Evaluation of Green-Synthesized Silver Nanoparticles with Origanum majorana Essential Oil: Physicochemical Properties and Antimicrobial Effectiveness

The rising prevalence of antibiotic-resistant bacteria highlights the urgent need for alternative therapies. Green-synthesized silver nanoparticles (AgNPs) coated with essential oils (EOs) offer a promising solution, combining low toxicity with synergistic antibacterial effects. AgNPs are biosynthesized using Origanum majorana (O. majorana) EO as a stabilizer and reducing agent. Physicochemical properties of EO-AgNPs are assessed using UV-Vis spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), zeta potential analysis, and Fourier Transform Infrared Spectroscopy (FTIR). In addition, their antibacterial activity and biofilm-eradicating potential against nine bacterial strains are evaluated. The formation of EO-AgNPs was detected with an absorption peak at 418 nm, and the particle size averaged 56.53 nm according to TEM analysis with the NPs exhibiting a spherical shape. SEM indicated that the AgNPs were coated with O. majorana EO components, as confirmed by FTIR analysis. EO-AgNPs exhibited antibacterial efficacy against E. coli, E. faecalis, P. vulgaris, B. subtilis, S. agalactiae, P. aeruginosa, S. epidermidis, S. pyogenes, and S. aureus with Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) values ranging between 250 and 1000 µg/mL. EO-AgNPs inhibited bacterial biofilms with varying inhibition percentages. O. majorana EO-AgNPs can serve as antimicrobial agents, offering the potential for developing innovative treatment strategies to combat antimicrobial resistance. This research contributes to the scientific literature by promoting the use of innovative, environmentally friendly antimicrobial agents and nanotechnology-based therapies in both the medical, and food industries.