Photothermal responsive insect pheromone sustained-release preparation and application

Abstract

The present invention discloses a photothermal responsive insect pheromone sustained-release preparation and application. The preparation includes 54.55-59.41 wt% of thermal responsive hydrogel, 0.99-9.09 wt% of copper-polyphenol nanoparticles and 36.36-39.6 wt% of insect pheromone emulsion; the insect pheromone emulsion, copper-phenol nanoparticles and thermal responsive hydrogel are mixed, stirred for 30 minutes to ensure that the insect pheromone is evenly distributed in the thermal responsive hydrogel solution, cooled below 30°C to form a hydrogel, and a photothermal responsive insect pheromone sustained-release preparation is obtained; the release rate of the insect pheromone is synergistically controlled by the photothermal conversion effect of the copper-polyphenol nanoparticles and the temperature response of the thermal responsive hydrogel. The release rate of the insect pheromone in the present invention can be controlled by controlling different light intensity, light exposure time and temperature conditions, and the present invention significantly prolongs the duration of the insect pheromone.

Description

Technical Field

[0001] The invention belongs to the field of agricultural and animal husbandry pest control, and specifically relates to a photothermal responsive insect pheromone slow-release preparation and application. Background Art

[0002] Insect pheromones play a vital role in green agricultural and animal husbandry pest control and can effectively interfere with the mating behavior of pests. However, traditional insect pheromone release systems have problems such as uncontrollable release rate, poor environmental adaptability, and easy oxidation and ineffectiveness of pheromones. Especially in high temperature and oxidative environments, the stability of pheromones is poor, which affects their long-term control effect.

[0003] Thermosensitive hydrogels have been widely used in drug sustained-release systems due to their sol-gel phase transition properties when the temperature changes. However, it is difficult to accurately control the release of insect sex pheromones by relying solely on thermosensitive materials, especially under variable environmental conditions, and it is difficult to ensure the stable sustained release of insect sex pheromones. In recent years, photothermal nanoparticle technology has brought new breakthroughs in controlled-release systems. By introducing photothermal nanoparticles into hydrogels, the photothermal effect can be used to control the local temperature, thereby regulating the release of insect sex pheromones. Metal nanoparticles (such as gold nanoparticles, AuNPs) are widely used in the field of drug release due to their photothermal effect, but their high cost limits large-scale agricultural applications. Furthermore, insect sex pheromones are unstable in the natural environment and are easily oxidized and ineffective, which becomes a key challenge to further improve the performance of the system.

[0004] Therefore, there is an urgent need in the prior art for a photothermal responsive insect pheromone sustained-release preparation with good stability and controllability. Summary of the invention

[0005] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a photothermal responsive insect sex pheromone sustained-release preparation with good stability and controllability.

[0006] The objective of the present invention is achieved through the following technical scheme: a photothermal responsive insect sex pheromone sustained-release preparation, comprising 54.55-59.41 wt% of a thermal responsive hydrogel, 0.99-9.09 wt% of copper-polyphenol nanoparticles and 36.36-39.6 wt% of an insect sex pheromone emulsion; the insect sex pheromone emulsion, the copper-phenol nanoparticles and the thermal responsive hydrogel are mixed, and fully stirred for 30 minutes to ensure that the insect sex pheromone is evenly distributed in the thermal responsive hydrogel solution, and cooled below 30°C to form a hydrogel, thereby obtaining a photothermal responsive insect sex pheromone sustained-release preparation; the release rate of the insect sex pheromone is synergistically controlled by the photothermal conversion effect of the copper-polyphenol nanoparticles and the temperature response of the thermal responsive hydrogel.

[0007] The thermal responsive hydrogel is prepared by adding 4.76 wt% poly(N-isopropylacrylamide) and 0.74 wt% low melting point agarose into 94.50 wt% sterile water, stirring at 30°C until the solution is transparent, thereby preparing solution A; dissolving 0.98 wt% vaseline and 2.93 wt% Tween 80 into 96.09 wt% water, ultrasonicating at 70°C for 20 minutes, thereby preparing solution B; and mixing solution A and solution B in equal volumes, ultrasonicating for 20 minutes, stirring for 30 minutes, and cooling at below 30°C until gelation occurs, thereby preparing the thermal responsive hydrogel.

