Free Radical Scavenging Potential of Cobalt Nanoparticles Synthesized from Ipomoea Batatas Leaves Extract

Synthesizing nanoparticles with high antioxidant capacity through green routes is critical for creating biocompatible antioxidants. This present study investigated the free-radical scavenging potential of cobalt nanoparticles (CoNPs) synthesized from Ipomoea batatas leaf extract. Air-dried leaf powder was macerated separately with distilled water and ethanol for 48 h, respectively. The filtrates were lyophilized to give aqueous and ethanol extracts. Total phenolic, flavonoid and tannin contents were quantified on both extracts, followed by DPPH scavenging assay. The ethanol extract that exhibited higher activity was utilized in the synthesis of CoNPs. The NPs were characterized via UV, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM-EDX) analysis. The results showed that the ethanol extract demonstrated higher DPPH scavenging activity (IC₅₀ 66.49 µg/ml) than aqueous extract (IC₅₀: 641.35 µg/ml) and CoNPs (IC₅₀: 175.18 µg/ml). The CoNPs also competed favorably with ascorbic acid for ferric reducing potential. UV absorption peak was observed at 220 nm, corresponding to the surface plasmon resonance of CoNPs. The FT-IR showed characteristic peaks at <800 cm⁻¹ which is characteristic of cobalt oxide bond. The XRD and SEM-EDX analyses showed that the CoNPs were nanocrystalline, spherical, and well-dispersed with an average size of 17–22 nm. The study concludes that the synthesized CoNPs exhibited significant in vitro antioxidant potential which could be further explored for in vivo antioxidant potential.