Fabrication of Silver Nanoparticles Using Fimbristylis miliacea: A Cheap and Effective Tool against Invasive Mosquito Vector, Aedes albopictus

Abstract

Mosquitoes are the most critical group of insects in the context of public health, since they transmit key parasites and pathogens, causing millions of deaths annually. Aedes albopictus is an important invasive mosquito vector of dengue fever across urban and semiurban areas of India. In this study, we biofabricated silver nanoparticles (AgNPs) using the Fimbristylis miliacea aqueous leaf extract (Fm-ALE) as reducing and stabilizing agent. The synthesis of Fm-AgNPs was confirmed by the excitation of surface plasmon resonance and orange-brown color using ultraviolet-visible (UV-vis) spectrophotometry. High-resolution scanning electron microscopic (HR-SEM) and transmission electron microscopic (TEM) showed the clustered (size 0.5 μm) and quasi-spherical structures of Fm-AgNPs. The formation of AgNPs has been characterized by X-ray diffraction (XRD) spectroscopy. Fourier transform infrared (FTIR) spectroscopy investigated the identity of secondary metabolites, which may act as Fm-AgNP capping agents. These results propose that AgNPs synthesized provided from those Fm-ALE have the high sources to be improved into the most suitable materials useful for protecting and killing the invasive mosquito vector, Ae. albopictus populations. The acute toxicity of Fm-ALE synthesized Ag NPs, and a combined treatment testing blends of mosquito vector was evaluated against I, II, III, and IV instar larva’s (ILs) of Ae. albopictus. The LC50 values of Fm-ALE (174.39 ppm I-ILs, 214.40 ppm II-ILs, 232.38 ppm III-ILs, and 251.62 ppm IV-ILs) and Fm-AgNPs synthesized were 23.78 ppm I-ILs; 27.88 ppm II-ILs; 31.47 ppm III-ILs; 36.68 ppm IV-ILs, respectively. Likewise, Fm-AgNP synthesis was more toxic than ALE in the invasive mosquito vector and recorded from UV-vis spectrum, FTIR, TEM, and XRD analysis. These results propose that AgNPs synthesized provided from those Fm-ALE have the high sources to be improved into the most suitable materials useful for protecting and killing the invasive mosquito vector, Ae. albopictus populations.