Green‐Synthesized Silver Nanoparticles From Acacia nilotica Bark Extract: Characterization and Antioxidant, Antimicrobial, and Larvicidal Activities Against Aedes aegypti, Anophele
Bruntha Ramaraj, Lokeshwaran Selvam, Subala Subramanian Panchuravindrarajan, Muthusamy Ranganathan, Suresh Kumarasamy, Mathiyazhagan NarayananABSTRACT
The continuous increase in mosquito resistance and the frequent use of chemical pesticides pose a significant threat, and we are in need of eco‐friendly alternatives for vector control. In this study, the larvicidal efficacy of Acacia nilotica bark extract‐synthesized silver nanoparticles (AgNPs) was evaluated against three major mosquito vectors. Synthesized AgNPs were characterized by UV–visible spectroscopy, Fourier transform infrared spectroscopy (FT‐IR), scanning electron microscopy (SEM) with EDax (EDAX), and x‐ray diffraction (XRD). UV–visible spectroscopy confirmed the formation of AgNPs with a peak at 427 nm, and XRD determined the crystalline properties. SEM and EDAX confirmed the spherical shape and Ag peak at 3.15 keV. The antioxidant potential of AgNPs was confirmed with the highest inhibition (84%) of hydroxyl radicals, while DPPH and ABTS showed 63% and 58% inhibition, respectively. Higher antibacterial activity was found against Streptococcus pyrogenes, Pseudomonas aeruginosa, and Proteus vulgaris , and it exhibited potent larvicidal (240.714, 104.13, and 99.602) and adulticidal activities (13.560, 16.854, and 17.012), with LC 50 values. Smoke toxicity revealed 92% mortality in Aedes aegypti , while 85% and 83% were observed in Anopheles stephensi and Culex quinquefasciatus , respectively. This study demonstrates the potential of an innovative plant‐based nanobiopesticide for sustainable mosquito control, addressing the challenges of insecticide resistance.