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.