Microwave Mediated Fast Synthesis of Silver Nanoparticles and Investigation of Their Antibacterial Activities for Gram-Positive and Gram-Negative Microorganisms

Herein, a simple one-step microwave irradiation technique has been used to synthesize the silver nanoparticles using silver nitrate (AgNO3) solution and cetyltrimethyl ammonium bromide (CTAB) as a stabilizing agent. The crystals of as-prepared nanoparticles were studied using X-ray diffraction (XRD) and a selected area electron diffraction (SAED) pattern, confirming the single-phase face-centered cubic structure. The optical property measured using UV-Vis spectroscopy shows an absorption maximum at 420 nm, which also confirms the formation of silver nanoparticles. Transmission electron microscopy (TEM) analysis revealed that the silver nanoparticles have a spherical shape with an average diameter of similar to 6 nm. The antibacterial properties of silver nanoparticles were investigated using both Gram-positive and Gram-negative microorganisms, such as Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli. Klebsiella pneumoniae, and Candida albicans. Results showed a highest zone of inhibition of about 35 mm against P. aeruginosa as compared with E. coli (21 mm), S. aureus (30 mm), K. pneumonia (28 mm), and C. albicans (29 mm). These studies suggested that silver nanoparticles prepared by this fast and effective method might be developed as antibacterial agents against an extensive range of microorganisms to control and stop the spreading and persistence of bacterial infections.

Automated summary

The silver nanoparticles synthesized using a one-step microwave irradiation technique exhibited a single-phase face-centered cubic structure with an absorption maximum at 420 nm, confirming their formation. Transmission electron microscopy analysis revealed the nanoparticles to be spherical with an average diameter of approximately 6 nm. These nanoparticles showed strong antibacterial properties against various microorganisms, with the highest zone of inhibition observed against Pseudomonas aeruginosa.