Abstract:Nano-controlled release formulation based on mesoporous silica nanoparticles(MSNs)provides an effective way for accurate pesticide delivery. In this study, temperature-responsive emamectin
benzoate (EB) nano-controlled release formulation ( EB@ MSNs@ K(NIPAAM-MAA))was prepared by sol-gel method. The appearance, release behavior, insecticidal activity and safety to non-target organisms
were studied systematically. The results of TEM showed that the unloaded particles MSNs@K( NIPAAM-MAA)were round in shape, uniform in size and rough in surface, and the particle size is distributed in
the range of 150~170 nm. The results of BET, FTIR and TGA showed that the thermosensitive polymer was successfully grafted ( grafting rate of 19.5%)and EB was successfully loaded into MSNs ( drug load-
ing of 15.7% ). Release behavior studies showed that higher temperatures(28 ℃ and 24 ℃ ) were benefical for the release of EB.Both EB@ MSNs@ K( NIPAAM-MAA)and commercial EB@ EC had reasonable control effect against Spodoptera frugiperda at the same concentration, but the insecticidal effect of EB@ EC was lower than that of EB@ MSNs@ K( NIPAAM-MAA) with time extension,indicating that
EB@ MSNs@ K( NIPAAM-MAA)had a longer effective duration. The biosafety test showed that the LCso of EB@ MSNs@ K( NIPAAM-MAA)was 26.62 mg/kg at 14 d on carthworms, which showed low toxicity. In addition, EB@ MSNs@K(NIPAAM-MAA) had no significant effect on the changes in chlorophyll content of corn leaves at a range of concentrations.