Layer-by-layer assembled decomposable nanocapsules for light responsive release of pesticide imidacloprid on Aphis craccivora Koch

Background Conventional pesticide formulations are often griped about inefficiency due to the low biological uptake after spraying. Controlled release nanopesticides can precisely release pesticides in response to specific stimuli, thereby killing pests and pathogens with the least effective concentration. This study aims to develop nanocapsules-based photo decomposable nanopesticides for efficient pesticide control. Results The target nanopesticides were successfully fabricated by using layer-by-layer assembly of azobenzene grafted hyaluronic acid (Azo-HA) and PolyDADMAC, confirmed by UV–vis, DLS, Zeta potential and TEM measurements. Particle size and Zeta potential of the fabricated nanocapsules were 220 nm and + 46.1 mV, respectively, and the nanocapsules were found to maintain stable for up to 30 days. The optimized drug loading and encapsulation ratio of Imidacloprid (IMI) in IMI/Azo-HA@PolyDADMAC were 21.5% and 91.3%, respectively. Cumulative release of IMI from the nanopesticides was increased from ~50% to ~95% upon UV-light irradiation (365 nm). LC 50 value of the nanopesticides towards Aphis craccivora Koch was decreased from 2.22 mg/L to 0.55 mg/L upon UV-light irradiation. Conclusion The trans to cis transformation of Azo group in HA will decompose IMI/Azo-HA@PolyDADMAC nanopesticides upon UV irradiation, thus facilitated the IMI release, resulting in decreased concentration of pesticides for efficient pesticide control. Our work demonstrated the great potential of light-responsive nanocapsules as controlled release nanocarrier for efficient and eco-friendly pesticide-control in sustainable agriculture. This article is protected by copyright. All rights reserved.