Green synthesis of silver oxide nanoparticles and its antibacterial activity against dental pathogens

Abstract

In the present study, the use of silver oxide nanoparticles (Ag₂O NPs) synthesized using Ficus benghalensis prop root extract (FBPRE) as a reducing and stabilizing agent is reported and evaluated for its antibacterial activity against dental bacterial strains. The effects of pH, extract concentration, metal ion concentration, and contact time were studied to confirm the optimum production of Ag₂O NPs. Our results suggest that, by increasing the extract concentration and the time frame, there will be a significant increase in the formation of nanoparticles. The UV-vis adsorption spectra show the absorbance peak in the range of 430 nm, and FTIR spectral peaks indicate that the phytochemicals in the extract are responsible for the formation of the nanoparticles. The HR-TEM image, SAED, and XRD pattern confirmed the morphology (spherical), silver oxide 42.7 nm and silver 51.4 nm, and crystalline nature of the obtained nanoparticles, respectively. The blend of FBPRE and Ag₂O NPs showed excellent antibacterial activities against the two-dental bacteria Streptococcus mutans and Lactobacilli sp. The study results suggest that the blend of synthesized Ag₂O NPS and FBPRE will be useful in tooth paste as a germicidal agent after extensive investigation with animal models.

Keywords: Antibacterial; Characterization; Ficus benghalensis; Nanoparticles; Optimization; Silver oxide.

Fig. 1

UV–vis adsorption spectra of Ag₂O NPs, FBPRE, and Ag⁺; the inset shows the color change in the reaction mixtures of whole tree (Ficus benghalensis), prop root, and powder of the Ficus benghalensis prop root

Fig. 2

UV–vis absorption spectra of the optimization of parameters for the production of Ag₂O NPs with different pHs (a), ratios of FBPRE from 0.5 to 5 mL (b), concentration of metal ions Ag⁺ from 0.1 to 1.0 mM (c) and different times from 0 to 270 min (d)

Fig. 3

FTIR spectra of FBPRE and Ag₂O NPs

Fig. 4

TEM images of Ag₂O NPs, particle size histogram, and corresponding SAED pattern of Ag₂O NPs

Fig. 5

X-ray diffraction patterns of synthesized Ag₂O NPs