Biosynthesis, Characterization, Evaluation, and Shelf-Life Study of Silver Nanoparticles against Cotton Bollworm, Helicoverpa armigera (Hubner) (Noctuidae: Lepidoptera)

Abstract

Nanoparticles provide a promising and alternative platform of eco-friendly technologies that encompasses better cost-resilient remedies against one of the most economically harnessing insect pests of cotton. The main goal of this research was to provide a better management strategy through biologically synthesizing (sunlight exposure method) green nanoparticles from leaf extracts of Azadirachta indica and Pongamia pinnata and proving their bioefficacy on H. armigera (2nd instar). Characterization of bio-synthesized silver nanoparticles was carried out using UV-Visible spectroscopy for confirming the formation of nanoparticles, a Particle Size Analyzer (PSA) for determining the size/distribution of particles, and a Scanning Electron Microscope (SEM) for analyzing the surface topology of nanoparticles. The results obtained from PSA analysis showed that A. indica and P. pinnata-based silver nanoparticles had an average diameter of 61.70 nm and 68.80, respectively. Topographical images obtained from SEM proved that most of the green synthesized silver nanoparticles were spherical in shape. A. indica-based silver nanoparticles were found to be comparatively more efficient and have higher insecticidal activity compared to P. pinnata-based nanoparticles. A. indica-based AgNPs recorded larval mortality of 60.00 to 93.33 percent at the concentrations of 500 to 2000 ppm, followed by P. pinnata-based nanoparticles, with 60.00 to 90.00 percent larval mortality. Shelf-life studies revealed that A. indica-based AgNPs had the maximum negative zeta potential of −58.96 mV and could be stored for three months without losing bioefficacy and up to six months with negligible reduction in bioefficacy. Symptoms caused by silver nanoparticles were leakage of body fluids, sluggishness, inactiveness, brittleness, etc.

Nano-bioformulations: emerging trends and potential applications in next generation crop protection

“…The symptoms induced by silver nanoparticles included body fluid leakage, sluggishness, inactiveness, and brittleness (Table 2). 184 Currently, biopesticides were less effective because of their less persistence and shelf-life under field conditions. Nano-based production and application of biopesticides enhance the persistence and efficacy through an eco-friendly manner.…”

Synthesis, Characterization and Performance of Materials for a Sustainable Future

“…Biosynthesis can be used for the production of nanomaterials in some cases. In the study of Anees et al [ 19 ], the green synthesis (sunlight exposure method) of Ag nanoparticles from leaf extracts of Azadirachta indica and Pongamia pinnata was performed. The nanoparticles were tested, which demonstrated their bioefficacy on H. armigera (2nd instar).…”