Facile fabrication of pesticide nanocapsules using cinnamaldehyde derived imide polymer as wall material for pH-responsive and ultraviolet shielding properties

Abstract

The low utilization efficiency of pesticides poses a significant challenge to the sustainable development of agriculture. The nanocapsule-based pesticide delivery systems combine the advantages of nanotechnology and advanced materials to achieve on-demand and accurately targeted release. Herein, a facile and universal strategy was used to fabricate photosensitive pesticide nanocapsules using a versatile imine polymer derived from cinnamaldehyde (CIN) and ε-poly-L-lysine (PLL). Characterization results demonstrated that the nanocapsules prepared under optimal conditions exhibited uniform sizes (200–400 nm) and high encapsulation efficiency (>90 %). Photodegradation experiments revealed a significant increase of half-lives (7.21–55.57 times) under UV irradiation for the different pesticide nanocapsules. Furthermore, the pesticide nanocapsules demonstrated a high biological activity and excellent physicochemical properties, including pH-responsive release, maximum retention, and rain erosion resistance. The results of the mechanistic studies on the increased biological activity indicated that the nanocapsules could be adsorbed on the surface of target pathogenic cells and then released CIN and PLL, destroying the integrity of the cell membrane, and synergistically and effectively eradicating the pathogen with pesticide. Additionally, nanocapsules exhibited lower toxicity to zebrafish and genetic toxicity to Vicia faba than pesticide technical. Therefore, stimuli-responsive nanocapsules based on imide polymer have broad application prospects in the field of pesticides.