Development of Tridax procumbens-Mediated Silver Nanoparticles and Their Antioxidant Properties

Abstract

Plant-mediated synthesis of metal nanoparticles provides a sustainable alternative to conventional chemical routes. This study reports the green synthesis of silver nanoparticles (AgNPs) using Tridax procumbens root extract as a source of reducing and stabilizing phytochemicals and evaluates their antioxidant activity. Qualitative phytochemical screening confirmed the presence of different phytochemicals. FTIR, XRD, SEM, TEM, and EDX analyses confirmed the formation of crystalline, predominantly spherical, silver-rich nanoparticles with some agglomeration. Antioxidant activity was evaluated using the DPPH free-radical scavenging assay. The AgNPs exhibited moderate, concentration-dependent activity, with inhibition increasing from 28.6% at 25 µg/mL to 61.8% at 200 µg/mL, compared with 18.4–46.2% for the crude root extract and 42.7–85.9% for ascorbic acid over the same concentration range. The estimated IC₅₀ values were 132.4 µg/mL for the AgNPs, 226.7 µg/mL for the crude extract, and 58.3 µg/mL for ascorbic acid. These findings indicate that T. procumbens-mediated AgNPs have measurable but moderate antioxidant activity.