阅读说明：本技术 一种烯酰吗啉胶体金试剂盒及其应用 (Dimethomorph colloidal gold kit and application thereof ) 是由 逄涛 李勇 师君丽 邓小鹏 李永平 罗贵昆 孔光辉 于 2019-09-30 设计创作，主要内容包括：本发明公开了一种烯酰吗啉胶体金检测试剂盒及其应用。所述的烯酰吗啉胶体金检测试剂盒包括试剂盒盒体、检测试纸条、样品提取液、样品复溶液；其中,所述检测试纸条包括样品吸收垫、结合物释放垫、反应膜、吸水垫、PVC底板；所述结合物释放垫上包被有烯酰吗啉特异性抗体-胶体金标记物；所述反应膜上包被有烯酰吗啉半抗原-OVA偶联物构成的检测线和包被抗抗体构成的质控线。本发明烯酰吗啉胶体金检测试剂盒,能够实现对烟草中烯酰吗啉的半定量检测,具有检测快速,准确,便捷的优点,且能够同时检测大批量样本,能满足市场对烟草中烯酰吗啉残留的快速检测需求。(The invention discloses a dimethomorph colloidal gold detection kit and application thereof. The dimethomorph colloidal gold detection kit comprises a kit body, a detection test strip, a sample extracting solution and a sample complex solution; the detection test strip comprises a sample absorption pad, a conjugate release pad, a reaction membrane, a water absorption pad and a PVC bottom plate; the conjugate release pad is coated with a dimethomorph specific antibody-colloidal gold marker; the reaction membrane is coated with a detection line formed by dimethomorph hapten-OVA conjugate and a quality control line formed by coating anti-antibody. The dimethomorph colloidal gold detection kit can realize semi-quantitative detection of dimethomorph in tobacco, has the advantages of rapidness, accuracy and convenience in detection, can detect a large batch of samples simultaneously, and can meet the market demand for rapid detection of dimethomorph residues in tobacco.)

1. A dimethomorph colloidal gold detection kit is characterized by comprising a kit body, a detection test strip, a sample extracting solution and a sample complex solution, wherein the detection test strip comprises a sample absorption pad, a conjugate release pad, a reaction membrane, a water absorption pad and a PVC bottom plate; the conjugate release pad is coated with a dimethomorph specific antibody-colloidal gold marker; the reaction membrane is coated with a detection line formed by dimethomorph hapten-OVA conjugate and a quality control line formed by coating anti-antibody.

2. The dimethomorph colloidal gold assay kit according to claim 1, wherein the dimethomorph hapten-OVA conjugate is obtained by conjugating dimethomorph hapten with OVA, and the structural formula of the dimethomorph hapten is as follows:

the preparation process comprises the following steps:

(a) adding 8.0 g of p-nitrobenzoyl chloride 8.0 ~ 10.0.0 g and 90 ~ 110ml of chlorobenzene into a 250M three-necked bottle, controlling the temperature of an ice salt bath to be 0 ~ 5 ℃, adding 10 ~ 15g of anhydrous aluminum trichloride, reacting at room temperature for 10 ~ 15 hours, pouring the reaction liquid into 250ml of 2M aqueous solution of hydrochloric acid added with ice after the reaction is finished, separating liquid, performing organic phase desolventizing column chromatography, and obtaining white solid 4-chloro-4' -nitrobenzophenone by using ethyl acetate-petroleum ether with the volume ratio of 1:3 as a mobile phase;

(b) adding 6.2g triethyl phosphonoacetate and 150ml tetrahydrofuran into a 250ml three-necked flask, controlling the temperature of an ice salt bath to be 0 ~ 5 ℃, adding 2.7g sodium tert-butoxide, reacting at room temperature for 0.4 ~ 0.6.6 h, adding 6.0g 4-chloro-4' -nitrobenzophenone which is a product obtained in the step (a), reacting at room temperature for 10 ~ 15h, washing a reaction solution by 50ml multiplied by 3 of 4M ammonium chloride aqueous solution, performing organic phase desolventizing column chromatography, and obtaining a white solid by using ethyl acetate-petroleum ether with the volume ratio of 1:3 as a mobile phase;

