Preparation of pH-Responsive GO-L-Ser-KM Nano-pesticide and Its Control Effect on Tobacco Brown Spot
Zhao Qingxun
Song Saijie
Liu Jianfeng
Sun Guangjun
Yang Maofa
Yin Guiji
Shen Jian
Ai Yongfeng
Wen Yun
Lu Guanlin
Abstract：Stimuli-responsive controlled-release pesticide delivery systems(PDS)based on nanocarriers have emerged as novel and promising approaches for efficient utilization of pesticides.In this study,L-serine(L-Ser)modified graphene oxide(GO)was ingeniously utilized as the delivery vehicle for kresoxim-methyl(KM),enabling the construction of a highly efficient and pH-responsive controlled-release nano-pesticide sys-tem,namely GO-L-Ser-KM.This system was then applied to control two prevalent species of tobacco brown spot pathogens(Alternaria longipes and Alter n aria alternata).The results indicated that the SEM,FT-IR and XDR characterizations demonstrated the successful preparation of GO-L-Ser-KM,with a drug-loading rate of 152.96％.Under diverse pH conditions,the system effectively achieved controlled and sustained release of the pesticide,while simultaneously enhanced the photolysis resistance and dispersion stability of KM.Compared with KM alone,GO-L-Ser-KM exhibited superior wetting ability on tobacco leaves and significantly improved the resistance to rainwater wash-off.Moreover,GO-L-Ser-KM demonstrated more potent antibacterial activity against the tobacco brown spot pathogens.It effectively reduced the half-maximal effective concentration(EC50)of the pesticide,with a synergistic ratio(SR)value exceeding 1.5.This indicated that GO-L-Ser-KM not only exerted a synergistic bactericidal effect but also possessed a targeted adsorption capacity for pathogenic spores.In addition,GO-L-Ser displayed excellent biosafety towards tobacco and mung beans.By encapsulating KM,the biotoxicity of KM was mitigated to a certain extent.Overall,it was highly anticipated that GO-L-Ser-KM would hold great potential and broad application prospects in terms of functional release,improving the comprehensive performance of pesticides,and achieving highly efficient disease control.
Keywords：Nano-pesticideGraphene oxidepH-Controlled releaseTobacco brown spot
Publication Date：2025-06-30
Online Publishing Date：2026-05-22(First online date of this platform, not the publication date of the document)
Pages：12( 121-132 )