Biogenic Synthesis of Silver Nanoparticles Using Guava (<i>Psidium guajava</i>) Leaf Extract and Its Larvicidal Action against <i>Anopheles gambiae</i>

The progress in the field of nanotechnology has contributed to the development of tools for combating the most critical problems in developing countries. The requirements that such tools should meet are low-cost and resource settings, environmental protection, ease of use, and availability. The use of plant properties for the generation of nanoparticles (NPs), which serve as bioinsecticides to combat the plasticity and resistance of mosquitoes and parasites, is considered possible. Here, we report for the first time the larvicidal activity of silver (Ag) NPs (AgNPs) synthesized from Psidium guajava (P. guajava) extract, which targets the 4th instar larvae of Anopheles gambiae. Concentrations of AgNPs between 0 and 200 ppm were used and their LC50 at 24 h and 48 h were determined as 19.55 ppm and 8.737 ppm, respectively. The AgNPs were stable and highly effective against the larvae of A. gambiae and thereby we anticipate that they can be used to combat vector-borne diseases in developing countries.