(c) adding 4.7g of the product in the step (b) and 150ml of absolute ethyl alcohol into a 250ml three-neck flask, adding 6.0g of sodium hydroxide at room temperature, stirring at room temperature for reaction for 3 ~ 5h, removing the solvent, adding 100ml of deionized water, adjusting the pH value to 4 by using 6M hydrochloric acid, extracting by using 100ml of ethyl acetate multiplied by 2, drying an organic phase by using anhydrous sodium sulfate, and removing the solvent to obtain a white solid product;

(d) adding 3.0g of the product obtained in the step (c), 1.5g of HOBt and 100ml of ethyl acetate into a 250ml single-neck bottle, stirring at room temperature for reaction for 0.5 ~ 1.5.5 h, adding 1.0g of morpholine and 1.0g of EDCI, stirring at room temperature for reaction for 12h, washing with 50ml of water multiplied by 3, and using the product obtained after organic phase desolvation for the next reaction;

(e) and (d) adding the product obtained in the step (d) into a 250ml single-mouth bottle, adding 10.0g of stannous chloride dihydrate and 100ml of ethyl acetate, heating and refluxing for reaction for 6 hours, cooling the reaction liquid, washing with 50ml multiplied by 3 of saturated potassium carbonate aqueous solution, purifying by using an organic phase desolvation column chromatography, and obtaining a light yellow solid which is the dimethomorph amino analogue, namely the dimethomorph hapten, further drying, and storing at 4 ℃.

3. The dimethomorph colloidal gold assay kit according to claim 1, wherein the dimethomorph-specific antibody is a monoclonal antibody obtained by immunizing Balb/c mice with a dimethomorph hapten-BSA conjugate.

4. The dimethomorph colloidal gold assay kit according to claim 3, wherein the dimethomorph hapten-BSA conjugate is prepared by the following steps:

(a) preparing 4 mM dimethomorph hapten by using 0.1M hydrochloric acid solution, stirring at 4 ℃, and dropwise adding 1% NaNO₂To excess, NaNO₂Monitoring with starch-potassium iodide paper strips until the solution turns blue-black, and continuing to react for 15 min, wherein the percentage is mass percentage;

(b) BSA was dissolved in 0.1M carbonate buffer at pH 8.2 at a protein concentration of 18.9 mg/mL;

(c) adding the dimethomorph hapten obtained in the step (a) into the BSA obtained in the step (b), adjusting the pH to 9.5, continuing stirring at 4 ℃ for 2h, adjusting the pH to 9.0, dialyzing with 0.1mol/LPB for two days, and removing unreacted small molecular substances to obtain the dimethomorph hapten-BSA conjugate.

5. The dimethomorph colloidal gold assay kit according to claim 1, wherein the sample extract is a 20% aqueous solution of N, N-dimethylformamide, and the percentage is volume percentage.

6. The dimethomorph colloidal gold assay kit according to claim 1, wherein the complex sample solution is pH6.0, 0.05mol/LMES buffer.

7. The dimethomorph colloidal gold assay kit according to claim 1, wherein the particle size of the colloidal gold is 30 nm.

8. The dimethomorph colloidal gold assay kit according to claim 1, wherein the anti-antibody coated on the quality control line is a goat anti-mouse anti-antibody.

9. The dimethomorph colloidal gold assay kit according to claim 1, wherein the test strip is further provided with a plastic outer case, the plastic outer case is provided with a sample application hole above the corresponding sample absorbing pad, and the plastic outer case is provided with an observation window above the corresponding detection line and quality control line.

10. The use of the dimethomorph colloidal gold assay kit according to claim 1 ~ 9, wherein the dimethomorph colloidal gold assay kit is used for assaying the residual amount of dimethomorph in tobacco.

Technical Field

The invention belongs to the technical field of biological engineering, and particularly relates to a dimethomorph colloidal gold kit and application thereof.