[0008] Thermoresponsive hydrogels have excellent temperature responsiveness and reversible phase change properties. They shrink when the local temperature rises due to ambient temperature or photothermal effect, promoting the release of insect pheromones. They return to their original state when the temperature drops, achieving controllable release of insect pheromones. At the same time, thermoresponsive hydrogels have good biocompatibility and environmental friendliness.

[0009] The thermoresponsive hydrogel component can be selected from one or more of poly(N-isopropylacrylamide), polyacrylic acid, polyacrylic acid, agarose, xanthan gum, gelatin, paraffin, and vaseline.

[0010] The copper-phenol nanoparticles are prepared by adding copper sulfate, sodium dodecyl sulfate and cottonyphenol into water under ultrasonic conditions to prepare an aqueous solution, wherein the aqueous solution contains 0.0313 wt% copper sulfate, 0.0625 wt% sodium dodecyl sulfate and 0.0313 wt% cottonyphenol, and after ultrasonication for 10 minutes, stirring is continued for 20 hours, and the supernatant is removed by centrifugation. The precipitate is washed with pure water for 3 times, and freeze-dried at -40°C to obtain dark red solid copper-phenol nanoparticles, which are stored in the dark.

[0011] Copper nanoparticles (CuNPs) have excellent photothermal effects and lower costs, making them an ideal choice for photothermal responsive materials. Through light irradiation, copper nanoparticles can locally heat the thermoresponsive hydrogel, causing the hydrogel to soften and achieve the release of insect pheromones. The present invention combines phenolic compounds on the basis of copper nanoparticles. As natural antioxidants, phenolic compounds can effectively reduce the oxidative failure of insect pheromones during the release process. By compounding with copper elements to form nanoparticles, phenolic compounds not only retain the photothermal effect of copper, but also enhance the protective effect on insect pheromones, thereby significantly improving the stability and effectiveness of insect pheromones in complex environments. Copper-phenol nanoparticles produce a photothermal effect under the irradiation of a light source, triggering the volume phase change of the thermoresponsive hydrogel, and achieving the regulation of the release of insect pheromones.

[0012] The phenolic compounds involved in the copper-phenol nanoparticles can be selected from one or more of catechins, resveratrol, tannic acid, quercetin, anthocyanins, caffeic acid, vanillic acid, gallic acid, pyrogallic acid, ferulic acid and rosmarinic acid. Phenolic compounds act as antioxidants to enhance the protection of insect pheromones.

[0013] The insect pheromone emulsion is prepared by dissolving and mixing 0.0286 wt% of trans-11-tetradecene acetate, 0.0171 wt% of trans-11-tetradecenal, 0.0686 wt% of trans-11-tetradecenol and 0.572 wt% of Tween 80, adding the mixture into 99.3137 wt% of water, and ultrasonicating the mixture for 5 minutes at a power of 180 W to prepare the insect pheromone emulsion.

[0014] The insect sex pheromone is selected from one or more of trans-11-tetradecene acetate, trans-11-tetradecenal, trans-11-tetradecenol, n-tetradecyl alcohol and n-tetradecene acetate.

[0015] This insect sex pheromone has a trapping effect on a variety of agricultural and animal husbandry pests. Through the controlled release of the slow-release system, the effective concentration can be maintained for a long time, thereby improving the trapping efficiency.

[0016] The invention also includes a functional additive in an amount of 0.01-5 wt %, wherein the additive is selected from one or more of an antioxidant, a stabilizer, and a dispersant. The antioxidant cooperates with phenol to enhance the protection of insect pheromones; the stabilizer improves the structural stability of the hydrogel network; and the dispersant improves the dispersibility of the nanoparticles to ensure the uniformity of the photothermal effect.

[0017] The present invention also relates to the application of a photothermal responsive insect pheromone slow-release preparation in agricultural and animal husbandry pest control. The photothermal responsive insect pheromone slow-release preparation is placed in an area where pests are active frequently, and the release rate of the insect pheromone is controlled by combining lighting, natural light, and shading treatment of natural light.

