Green synthesis of silver nanoparticles using leaf extract of the hydrophyte <italic>Persicaria senegalensis</italic>: Preparation and antioxidant activity.

AbstractFor the first time, methanolic leaf extract of the hydrophyte <italic>Persicaria senegalensis</italic> L. was evaluated for its ability to silver nanoparticles (AgNPs) biosynthesis. The effect of stirring time and plant extract concentrations was studied. X-ray diffraction (XRD) and scanning electron microscope (SEM) were used for characterization of AgNPs. XRD confirmed the AgNPs formation with crystallite size in the range 23–71 nm. The crystallite size increased with increasing both stirring time and plant extract concentration. Antioxidants, including secondary metabolites such as flavonoids and phenols are substances that inhibit oxidative damage to the cell organisms by scavenging the free radicals and thus reducing the hazard of diseases. The scavenging and antioxidant activities of the plant leaf extract and AgNPs were evaluated and exhibited potent antioxidant activity. The total antioxidant capacity (TAC) of plant leaf extract and AgNPs was 52.41 and 10.13 µg AA equivalent/mg DW, respectively. Total phenolics (TPs) and total flavonoids (TFs), revealed high contents equal to 154.83 µg gallic acid equivalent and 100.05 µg quercetin equivalent/mg DW plant extract, respectively. [ABSTRACT FROM AUTHOR]