Background

Dimethomorph (dimethomorph) is a morpholine bactericide developed by basf in germany and widely applied all over the world, and is registered and popularized by cyanamide company in the united states in China, and has the trade names of 'ank' and 'ank manganese zinc'. Dimethomorph is a broad-spectrum bactericide, and causes cell death mainly by causing decomposition of the cyst wall. The dimethomorph has good control effect on low fungal diseases such as downy mildew, peronophythora, late blight, phytophthora blight, rot, phytophthora parasitica, black shank and the like. The dimethomorph has strong systemic property, and the dimethomorph can be applied to roots, enter each part of a plant through the roots, be sprayed on leaf surfaces, and also can enter the interior of the leaves to timely prevent and control germs invading into the crop body.

At present, the crops registered and used in the pesticide preparation taking dimethomorph as a main component in China are mainly vegetables and fruits, are used for preventing and treating downy mildew and epidemic diseases, and are mainly used for preventing and treating black shank in tobacco. Dimethomorph belongs to a low-toxicity pesticide, but has the defects of slow degradation, easy formation of residues in crops and serious threat to human health. Consequently, the level of residual dimethomorph pesticide is also receiving much attention. At present, food safety regulations in some countries and regions stipulate the maximum residual limit of dimethomorph in some crops.

For the detection of dimethomorph, the prior art has physicochemical methods and biological methods. The physical and chemical detection method mainly comprises gas chromatography, liquid chromatography-mass spectrometry, gas chromatography-mass spectrometry and the like, and has the defects of high detection cost, extremely strict requirements on the specialty of equipment and detection personnel, easily influenced detection results by impurities in samples, need of a complex sample pretreatment process, long required detection time, incapability of realizing rapid detection and the like. The enzyme linked immunosorbent assay technology in the biological method is also disclosed, and the patent document with the publication number of CN108205060A discloses an enzyme linked immunosorbent assay kit for detecting dimethomorph and application thereof. At present, no relevant report is found in the biological detection method for the dimethomorph residue in the tobacco.

Disclosure of Invention

The invention provides a dimethomorph colloidal gold kit; the second purpose is to provide the application of the dimethomorph colloidal gold kit.

The first purpose of the invention is realized in such a way that the dimethomorph colloidal gold detection kit comprises a kit body, a detection test strip, a sample extracting solution and a sample complex solution.

The detection test strip comprises a sample absorption pad, a conjugate release pad, a reaction membrane, a water absorption pad and a PVC bottom plate;

wherein the conjugate release pad is coated with a dimethomorph-specific antibody-colloidal gold label;

wherein, the reaction membrane is coated with a detection line consisting of the dimethomorph hapten-OVA conjugate and a quality control line consisting of the coating anti-antibody.

Preferably, the dimethomorph hapten-OVA conjugate is obtained by coupling dimethomorph hapten and OVA, wherein the structural formula of the dimethomorph hapten is shown as the following,

the preparation process comprises the following steps:

(a) adding 9.0 g of paranitrobenzoyl chloride and 100mL of chlorobenzene into a 250mL three-necked bottle, controlling the temperature of an ice salt bath to be 0-5 ℃, adding 13 g of anhydrous aluminum trichloride, reacting at room temperature for 12h, pouring the reaction liquid into 250mL of 2M aqueous solution of hydrochloric acid added with ice after the reaction is finished, separating liquid, performing organic phase desolventizing column chromatography, wherein the mobile phase is ethyl acetate: petroleum ether =1:3 to obtain white solid 4-chloro-4' -nitrobenzophenone;

(b) adding 6.2g triethyl phosphonoacetate and 150mL tetrahydrofuran into a 250mL three-necked flask, controlling the temperature of an ice salt bath to be 0-5 ℃, adding 2.7g sodium tert-butoxide, reacting at room temperature for 0.5 h, adding 6.0g 4-chloro-4' -nitrobenzophenone which is a product in the step (a), reacting at room temperature for 12h, washing a reaction solution by 50mL multiplied by 3 of 4M ammonium chloride aqueous solution, performing organic phase desolvation column chromatography, and obtaining ethyl acetate as a mobile phase: petroleum ether =1:3 to give a white solid;

