Green synthesis of silver nanoparticles from Cassia roxburghii-a most potent power for mosquito control.

Mosquitoes transmit serious human diseases, causing millions of deaths every year. The use of synthetic insecticides to control vector mosquitoes has caused physiological resistance and adverse environmental effects in addition to high operational cost. Insecticides of synthesized natural products for vector control have been a priority in this area. In the present study, silver nanoparticles (AgNPs) synthesized using Cassia roxburghii plant leaf extract against Anopheles stephensi, Aedes aegypti, and Culex quinquefasciatus were determined. Larvae were exposed to varying concentrations of synthesized AgNPs (12, 24, 36, 48, and 60 μg/mL) and aqueous leaf extracts (60, 120, 180, 240, and 300 μg/mL) for 24 h. The synthesized AgNPs were characterized by UV-Vis spectrum, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), with energy-dispersive X-ray spectroscopy analysis (EDX), transmission electron microscopy, and X-ray diffraction analysis (XRD). Compare to aqueous extracted synthesized AgNPs showed extensive mortality rate against An. stephensi, Ae. aegypti, and C. quinquefasciatus with the LC50 and LC90 values that were 26.35, 28.67, 31.27 and 48.81, 53.24, and 58.11 μg/mL, respectively. No mortality was observed in the control. This is the first report on mosquito larvicidal activity of plant-synthesized nanoparticles. Thus, the use of C. roxburghii to synthesize silver nanoparticles is a rapid, eco-friendly, and a single-step approach, and the AgNPs formed can be potential mosquito larvicidal agents. Therefore, this study proves that C. roxburghii is a potential bioresource for stable, reproducible nanoparticle synthesis (AgNPs) and also can be used as an efficient mosquito control agent. This is the first report on the larvicidal activity of the plant extract and AgNPs.