CN114279902B - Organophosphorus pesticide detector based on intelligent response surface and organophosphorus pesticide detection method thereof - Google Patents

Abstract

The invention discloses an organophosphorus pesticide detector based on an intelligent response surface and a method for detecting organophosphorus pesticides, and belongs to the technical field of organophosphorus pesticide detection. The organophosphorus pesticide detector based on the intelligent response surface of the present invention immerses the glass substrate in a mixed aqueous solution of CoCl ₂ ·6H ₂ O and (NH ₂ ) ₂ CO to construct a super hydrophilic surface, and then performs acetylcholinesterase or butyrylcholine It is modified with esterase and finally immersed in perfluorooctyltriethoxysilane solution. The present invention can realize the detection of different organophosphorus pesticides by observing the changes in the contact angle of different organophosphorus pesticides on the surface of the detector. It does not require large instruments and is not interfered by ambient light and color. Moreover, the organophosphorus pesticide detector based on the intelligent response surface can be used for on-site detection of organophosphorus pesticides. It is easy to carry and can be applied to the detection of organophosphorus pesticide residues on vegetables, fruits and grains.

Description

Organophosphorus pesticide detector based on intelligent response surface and its detection of organophosphorus pesticides Methods

Technical field

The invention belongs to the technical field of organophosphorus pesticide detection, and specifically relates to an organophosphorus pesticide detector based on an intelligent response surface and a method for detecting organophosphorus pesticides.

Background technique

In recent years, with the continuous expansion of the scale of my country's pesticide industry and the continuous upgrading of technology, pesticide development has begun to develop in the direction of high efficiency, low toxicity, low residue, high biological activity and high selectivity. The scale of agricultural production in our country is also constantly expanding, but some problems related to pests and diseases have also arisen. In order to ensure food security, pesticides must be used to prevent and control pests at all stages from planting, production to storage. Organophosphorus pesticides are a type of highly efficient pesticides. Pesticides that are broad-spectrum and easily degraded are being widely used in food production and storage, and are the most commonly used choice for chemical control. This has also led to the increasing use of pesticides, which has led to the use of pesticides permeating agricultural production, causing pesticide residues in food to continue to affect consumers' food safety.

At present, the main methods for detecting organophosphorus pesticides are gas chromatography/mass spectrometry (GC/MS) and high-performance liquid chromatography (HPLC). Although they can detect pesticide residues more accurately, these methods are cumbersome to operate and require frequent samples. Pretreatment is required, and most of the instruments required for analysis are expensive and bulky and must be operated by professionals, which cannot meet the needs of rapid on-site detection. Therefore, establishing fast, reliable, sensitive and practical analytical devices and methods for detecting organophosphorus pesticides is of great practical significance for environmental protection and food safety.

Contents of the invention

In view of the problems existing in the prior art, one of the purposes of the present invention is to provide a preparation method for an organophosphorus pesticide detector based on an intelligent response surface. The specific steps are as follows:

(1) Immerse the glass substrate into a mixed aqueous solution of CoCl ₂ ·6H ₂ O and (NH ₂ ) ₂ CO, perform a hydrothermal reaction at a temperature of 55-65°C, and obtain a super-hydrophilic surface after drying;

(2) Drop 100 μL of the response molecule solution on every 4-6 cm ² hydrophilic surface and dry at room temperature;

(3) Dip the modified hydrophilic surface obtained in step (2) into the perfluorooctyltriethoxysilane solution for 30-40 minutes, and dry it to obtain a hydrophobic surface; that is, organophosphorus pesticide detection based on intelligent response surfaces is obtained device;

The response molecule solution is acetylcholinesterase phosphate buffered saline solution or butyrylcholinesterase phosphate buffered saline solution, with a concentration of 1U·mL ^-1 . Butyrylcholinesterase and acetylcholinesterase have similar properties but different substituent groups. Both can respond to organophosphorus pesticides. Different organophosphorus pesticides have different response strengths. Different detection arrays can be constructed by adjusting the types of response molecules.