(c) adding 4.7g of the product in the step (b) and 150mL of absolute ethyl alcohol into a 250mL three-necked flask, adding 6.0g of sodium hydroxide at room temperature, stirring at room temperature for reaction for 4 hours, carrying out desolventizing, adding 100mL of deionized water, adjusting the pH to 4 by using 6M hydrochloric acid, extracting by using 100mL of ethyl acetate multiplied by 2, drying an organic phase by using anhydrous sodium sulfate, and carrying out desolventizing to obtain a white solid product;

(d) adding 3.0g of the product obtained in the step (c), 1.5g of HOBt and 100mL of ethyl acetate into a 250mL single-neck flask, stirring at room temperature for reaction for 1 h, adding 1.0g of morpholine and 2.0g of EDCI, stirring at room temperature for reaction for 12h, washing with 50mL of multiplied by 3 water, and using the product obtained after organic phase desolvation for the next reaction;

(e) adding the product obtained in the step (d) into a 250mL single-mouth bottle, adding 10.0g of stannous chloride dihydrate and 100mL of ethyl acetate, heating and refluxing for reaction for 6h, cooling the reaction liquid, washing with 50mL of saturated potassium carbonate aqueous solution multiplied by 3, and purifying by organic phase desolventizing column chromatography, wherein the mobile phase is ethyl acetate: petroleum ether =7:3 to obtain a light yellow solid which is the dimethomorph amino analogue, namely the dimethomorph hapten, and the light yellow solid is further dried and stored at 4 ℃.

Preferably, the dimethomorph-specific antibody is a monoclonal antibody obtained by immunizing Balb/c mice with a dimethomorph hapten-BSA conjugate.

Preferably, the preparation process of the dimethomorph-BSA conjugate is as follows:

(a) preparing 4 mM dimethomorph hapten by using 0.1M hydrochloric acid solution, stirring at 4 ℃, and dropwise adding 1% NaNO₂To excess, NaNO₂Monitoring with starch-potassium iodide paper until the solution turns blue-black, and continuing to react for 15 min;

(b) BSA was dissolved in 0.1M carbonate buffer at pH 8.2 at a protein concentration of 18.9 mg/mL;

(c) adding the dimethomorph hapten obtained in the step (a) into the BSA obtained in the step (b), adjusting the pH to 9.5, continuing stirring at 4 ℃ for 2h, adjusting the pH to 9.0, dialyzing with 0.1mol/LPB for two days, and removing unreacted small molecular substances to obtain the dimethomorph hapten-BSA conjugate.

Preferably, the sample extracting solution is 20% of N, N-dimethylformamide aqueous solution, and the percentage is volume percentage.

Preferably, the complex sample solution is 0.05mol/LMES buffer solution with pH 6.0.

Preferably, the colloidal gold has a particle size of 30 nm, and the 30 nm colloidal gold has more ideal binding performance for the specific antibody of dimethomorph and more effective absorption of dimethomorph in the sample.

Preferably, the anti-antibody coated on the quality control line is a goat anti-mouse anti-antibody.

As preferred, the test strip can also be established outer plastic box, and the top that corresponds sample absorption pad on the outer plastic box is provided with the application of sample hole, and the outer plastic box is last to correspond detection line and matter control line top and be provided with observation window for the protection test strip, reduces external disturbance, and the test strip of being convenient for simultaneously is got and is put.

The second purpose of the invention is realized by the application of the dimethomorph colloidal gold detection kit in detecting the residual amount of the dimethomorph in the tobacco.

The immunochromatography colloidal gold technology is an ideal rapid detection method at present as an immunological method, and has the characteristics of simple, rapid and accurate detection, small pollution, capability of simultaneously detecting a large batch of samples and the like.

