Tebuconazole-Loaded Mesoporous Silica Nanoparticles Encapsulated with Chitosan and Their Application in Wheat Growth

Controlled-release pesticide formulation exhibiting low phytotoxicity and long-term effectiveness is highly promising. In this work, a novel pH stimuli-responsive pesticide delivery system was established by combining spray drying with ion cross-linking to coat chitosan onto tebuconazole-loaded mesoporous silica nanoparticles (Teb@MSNs@CS). The results demonstrated that the loading capacity of Teb@MSNs@CS for tebuconazole (Teb) was approximately 25.80%. The chitosan attached on the mesoporous silica nanoparticles could extend the release time of Teb both in the solution medium and soil column. Meanwhile, the coated chitosan endowed the pH-responsive release of Teb. The bioactivity survey confirmed that Teb@MSNs@CS exhibited enhanced control of Fusarium graminearum compared to pure Teb. Moreover, Teb@MSNs@CS displayed lower phytotoxicity than both Teb@MSNs and pure Teb during wheat germination and seeding growth experiments. As revealed by the above-mentioned results, the use of responsive carriers as the pesticide-delivery systems can be potentially implemented in wheat growth.