ECO-FRIENDLY SYNTHESIS AND ANTIOXIDANT POTENTIAL OF IRON NANOPARTICLES MEDIATED by AVOCADO SEED EXTRACT

Abstract

The contribution of oxidative stress to chronic diseases has prompted the exploration of sustainable antioxidant agents derived from natural sources. This study aimed to develop and characterize iron nanoparticles (FeNPs-A) synthesized through a green approach using aqueous avocado (Persea americana) seed extract as a biogenic reducing and stabilizing agent. The formation of FeNPs-A was initially identified through visual observation of the colloidal color, followed by UV-Visible spectrophotometric analysis to determine the absorption wavelength. Changes in the hydroxyl functional groups of the extract and FeNPs-A were further examined using FTIR spectroscopy, and the antioxidant activity was evaluated using the DPPH assay. The synthesis process was visually indicated by a distinct color transition from brownish yellow to deep black, confirming the reduction of Fe³? ions. UV-Vis analysis exhibited a characteristic absorption peak at 282 nm, validating nanoparticle formation through surface plasmon resonance (SPR). FTIR spectra showed significant shifts in O-H, C=O, and C-O stretching vibrations and the appearance of a Fe-O band at 399-433 cm?¹, indicating the participation of hydroxyl and carbonyl groups in nanoparticle nucleation and stabilization. Antioxidant assessment revealed an IC?? value of 78.20 ± 12.44 µg/mL, demonstrating substantial free radical scavenging capacity, with inhibition percentages increasing from 65.83 ± 4.08% to 91.55 ± 0.92% as the concentration increased from 312.5 to 5000 ppm.

Keywords: Antioxidant activity, DPPH assay, Green synthesis, Iron nanoparticles, Persea americana,