In the mixed aqueous solution of CoCl ₂ ·6H ₂ O and (NH ₂ ) ₂ CO, the concentration of CoCl ₂ ·6H ₂ O is 0.20-0.50g L ^-1 and the concentration of (NH ₂ ) ₂ CO is 150-250g L ^-1 .

In the step (1), the hydrothermal reaction time is 22-26 hours; the glass substrate used can be any type of glass material.

In the step (3), the perfluorooctyltriethoxysilane solution is an ethanol aqueous solution of perfluorooctyltriethoxysilane (PFOTES, CAS No.: 51851-37-7), where the volume of ethanol and water is The ratio is 1:1 and the volume percentage of PFOTES is 1%.

The second object of the present invention is to provide an organophosphorus pesticide detector based on an intelligent response surface prepared by the above method.

The third object of the present invention is to provide the application of the above-mentioned organophosphorus pesticide detector based on intelligent response surface in the detection of organophosphorus pesticides. Wherein, the organophosphorus pesticide may be one of profenofos, dichlorvos, fenitrothion, chlorpyrifos, malathion, methyl parathion, glyphosate, chlorpyrifos, methomyl, and fenthion or several, known but not limited to these organophosphorus pesticide molecules.

The fourth object of the present invention is to provide a method for detecting organophosphorus pesticides. Specifically, known organophosphorus pesticides of different types and concentrations or a mixture of known organophosphorus pesticides of different concentrations and types are added dropwise to the above-mentioned intelligent response-based On the surface of the organophosphorus pesticide detector, detect the change range of the contact angle of the organophosphorus pesticide on the surface of the organophosphorus pesticide detector based on the intelligent response surface, and build a database of the change range of the contact angle of the organophosphorus pesticide-based intelligent response surface;

Drop the sample to be tested onto the surface of the above-mentioned smart response surface-based organophosphorus pesticide detector, detect the change range of the contact angle of the sample to be tested on the surface of the smart response surface-based organophosphorus pesticide detector, and compare it with the constructed organophosphorus pesticide-based detector. Intelligent response surface contact angle change range database to obtain the type and concentration of organophosphorus pesticides in the sample to be tested;

Among them, the detection temperature is 20-40°C, and the detection time is 20-60 minutes; the organophosphorus pesticide can be profenofos, dichlorvos, fenithion, chlorpyrifos, malathion, methyl parathion, parathion, One or more of glyphosate, chlorpyrifos, methomyl, and fenthion are known but not limited to these organophosphorus pesticide molecules.

Advantages of the technical solution of the present invention

Traditional organophosphorus pesticide detection methods often rely on large laboratory instruments such as electrochemistry, mass spectrometry, and chromatography, which require professional operators and a relatively long detection process, making on-site detection impossible. Colorimetric methods were developed in the later period, but the observation of color changes often requires the use of optical excitation instruments, and it is impossible to accurately test samples in dim light environments that interfere with color display, and some people with color weakness cannot use related detection methods. The present invention indicates the type and concentration of organophosphorus pesticides by means of changes in contact angle observable by the naked eye, and can accurately measure changes in angles with the help of mobile phone software, without the need for large instruments and without interference from ambient light and color.

The present invention prepares a super-hydrophilic surface on a glass substrate, introduces acetylcholinesterase or butyrylcholinesterase for modification, and obtains a hydrophobic surface. Then, different organophosphorus pesticides can be detected through changes in contact angle. By adjusting the type and concentration of response molecules (acetylcholinesterase, butyrylcholinesterase), an array based on organophosphorus pesticide detection was constructed. Through the laboratory testing of different concentrations, different types of organophosphorus pesticides and mixed organophosphorus pesticide samples Detection, establish a complete database of contact angle change range of intelligent response surfaces based on organophosphorus pesticides. During on-site detection, the type and residual amount of organophosphorus pesticides can be determined by comparing with the database.

