Larvicidal Activity of Chemically Synthesized Silver Nanoparticles Against Anopheles stephensi

Background: Silver nanoparticles (AgNPs) have wide applications in different fields such as medicine, food industry, and pest management. Larvicidal activity of many herbally biosynthesized AgNPs have been evaluated against main malaria vector, that is, Anopheles stephensi. However, results of the studies are very different. No report has been found on larvicidal activity of chemically synthesized AgNPs against A. stephensi. Materials and Methods: AgNPs were synthesized using chemical reduction and characterized by dynamic light scattering and transmission electron microscopy. Concentration of silver ion in the final solution was determined by ICP-AES. Turbidity of solutions of AgNPs at different concentrations (i.e., 0.2-100 ppm) was studied. Subsequently, larvicidal activity of nanoparticles was evaluated, in line with the WHO guideline for laboratory tests. Results: AgNPs were synthesized successfully and confirmed by ultraviolet analysis. Nanoparticles were spherical with a diameter of similar to 30 nm. AgNPs had no larvicidal activity up to 80 ppm and showed a small larvicidal effect (similar to 20%) at 100 ppm. Conclusion: Chemically synthesized AgNPs are not proper candidates for control of larvae due to their low efficacy and effects on nontarget specious lived in stagnant water.