[0018] The photothermal responsive insect pheromone slow-release preparation of the present invention can be further processed into granules, tablets or microspherical solid preparations during the application of agricultural and animal husbandry pest control; the preparation is placed in the target farmland where pests are active frequently to form trapping or mating interference for specific pests; the insect pheromone release of the slow-release system is activated by regular use of light source illumination, thereby achieving dynamic control of the release rate; when no light source is used, under natural environmental conditions, its effective period is higher than 20 days. The present invention can also be subjected to shading treatment according to actual conditions to delay the release of insect pheromones. The present invention can optimize the trapping effect according to the law of pest activity, combined with natural light, shading treatment of natural light, and illumination time and intensity of light source.

[0019] The beneficial effects of the present invention are as follows: the present invention combines thermal responsive hydrogel, copper-phenol nanoparticles and insect sex pheromones to develop a new sustained-release preparation, which has both high efficiency and controllability of release. The thermal responsive hydrogel system based on copper-phenol nanoparticles can control the release rate of insect sex pheromones by controlling different light intensity, light time and temperature conditions. The present invention has good stability in the natural environment, reduces the degradation of insect sex pheromones in the natural environment, and significantly prolongs the duration of the insect sex pheromones. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It simulates the sustained release of the present invention under natural conditions and darkroom conditions;

[0021] Figure 2 is the sustained release of the insect sex pheromone of the present invention under different light intensity conditions;

[0022] Figure 3 The present invention has the trapping effect on grass borers under different outdoor conditions. DETAILED DESCRIPTION

[0023] The present invention is described in detail below in conjunction with the accompanying drawings.

[0024] Example 1. Preparation of thermal responsive hydrogel

[0025] 4.76 wt% poly(N-isopropylacrylamide) and 0.74 wt% low melting point agarose (melting point ≤65°C, CAS: 9012-36-6) were added to 94.50 wt% sterile water and stirred at 30°C until the solution was transparent to prepare solution A. 0.98 wt% vaseline and 2.93 wt% Tween 80 were dissolved in 96.09 wt% water and ultrasonicated at 70°C for 20 minutes to prepare solution B. Solution A and solution B were mixed in equal volumes, ultrasonicated for 20 minutes, stirred for 30 minutes, and then cooled at below 30°C until gelation to form a thermally responsive hydrogel.

[0026] Example 2. Preparation of copper-phenol nanoparticles

[0027] Under ultrasonic conditions, copper sulfate, sodium dodecyl sulfate and gossypol were added to water to prepare an aqueous solution containing 0.0313 wt% copper sulfate, 0.0625 wt% sodium dodecyl sulfate and 0.0313 wt% gossypol. Ultrasonication was performed for 10 minutes, stirring was continued for 20 hours, the supernatant was removed by centrifugation, the precipitate was washed 3 times with pure water, and freeze-dried at -40°C to obtain dark red solid copper-phenol nanoparticles, which were stored in the dark.

[0028] Example 3 Preparation of insect pheromone emulsion

[0029] 0.0286 wt% trans-11-tetradecene acetate, 0.0171 wt% trans-11-tetradecenal, 0.0686 wt% trans-11-tetradecenol and 0.572 wt% Tween 80 were dissolved and mixed, added into 99.3137 wt% water, and ultrasonicated at 180 W power for 5 minutes to prepare an insect pheromone emulsion.

[0030] Example 4 Thermoresponsive hydrogel loaded with insect sex pheromones

[0031] The key to the responsiveness of the thermoresponsive hydrogel lies in the content of copper-phenol nanoparticles. The following is the preparation process of thermoresponsive hydrogel loaded with insect sex pheromones with copper-phenol nanoparticle contents of 0.99 wt% and 9.09 wt%.

