Metal-phenolic coated rod-like silica nanocarriers with pH responsiveness for pesticide delivery

Entrapping pesticides in carriers would be beneficial to reduce the risk to environmental safety caused by the heavy use of pesticides. In this paper, hollow silica (hSiO2) nanorods were synthesized by sodium carbonate etching silica nanorods. The prepared hSiO2 nanocarriers have an average diameter of 100 nm and 200 nm in length, and possess good biocompatibility. Compared with spherical silica carriers, the LCH of hSiO2 carrier was increased by 35 %. After loading dinotefuran (DNF) pesticide, tannic acid-Cu complexes (TA/Cu) were coated to block the loaded DNF (DNF@hSiO2 @TA/Cu). Compared with free DNF, the half-life of DNF entrapped in hSiO2 carriers was extended by about 10 times under UV irradiation. The DNF@hSiO2 @TA/Cu system displays excellent wettability to cucumber leaves and good inhibitory effect on Penicillium and diamondback moth. The DNF@hSiO2 @TA/Cu system displays pH-responsive release. This work provides an efficient nanoplatform for effective utilization of pesticides.