Cu-Zn and Ag-Cu bimetallic nanoparticles as larvicide to control malaria parasite vector: A comparative analysis

A single mosquito can often threaten public health and well-being. With emerging mosquito-borne zoonotic diseases and emerging insecticide resistance, demand for new insecticidal formulations has been increased. Studies on the use of monometallic nanoparticle formulation like nanosilver, nanocopper and nanozinc, synthesized with biological components to kill mosquito larvae are efficient. Our hypothesis is that the bimetallic combination of nanoparticles can kill mosquito larvae more efficiently at lower concentrations than their respective monometallic form. To carry out experimentation on the above hypothesis, extracellular synthesis of monometallic Copper-, Zinc-, and Silver-nanoparticles, and bimetallic Copper-Zinc and Silver-Copper nanoparticles is done with the help of aqueous leaf extract of Ocimum sanctum (Linn.). The characterization study was done through U.V.-Vis spectroscopy and XRD which indicated the presence of nanoparticles in the solution. Efficacy on 3rd instar larvae of Anopheles mosquito was performed by following WHO's guidelines. Lethal concentration values (LC) for each nanoparticles were obtained. Results of efficacy showed bimetallic Silver-Copper nanoparticles followed by Copper-Zinc nanoparticles, can potentially kill mosquito larvae in lower concentrations as compare to their respective monometallic forms.