Infrared-Light-Responsive Controlled-Release Pesticide Using Hollow Carbon Microspheres@Polyethylene Glycol/α-Cyclodextrin Gel

Controlled release of pesticides by light regulation is one of the most viable strategies recently developed for the highly efficient utilization of agrochemicals. Herein, we report an infrared-light-responsive pesticide delivery system for the controlled release of imidacloprid (IMI) by preparation of functional hollow carbon microspheres (HCMs). After IMI loading and surface functionalization with polyethylene glycol (PEG) and alpha-cyclodextrin (alpha-CD), IMI was sequestered in the pesticide system (denoted as HCMs/IMI/PEG/alpha-CD) as a result of the formation of a PEG/alpha-CD gel network. Upon the irradiation of infrared light, HCMs with high photothermal conversion efficiency (42.8%) raised the local temperature effectively, leading to the collapse of the gel network and the release of IMI. In comparison to the amount of pesticide release (29%) under sunlight, it could reach 77% driven by infrared light, which was an intriguing improvement. Consequently, HCMs/IMI/PEG/alpha-CD under infrared light showed significantly higher pest control efficacy on corn borers by 125% than itself alone. This work provides a promising method to intentionally regulate pesticide release and enhance utilization efficiency.

Automated summary

The study presents an infrared-light-responsive pesticide delivery system using functional hollow carbon microspheres for controlled release of imidacloprid. The system demonstrated a significantly higher pesticide release efficiency under infrared light compared to sunlight, resulting in enhanced pest control efficacy on corn borers. This work offers a promising approach for intentionally regulating pesticide release and improving utilization efficiency.