Preparation of zein-grafted mesoporous silica nanoparticles for improving Lambda-cyhalothrin insecticidal activity and biosafety

Currently, stimuli-responsive pesticide carriers can effectively enhance the insecticidal effectiveness against target pests and safety to nontarget organisms , and further reduce environmental pollution. In this work, a pesticide delivery system (LCN@MSN-SS-Zein) based on pH and redox dual-stimuli-responsive was prepared by loading Lambda-cyhalothrin (LCN) onto biodegradable disulfide-functionalized mesoporous silica nanoparticles and combining with gatekeeper zein. The results showed that LCN@MSN-SS-Zein had a high pesticide loading (24.7%, w/w). The nanoparticles have excellent pH and redox dual response behavior and have significant controlled release characteristics. Under the stimulation of pH and glutathione , the disulfide bond and zein structure of the nanoparticles are decomposed to release LCN on demand. Compared with LCN technical, the stability of LCN@MSN-SS-Zein nanoparticles under ultraviolet light was significantly enhanced, and the adhesivity of these nanoparticles on the cabbage leaf surface was significantly improved. Biological activity tests showed that LCN@MSN-SS-Zein nanoparticles had higher insecticidal activity against Spodoptera exigua than Lambda-cyhalothrin emulsion oil in water (LCN@EW), and the control effect was more lasting, while the toxicity to zebrafish was significantly reduced. In addition, MSN-SS-Zein nanoparticles were safe for the growth of cabbage and had good biocompatibility. Therefore, LCN@MSN-SS-Zein nanoparticles provide a new strategy for effective pest control and have broad application prospects.