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CN-121511974-B - Lignin-based pesticide controlled release micro-nano particles with multiple stimulus responses and preparation method thereof

CN121511974BCN 121511974 BCN121511974 BCN 121511974BCN-121511974-B

Abstract

The invention belongs to the technical field of agricultural bio-based slow release carriers and pesticide preparations, and relates to lignin-based pesticide controlled release micro-nano particles with multiple stimulus responses and a preparation method thereof, wherein lignin and dopamine hydrochloride are dissolved in a buffer solution according to a proportion, an oxidant is added into the lignin-dopamine hydrochloride, stirring reaction is carried out to obtain lignin-polydopamine composite solution, and the lignin-polydopamine composite solution is dialyzed and purified in water and dried to obtain lignin-polydopamine solid powder; mixing lignin-polydopamine solid powder and abamectin with a mass ratio of 1-5:1, dissolving in an organic solvent, adding water in a divided manner, stirring simultaneously, changing the system polarity, separating out micro-nano medicine carrying particles of lignin-polydopamine-entrapped abamectin, and drying the micro-nano medicine carrying particles to obtain the abamectin-entrapped abamectin-encapsulated abamectin. The avermectin delivery system has multiple environmental responsiveness, long-acting foliar adhesion function and controllable release characteristic.

Inventors

  • YANG GUIHUA
  • MENG LINGSONG
  • LIU KEFENG
  • CHEN JIACHUAN

Assignees

  • 齐鲁工业大学(山东省科学院)

Dates

Publication Date
20260512
Application Date
20260115

Claims (9)

  1. 1. The preparation method of the lignin-based pesticide controlled release micro-nano particles with multiple stimulus responses is characterized by comprising the following steps: dissolving lignin and dopamine hydrochloride in a buffer solution according to a proportion, adding an oxidant into the buffer solution, stirring the mixture for reaction to obtain lignin-polydopamine composite solution, dialyzing the lignin-polydopamine composite solution in water for purification, and drying the lignin-polydopamine composite solution to obtain lignin-polydopamine solid powder; mixing lignin-polydopamine solid powder and abamectin according to the mass ratio of 1-5:1, dissolving in an organic solvent, adding water in a divided manner, stirring simultaneously, changing the system polarity to separate out micro-nano medicine carrying particles of the lignin-polydopamine entrapped abamectin, and drying the micro-nano medicine carrying particles to obtain the abamectin-coated abamectin; the lignin is at least one selected from alkali lignin, kraft lignin, enzymatic lignin or lignin extracted by organic solvent.
  2. 2. The method for preparing lignin-based pesticide controlled release micro-nano particles with multiple stimulus responses according to claim 1, wherein the buffer solution is Tris-HCl buffer solution with a pH value of 8-9 and a concentration of 0.08-0.12 mol/L.
  3. 3. The preparation method of the lignin-based pesticide controlled release micro-nano particles with multiple stimulus responses, which is disclosed in claim 1, is characterized in that the oxidant is at least one of hydrogen peroxide, ammonium persulfate or laccase, the dosage of the hydrogen peroxide is 1-10% of the mass of lignin, the dosage of the ammonium persulfate is 3-15% of the mass of dopamine hydrochloride, and the dosage of the laccase is 5-10 IU/g lignin.
  4. 4. The method for preparing lignin-based pesticide controlled release micro-nano particles with multiple stimulus responses according to claim 1, wherein the dialysis purification dialysis bag has a molecular weight cutoff of 800-1200 Da and a dialysis time of 1-3 d.
  5. 5. The method for preparing lignin-based pesticide controlled release micro-nano particles with multiple stimulus responses according to claim 1 wherein the organic solvent is at least one selected from acetonitrile, ethanol or acetone.
  6. 6. The method for preparing lignin-based pesticide controlled release micro-nano particles with multiple stimulus responses according to claim 1, wherein the concentration of the lignin-polydopamine solid powder after being dissolved in an organic solvent is 0.5-1.5 wt%.
  7. 7. The method for preparing lignin-based pesticide controlled release micro-nano particles with multiple stimulus responses according to claim 1, wherein the volume ratio of the organic solvent to the water is 1-4:1.
  8. 8. The preparation method of the lignin-based pesticide controlled release micro-nano particles with multiple stimulus responses, which is characterized by further comprising the step of dialyzing a reaction system after the lignin-polydopamine entrapped abamectin is separated out, wherein the molecular weight cut-off of a dialysis bag is 800-1200 Da, and the dialysis time is 1-3 d.
  9. 9. A lignin-based pesticide controlled release micro-nano particle with multiple stimulus responses is characterized by being prepared by the preparation method of any one of claims 1-8.

