One pot chemical co-precipitation preparation of magnetic graphene oxide-deltamethrin nanoformulations for management of Aedes aegypti

Abstract

Aedes-borne diseases are of worldwide concern due to the lack of effective medicine and vaccination. Frequent use of chemical intervention has developed insecticide resistance in mosquitoes and posed health risks to humans and the environment, necessitating an effective and safer intervention. Graphene Oxide (GO) is an efficient material that can absorb pesticide particles and release pesticide macromolecules in a controlled manner. With the proposition that magnetic graphene oxide (MGO)-based nanoformulations can be an eco-safe and effective material for pesticide conjugation, the present study synthesized these nanoformulations conjugated with a pyrethroid, deltamethrin (DL) through chemical co-precipitation method. The formulations were validated using biophysical techniques and investigated for their efficacy against Aedes aegypti. The X-ray diffraction (XRD) pattern of nanocomposites showed six intense diffraction peaks of Fe3O4 particles, X-ray photoelectron spectroscopy (XPS) displayed the C1s, O1s, and Fe2p photoelectron lines in the MGO nanocomposite's spectra, while Field Emission Scanning Electron Microscopy (FESEM) revealed the small size and uniformity of Fe3O4 nanoparticles on the GO surface. The individual MGO and DL, as well as MGO-DL binary combinations (1:1, 1:2, and 1:3) imparted significant larval toxicity, demonstrating 30%, 50%, and 85% CTC (Co-toxicity coefficient), respectively. High corresponding Synergistic factor (SF) values indicated significant synergism increasing with the rise in deltamethrin proportion. The MGO-DL combinations also increased irritancy and flight response in adults, the notable synergistic effects imparted by the 1:3 combination. The effective actions of MGO-DL nanoformulations against mosquitoes suggest their possible use for mosquito management as a safer and more operative intervention.