Silver Nanoparticles Synthesized from Water Extracts of <i>Artemisia annua</i> and Their Antibacterial Activity Against Aquatic Pathogens

Abstract Silver nanoparticles (AgNPs) by biological synthesis have many advantages. Among them, herbs attract wide attention due to their unique medicinal effects. In this paper, the water/alcohol/ether extracts of dried or fresh Artemisia annua were used as reducing agents and stabilizers to synthesize AgNPs. Water is a highly polar solvent that can effectively extract polar compounds such as phenolic profile, which possesses strong reducing properties and enables the reduction of Ag + to AgNPs. The prepared AgNPs were characterized using ultraviolet–visible (UV–vis) absorption spectra, X‐ray diffraction (XRD), Fourier transform infrared (FT‐IR) spectroscopy, transmission electron microscopy (TEM), and zeta potential analysis. The AgNPs prepared from the water extracts of dried Artemisia annua have obvious bacteriostatic effects on six common aquatic pathogens and have a wide application prospect in aquaculture. The inhibition zone against Vibrio anguillarum is up to 16.88 mm. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) against Vibrio anguillarum are 1.09 µg/mL and 2.17 µg/mL, respectively, which is lower than most published reports.