The organophosphorus pesticide detector based on the intelligent response surface of the present invention can be used for on-site detection of organophosphorus pesticides and is easy to carry. It can be applied to the detection of organophosphorus pesticide residues on vegetables, fruits and grains.

Description of the drawings

Figure 1 is a scanning electron microscope image and contact angle of the hydrophilic surface prepared by the present invention;

Figure 2 is a scanning electron microscope image and contact angle of the hydrophobic surface prepared by the present invention;

Figure 3 is a picture of the hydrophobic surface prepared by the present invention;

Figure 4 Changes in contact angle of dichlorvos solution with different concentration gradients;

Figure 5 Changes in contact angle of malathion solution with different concentration gradients;

Figure 6 Changes in contact angle of glyphosate solution at different concentration gradients;

Figure 7 Changes in contact angle of chlorpyrifos solutions with different concentration gradients;

Figure 8 Changes in contact angle of methyl parathion solution with different concentration gradients;

Figure 9 Changes in contact angle of profenofos solutions with different concentration gradients;

Figure 10 Changes in contact angle of methomyl solutions with different concentration gradients;

Figure 11 Changes in contact angle of fenitrothion solutions with different concentration gradients;

Figure 12 Histogram of contact angle changes of nine organophosphorus pesticides of the same concentration at 20°C;

Figure 13 Histogram of contact angle changes of nine organophosphorus pesticides of the same concentration under 30°C.

Detailed ways

The terms used in the present invention generally have the meanings commonly understood by those of ordinary skill in the art, unless otherwise stated.

The present invention will be described in further detail below with reference to specific embodiments and data. The following examples are only intended to illustrate the present invention and do not limit the scope of the present invention in any way.

The principle of the present invention is:

A superhydrophilic surface is constructed on the surface of the glass substrate, and then modified with acetylcholinesterase or butyrylcholinesterase. Through the difference in the interaction strength between acetylcholinesterase (or butyrylcholinesterase) and different organophosphorus pesticide molecules, And the weak substrate interaction between acetylcholinesterase (or butyrylcholinesterase) and the superhydrophobic surface produces detection interactions for organophosphorus pesticide molecules, causing varying degrees of damage to the hydrophobic surface structure, thereby producing surface contact Angle changes. By adjusting the type and concentration of response molecules (acetylcholinesterase, butyrylcholinesterase), an array based on organophosphorus pesticide detection was constructed. Through the laboratory testing of different concentrations, different types of organophosphorus pesticides and mixed organophosphorus pesticide samples Detection, establish a complete database of contact angle change range of intelligent response surfaces based on organophosphorus pesticides. During on-site detection, the type and residual amount of organophosphorus pesticides can be determined by comparing with the database.

In the above detection system, acetylcholinesterase (or butyrylcholinesterase) is an organophosphorus pesticide-responsive molecule. It has different binding strengths with different organophosphorus pesticides and produces different degrees of reaction; the reaction will produce different degrees of changes in the hydrophobic surface structure. damage, thereby producing a signal of change in surface contact angle. Different concentrations of organophosphorus pesticides will produce different contact angle changes within a certain range, while non-organophosphorus pesticide molecules that do not respond to acetylcholinesterase (or butyrylcholinesterase) will not produce contact angle change signals. The organophosphorus pesticide molecules to be detected are dropped on the hydrophobic surface of the prepared organophosphorus pesticide detector based on intelligent response surface, and the contact angle is measured; different types and concentrations of organophosphorus pesticides will obtain different contact angle information, and then Obtain molecular information on different organophosphorus pesticides.

Example 1

An organophosphorus pesticide detector based on an intelligent response surface, prepared by the following method:

(1) Preparation of hydrophilic surface: Put the aqueous solution of CoCl ₂ ·6H ₂ O and (NH ₂ ) ₂ CO into a sealed container, where the concentration of CoCl ₂ ·6H ₂ O is 0.36g L ^-1 , (NH ₂ ) The concentration of ₂ CO is 200g L ^-1 , and a common borosilicate glass slide is used as the deposition matrix. After reacting at 60°C for 24 hours, the deposited surface is rinsed with deionized water and dried to prepare hydrophilic surface;

(2) Modification of acetylcholinesterase: Drop 100 μL of acetylcholinesterase phosphate buffered saline solution with a concentration of 1U·mL ^-1 on every 5 cm ² hydrophilic surface, and dry at room temperature.

