Green Synthesis of Tin Oxide Nanoparticles using Psidium guajava Leaves Extract and its Applications in Antibacterial and Antioxidant Activities

Abstract

In this study, tin oxide (SnO₂) nanoparticles was synthesized via green synthetic route using Psidium guajava (Guava) leaf extract as reducing, capping and stabilizing agents. The synthesized SnO₂ NPs were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and UV-visible spectroscopy. The XRD analysis revealed that synthesized SnO₂ nanoparticles have tetragonal rutile structure, and the particle size was found to be 19.5 nm estimated by using Debye-Scherer’s equation. In addition, the average particle size calculated by using Williamson-Hall plot method was found to be 21.5 nm. The FTIR spectra reveals hydroxyl, alkyl, alkane, amide and hydroxyl tin group as a functional group. UV-Visible absorption spectra were found to be 270 nm, and its corresponding band gap energy was found to be 3.88 eV. Moreover, the antimicrobial activities of different concentrations of SnO₂ NPs using Psidium guajava leaf extract were also tested. Accordingly, the result showed that the highest zone of inhibitions was measured for SnO₂ NPs using 30mg/mL solution concentration and observed to be 18mm, 21mm and 20mm for S. aereus, P. aeruginosa and K. pneumoniae respectively. As synthesized SnO₂ NPs also showed significant antioxidant efficacy against 2,2-diphenyl-1-picrylhydrazyl radical.