[0032] 1. Preparation process of photothermal responsive insect pheromone sustained-release preparation A

[0033] 39.60 wt% insect pheromone emulsion, 0.99 wt% copper-phenol nanoparticles and 59.41 wt% thermoresponsive hydrogel were mixed and stirred for 30 minutes, followed by ultrasonic treatment for 15 minutes to ensure that the insect pheromone was evenly distributed in the hydrogel matrix. Subsequently, the mixture was injected into a mold and cooled at below 30°C to prepare a photothermal responsive insect pheromone sustained-release preparation sample A.

[0034] 2. Preparation process of photothermal responsive insect pheromone sustained-release preparation B

[0035] 36.36 wt% insect pheromone emulsion, 9.09 wt% copper-phenol nanoparticles and 54.55 wt% thermoresponsive hydrogel were mixed and stirred for 30 minutes, followed by ultrasonic treatment for 15 minutes to ensure that the insect pheromone was evenly distributed in the hydrogel matrix. Subsequently, the mixture was injected into a mold and cooled at below 30°C to prepare a photothermal responsive insect pheromone sustained-release preparation sample B.

[0036] Example 5 Temperature changes of the photothermal responsive insect pheromone sustained-release preparation under different light sources and the cooling conditions under different ambient temperatures

[0037] 1. Temperature changes under different light sources

[0038] The photothermal responsive insect pheromone sustained-release preparation samples A and B of Example 4 were selected and subjected to illumination tests under natural light, laser and LED light sources, respectively. The photothermal responsive insect pheromone sustained-release preparation samples were placed in a transparent container to ensure that the samples were evenly illuminated. A temperature sensor was used to monitor the sample temperature in real time, and the temperature changes before, during and after illumination were recorded. The test lasted for 3 hours, and the temperature data was recorded every minute.

[0039] As shown in Table 1 and Table 2, both formulation samples A and B can achieve significant temperature rise under illumination conditions. Formulation sample A exhibits stable temperature rise characteristics under relatively mild light sources (sunlight), with the temperature rising to 52.49±3.28°C in 3 hours, which is suitable for long-term stable sustained-release applications; because the content of copper-phenol nanoparticles in formulation sample B is higher, the temperature rise rate is significantly increased under strong light sources (such as incandescent lamps and high-pressure mercury lamps). Under high-pressure mercury lamps (13000W / m²), the temperature can reach 83.82±2.16°C within 3 hours, which is particularly suitable for rapid temperature rise and short-term high-efficiency release scenarios. The experiment further showed that there are significant differences in the effects of different light sources on the temperature rise performance. High-energy light sources (such as incandescent lamps and high-pressure mercury lamps) can significantly improve the photothermal conversion efficiency of formulation samples A and B, among which the temperature rise effect under high-pressure mercury lamps (13000 W / m²) is the best. In addition, preparation sample B still maintains a high heating capacity and heating rate under low light intensity conditions (high-pressure mercury lamp 6500 W / m²), showing excellent adaptability.

[0040] In summary, by adjusting the content of the photothermal agent (copper-phenol nanoparticles) and the intensity of light radiation, the final heating temperature and the heating response speed of the photothermal-responsive insect pheromone sustained-release preparation can be controlled.

[0041] Table 1 Temperature changes of photothermal responsive insect pheromone sustained-release preparation sample A under different light sources

[0042] Time (hours) Sunlight Incandescent lamp (13000W / m²) High pressure mercury lamp (13000W / m²) High pressure mercury lamp (6500W / m²) 1 47.54 ± 2.14 °C 63.58 ± 1.41 °C 68.33 ± 1.62 °C 53.08 ± 2.76 °C 2 50.36± 2.53 °C 65.72± 1.86 °C 69.74 ± 1.35 °C 55.50± 1.43°C 3 52.49± 3.28 °C 70.13± 1.35 °C 71.24 ± 1.75 °C 56.47± 2.51 °C

[0043] Table 2 Temperature changes of photothermal responsive insect pheromone sustained-release preparation sample B under different light sources

