pH-responsive release and washout resistance of chitosan-based nano-pesticides for sustainable control of plumeria rust

• Published in: International journal of biological macromolecules 2022-12, Vol.222, p.188-197
• Main Authors: Zhou, Yi, Wu, Jiyingzi, Zhou, Jun, Lin, Sukun, Cheng, Dongmei
• Format: Article
• Language: English
• Subjects: chitosan; Coleosporium plumeria; crosslinking; field experimentation; Nanoparticles; penconazole; pH-responsive release; spore germination; wettability
• ISSN: 0141-8130; 1879-0003
• DOI: 10.1016/j.ijbiomac.2022.09.144

Controlled pesticide release in response to environmental stimuli by encapsulating pesticides in a carrier is a feasible approach to improve the effective utilization rate. In this study, pH-responsive release nanoparticles loaded with penconazole (PE) were prepared by ionic cross-linking of chitosan and carboxymethyl chitosan (PE@CS/CMCS-NPs). PE@CS/CMCS-NPs exhibited good washout resistance and wettability properties, increasing the washing resistance of the pesticide by approximately 20 times under continuous washing. The results of the release experiments showed that nanoparticles had adjustable controlled-release characteristics with the change in pH based on the swelling of nanoparticles. The results of spore germination experiments showed that PE@CS/CMCS-NPs enhanced the inhibitory effect under acidic conditions. The field experiment results showed that PE@CS/CMCS-NPs had a better control effect than PE-aqueous solution, extended the duration and slowed down the dissipation of PE. These results indicated that the CS/CMCS-NPs pH-responsive release system has great potential in the development of an effective pesticide formulation. •A pH-responsive nanoparticles loaded penconazole (PE@CS/CMCS) was constructed.•Combined with the fitting equation of pH swelling and release, the drug release mechanism of PE@CS/CMCS was revealed.•The control efficacy of PE@CS/CMCS against plumeria rust was correlated with pH.•PE@CS/CMCS exhibited good washout resistance and wettability properties.•PE@CS/CMCS had better control effect than PE-aqueous solution, extended the duration and slowed down the dissipation of PE.