CaCO3-coated hollow mesoporous silica nanoparticles for pH-responsive fungicides release

The utilization of fungicides in plants is very low, emphasizing the need to improve their utilization rates. In this study, the fungicide dimethachlon (Dim) was encapsulated within hollow mesoporous silica (HMSNs), and a coating was formed on the HMSNs surface through the reaction of Na2 CO3 and CaCl2 , resulting in a pH-responsive delivery system named D/H@CaCO3 , proven valuable in preventing sclerotinia diseases in romaine lettuce. When disease-infested romaine lettuce was treated with D/H@CaCO3 , it degraded in the acidic microenvironment of Sclerotinia sclerotiorum ( S. sclerotiorum ), allowing for the pH-responsive release of Dim and effectively killing S. sclerotiorum . Moreover, the degraded CaCO3 coating releases CO2 , which enhances the photosynthetic pigment contents, such as chlorophyll a, chlorophyll b, and carotenoids, in turn promoting plant growth. D/H@CaCO3 is biologically safe for plants and is environmentally friendly, as confirmed by assessments involving zebrafish and earthworms. Given their antifungal capabilities, the controlled release of fungicides offers potential for plant protection. (c) 2024 Published by Elsevier B.V. on behalf of Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences.