Biosynthesis of Curcuma longa-mediated silver nanoparticles for enhanced antibacterial efficacy

An economical and environment-friendly biosynthesis of silver nanoparticles (AgNPs) was attained utilizing an aqueous extract of the rhizome of Curcuma longa ( Cl ). Comprehensive characterization of Cl -AgNPs was performed employing relevant analytical tools, such as Fourier-transform infrared spectroscopy (FTIR), UV-visible spectroscopy, dynamic light scattering (DLS), X-ray diffraction (XRD), scanning electron microscopy (SEM), Energy-dispersive X-ray analysis (EDAX) with elemental mapping, and transmission electron microscopy (TEM). The UV-Vis spectroscopy indicated the effective synthesis of Cl -AgNPs, as indicated by an alteration in the surface plasmon resonance (SPR) peak at λ _max 416 ( Cl extract) to λ _max 423 nm ( Cl -AgNPs). Cl -AgNPs were observed to be spherical, with 30-70 nm average size, and exhibited a face-centred cubic (fcc) crystalline structure, as evident by XRD analysis. The crystallite size was determined to be 16 nm via the Debye-Scherrer equation. The antibacterial potential of Cl -AgNPs was measured using the broth dilution method to establish the minimum inhibitory concentration (MIC) and the maximum bactericidal concentration (MBC), as well as the well-diffusion technique at 1 mg/ml concentration. The Cl -AgNPs demonstrated bactericidal efficiency against Escherichia coli and Staphylococcus aureus, with inhibition zones measuring 8 mm and 6 mm, respectively. Additionally, Cl -AgNPs exhibited concentration-dependent total antioxidant capacity as compared to the standard (ascorbic acid) and Cl extract. These findings indicate that Cl -AgNPs hold a promising capacity for applications in biomedicine and nanomedicine.