[0044] Time (hours) Sunlight Incandescent lamp (13000W / m²) High pressure mercury lamp (13000W / m²) High pressure mercury lamp (6500W / m²) 1 65.05 ± 1.54 °C 79.35 ± 1.26 °C 80.61 ± 1.86 °C 70.45 ± 1.09 °C 2 66.40± 3.04°C 80.74± 2.30 °C 81.91 ± 1.58 °C 71.68 ± 1.36 °C 3 67.08± 2.72°C 81.28± 1.85 °C 83.82± 2.16 °C 70.46± 1.67 °C

[0045] 2. Cooling effect of photothermal responsive insect pheromone sustained-release preparation under different ambient temperatures

[0046] This test selected the thermal responsive insect pheromone sustained-release preparation sample A, which heats up slowly under natural light, as the test material. The heat preservation ability of the photothermal responsive insect pheromone sustained-release preparation is directly related to its application. In order to verify the heat preservation ability of the photothermal responsive insect pheromone sustained-release preparation, the following test was conducted. Under light-proof conditions, the photothermal responsive insect pheromone sustained-release preparation sample A with an initial temperature of 50°C and a length, width and height of 1cm was placed in different temperature environments (25°C, 30°C and 35°C). At different time points, its temperature was detected and its temperature changes were recorded.

[0047] Table 3 Cooling of photothermal responsive insect pheromone sustained-release preparation sample A under different ambient temperatures

[0048] Time (h) 25℃ ambient temperature(℃) 30℃ ambient temperature(℃) 35℃ ambient temperature(℃) 0 50.00 50.00 50.00 1 38.72± 3.04 40.98± 4.32 43.23± 2.30 2 32.53± 2.36 36.02± 2.80 39.52± 1.98 3 29.13± 2.08 33.31±2.36 37.48± 3.81 4 27.27± 3.04 31.81± 3.34 36.36±2.42 5 26.24± 2.21 31.00± 2.65 35.75± 2.87 6 25.68± 1.86 30.55± 2.66 35.45± 3.08

[0049] As shown in Table 3, the cooling speed of the samples under different ambient temperatures showed significant differences. After 1 hour, the temperature of the samples in a 25°C environment dropped to 38.72±3.04, the temperature of the samples in a 30°C environment dropped to 40.98±4.32°C, and the temperature of the samples in a 35°C environment dropped to 43.23±2.30. The lower the ambient temperature, the faster the sample cooled. After 6 hours, the sample temperature under each temperature condition was very close to the ambient temperature. The test results show that for early spring or late autumn, when the outdoor ambient temperature is low, the sample cools down faster, which can effectively reduce the release rate of insect pheromones and avoid waste of resources.

[0050] Example 6 Sustained-release ability of photothermal responsive insect pheromone sustained-release preparation at different temperatures and different light intensities

[0051] 1. Sustained release test at different temperatures

[0052] This test selected the thermal responsive insect pheromone sustained-release preparation sample A with a slow temperature rise under natural light as the test material. The photothermal responsive insect pheromone sustained-release preparation sample A prepared in Example 4 was divided into a plurality of equal sample groups and placed in different constant temperature closed environments, with the temperatures set to 35°C, 55°C, 65°C and 75°C, respectively. At 1h, 5h, 10h, 2d, 5d, 10d, 15d and 20d, gas samples were extracted from the sample bottles using a gas sampler, ensuring rapid sealing to avoid gas leakage. Subsequently, the collected gas samples were analyzed by gas chromatography-mass spectrometry (GC-MS), the concentration of insect pheromones at each time point was recorded, and the release amount at each time point was calculated. To evaluate the sustained-release effect of insect pheromones under different temperature conditions.

[0053] As shown in Table 4, the rate of release of insect sex pheromones from sample A significantly increased with increasing temperature. At 35°C, the release was slow, with a release of 38.39% after 20 days; while at 55°C, the release was nearly complete (89.25%) within 20 days. As the temperature further increased to 65°C and 75°C, the release process accelerated. This shows that higher temperatures can significantly increase the release rate of insect sex pheromones from the sample, making it more suitable for application scenarios requiring rapid release, while lower temperatures provide a more obvious slow-release effect.

