Curcuma longa-mediated Biogenic and Eco-friendly Silver Nanoparticles with Promising Antibacterial Activity

Abstract

An affordable and environmentally suitable method for generating AgNPs (silver nanoparticles) was attained utilizing an aqueous rhizome extract of Curcuma longa (Cl). A detailed analysis of the synthesized Cl-AgNPs was performed utilizing a number of analytical techniques, comprising UV-vis spectroscopy, DLS, FTIR, XRD, SEM, EDAX along with elemental mapping, and TEM. UV-vis spectroscopy substantiated successful synthesis of Cl-AgNPs, as there was a change in the surface plasmon resonance (SPR) peak from λmax 416 nm to λmax 423 nm. XRD showed that the nature of Cl-AgNPs is crystalline and possess a face-centered cubic (FCC) structure. The average size of the crystallites was observed to be 16 nm through Debye-Scherrer equation. Further, SEM/TEM analysis depicted that the size range of the NPs are of 30-70 nm and spherical in shape. Additionally, antibacterial effect of the Cl-AgNPs were assessed through the broth dilution method and well-diffusion method to find out the MIC and MBC. Results showed Cl-AgNPs are effective in inhibiting E. coli (Gram-negative) as well as S. aureus (Gram-positive), with 8 mm and 6 mm inhibition zones, respectively. Besides, Cl-AgNPs displayed a concentration-dependent antioxidant activity, suggesting ROS-mediated antibacterial activity. These findings highlight the anti-bacterial capability of these biogenic Cl-AgNPs.