Enzyme and redox responsive mesoporous silica nanoparticles: Enhancing the insecticidal efficacy and biosafety of indoxacarb

Stimuli-responsive pesticide nanocarriers allow precise delivery of pesticides to target pests, enhancing insecticidal efficacy while improving safety for non-target organisms. Herein, mesoporous silica nanoparticles (MSNs) were synthesized via the sol–gel method, followed by encapsulation of indoxacarb (IN) within their pores. Disulfide bonds (SS) were grafted onto the MSN surface, and cyclodextrin (CD) was incorporated to obtain enzyme/redox dual-responsive nanoparticles (IN@MSNs@SS@CD). Physicochemical characterization revealed a well-defined spherical core–shell structure. The encapsulated IN content was approximately 22.27%. In the presence of α-amylase and glutathione, the highest cumulative release (72.9%) occurred at 7 days, demonstrating dual-responsive release behavior. The contact angle and resistance to rain erosion experiments show that the nanoparticles have good wettability and adhesion. Insecticidal activity tests showed that IN@MSNs@SS@CD caused higher mortality in Cnaphalocrocis medinalis than commercial IN@EC. Moreover, the nanoparticles exhibited enhanced biocompatibility toward earthworms, zebrafish, and human bronchial epithelial cells (BEAS-2B), supporting their environmentally benign potential. Herein, a dual-responsive nanoparticle that can be used for precise pest management to improve biosafety and wettability has been developed. It provides a transformative approach for precision agriculture.