Synthesis, Characterization, and Pesticidal Activity of Emamectin Benzoate Nanoformulations against Phenacoccus solenopsis Tinsley (Hemiptera: Pseudococcidae).

Asem Elabasy,Zuhua Shi,Ali Shoaib,Muhammad Waqas,Mingxing Jiang

doi:10.3390/molecules24152801

Asem Elabasy, Zuhua Shi + Show 3 more

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https://doi.org/10.3390/molecules24152801

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Abstract

Using nanotechnology to develop new formulations of pesticides is considered a possible option in enhancing the efficiency, safety, and photostability of pesticides under various climatic conditions. In the present study, two novel nanoformulations (NFs) were successfully prepared based on nano-delivery systems for emamectin benzoate (EMB) by loading it on cellulose nanocrystals (CNCs) and silicon dioxide nanoparticles (SNPs) as carriers through a freeze-drying method. The synthesized nanoformulations were examined using field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and dynamic light scattering (DLS). The results showed that SNPs and CNCs had a loading efficiency of 43.31% and 15.04% (w/w) for EMB, respectively, and could effectively protect EMB from photolysis under UV radiation. The LC50 values for EMB + SNPs, EMB + CNCs, and EMB commercial formulation against Phenacoccus solenopsis were 0.01, 0.05, and 0.31 μg/mL, respectively, indicating that both NFs were more effective than the EMB commercial formulation. This work seeks to develop new nano-carriers for potential applications of pesticides in plant protection, which will reduce the recommended dose of pesticides and thereby decrease the amount of pesticide residue in food and the environment.

Highlights

Pesticides play a crucial role in agriculture to obtain high crop productivity and adequate food supplies
Technical, and it is better than that of emamectin benzoate (EMB) 1% only after exposure to ultraviolet irradiation for 48 h or more hours. These results clearly show that cellulose nanocrystals (CNCs) can protect EMB well and can improve the photostability of EMB
Formulation at 72 h after exposure. These results demonstrated that the NFs were more efficient than commercial EMB emulsifiable concentrate (EC) formulation, suggesting that silicon dioxide nanoparticles (SNPs) and CNCs as carriers can considerably improve the insecticidal activity of EMB

Summary

Introduction

Pesticides play a crucial role in agriculture to obtain high crop productivity and adequate food supplies. Repeated and indiscriminate application of pesticides has led to numerous issues, including increasing health risks to humans and animals, killing nontarget animals (e.g., predators and parasitoids of insect pests, and pollinators), polluting the environment, and increasing pest resistance [1]. Conventional pesticide formulations have several drawbacks, including poor solubility in water, high sensitivity to photolysis/hydrolysis, and easiness of evaporating and drifting along with the wind [2,3]. More than 90% of pesticide formulations run off into the environment instead of reaching target sites, which reduces the pesticide-use efficiency and worsens the pesticide-related issues [4]. It is essential to develop new routes and nanomaterials to improve pesticide formulations and to overcome their drawbacks.

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