[0054] Table 4 The sustained-release effect of photothermal responsive insect pheromone sustained-release preparation sample A at different temperatures

[0055] Time Release at 35°C Release at 55°C Release at 65°C Release at 75°C 1 hour 2.23% 5.37% 8.86% 20.74% 5 hours 4.12% 12.23% 20.35% 45.92% 10 hours 5.76% 15.83% 37.23% 63.34% 2 days 7.45% 29.69% 65.08% 100% 5 days 9.87% 44.32% 83.35% 100% 10 days 15.64% 68.08% 100% 100% 15 days 25.34% 84.68% 100% 100% 20 days 38.39% 89.25% 100% 100%

[0056] 2. Experiment on sustained release of insect pheromones under simulated natural conditions and darkroom conditions

[0057] This test selected sample A of the thermal responsive insect pheromone sustained-release preparation with a slow temperature rise under natural light as the test material. A 65W incandescent light source was installed on an adjustment arm so that the irradiation distance could be adjusted. An illuminometer or radiometer was used to detect the light intensity on the surface of sample A, and the distance between the incandescent lamp and the sample was gradually adjusted so that the light intensity on the surface of the sample reached the predetermined test value of 5700-6500 W / m², simulating the natural radiation intensity in the summer in the "Three Norths" region of my country. After reaching the target radiation intensity, the distance between the incandescent lamp and the sample surface was recorded. A timer was used to set the illumination time to 10 hours, the ambient temperature was controlled at 30°C, and there was no illumination for 14 hours, and the temperature was controlled at 20°C. Gas samples around the sample A of the photothermal responsive insect pheromone sustained-release preparation were collected regularly every other day during the test, and the concentration of the released insect pheromone was measured using GC-MS to compare and analyze the effects of different illumination conditions on the sustained-release effect.

[0058] Figure 1 Comparison of the active release curves of sample A under simulated natural light conditions and darkroom conditions. The results show that the active release rate of the preparation under simulated natural conditions is significantly higher than that under darkroom conditions in the early stage (0-20 days), and can reach nearly 90% of the target activity at 25 days; while for the samples under darkroom conditions, although the activity release is relatively slow in the early stage, it shows a rapid upward trend during the period of 25-35 days. In the end, the preparations under both conditions can reach an activity level close to 100%. The difference in activity under the two conditions is mainly reflected in the release kinetics, among which the difference in the 10-30 day period is the most significant. This difference can effectively meet the differentiated needs of different application scenarios for active release rates.

[0059] 3. Sustained release test under different light intensities

[0060] This test selected sample A, a thermal-responsive insect pheromone sustained-release preparation with a slow temperature rise under natural light, as the test material. A 65W incandescent light source was mounted on an adjustment arm, and a light intensity radiometer was used to detect the light intensity on the sample surface. The distance between the incandescent lamp and sample A of the photothermal-responsive insect pheromone sustained-release preparation was gradually adjusted to achieve a target radiation intensity of 13000W / m²-26000W / m². During the test, gas samples around sample A were collected at regular intervals of one hour, and the concentration of released grass moth sex pheromones was measured using GC-MS to compare the effects of light and heat on the release of insect sex pheromones under light. Figure 2As shown, with the increase of light intensity, the photothermal responsive insect sex pheromone sustained-release preparation sample A showed a continuously enhanced release effect, which indicates that the photothermal responsive insect sex pheromone sustained-release preparation can be used in combination with light attractants, and the insect sex pheromone release effect of the photothermal responsive insect sex pheromone sustained-release preparation can be adjusted by light intensity.

[0061] Example 7 Comparison of the trapping effects of photothermal responsive insect pheromone slow-release preparations on grass borers under different conditions

[0062] This experiment was conducted at the Sharqin Experimental Demonstration Base in the agricultural and pastoral transition area of ​​the Grassland Research Institute of the Chinese Academy of Agricultural Sciences (latitude: 40.8217888, longitude: 111.7058483, altitude: 1278 meters). Trapping experiments were conducted under different conditions on the dates shown in Table 5. See Table 5 for weather conditions during the experimental period.