(3) Preparation of hydrophobic surface: Immerse the modified surface in PFOTES solution for 40 minutes, rinse the prepared surface with ethanol solution, and then dry naturally to obtain a hydrophobic surface; that is, organophosphorus pesticide detection based on intelligent response surface device.

In the step (3), the PFOTES solution is an aqueous ethanol solution of PFOTES, where the volume ratio of ethanol and water is 1:1, and the volume percentage of PFOTES is 1%.

The scanning electron microscope image and contact angle of the hydrophilic surface prepared in the above step (1) are shown in Figure 1, and the scanning electron microscope image and contact angle of the hydrophobic surface prepared in step (3) are shown in Figure 2. The final product based on A picture of the hydrophobic surface of the smart responsive surface organophosphorus pesticide detector is shown in Figure 3.

Example 2

The method for detecting organophosphorus pesticides using the organophosphorus pesticide detector based on the intelligent response surface prepared in Example 1 is as follows:

(1) Add 3 μL of known different types of organophosphorus pesticides with different concentrations or a mixture of known different types of organophosphorus pesticides with different concentrations onto the surface of the above-mentioned organophosphorus pesticide detector based on intelligent response surface. Respond to the change range of the surface contact angle of the organophosphorus pesticide detector on the surface, and construct a database of the change range of the contact angle of the intelligent response surface based on organophosphorus pesticides;

(2) Drop the sample to be tested onto the surface of the above-mentioned smart response surface-based organophosphorus pesticide detector, detect the change range of the contact angle of the sample to be tested on the surface of the smart response surface-based organophosphorus pesticide detector, and compare it with the constructed organic-based pesticide detector. Intelligent response surface contact angle change range database of phosphorus pesticides to obtain the type and concentration of organophosphorus pesticides in the sample to be tested;

Among them, the detected temperature is 20-40°C, and the detection time is 20-60 minutes.

Example 3

Changes in contact angle of organophosphorus pesticide molecules with different concentrations on the surface of organophosphorus pesticide detector based on smart response surface

Organophosphorus pesticide molecules of different concentrations were dropped on the hydrophobic surface of the organophosphorus pesticide detector based on the intelligent response surface prepared in the above Example 1, and the detection temperature was 20°C. Measure the contact angle when the pesticide molecule droplets initially contact the hydrophobic surface and the contact angle after 20 minutes, 25 minutes, and 30 minutes. The contact angle angle value is used as the ordinate, and the response time of acetylcholinesterase and organophosphorus pesticide molecules is used as the abscissa. Draw a graph to detect the change range of the contact angle of different types and concentrations of organophosphorus pesticide molecules.

The results are shown in Figure 4-11, where -1 means the concentration is 10 ^-1 mol/L, -2 means the concentration is 10 ^-2 mol/L, -3 means the concentration is 10 ^-3 mol/L, and so on. ;water represents the change in the contact angle of water within the measurement time range. On the superhydrophobic surface, the response of different concentrations of organophosphorus pesticide molecules to acetylcholinesterase was detected by comparing the contact angle changes with water. In the initial stage of detection, the difference in contact angles between the four concentrations of solutions was small. As time went by, there was an obvious gap in the contact angles between solutions of different concentrations. The contact angle of water changes approximately at about 10° within 30 minutes. Compared with water, the changes of glyphosate, chlorpyrifos, and methyl parathion are not obvious. This result may be due to the weak response intensity of these three pesticide molecules to acetylcholinesterase. Malathion, profenofos, dichlorvos, methomyl, and fenitrothion are respectively at 10 ^-3 mol/L, 10 ^-1 mol/L, 10 -1 mol/L, ^{10 -1 mol} /L, 10 The maximum change in contact angle occurs at ^-3 mol/L. By comprehensively analyzing the detection data of various organophosphorus pesticide molecules, the results show that the higher the concentration of pesticide molecules, the more obvious the change in contact angle. However, in order to ensure that the best detection effect can be found under low concentration conditions, 10 ^-3 mol/ L is the optimal detection condition.

