Cockroach wings-promoted safe and greener synthesis of silver nanoparticles and their insecticidal activity

Simpler and biocompatible greener approaches for the assembly of nanoparticles (NPs) have been the focus lately which have minimum environmental damage and often entails the use of natural biomolecules to synthesize NPs. Such greener synthesis of nanoparticles has capitalized on the use of microbes, fungi, and plants using biological resources. In this study, Periplaneta americana (American cockroach) wings' extract (chitin-rich) is studied as a novel biomaterial for the first time to synthesize silver NPs (less than 50 nm); chitin is the second most abundant polymer after cellulose on earth. The physicochemical properties of these NPs were analyzed using UV-visible spectroscopy, X-ray diffraction, and transmission electron microscopy (TEM). The insecticidal effect of ensuing NPs was examined on the mortality of Aphis gossypii under laboratory conditions; 48 h after treatments of A. gossypii with silver NPs (100 mu g/ml), the mortality rate in treated aphids was about 40% (an average), while an average percentage of losses in the control sample was about 10%. These results indicate the lethal effect of green-synthesized silver NPs on A. gossypii, in vitro.