Auxin-mediated biosynthesis of silver nanoparticles: comprehensive characterisation and antibacterial activity...

Silver nanoparticles (AgNPs) are well-known for their potent antibacterial properties. However, the rise of antibiotic-resistant bacteria highlights the need for alternative antimicrobial strategies. Green synthesis using biological molecules offers an eco-friendly route to nanoparticle production.

This study aims to synthesise AgNPs using plant growth hormones (Auxins), specifically indole-3-acetic acid (IAA) and indole-3-butyric acid (IBA), and to evaluate their antibacterial activity against pathogenic bacteria.

AgNPs were synthesised using IAA and IBA as reducing and stabilising agents. The synthesised nanoparticles were characterised by UV-Visible spectroscopy, Fourier Transform Infrared Spectroscopy (FTIR), Particle Size Analysis, Dynamic Light Scattering (DLS) for hydrodynamic diameter, Zeta potential for surface charge, and Field Emission Scanning Electron Microscopy (FE-SEM) for morphological analysis. Antibacterial assays were performed against Staphylococcus aureus and Escherichia coli.

The IAA and IBA-mediated AgNPs showed controlled size distribution, stability, and uniform morphology. Enhanced antibacterial activity was observed, particularly against S. aureus, compared to E. coli.

IAA and IBA-mediated synthesis provide a green, sustainable method for producing AgNPs with significant antibacterial potential. These Auxin-based AgNPs represent promising candidates for combating antibiotic-resistant bacterial strains.