Evaluation of antimicrobial activity of synthesised silver nanoparticles using Thymus kotschyanus aqueous extract

Development of a green chemistry process for the synthesis of silver nanoparticles (AgNPs) has become a focus of interest. Characteristics of AgNPs were determined using techniques, such as ultraviolet-visible spectroscopy (UV-vis), Fourier transform infrared (FTIR) analysis, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy and X-ray diffraction (XRD). The synthesised AgNPs using Thymus kotschyanus had the most growth inhibition against gram-positive bacteria such as Staphylococcus aureus and Bacillus subtilise, while the growth inhibition of AgNPs at 1000-500 µg/ml occurred against Klebsiella pneumonia and at 1000-250 µg/ml of AgNPs was observed against E. coli. The UV-vis absorption spectra confirmed the formation of the AgNPs with the characteristic peak at 415 nm and SEM micrograph acknowledged spherical particles in a nanosize range. FTIR measured the possible biomolecules that are responsible for stabilisation of AgNPs. XRD analysis exhibited the crystalline nature of AgNPs and showed face-centred cubic structure. The synthesised AgNPs revealed significant antibacterial activity against gram-positive bacteria.