A novel dual stimuli-responsive and double-loaded insecticidal nanoformulation for efficient control of insect pest

The dual stimuli-responsive nanoformulations with two insecticides promise to improve insecticidal efficacy, which has yet to be developed for insect pest control. In this study, glutathione (GSH)/pH dual stimuli-responsive and chlorantraniliprole (CHL)/spinosad (SPI) double-loaded nanoformulations (DMSNs-CHL-polyethyleneimine (PEI)-SPI) are designed to manage Spodoptera frugiperda. The dendritic mesoporous silica nanoparticles (DMSNs)-based DMSNs-CHL-PEI-SPI exhibit a high insecticide loading content (52.03%), strong corn leave adhesion (87.63%), and enhanced insecticide release behaviors (94.53% for CHL and 57.05% for SPI at 144 h) in response to GSH and alkaline conditions. DMSNs-CHL-PEI-SPI can effectively enhance the utilization efficiency of insecticides for the dual stimuli-responsive. Bioactivity tests showed that the corn leaves sprayed with DMSNs-CHLPEI-SPI possess higher toxicity to Spodoptera frugiperda than physical mixture and single-loaded nano-formulations with the same amount of active ingredients. DMSNs-CHL-PEI-SPI also possesses a long-term control efficacy, with similar to 20% pest mortality on corn leaves at 21 d after spraying. In fields, two or more insecticides are usually used to control one insect pest, instead of a single active ingredient. That means the double-loaded insecticide nanoformulation is a practical tool for developing novel insecticide formulations. These results reveal that the dual stimuli-responsive and double-loaded insecticidal nanoformulations are highly promising for sustainable management of insect pests.