[0063] Table 5 Weather conditions during the test period

[0064] date weather Temperature Wind direction and wind force 2024-06-20 Cloudy to moderate rain 17°C - 30°C Southwest wind level 3-4 2024-06-19 Cloudy to light rain 19°C - 28°C Southwest wind level 3-4 turning to level 3 2024-06-18 Overcast to cloudy 19°C - 29°C Southwest wind 4-5 to 3-4 2024-06-17 Overcast to cloudy 18°C - 30°C Southwest wind level 3-4 2024-06-16 clear 16°C - 31°C Northeast wind level 3-4 turning to level 3 2024-06-15 Cloudy to sunny 15°C - 27°C North wind 3-4 to 3 2024-06-14 partly cloudy 14°C - 27°C Southwest wind level 3-4 turning to level 3 2024-06-13 partly cloudy 14°C - 29°C North wind 5-6 to 3-4 2024-06-12 Cloudy to sunny 19°C - 33°C Southwest wind 3-4 2024-06-11 Overcast to cloudy 17°C - 30°C Southwest wind level 3-4 turning to level 3 2024-06-10 Cloudy to sunny 17°C - 30°C Southwest wind 3-4 2024-06-09 Overcast to cloudy 17°C - 29°C South wind 3-4 to 3 2024-06-08 Overcast to cloudy 14°C - 29°C Southwest wind 3-4 2024-06-07 partly cloudy 13°C - 22°C Northwest wind 3-4 to 3 2024-06-06 Overcast to cloudy 14°C - 21°C Northeast wind level 3-4 turning to level 3 2024-06-05 Moderate rain turning to cloudy 13°C - 13°C Northeast wind level 3-4

[0065] This test selected the thermal responsive insect pheromone sustained-release preparation sample A with a slow temperature rise under natural light as the test material. Three partitions were set in the test area to ensure that the spacing between the three partitions was large enough to avoid mutual influence between different test groups. A light source was set in the first partition, and insect traps were arranged. The photothermal responsive insect pheromone sustained-release preparation sample A prepared in Example 4 was placed in the insect traps. The distance between the light source and the insect traps was adjusted by an illuminance meter to make the radiation intensity at 13000W / m². In the second partition, insect traps were arranged, and photothermal responsive insect pheromone sustained-release preparation sample A was placed in the insect traps. Sample A was shading treated to ensure that it was not affected by various lights; insect traps were arranged in the third partition, and photothermal responsive insect pheromone sustained-release preparation sample A of the same specifications was placed in the insect traps without shading treatment to ensure that it could be exposed to natural light.

[0066] In the first sub-area test, the light source was turned on from 21:30 every night to 00:30 the next morning. At other times, the light-response insect pheromone slow-release preparation sample A was covered to avoid light, and the insect trap was closed. This operation was to ensure that the test in this sub-area was not affected by natural light and the release of insect pheromone slow-release preparations at other times on insect attraction, and to ensure that the grass borers entering the insect trap were only trapped under the conditions of light plus light-response insect pheromone slow-release preparation sample A during the test period. The test covered the main peak activity period of grass borers from 21:00 to 2:00 the next morning, excluding natural light factors. The test in the second and third sub-areas started from 8:00 every day and lasted until 7:30 the next day. The number of grass borers captured was recorded regularly every day, and the total number of grass borers in the insect traps of each test group was recorded after the end of each day's test. The test lasted for 15 days, covering the peak period of the overwintering generation of grass borers, and the changes in the capture volume on different days were observed.

[0067] like Figure 3 As shown, in all test time periods, the number of grass borers captured by the combination of photothermal responsive insect sex pheromone slow-release preparation sample A and light lure was significantly higher than the trapping effect under natural light and sample A light-shielding treatment conditions, indicating that the combination of photothermal responsive insect sex pheromone slow-release preparation sample A and light lure has a promoting effect on the capture of grass borers. Under natural light irradiation conditions, the number of grass borers captured by the photothermal responsive insect sex pheromone slow-release preparation was significantly higher than the number of grass borers captured under light-shielding treatment conditions, indicating that natural light has a promoting effect on the capture of grass borers. It can be seen that by controlling the switch of the light source, the release of sex pheromones can be controlled, further improving the trapping effect of pests.

