Environmentally Friendly Zr-Based MOF for Pesticide Delivery: Ultrahigh Loading Capacity, pH-Responsive Release, Improved Leaf Affinity, and Enhanced Antipest Activity.

The stimuli responsive pesticide delivery system (PDS) has drawn increasing attention in recent years, a system which can effectively improve the utilization of pesticides. In the current research, we report a pH responsive PDS by using carboxymethyl cellulose (CMC) modified Zr-based metal organic frameworks (UiO-66-NH) as the nanocarrier for acetamiprid (ATP). UiO-66-NH-CMC possesses a large surface area and abundant pores, which can effectively load ATP, and the loading rate is as high as 90.79%. Compared with free ATP, the ATP@UiO-66-NH-CMC nanopesticide exhibits pH responsive controlled release behavior, and the pesticide can sustained release to the medium. In addition, it also shows improved leaf affinity, which makes it easier to wet the leaf surface and improve the utilization of pesticide. Therefore, ATP@UiO-66-NH-CMC displays better antipest activity against aphids than free ATP does. Meanwhile, ATP@UiO-66-NH-CMC shows no negative effects on the germination and growth of maize, showing good biosafety. Moreover, the ATP@UiO-66-NH-CMC nanopesticide does not contain any toxic organic solvents or additives. Therefore, we hope that it can be a suitable candidate for plant protection and sustainable agriculture.