Larvicidal Efficacy of Green Synthesized Silver Nanoparticles on Aedes aegyptii and its Impact on Nontarget Daphnia magna

Abstract

The current study is based on the synthesis of silver nanoparticles using Aspergillus fumigatus and its larvicidal activity against Aedes aegyptii. The optical, morphological, structural, and elemental properties of synthesized silver nanoparticles were investigated by UV–Vis spectroscopy, Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Energy-dispersive X-ray analysis (EDX) and Zeta potential. The characterization was confirmed by the surface plasmon resonance band at 434 nm. The results validated the spherical shape and size (28–33 nm) of the nanoparticles. Biosynthesized silver nanoparticles (AgNPs) have been evaluated for their effectiveness in controlling Aedes aegyptii larvae. The larvicidal effect was evident in the experiment when Aedes larvae were exposed to five different log concentrations of Aspergillus fumigatus based-AgNPs. The mortality in the larvae had been observed at various exposure times. Exposure of third instar larvae of Aedes aegypti to biosynthesized silver nanoparticles resulted in lethal concentrations (LC₅₀ and LC₉₀) of 2.624 and 4.728 ppm, respectively. Moreover, the biotoxicity screening against non-target organism Daphnia magna revealed the nontoxic nature of biogenic nanosilver against non-target fauna. The findings indicate that Aspergillus fumigatus has the potential to facilitate the swift synthesis of silver nanoparticles, presenting a novel approach for vector control strategies, without causing any harm to other aquatic organisms occupying the same ecological niche.