Biosynthesis of silver nanoparticles using Ocimum tenuiflorum extract and its efficacy assessment against Helicoverpa armigera

Abstract

Traditional methods of pest control are not able to prevent crop damage due to devastating pests. Therefore, through nanobiotechnology nano-bio pesticides and conjugated nanoparticles are produced as a pest control agent. The present work focused on the synthesis, characterization of silver nanoparticles (AgNPs) using Ocimum tenuiflorum leave extract and its larvicidal activity against Helicoverpa armigera. AgNPs were characterized by UV–Vis spectral analysis, indicated an absorbance of 4.695 at 560 nm. Moreover, Scanning Electron Microscope and X-ray Powder Diffraction showed that particles were spherical, ranging from 10 nm to 65 nm. The larvae of H. armigera were provided with an artificial diet with AgNPs coating of 0.25%, 0.5%, 0.75%, and 100% pure concentration. After 24 h, a dose response relationship in mortality was found maximum in pure AgNPs treated group, 83.33% and 75% in 0.75% treated group and 0.5% treated group, respectively. While the least mortality of 50% was observed in the 0.25%, AgNPs treated group. The LC50 calculated was 20.33 µL for AgNPs. It can be concluded that silver-nanoparticles possess a larvicidal effect. Furthermore, the biosynthesis of these particles is an efficient and profitable approach.