Green Synthesis of Silver Nanoparticles Using Artemisia vestita : Phytochemical Insights and Bioactivity Against Fish Pathogens

ABSTRACT The rapid emergence of multidrug‐resistant fish pathogens poses a significant threat to sustainable aquaculture and underscores the urgent need for eco‐friendly alternatives to conventional antibiotics. This study presents a comprehensive investigation into the green synthesis of silver nanoparticles using the aqueous extract of Artemisia vestita and their antioxidant and antibacterial potential against fish‐pathogenic bacteria. Silver nanoparticles (AvAgNPs) were synthesised under optimised conditions (30°C, 50 min, neutral pH) and characterised using UV–Vis spectroscopy, FESEM‐EDX, XRD, FTIR, and zeta potential analyses, confirming spherical morphology (size ∼46.46 nm) and crystalline face‐centred cubic structure. Antibacterial activity, assessed by the agar diffusion method, showed significantly higher efficacy of AvAgNPs than the A. vestita extract, with maximum inhibition against Aeromonas salmonicida (ZOI = 20.03 mm; MIC = 32 µg/mL; MBC = 64 µg/mL). Antioxidant evaluation using the DPPH assay revealed enhanced free radical scavenging activity of AvAgNPs (IC 50 = 120.8 µg/mL) compared to the A. vestita extract (IC 50 = 141.7 µg/mL). Furthermore, LC–MS–based phytochemical profiling identified common bioactive flavonoids and sesquiterpenoids in the extract that may contribute to nanoparticle formation and stabilisation. These findings highlight A. vestita ‐mediated AgNPs as a promising bio‐nanotechnological approach for sustainable aquaculture therapeutics.