Evaluating the Antibacterial Efficacy of Nanocomposite Rare Earth Oxide (CeO₂: Nd₂O₃): An Experimental and Analytical Study

Abstract This research employed a biochemical synthesis approach to fabricate CeO2:Nd2O3 nanocomposite, accompanied by comprehensive characterization and evaluation of its antibacterial efficacy. X-ray diffraction analysis confirmed the formation of a highly crystalline cubic structure, with an average crystallite size of 9.25 nm calculated using the Scherrer equation. Transmission electron microscopy revealed uniform nanoparticles with a mean diameter of 14.53 nm. The nanocomposite demonstrated exceptional colloidal stability with a zeta potential of +79.01 mV. FTIR spectroscopy identified characteristic vibrational modes at 480.47 cm −1 (C-I stretching), 536.68 cm −1 (C-Br stretching), 1626.31 cm −1 (C=C stretching), and 3424.11 cm −1 (O-H stretching). The material exhibited concentration-dependent antioxidant activity through DPPH radical scavenging, ranging from 14.91% at 5 μg/mL to 34.72% at 60 μg/mL. Antibacterial assessment using the agar well diffusion method revealed significant inhibition zones against both Gram-positive and Gram-negative bacteria at 100 μg/mL concentration: Pseudomonas aeruginosa (28 mm), Staphylococcus aureus (23 mm), Streptococcus mutans (18 mm), and Escherichia coli (16 mm).