Size Controlled Green Synthesis of Biocompatible Silver Nanoparticles with Enhanced Mosquito Larvicidal Activity

Abstract

The present study focuses on rapid and green synthesis of silver nanoparticles (AgNPs) by using aqueous extract of Indian spice Asafoetida. To study the enhanced reducing and capping activity of Agave americana, four different combinations were employed, where a fixed volume of Asafoetida aqueous solution was mixed with different proportions of 1\xa0mM aqueous silver nitrate solution and A. americana extract. Formation of AgNPs was signified through color change from colorless to dark brown and confirmed using UV–Vis spectral analysis. SEM and TEM results showed spherical and well dispersed AgNPs with particle size ranging between 50 and 125\xa0nm, more over the X-ray diffraction patterns signified their crystalline nature. FTIR spectra of different combinations exhibited consistent pattern of decreasing particle size with increasing ratios of extracts which was also reflected in their larvicidal activity. The larvicidal application of these nanoparticles was also studied against three mosquito vectors and found most effective against malaria vector, Anopheles stephensi. Risk assessment was monitored on HEK 293 cell lines and proved safer with range of 92.8–78.2% cell viability after 24\xa0h. This is first report where size of AgNPs was controlled through phytoextract combinations and additive effect was validated through enhanced larvicidal activity and biocompatibility.