The present study focused on the preparation of nanoemulsions of three organophosphorus compounds (chlorpyrifos-methyl, diazinon, and malathion) as insecticides against larvae of the cotton leafworm (Spodoptera littoralis). Oil-in-Water (O/W) nanoemulsions were prepared by the ultrasonication method and characterized by Transmission Electron Microscopy (TEM) and Dynamic Light Scattering (DLS) for droplet size analysis. The droplet size values of nanoemulsions were 18.35, 33.05, and 177.20 nm for chlorpyrifos-methyl, diazinon, and malathion, respectively. TEM image and DLS revealed that the droplets were spherical in shape and fall in the nanoemulsion range. The developed formulations were evaluated for insecticidal action against the 4th instar larvae of S. littoralis. Median lethal concentration (LC₅₀) values during a 24 h exposure were 1.27, 2691.12, and 1779.58 mg/L for chlorpyrifos-methyl, diazinon, and malathion nanoemulsions, respectively using a leaf-dip method. However, the LD₅₀ values were 7.84, 400.41, and 312.67 ng/larva using a topical application. The effect of nanoemulsions on the activity of acetylcholinesterase (AChE), adenosine triphosphate (ATPase) carboxylesterase (CaE), and glutathione S-transferase (GST) was studied. The nanoemulsions showed good toxicity compared to the active ingredient and emulsifiable concentrate (EC) formulations. The protein-ligands docking was also studied and the docking poses showed that the insecticides had a good binding affinity to the active site of the target enzymes. On this basis, these results suggest that O/W nanoemulsion could be applied for the delivery of these insecticides.

本研究集中于三种有机磷化合物（甲基毒死py，二嗪农和马拉硫磷）的纳米乳剂作为对棉叶虫（Spodoptera littoralis）幼虫的杀虫剂。通过超声方法制备水包油（O / W）纳米乳剂，并通过透射电子显微镜（TEM）和动态光散射（DLS）对液滴大小进行分析。毒死rif甲基，二嗪农和马拉硫磷的纳米乳剂液滴尺寸分别为18.35、33.05和177.20 nm。TEM图像和DLS显示液滴为球形，并且落在纳米乳液范围内。评价了所开发的制剂对滨海链球菌第四龄幼虫的杀虫作用。。毒死rif甲基，二嗪农和马拉硫磷纳米乳剂在24 h暴露期间的中位致死浓度（LC ₅₀）值分别为1.27、2691.12和1779.58 mg / L（采用叶浸法）。但是，使用局部施用时，LD ₅₀值为7.84、400.41和312.67 ng /幼虫。纳米乳液对乙酰胆碱酯酶（AChE），三磷酸腺苷（ATPase）羧酸酯酶（CaE）和谷胱甘肽S活性的影响研究了转移酶（GST）。与活性成分和乳油（EC）制剂相比，纳米乳剂显示出良好的毒性。还研究了蛋白质-配体的对接，对接姿势表明杀虫剂对目标酶的活性位点具有良好的结合亲和力。在此基础上，这些结果表明O / W纳米乳液可用于这些杀虫剂的递送。