Fabrication of jellyfish-like porous polydopamine carriers for pesticide with pH-responsive release and UV-shielding performance

Conventional pesticides generally suffer from low actual utilization efficiency due to their large particle sizes, weak leaf adhesion and rain erosion. Developing functional nanomaterials with high foliar affinity and rain-fastness remains a major challenge for enhancing pesticide utilization efficiency. Herein, we developed novel jellyfish-like nanocarriers for pesticide delivery. Firstly, jellyfish-like mesoporous polydopamine (J-mPDA) were prepared via an interface anisotropic self-assembly strategy. The unique jellyfish-like structure may enlarge the contact area and the topological interaction between the leaf surface and the nanocarrier. The synthesized J-mPDA carriers presented radial mesopores with a cross-sectional size of about 290 nm and an imidacloprid (IMI) loading efficiency of 22.4%. After loading IMI, tannic acid-copper ions (TA/Cu) networks were utilized to cap the loaded-pesticide pores (IMI@J-mPDA@TA/Cu). The obtained IMI@J-mPDA@TA/Cu exhibited pH/near-infrared dual responsiveness release properties. The IMI@J-mPDA@TA/Cu significantly improved the adhesion and retention efficiency of the foliar surface. Furthermore, the obtained nanoparticles displayed good biosafety and no significant inhibitory effect on bacteria and seed germination. In addition, IMI@J-mPDA@TA/Cu possessed an improved 6-fold anti-UV photostability compared with IMI, and high control efficacy against Plutella xylostella . As a result, this work provides a novel option to address adhesion inefficiencies and reduce pesticide runoff, making it a promising for efficient pesticide delivery.