Description

Lignin-based pesticide controlled release micro-nano particles with multiple stimulus responses and preparation method thereof Technical Field The invention belongs to the technical field of agricultural bio-based slow release carriers and pesticide preparations, and particularly relates to lignin-based pesticide controlled release micro-nano particles with multiple stimulus responses and a preparation method thereof. Background The statements herein merely provide background information related to the present disclosure and may not necessarily constitute prior art. The precise, efficient and green application of pesticides is a central challenge for sustainable development of modern agriculture. The traditional pesticide formulation represented by avermectin has the problems of rapid photodecomposition, weak foliar adhesion, uncontrollable release, low utilization rate and the like, so that frequent pesticide application, increased cost and serious environmental residue and ecological toxicity are caused. In addition, biological microenvironments (such as pH of intestinal tract of pests, specific enzymes secreted by plant wounds or pathogenic bacteria) and natural environment factors (day-night temperature difference) in the occurrence process of insect pests together form a scene of multiple trigger release, and development of a multi-response system capable of synchronously responding to pH, biological enzymes and temperature is needed. However, most existing carriers only have response capability to single environmental signals (such as pH or temperature), and are difficult to adapt to complex and changeable environments in the field. Disclosure of Invention Aiming at the problems of single environmental response dimension, complex preparation process and weak bonding capability with leaf surface interfaces commonly existing in pesticide controlled release carriers in the prior art, the invention provides lignin-based pesticide controlled release micro-nano particles with multiple stimulus responses and a preparation method thereof. The abamectin intelligent delivery system has the advantages of natural sources, multiple environmental responsiveness, long-acting foliar adhesion function and controllable release characteristic, and has important scientific value and application prospect for breaking through the common technical bottleneck that the traditional pesticide has low utilization rate, short duration and mismatching of release behavior and occurrence rule of diseases and insects under complex field conditions. In order to achieve the above object, the present invention is realized by the following technical scheme: In a first aspect, the invention provides a method for preparing lignin-based pesticide controlled release micro-nano particles with multiple stimulus responses, comprising the following steps: dissolving lignin and dopamine hydrochloride in a buffer solution according to a proportion, adding an oxidant into the buffer solution, stirring the mixture for reaction to obtain lignin-polydopamine composite solution, dialyzing the lignin-polydopamine composite solution in water for purification, and drying the lignin-polydopamine composite solution to obtain lignin-polydopamine solid powder; mixing lignin-polydopamine solid powder and abamectin with a mass ratio of 1-5:1, dissolving in an organic solvent, adding water in a divided manner, stirring simultaneously, changing the system polarity, separating out micro-nano medicine carrying particles of lignin-polydopamine-entrapped abamectin, and drying the micro-nano medicine carrying particles to obtain the abamectin-entrapped abamectin-encapsulated abamectin. In a second aspect, the invention provides lignin-based pesticide controlled release micro-nano particles with multiple stimulus responses, which are prepared by the preparation method. The beneficial effects achieved by one or more embodiments of the present invention described above are as follows: (1) The lignin-based pesticide controlled release micro-nano particles prepared by the method have multiple environmental stimulus response characteristics, and the intellectualization and the precision of pesticide release behaviors are realized. The micro-nano particles can synchronously respond to various common environmental signals in the field, and under the conditions of alkaline environment of intestinal tracts of pests or laccase secreted by plant pathogenic bacteria, chemical bond rupture or conformational change can occur to the lignin-polydopamine composite structure so as to accelerate pesticide release. Under the condition of temperature rise, the system can further regulate the release rate by diffusion. The pH-enzyme-temperature cooperative response mechanism enables pesticide release to be matched with the occurrence rule and environmental change of plant diseases and insect pests, and the pertinence and timeliness of pesticide application are obviously improved. (2) The mi