The dimethomorph colloidal gold detection kit disclosed by the invention adopts the principle of competitive inhibition immunochromatography, wherein dimethomorph in a sample is combined with a specific antibody of the dimethomorph marked by colloidal gold in the flowing process, and the combination of the antibody and a dimethomorph hapten-OVA conjugate on a reaction film detection line is inhibited, so that the change of the shade of the color of the detection line is caused, and the residue condition of the dimethomorph in the sample is quickly judged. The dimethomorph colloidal gold detection kit has the advantages of quick, accurate and convenient detection and low cost, is very suitable for quickly detecting dimethomorph residues in a large batch of tobacco samples, and is an ideal quick detection product.

Drawings

FIG. 1 is a schematic structural diagram of a detection strip in the dimethomorph colloidal gold detection kit of the present invention.

Detailed Description

The present invention is further illustrated by the following examples and the accompanying drawings, but the present invention is not limited thereto in any way, and any modifications or alterations based on the teaching of the present invention are within the scope of the present invention.

The dimethomorph colloidal gold detection kit comprises a kit body, a detection test strip, a sample extracting solution and a sample complex solution, wherein the detection test strip comprises a sample absorption pad, a conjugate release pad, a reaction membrane, a water absorption pad and a PVC bottom plate; the conjugate release pad is coated with a dimethomorph specific antibody-colloidal gold marker; the reaction membrane is coated with a detection line formed by dimethomorph hapten-OVA conjugate and a quality control line formed by coating anti-antibody.

The detection test strip is shown in figure 1 and comprises a sample absorption pad 1, a conjugate release pad 2, a reaction membrane 3, a water absorption pad 4 and a PVC bottom plate 7; the sample absorption pad 1 is non-woven fabric or a blood filtering membrane, the water absorption pad 4 is absorbent paper, the conjugate release pad 2 is glass fiber, the conjugate release pad 2 is positioned at 1/4 below the front end of the sample absorption pad, the reaction membrane 3 is a cellulose acetate membrane, and the reaction membrane is provided with a detection line T line 5 and a quality control line C line 6, wherein the detection line 5 of the reaction membrane is coated with a dimethomorph hapten-OVA conjugate, and the quality control line 6 of the reaction membrane is coated with a goat anti-mouse anti-antibody; wherein, the conjugate release pad 2 is coated with a dimethomorph monoclonal antibody-colloidal gold label. Furthermore, the test strip can also be provided with a plastic outer box, a sample adding hole is arranged above the plastic outer box corresponding to the sample absorption pad 1, and an observation window is arranged above the plastic outer box corresponding to the detection line 5 and the quality control line 6.

Wherein, the coating substance dimethomorph hapten-OVA conjugate at the detection line 5 is diluted to 0.5 mg/mL by 0.1mol/L phosphate solution, the coating substance goat anti-mouse antibody at the quality control line 6 is diluted to 0.5 mg/mL by 0.1mol/L phosphate solution, and the coating amounts of the dimethomorph hapten-OVA conjugate and the goat anti-mouse anti-antibody are both 1.0 mu g/cm²And drying for 1.5h at 37 ℃ after coating.

The sample pad 1 was soaked in a phosphate solution of pH7.2 containing 1.0% bovine serum albumin for 1 hour before assembly and dried at 37 ℃ for 2 hours. The percentage is volume percentage.

Conjugate release pad treatment prior to assembly: soaking the conjugate release pad before coating in the following solution for 20-40 s, drying, and coating the dimethomorph monoclonal antibody-colloidal gold marker: contains 1.2% bovine serum albumin, pH 7.5, 0.1mol/L phosphate buffer. The percentage is volume percentage.

The preparation method of the main component comprises the following steps:

firstly, preparing dimethomorph hapten, dimethomorph hapten-BSA and dimethomorph hapten-OVA conjugate

1. The preparation method of the dimethomorph hapten comprises the following steps:

(a) adding 9.0 g of paranitrobenzoyl chloride and 100mL of chlorobenzene into a 250mL three-necked bottle, controlling the temperature of an ice salt bath to be 0-5 ℃, adding 13 g of anhydrous aluminum trichloride, reacting at room temperature for 12h, pouring the reaction liquid into 250mL of 2M aqueous solution of hydrochloric acid added with ice after the reaction is finished, separating liquid, performing organic phase desolventizing column chromatography, wherein the mobile phase is ethyl acetate: petroleum ether =1:3, and white solid 4-chloro-4' -nitrobenzophenone is obtained, wherein the synthesis line is as follows:

(b) adding 6.2g triethyl phosphonoacetate and 150mL tetrahydrofuran into a 250mL three-necked flask, controlling the temperature of an ice salt bath to be 0-5 ℃, adding 2.7g sodium tert-butoxide, reacting at room temperature for 0.5 h, adding 6.0g 4-chloro-4' -nitrobenzophenone which is a product in the step (a), reacting at room temperature for 12h, washing a reaction solution by 50mL multiplied by 3 of 4M ammonium chloride aqueous solution, performing organic phase desolvation column chromatography, and obtaining ethyl acetate as a mobile phase: petroleum ether =1:3 to obtain white solid, and the synthesis line is as follows:

(c) adding 4.7g of the product in the step (b) and 150mL of absolute ethyl alcohol into a 250mL three-neck flask, adding 6.0g of sodium hydroxide at room temperature, stirring at room temperature for reaction for 4 hours, then carrying out desolventizing, adding 100mL of water, adjusting the pH to 4 by using 6M hydrochloric acid, extracting by using 100mL multiplied by 2 of ethyl acetate, drying an organic phase by using anhydrous sodium sulfate, and carrying out desolventizing to obtain a white solid product, wherein the synthetic line is as follows:

(d) in a 250mL single-neck flask were added 3.0g of the product of step (c), 1.5g of HOBt, 100mL of ethyl acetate, stirred at room temperature for 1 h, added morpholine 1.0g, EDCI2.0g, stirred at room temperature for 12h, washed with 50mL of X3 water, and the product was used in the next step after organic phase desolvation, as follows:

(e) adding the product obtained in the step (d) into a 250mL single-mouth bottle, adding 10.0g of stannous chloride dihydrate and 100mL of ethyl acetate, heating and refluxing for reaction for 6h, cooling the reaction liquid, washing with 50mL of saturated potassium carbonate aqueous solution multiplied by 3, and purifying by organic phase desolventizing column chromatography, wherein the mobile phase is ethyl acetate: petroleum ether =7:3 to obtain a light yellow solid which is the dimethomorph amino analogue, namely the dimethomorph hapten, the dimethomorph hapten is further dried and stored at 4 ℃, and the synthetic route is as follows:

2. preparation of Dimethomorph hapten-BSA conjugate (Immunity antigen)

(a) Preparing 4 mM dimethomorph hapten by using 0.1M hydrochloric acid solution, stirring at 4 ℃, and dropwise adding 1% NaNO₂To excess, NaNO₂Monitoring with starch-potassium iodide paper strips until the solution turns blue-black, and continuing to react for 15 min, wherein the percentage is mass percentage.

(b) BSA was dissolved in 0.1M carbonate buffer at pH 8.2 at a protein concentration of 18.9 mg/mL;

(c) adding the dimethomorph hapten obtained in the step (a) into the BSA obtained in the step (b), adjusting the pH to 9.5, continuing stirring at 4 ℃ for 2h, adjusting the pH to 9.0, dialyzing with 0.1mol/L PB for two days, and removing unreacted small molecular substances to obtain the dimethomorph hapten-BSA conjugate.

3. Preparation of Dimethomorph hapten-OVA conjugate (coating antigen)

Preparation of dimethomorph hapten-OVA conjugate (envelope antigen): the coating antigen was synthesized in the same manner as the dimethomorph hapten-BSA conjugate except that the carrier protein was OVA.

Secondly, preparing dimethomorph monoclonal antibody

1. Animal immunization

6-8 week old Balb/c mice were selected and injected subcutaneously with dimethomorph hapten-BSA conjugate containing Freund's complete adjuvant at an immunization dose of 80. mu.g/mouse, boosted at weeks 2, 4 and 6, and finally immunized at week 8 to generate antiserum.

