Investigation of structural properties and antibacterial activity of AgO nanoparticle extract from Solanum nigrum/Mentha leaf extracts by green synthesis method

Abstract

Solanum nigrum and Mentha leaf extracts were used as reducing and stabilizing reagents in the green synthesis of silver oxide nanoparticles (AgO NPs), and their antibacterial efficacy was subsequently evaluated. The structure and morphology of AgO NPs were evaluated using X-ray diffraction and filed emission scanning electron microscope. High-resolution transmission electron microscopy images were used to analyze the characteristics of certain particles with clearly discernible atomic structures. The functional group and elemental composition of AgO NPs were investigated using fourier transform infrared spectroscopy and energy dispersive X-ray spectroscopy. Ultraviolet–visible spectroscopy was used to determine the energy band gap (E g) of the sample. The dielectric constant of both samples was found to be inversely proportional to frequency, whereas the dielectric loss was found to be directly proportional to temperature but directly proportional to frequency. This suggests that the space charge has an effect on the mechanism of charge transfer as well as polarizability. AC conductivity rises and is inversely proportional to temperature increases. AgO NPs had a size range of around 56 nm and were mostly spherical. The antibacterial potential of the synthesized AgO NPs using both extracts was compared by the well-diffusion method. AgO NPs at 50–100 µg·mL−1 concentration significantly inhibited the bacterial growth of Bacillus cereus, Staphylococcus aureus, Escherichia coli, and Klebsiella pneumonia.

Keywords

• silver nanoparticles
• solanum nigrum
• mentha
• green synthesis
• structural properties