Biogenic synthesis of silver nanoparticles using Sida cuneifolia leaf extract for enhanced antibacterial, cytotoxic, and anti-biofilm activities

Abstract

Antimicrobial resistance (AMR) is one of the global threats that needs to be addressed. Nanotechnology represents a promising way to address this issue due to its multifaceted mode of action. This study aimed to synthesize and evaluate the antimicrobial and anti-biofilm properties of silver nanoparticles using S. cuneifolia leaves extract. The formation and properties of AgNPs were characterized using a UV–Vis spectrophotometer, an FT-IR spectrophotometer, TEM, and XRD. Disc diffusion and MIC were used to evaluate the antibacterial activity of AgNPs towards E. coli, S. flexneri, and S. aureus. The antibacterial action of silver NPs was observed using SEM, and cytotoxicity was assessed using the hemolysis assay. The anti-biofilm was evaluated against E. coli and S. aureus. From the results obtained, a sharp peak in the UV–Vis spectra centered at 419 nm was associated with AgNPs, while the sharp, distinct peaks in the powder diffractograms were linked to the face-centered cubic (fcc) of crystalline AgNPs. TEM micrographs confirmed their spherical morphology, with dimensions varying from 4 to 31 nm. The nanoparticles showed significant antibacterial and anti-biofilm activities against the tested isolates. Additionally, SEM confirmed that they could destroy the cell membrane and cause death. The biocompatibility of the synthesized AgNPs was safe at 100 μg/mL. Therefore, S. cuneifolia leaf extract has the potential to be an environmentally friendly substitute for the fabrication of Ag nanoparticles. The findings reveal that the synthesized nanoparticles could serve as a secure and effective alternative for addressing AMR.