2. Cell fusion and monoclonalization

Mice splenocytes and myeloma cells were fused at 5:1 under PEG6000 and screened for positive wells using an indirect competitive ELISA assay. And (3) adopting a limiting dilution method to perform monoclonality on the positive hole until obtaining a hybridoma cell strain secreting the monoclonal antibody. The detection limit of the monoclonal antibody on dimethomorph in tobacco can reach 2 mu g/g.

3. Cell cryopreservation and recovery

Freezing and storing the monoclonal hybridoma cell strain of dimethomorph into 2 multiplied by 10⁶Cell suspension per mL, stored in liquid nitrogen. Taking out the frozen tube during recovery, immediately putting the tube into a water bath at 37 ℃ for fast melting, centrifuging to remove frozen liquid, and transferring the tube into a culture bottle for culture.

4. Culture in increments

Placing hybridoma cell in RPMI-1640 conventional cell culture medium, culturing at 37 deg.C, purifying the obtained culture solution with octanoic acid-saturated ammonium sulfate method to obtain monoclonal antibody, and storing at-20 deg.C.

Thirdly, preparing the goat anti-mouse anti-antibody: sheep are used as immune animals, and a murine antibody is used as an immunogen to immunize a disease-free thallus sheep, so that the goat anti-mouse anti-antibody is obtained.

Preparation of colloidal gold and preparation of dimethomorph monoclonal antibody-colloidal gold marker

1. The colloidal gold marker is colloidal gold with the particle size of 30 nm, and the preparation method comprises the following steps: diluting 1% chloroauric acid to 0.01% with double-distilled deionized water, placing 100mL into a conical flask, heating to boil with a constant temperature electromagnetic stirrer, adding 0.75 mL 1% trisodium citrate under continuous stirring at high temperature, stirring and heating at constant speed until the solution is bright red, cooling to room temperature, and recovering to original volume with deionized water. The percentage is mass percentage.

2. Preparation of dimethomorph monoclonal antibody-colloidal gold marker

Under magnetic stirring, adjusting the pH value of the colloidal gold to 7.0 by using 0.1mol/L potassium carbonate solution, adding the dimethomorph monoclonal antibody into the colloidal gold solution according to the standard that 100-300 mu g of the antibody is added into each milliliter of the colloidal gold solution, continuously stirring and uniformly mixing, standing for 10 min, adding BSA (bovine serum albumin) and trehalose, and stirring and uniformly mixing to ensure that the final concentrations of the BSA and the trehalose in the colloidal gold solution are 0.5g/100mL and 1g/100mL respectively. Standing for 30 min, centrifuging at 12000 rpm at 4 ℃ for 30 min, removing supernatant, washing the precipitate twice with 0.1mol/L phosphate solution containing 0.5-1% of bovine serum albumin, 0.05-0.1% of Tween-20 and pH 7.4, and re-suspending the precipitate with 1/10 volume of phosphate solution of the initial volume of colloidal gold to obtain the colloidal gold monoclonal antibody-colloidal gold marker. The percentage is volume percentage.

The dimethomorph hapten-OVA conjugate is obtained by coupling dimethomorph hapten and OVA, and the structural formula of the dimethomorph hapten is as follows:

the preparation process comprises the following steps:

(a) adding 8.0 g of p-nitrobenzoyl chloride 8.0 ~ 10.0.0 g and 90 ~ 110ml of chlorobenzene into a 250M three-necked bottle, controlling the temperature of an ice salt bath to be 0 ~ 5 ℃, adding 10 ~ 15g of anhydrous aluminum trichloride, reacting at room temperature for 10 ~ 15 hours, pouring the reaction liquid into 250ml of 2M aqueous solution of hydrochloric acid added with ice after the reaction is finished, separating liquid, performing organic phase desolventizing column chromatography, and obtaining white solid 4-chloro-4' -nitrobenzophenone by using ethyl acetate-petroleum ether with the volume ratio of 1:3 as a mobile phase;

