Ming Zhao,Peiquan Li,Hongjun Zhou,Li Hao,Huayao Chen,Xinhua Zhou
With the increase in global food demand and the destruction of environment, the development of sustainable agriculture has become increasingly more important. Stimuli-responsive controlled-release agrochemicals enhance the bioavailability of active ingredients and reduce the frequency of use and environmental pollution. Herein, 3,3′-dithiodipropionic acid was used as a functional bridge to covalently link the degradable natural polymer zein and chitosan oligosaccharides (CS) to prepare a water-dispersed environmentally friendly pesticide carrier. Subsequently, via hydrophobic and hydrogen bonding interactions photo-decomposable avermectin (AVM) was encapsulated forming a stimuli-responsive intelligent nanopesticide delivery system (AVM@CS-SS-Zein) was developed by encapsulating in the carrier. AVM was released slowly from AVM@CS-SS-Zein particles in a neutral condition and was released rapidly under stimulation of glutathione and alkalinity in simulated insects. The photostability of AVM@CS-SS-Zein was improved by 6-fold compared with that of AVM and the nanoparticles had good adherence to the leaves, slowly releasing AVM and avoiding the light decomposition of active ingredients. When the pests ingest the leaves containing AVM@CS-SS-Zein, the rapid disintegration of the nanoparticles in vivo leads to a good insecticidal effect and the control rate of AVM@CS-SS-Zein on Plutella xylostella was higher than that of AVM. After 120 h of UV irradiation, the pest mortality rate of AVM@CS-SS-Zein was 46.7% while that of AVM and AVM emulsifiable concentrate was only 13.3% and 20.0%, respectively. Therefore, this pH/redox dual stimuli-responsive nanopesticide formulation achieves target control of pests and provides an efficient nanoplatform for green agriculture.
You Liang,Yunhao Gao,Weichen Wang,Hongqiang Dong,Rong Tang,Jiale Yang,Junfan Niu,Zhiyuan Zhou,Na Jiang,Yongsong Cao
It is highly desirable to construct stimuli-responsive nanocarriers for improving pesticides targeting and preventing the pesticides premature release. In this work, a novel redox and α-amylase dual stimuli-responsive pesticide delivery system was established by bonding functionalized starch with biodegradable disulfide-bond-bridged mesoporous silica nanoparticles which loaded with avermectin (avermectin@MSNs-ss-starch nanoparticles). The results demonstrated that the loading capacity of avermectin@MSNs-ss-starch nanoparticles for avermectin was approximately 9.3 %. The starch attached covalently on the mesoporous silica nanoparticles could protect avermectin from photodegradation and prevent premature release of active ingredient. Meanwhile, the coated starch and disulfide-bridged structure of nanoparticles could be decomposed and consequently release of the avermectin on demand when nanoparticles were metabolized by glutathione and α-amylase in insects. The bioactivity survey confirmed that avermectin@MSNs-ss-starch nanoparticles had a longer duration in controlling Plutella xylostella larvae compared to avermectin emulsifiable concentrate. In consideration of the superior insecticidal activity and free of toxic organic solvent, this target-specific pesticide release system has promising potential in pest management.
危险品化学品经营许可证（带存储）