Example 4

Changes in contact angle of organophosphorus pesticide molecules at the same concentration on the surface of an organophosphorus pesticide detector based on smart response surface

(1) Drop organophosphorus pesticide molecules at the same concentration (10 ^-3 mol/L) on the hydrophobic surface of the organophosphorus pesticide detector based on the intelligent response surface prepared in the above Example 1, and detect the temperature at 20°C. The contact angle when the pesticide molecule droplets initially contact the hydrophobic surface and the contact angle after 30 minutes of contact were measured respectively, and the change range of the contact angle of different types of organophosphorus pesticide molecules of the same concentration was calculated.

The results are shown in Figure 12. In the same time and in the same concentration gradient (30 min, 10 ^-3 mol/L), the contact angle changes of different organophosphorus pesticides from large to small are, chlorpyrifos Chl (57.82°) > glycerin Phosphate Gly(47.63°)＞Fenthion Fent(34.92°)＞Fenthion Fen(33.85°)＞Dichlorvos DDVP(28.67°)＞Malathion Mal(26.77°)＞Profenthion Pro(25.23° )> Methyl parathion Par (20.13°)> Methomyl Thi (14.79°). Under this condition, the contact angle of chlorpyrifos changed the most, and the contact angle of methomyl changed the smallest. By interacting with hydrophobic surfaces, different organophosphorus pesticide molecules can be preliminarily distinguished.

(2) Drop organophosphorus pesticide molecules at the same concentration (10 ^-3 mol/L) on the hydrophobic surface of the organophosphorus pesticide detector based on the intelligent response surface prepared in the above Example 1, and detect the temperature at 30°C. The contact angle when the pesticide molecule droplets initially contact the hydrophobic surface and the contact angle after 60 minutes of action were measured respectively, and the change range of the contact angle of different types of organophosphorus pesticide molecules of the same concentration was calculated.

The results are shown in Figure 13. In the same period of time, the changes in contact angles of different organophosphorus pesticides in the same concentration gradient from large to small are: dichlorvos DDVP (58.23°) > glyphosate Gly (54.65°) > profenofos Pro(38.55°)＞Fenthion Fen(30.24°)＞Methocarb Thi(27.98°)＞Methyl parathion Par(27.77°)＞Chlorpyrifos Chl(24.6°)＞fenthion Fent(22.98° )>Malathion Mal(18.76°). Under this condition, the contact angle of dichlorvos changed the most, and that of malathion changed the smallest. Under these conditions, it is beneficial to screen dichlorvos and glyphosate pesticide molecules.

The above are only preferred embodiments of the present invention, and are not intended to limit the present invention in other forms. Any skilled person familiar with the art may make changes or modifications to equivalent changes using the technical contents disclosed above. Example. However, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the protection scope of the technical solution of the present invention.

Claims (10)

