry at room temperature for later use.

d) Preparation of quick test card: Take a rectangular thick card backing paper with a width of 2 cm and a length of 5 cm, stick the round enzyme sheet prepared in a) on the top of the paper card with double-sided adhesive, and place the square substrate prepared in b) The sheet is glued to the bottom of the paper card with double-sided adhesive, and the enzyme sheet and the substrate of the quick test card are reversely folded, and they are not in contact with each other for use. Put the prepared quick test card into a small plastic bag, seal it, and put it in the refrigerator (frozen at -20°C) for later use.

2. Use of quick test card

a) Add 30 μl of pesticide or vegetable juice dropwise to the enzyme tablet and wet it for 30 seconds;

b) Put the enzyme tablet at room temperature for 8 minutes;

c) Superimpose the substrate sheet on the enzyme sheet and pinch it tightly for 3 minutes;

d) Uncover the enzyme sheet and observe the color development.

All blue, no pesticides, light blue or white with pesticides or pesticides exceeding the standard.

In order to further illustrate the positive effects of the present invention, the rapid test paper card prepared in Example 5 of the present invention was tested and investigated in vegetable fields in some parts of the country, and the results are shown in Table 8.

Table 8 The survey results of the quick test card in vegetable fields in some parts of the country

Types of Vegetables Tested Number of enzyme slices used sampling location Test results Organophosphorus pesticide concentration (mg/kg) Chinese cabbage 2^* Jiangsu Positive 0.4 Green vegetables 2^* Jiangqiao Positive 0.05 Hangzhou cabbage 2 zhejiang Positive 0.12 Chicken Feather 2 Shanghai Positive 0.38 water spinach 2 Cangqiao Positive 0.15 cucumber 2 Nanhui Positive 0.40 cabbage 2 Shandong Positive 0.18 Green vegetables 2 Shanghai Positive 0.6 Chinese cabbage 2 Jinshan Positive 0.79 cabbage 2 Shandong Positive 2.10 cabbage 2 Shanghai Positive 1.90

It can be seen from Table 8 that the detection sensitivity of vegetables by using the rapid test paper card of the present invention is 0.05-2.10 mg/kg, and the operation is simple and fast, and one measurement only takes 12 minutes. The cost is low (0.5 yuan), and it can clearly determine whether the residual pesticides on edible vegetables exceed the standard without the help of a pesticide residue detector. It is not only suitable for households to test edible vegetables, but also for market supervision and field vegetables. Rapid screening monitoring, health and epidemic prevention stations, agricultural system plant inspection stations and other units bring great convenience to the detection of vegetable pesticide residues. It can also be applied to the determination of organophosphorus pesticides and carbamate pesticides in water, soil and other agricultural products. The invention has strong practicability and is a product with broad market prospects.

Claims (9)

1. A quick test paper card for vegetable pesticide residues, the vegetable pesticide is selected from organophosphorus or carbamate pesticides, wherein the quick test paper card includes a backing paper, a substrate sheet and an enzyme sheet, characterized in that the The enzyme in the enzyme tablet is acetylcholinesterase extracted from human serum, Wherein, the enzyme tablet with a diameter of 1.0 cm contains 0.5-1.0 units of the acetylcholinesterase enzyme solution dried at room temperature. 2. The quick test paper card for pesticide residues in vegetables according to claim 1, characterized in that the enzyme tablet is obtained by diluting the acetylcholinesterase freeze-dried powder extracted from human serum with pH 8.0, 0.1M phosphate buffer to 0.5 - 1.0 unit of enzyme solution, and 30 microliters of the enzyme solution was added dropwise on a qualitative filter paper with a diameter of 1.0 cm and dried at room temperature. 3. The rapid test paper card for pesticide residues in vegetables according to claim 1, characterized in that 0.5-1.5% stabilizer is added to the solution of acetylcholinesterase extracted from human serum used to prepare the enzyme tablets. 4. The rapid test paper card for pesticide residues in vegetables according to claim 3, characterized in that 1% stabilizer is added to the solution of acetylcholinesterase extracted from human serum used to prepare the enzyme tablets. 5. The quick test paper card for pesticide residues in vegetables according to claim 3, characterized in that the stabilizer is selected from gelatin or trehalose. 6. The preparation method of the vegetable pesticide residue rapid detection paper card as claimed in claim 1, wherein the vegetable pesticide is selected from organophosphorus or carbamate pesticides, and the method comprises the following steps: 1) Enzyme extraction: Human serum was used as the material, and distilled water was added according to the ratio of human serum: distilled water 1:9 (W/V), homogenized for 3 minutes, centrifuged at 2000-3000r/min for 10 minutes, and the supernatant was washed by After filtering with filter paper, freeze-dry, separate for use, and freeze at -20°C, that is, the enzyme source; 2) Preparation of enzyme tablets: Dilute the acetylcholinesterase freeze-dried enzyme powder extracted from human serum with pH 8.0, 0.1M phosphate buffer solution to form 0.5-1.0 units of enzyme solution, and add the prepared enzyme solution dropwise to a surface with a diameter of 1.0cm On a round qualitative filter paper, place it at room temperature and dry it for later use; 3) Preparation of substrate sheet: Mix 0.0448g potassium ferricyanide and 0.0715g potassium ferrocyanide, add 100ml distilled water, take a drop of potassium ferricyanide and potassium ferrocyanide mixture with pH 5.5, 30 μl, First drop it on the qualitative filter paper with a side length of ^1.0cm2 , then mix 180-270mg of indole acetate with 10ml of acetone solution, then add a drop of 30μl of indole acetate acetone solution on the qualitative filter paper, and then Let it dry at room temperature for later use; 4) Preparation of quick test card: Take a rectangular thick card backing paper with a width of 2 cm and a length of 5 cm, stick the round enzyme sheet prepared in 2) on the top of the paper card with double-sided adhesive, and place the square substrate prepared in 3) Use double-sided adhesive on the bottom of the paper card, fold the enzyme sheet of the quick test card and the substrate in reverse, without touching each other, put the prepared quick test card into a small plastic bag and seal it, put it in the refrigerator, - Freeze at 20°C until use. 7. The method for preparing the vegetable pesticide residue rapid test paper card according to claim 6, characterized in that the enzyme liquid is 0.5-0.75 units of enzyme liquid. 8. The method for preparing the vegetable pesticide residue rapid detection paper card according to claim 7, characterized in that the enzyme liquid is 0.75 units of enzyme liquid. 9. The preparation method of the vegetable pesticide residue rapid detection paper card according to claim 6, characterized in that when the enzyme liquid is 0.5 units of enzyme liquid, the optimum concentration of indole acetate acetone solution on the substrate sheet is 180 mg Indole acetate/10ml acetone.