Pest Invasion-Responsive Hollow Mesoporous Silica-Linked Carboxymethyl Starch Nanoparticles for Smart Abamectin Delivery
Amir E. Kaziem, Liupeng Yang, Yigang Lin, Yuting Tan, Zixia Song, Hanhong Xu, Zhixiang Zhang
Abstract
Interactive release formulations are one of the best strategies for enhancing pesticides usage. A 112 nm α-amylase enzyme-responsive nanosystem loaded with abamectin (ABM) was synthesized by attaching carboxymethyl starch (CMS) to the surface of hollow mesoporous silica (HMS) to improve ABM insecticidal activity and photostability. ABM-loaded HMS–CMS characteristics were tested. ABM release behavior under different pH levels and in the presence or absence of α-amylase enzyme was investigated. The ultraviolet (UV) protection ability and the insecticidal activity against one of the model insects, Spodoptera littoralis, were examined. The adhesion properties of ABM-loaded HMS–CMS on corn leaves have been tested. The prepared ABM-loaded HMS–CMS presented a high loading efficacy of up to 24.77% and enzymatic release dependency of up to 88.34% after 17 days of adding α-amylase enzyme. After 60 h of UV radiation, only 17.7% of the loaded ABM into HMS–CMS has deteriorated. ABM-loaded HMS–CMS showed better insecticidal activity against S. littoralis than abamectin commercial formulation (ABM-EC). After 14 days, the LC50 of ABM-loaded HMS–CMS was 51.7% lower than that of ABM-EC. The prepared ABM-loaded HMS–CMS showed excellent adhesion on corn leaves. We recommend using such formulations to achieve better and sustainable farming.