Copper-fixed quat: a hybrid nanoparticle for application as a locally systemic pesticide (LSP) to manage bacterial spot disease of tomato

The development of bacterial tolerance against pesticides poses a serious threat to the sustainability of food production. Widespread use of copper (Cu)-based products for plant disease management has led to the emergence of copper-tolerant pathogens such as Xanthomonas perforans ( X. perforans ) strains in Florida, which is very destructive to the tomato ( Solanum lycopersicum ) industry. In this study, we report a hybrid nanoparticle (NP)-based system, coined Locally Systemic Pesticide (LSP), which has been designed for improved efficacy compared to conventional Cu-based bactericides against Cu-tolerant X. perforans . The silica core-shell structure of LSP particles makes it possible to host ultra-small Cu NPs (