Green-synthesis of Ag2O nanoparticles for antimicrobial assays**

Abstract

Silver oxide nanoparticles (Ag2O NPs) in the aqueous colloidal state were synthesized using the green method. Aqueous silver nitrate was prepared and mixed jointly with an aqueous extract of Lawsonia inermis (henna) leaf and heated with stirring at 75 °C for 1h. Then, an aqueous colloidal solution of Ag2O NPs with a dark brown colour is forming. The physicochemical characterization of Ag2O NPs was studied using different techniques. A polycrystalline structure of (Ag2O/Ag) in face-centred cubic and cubic phases was revealing via grazing incident X-ray diffraction (GIXRD) patterns. Energy-dispersive X-ray analysis (EDX) spectra confirmed GIXRD results through peaks corresponding to the silver and oxygen elements making up the accurate composition of the silver oxide. UV-Vis absorbance peak of the localized surface plasmon resonance (SPR) appeared at the visible region and exhibited a blueshift at ∼425 nm with an energy bandgap ∼2.8 eV. The surface morphology and the size of the silver nanoparticles were analyzed using high resolution (FE-SEM) microscopy. FTIR spectra of Ag2O NPs has showed a shift in the bands compared to those produced by aqueous extract of the henna leaf (only). (0.4 molars) Ag2O NPs has showed excellent antimicrobial activity assays against all the pathogens microbe's strains. Henna plant extract (only) has showed poor activity compared to Ag2O NPs. In comparison, the inhibition zone diameter of the gram-negative Bacteria is more considerable than the gram-positive bacteria. Moreover, Ag2O NPs activity against Bacteria is more prominent than fungi.

Keywords

• antimicrobial
• lawsonia inermis
• ag2o nps
• fungi