pH and NIR responsive polydopamine-doped dendritic silica carriers for pesticide delivery

The stimuli-responsive pesticide delivery system provides a powerful strategy for enhancing the effective utilization of pesticides and reducing environmental pollution. Here, we prepared a new polydopamine doped dendritic silica (SiO₂/PDA) nanocarriers for pesticide delivery. The SiO₂/PDA nanocarriers present uniform spheres with an average diameter of 250 nm and carry center-radial inner pores. After loading dinotefuran (DNF) insecticide, polyethyleneimine (PEI) was used to cap the loaded-pesticide pores. The resulting SiO₂/PDA@PEI displays high photothermal conversion effect (η = 35.1 %) and pH and near infrared (NIR) light-responsive release behavior. Meanwhile, the SiO₂/PDA and SiO₂/PDA@PEI carriers displayed high adhesion and wettability to leaves, and the photostability of DNF encapsulated in SiO₂/PDA@PEI was improved by nearly 10 times greater than for free DNF. Importantly, the SiO₂/PDA carriers possessed a benign biocompatibility on Escherichia coli (E. coli), seed and cells. Therefore, this work provides a promising approach to improve the utilization of pesticide.