Fabrication of abamectin-loaded mesoporous silica nanoparticles by emulsion-solvent evaporation to improve photolysis stability and extend insecticidal activity.

Mesoporous silica nanoparticles (MSNs) can be designed to effectively load, protect, and control the release of pesticides. In this study, emulsion-solvent evaporation was used to fabricate abamectin-loaded MSNs. Our method could deliver abamectin in the process of MSN self-assembly, resulting in simple operation, short preparation period, and outstanding drug carrying capacity. The characteristics of abamectin-loaded MSNs, including morphology, loading content, stability against photolysis, controlled release behavior, and toxicological effect, were systematically investigated. Abamectin-loaded MSNs were successfully produced, having spherical shape, rough surface, uniform particle sizes, typically hollow structure, high loading efficiency (44.8%), excellent photodegradation-reducing ability, and controlled-release properties. The biological activity survey for abamectin-loaded MSNs showed excellent toxicological properties against Plutella xylostella larvae, and maintained biological activity until the 15th day, with 70% mortality of the target insect. The results of this study are beneficial for the development of a delivery system for the rational and effective usage of pesticides.