Eco-Friendly Synthesis And Characterization Of Curcumin-Assisted Silver Nanoparticles With Enhanced Antimicrobial And Antioxidant Potential

Abstract

The present study reports the green synthesis of silver nanoparticles (CurAgNPs) using isolated curcumin from Curcuma longa as a reducing and stabilizing agent. Curcumin was extracted from rhizomes via Soxhlet method and purified using crystallization and spectroscopic confirmation. The synthesis of CurAgNPs was visually indicated by a color change from yellow to brown, and further confirmed by UV–Vis spectroscopy, which exhibited a characteristic Surface Plasmon Resonance (SPR) peak at ~421 nm. FTIR analysis revealed the participation of hydroxyl and carbonyl functional groups in the reduction and stabilization of nanoparticles. X-ray diffraction (XRD) confirmed the crystalline, face-centered cubic structure, while TEM and SEM imaging demonstrated spherical nanoparticles with uniform distribution and an average size range of 15–30 nm. Elemental composition was verified by EDX analysis. The biological evaluation of CurAgNPs revealed potent antimicrobial activity against Gram-negative and Gram-positive bacteria (E. coli, P. aeruginosa, S. aureus) and the fungal strain Candida albicans, with inhibition zones ranging between 17–22 mm and low MIC values (12.5–25 µg/mL). Antioxidant activity, determined by DPPH, ABTS, and reducing power assays, indicated strong radical scavenging potential (72.4% at 100 µg/mL), surpassing pure curcumin alone. These findings highlight the synergistic effect of curcumin and silver, resulting in nanoparticles with enhanced bioactivity. The study demonstrates that isolated curcumin can serve as an effective and reproducible bioreductant for the eco-friendly synthesis of silver nanoparticles. The dual antimicrobial and antioxidant properties of CurAgNPs suggest promising applications in medicine, agriculture, cosmetics, and food packaging. This research bridges a critical gap by shifting from crude plant extracts to isolated bioactive compounds, ensuring greater stability, control, and scalability of nanoparticle synthesis for future biomedical and industrial use.