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-13 NMR was utilized to confirm the presence of larvicidal compound Beta caryophyllene in the synthesized AuNPs. Larvicidal activity of the synthesized AuNPs was measured againstA. aegypti over 12 and 24 h exposure periods and compared with essential oil in various concentrations (25 ppm, 50 ppm, 100 ppm, 200 ppm and 400 ppm). After a 12 h exposure period, the larvicidal activity of 31 instar larva by AuNPs showed LC50 = 156.55 ppm and LC90 = 2506.21 ppm, while and essential oil displayed LC50 = 128.99 ppm and LC90 = 1477.08 ppm. Larvicidal activity of 4th instar larva by AuNPs showed LC50 = 97.90 ppm and LC90 = 1677.36 ppm, while essential oil displayed LC50 = 136.15 ppm and LC90 = 2223.55 ppm. After a 24 h of exposure period, larvicidal activity of 3rd instar larva by AuNPs showed LC50 = 62.47 ppm and LC90 = 430.16 ppm and essential oil showed LC50 = 111.15 ppm and LC90 = 1441.51 ppm. The larvicidal activity of 4th instar larva and AuNPs displayed LC50 = 43.01 ppm and LC90 = 376.70 ppm and for essential oil LC50 = 74.42 ppm, LC90 = 858.36 ppm. Histopathology of A. aegypti with AuNPs for 3rd and 4th stage larvae after 24 h exposure at the highest mortality concentration (400 ppm) 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. (C) 2017 Published by Elsevier GmbH.