Novel synthesis of gold nanoparticles using Artemisia vulgaris L. leaf extract and their efficacy of larvicidal activity against dengue fever vector Aedes aegypti L.

The Aedes aegypti L. mosquito transmits dengue and yellow fever, which cause millions of death every year. Dengue is a mosquito-borne viral disease that has rapidly spread worldwide particularly in countries with tropical and subtropical climates areas. The present study denotes a simple and eco-friendly biosynthesis of gold nanoparticles using Artemisia vulgaris L. leaf extract as reducing agent. The synthesized gold nanoparticles were characterized by UV-Visible Spectroscopy, X-Ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FT-IR), Dynamic Light Scattering (DLS), Zeta Potential (ZP), Transmission Electron Microscopy (TEM) and Energy Dispersive X-ray Spectroscopy (EDX). Solid state C NMR was utilized to confirm the presence of larvicidal compound Beta caryophyllene in the synthesized AuNPs. Larvicidal activity of the synthesized AuNPs was measured against A. aegypti over 12 and 24h exposure periods and compared with essential oil in various concentrations (25ppm, 50ppm, 100ppm, 200ppm and 400ppm). After a 12h exposure period, the larvicidal activity of 3 instar larva by AuNPs showed LC=156.55ppm and LC=2506.21ppm, while and essential oil displayed LC=128.99ppm and LC=1477.08ppm. Larvicidal activity of 4 instar larva by AuNPs showed LC=97.90ppm and LC=1677.36ppm, while essential oil displayed LC=136.15ppm and LC=2223.55ppm. After a 24h of exposure period, larvicidal activity of 3 instar larva by AuNPs showed LC=62.47ppm and LC=430.16ppm and essential oil showed LC=111.15ppm and LC=1441.51ppm. The larvicidal activity of 4 instar larva and AuNPs displayed LC=43.01ppm and LC=376.70ppm and for essential oil LC=74.42ppm, LC=858.36ppm. Histopathology of A. aegypti with AuNPs for 3and 4 stage larvae after 24h exposure at the highest mortality concentration (400ppm) showed that the area of the midgut, epithelial cells and cortex were highly affected. The present findings demonstrate that the biosynthesis of AuNPs using A. vulgaris leaf extracts could be an eco-friendly, safer nanobiopesticide and treatment against A. aegypti which could be used to combat of dengue fever.