[0068] See also Figure 3 During the 16-day test, the present invention can continuously trap target insects, which shows that the present invention significantly prolongs the effective period of insect sex pheromones in a natural environment.

[0069] The present invention constructs a sustained-release system with photothermal response performance by compounding a thermoresponsive hydrogel with copper-phenol nanoparticles and loading insect sex pheromones. The test results show that the preparation can achieve stable release of pheromones under both artificial light and natural light conditions, showing excellent ability to trap pests. In particular, when combined with artificial light, the release rate of pheromones can be adjusted by artificially controlling the light intensity and illumination time, effectively improving the efficiency of pest capture and meeting the needs of different application scenarios.

[0070] Finally, it should be noted that the above content is only used to illustrate the technical solution of the present invention, rather than to limit the scope of protection of the present invention. Simple modifications or equivalent substitutions of the technical solution of the present invention by ordinary technicians in this field do not deviate from the essence and scope of the technical solution of the present invention.

Claims

1. A photothermal responsive insect sex pheromone sustained-release preparation, characterized in that: The invention comprises 54.55-59.41wt% of a thermoresponsive hydrogel, 0.99-9.09wt% of copper-polyphenol nanoparticles and 36.36-39.6wt% of an insect pheromone emulsion; the insect pheromone emulsion, the copper-polyphenol nanoparticles and the thermoresponsive hydrogel are mixed, stirred for 30 minutes to ensure that the insect pheromone is evenly distributed in the thermoresponsive hydrogel solution, cooled below 30°C to form a hydrogel, and a photothermal responsive insect pheromone sustained-release preparation is obtained; the release rate of the insect pheromone is synergistically controlled by the photothermal conversion effect of the copper-polyphenol nanoparticles and the temperature response of the thermoresponsive hydrogel; The thermal responsive hydrogel is prepared by adding 4.76wt% poly(N-isopropylacrylamide) and 0.74wt% low melting point agarose to 94.50wt% sterile water, stirring at 30°C until the solution is transparent, to prepare solution A; dissolving 0.98wt% vaseline and 2.93wt% Tween 80 in 96.09wt% water, ultrasonicating at 70°C for 20 minutes, to prepare solution B; mixing solution A and solution B in equal volumes, ultrasonicating for 20 minutes, stirring for 30 minutes, and cooling at below 30°C until gelation, to prepare a thermal responsive hydrogel; The insect pheromone emulsion is prepared by dissolving and mixing 0.0286wt% trans-11-tetradecene acetate, 0.0171wt% trans-11-tetradecene aldehyde, 0.0686wt% trans-11-tetradecene alcohol and 0.572wt% Tween 80, adding the mixture into 99.3137wt% water, and ultrasonicating at 180W power for 5 minutes to prepare the insect pheromone emulsion.

2. The photothermal responsive insect sex pheromone sustained-release preparation according to claim 1, characterized in that: The copper-polyphenol nanoparticles are prepared by adding copper sulfate, sodium dodecyl sulfate and cottonyphenol into water under ultrasonic conditions to prepare an aqueous solution, wherein the aqueous solution contains 0.0313wt% copper sulfate, 0.0625wt% sodium dodecyl sulfate and 0.0313wt% cottonyphenol, and after ultrasonic treatment for 10 minutes, stirring is continued for 20 hours, and the supernatant is removed by centrifugation. The precipitate is washed with pure water for 3 times, and freeze-dried at -40°C to obtain dark red solid copper-polyphenol nanoparticles, which are stored in the dark.

3. The photothermal responsive insect sex pheromone sustained-release preparation according to claim 1, characterized in that: The invention also comprises a functional additive with an addition amount of 0.01-5wt%, wherein the additive is selected from one or more of an antioxidant, a stabilizer and a dispersant.

4. The use of the photothermal responsive insect pheromone sustained-release preparation according to claim 1 in agricultural and animal husbandry pest control, characterized in that: The photothermal responsive insect pheromone slow-release preparation is placed in areas where pests frequently move, and the release rate of the insect pheromone is controlled by combining lighting, natural light, and shading treatment of natural light.

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