(b) adding 6.2g triethyl phosphonoacetate and 150ml tetrahydrofuran into a 250ml three-necked flask, controlling the temperature of an ice salt bath to be 0 ~ 5 ℃, adding 2.7g sodium tert-butoxide, reacting at room temperature for 0.4 ~ 0.6.6 h, adding 6.0g 4-chloro-4' -nitrobenzophenone which is a product obtained in the step (a), reacting at room temperature for 10 ~ 15h, washing a reaction solution by 50ml multiplied by 3 of 4M ammonium chloride aqueous solution, performing organic phase desolventizing column chromatography, and obtaining a white solid by using ethyl acetate-petroleum ether with the volume ratio of 1:3 as a mobile phase;

(c) adding 4.7g of the product in the step (b) and 150ml of absolute ethyl alcohol into a 250ml three-neck flask, adding 6.0g of sodium hydroxide at room temperature, stirring at room temperature for reaction for 3 ~ 5h, removing the solvent, adding 100ml of deionized water, adjusting the pH value to 4 by using 6M hydrochloric acid, extracting by using 100ml of ethyl acetate multiplied by 2, drying an organic phase by using anhydrous sodium sulfate, and removing the solvent to obtain a white solid product;

(d) adding 3.0g of the product obtained in the step (c), 1.5g of HOBt and 100ml of ethyl acetate into a 250ml single-neck bottle, stirring at room temperature for reaction for 0.5 ~ 1.5.5 h, adding 1.0g of morpholine and 1.0g of EDCI, stirring at room temperature for reaction for 12h, washing with 50ml of water multiplied by 3, and using the product obtained after organic phase desolvation for the next reaction;

(e) and (d) adding the product obtained in the step (d) into a 250ml single-mouth bottle, adding 10.0g of stannous chloride dihydrate and 100ml of ethyl acetate, heating and refluxing for reaction for 6 hours, cooling the reaction liquid, washing with 50ml multiplied by 3 of saturated potassium carbonate aqueous solution, purifying by using an organic phase desolvation column chromatography, and obtaining a light yellow solid which is the dimethomorph amino analogue, namely the dimethomorph hapten, further drying, and storing at 4 ℃.

The dimethomorph specific antibody is a monoclonal antibody and is obtained by immunizing a Balb/c mouse with dimethomorph hapten-BSA conjugate.

The preparation process of the dimethomorph hapten-BSA conjugate is as follows:

(a) preparing 4 mM dimethomorph hapten by using 0.1M hydrochloric acid solution, stirring at 4 ℃, and dropwise adding 1% NaNO₂To excess, NaNO₂Monitoring with starch-potassium iodide paper strips until the solution turns blue-black, and continuing to react for 15 min, wherein the percentage is mass percentage;

(b) BSA was dissolved in 0.1M carbonate buffer at pH 8.2 at a protein concentration of 18.9 mg/mL;

(c) adding the dimethomorph hapten obtained in the step (a) into the BSA obtained in the step (b), adjusting the pH to 9.5, continuing stirring at 4 ℃ for 2h, adjusting the pH to 9.0, dialyzing with 0.1mol/LPB for two days, and removing unreacted small molecular substances to obtain the dimethomorph hapten-BSA conjugate.

The sample extracting solution is 20% of N, N-dimethylformamide aqueous solution, and the percentage is volume percentage.

The complex solution of the sample is pH6.0, 0.05mol/LMES buffer solution.

The grain diameter of the colloidal gold is 30 nm.

The anti-antibody coated on the quality control line is a goat anti-mouse anti-antibody.

The detection test strip still be provided with the outer box of plastics, the top that corresponds sample absorption pad on the outer box of plastics is provided with the application of sample hole, correspond detection line and quality control line top on the outer box of plastics and be provided with observation window.

The application of the dimethomorph colloidal gold detection kit disclosed by the invention is the application of the dimethomorph colloidal gold detection kit in detecting the residual amount of dimethomorph in tobacco.

The specific antibody of dimethomorph adopts a monoclonal antibody, and is suitable for a polyclonal antibody in the same way.

The dimethomorph colloidal gold detection kit is stored for one month under the condition of an aging test at 37 ℃, and all indexes still meet the detection requirements. Therefore, the product can be stored at 4-8 deg.C for at least 12 months.