1. A method for preparing an organophosphorus pesticide detector based on an intelligent response surface, which is characterized in that the steps are as follows: (1) Immerse the glass substrate into a mixed aqueous solution of CoCl ₂ ·6H ₂ O and (NH ₂ ) ₂ CO, perform a hydrothermal reaction at a temperature of 55-65°C, and obtain a super-hydrophilic surface after drying; (2) Drop 100 μL of the response molecule solution on every 4-6 cm ² hydrophilic surface and dry at room temperature; (3) Dip the modified hydrophilic surface obtained in step (2) into the perfluorooctyltriethoxysilane solution for 30-40 minutes, and dry it to obtain a hydrophobic surface; that is, organophosphorus pesticide detection based on intelligent response surfaces is obtained device; The response molecule solution is acetylcholinesterase phosphate buffered saline solution or butyrylcholinesterase phosphate buffered saline solution, with a concentration of 1U·mL ^-1 ; The method for detecting organophosphorus pesticides using the above-mentioned intelligent response surface-based organophosphorus pesticide detector is as follows: Known different types of organophosphorus pesticides with different concentrations or a mixture of known different types of organophosphorus pesticides with different concentrations are added dropwise to the surface of the above-mentioned organophosphorus pesticide detector based on the intelligent response surface, and the organophosphorus pesticide is detected on the organic phosphate detector based on the intelligent response surface. The variation range of the surface contact angle of the phosphorus pesticide detector is used to construct a database of the variation range of the surface contact angle of the intelligent response surface based on organophosphorus pesticides; Drop the sample to be tested onto the surface of the above-mentioned smart response surface-based organophosphorus pesticide detector, detect the change range of the contact angle of the sample to be tested on the surface of the smart response surface-based organophosphorus pesticide detector, and compare it with the constructed organophosphorus pesticide-based detector. Intelligent response surface contact angle change range database to obtain the type and concentration of organophosphorus pesticides in the sample to be tested. 2. The preparation method of an organophosphorus pesticide detector based on an intelligent response surface according to claim 1, characterized in that CoCl ₂ ·6H 2 in the mixed aqueous solution of CoCl _{2 ·} 6H ₂ O and (NH ₂ ) ₂ CO The concentration of O is 0.20-0.50g L ^-1 and the concentration of (NH ₂ ) ₂ CO is 150-250g L ^-1 . 3. The method for preparing an organophosphorus pesticide detector based on an intelligent response surface according to claim 1, characterized in that in step (1), the hydrothermal reaction time is 22-26 h. 4. The preparation method of an organophosphorus pesticide detector based on an intelligent response surface according to claim 1, characterized in that in the step (3), the perfluorooctyltriethoxysilane solution is perfluorooctyltriethoxysilane. An aqueous ethanol solution of ethoxysilane, the volume ratio of ethanol to water is 1:1, and the volume percentage of perfluorooctyltriethoxysilane is 1%. 5. Organophosphorus pesticide detector based on intelligent response surface prepared by the method of any one of claims 1-4. 6. The application of the organophosphorus pesticide detector based on the intelligent response surface according to claim 5 in the detection of organophosphorus pesticides. 7. Application according to claim 6, characterized in that the organophosphorus pesticide is profenofos, dichlorvos, fenitrothion, malathion, methyl parathion, glyphosate, chlorpyrifos, fenfos, One or more of Dovi and Fenthion. 8. A method for detecting organophosphorus pesticides, characterized by dropping known different types of organophosphorus pesticides with different concentrations or a mixture of known different types of organophosphorus pesticides with different concentrations onto the intelligent response surface of claim 5 The surface of the organophosphorus pesticide detector, detects the change range of the contact angle of the organophosphorus pesticide on the surface of the organophosphorus pesticide detector based on the intelligent response surface, and builds a database of the change range of the contact angle of the organophosphorus pesticide-based intelligent response surface; The sample to be tested is dropped onto the surface of the organophosphorus pesticide detector based on the intelligent response surface of claim 5, and the variation range of the contact angle of the sample to be measured on the surface of the organophosphorus pesticide detector based on the intelligent response surface is detected, and the control angle constructed based on Intelligent response surface contact angle change range database of organophosphorus pesticides to obtain the type and concentration of organophosphorus pesticides in the sample to be tested. 9. The method for detecting organophosphorus pesticides according to claim 8, characterized in that the detection temperature is 20-40°C and the detection time is 20-60 minutes. 10. The method for detecting organophosphorus pesticides according to claim 8 or 9, characterized in that the organophosphorus pesticides are profenofos, dichlorvos, fenithion, malathion, methyl parathion, parathion, One or more of glyphosate, chlorpyrifos, methomyl, and fenthion.