Antibacterial potential of zinc oxide nanoparticles derived from pineapple peel aqueous extract

Abstract

Pineapple peel waste contains antioxidant molecules. This paper describes a facile, efficient, and environmentally friendly approach for synthesizing ZnO nanoparticles using pineapple peel aqueous extract. This method aims to reduce the use of harmful chemicals in producing ZnO nanoparticles using zinc nitrate as a salt precursor and evaluating their antibacterial. Pineapple peel aqueous extract was obtained by macerating pineapple peel powder in distilled water. Engaging Zn(NO3)2, pineapple peel aqueous extract, and NaOH, ZnO NPs were successfully prepared by biosynthesis. X-ray diffraction (XRD) analysis and Fourier transform infrared (FTIR) spectroscopy was utilized to confirm the formation of ZnO NPs, while scanning electron microscopy (SEM) was employed to see the morphology and size distribution of nanoparticles. The antibacterial activity of pineapple peel extract-ZnO nanoparticles (pp-ZnO NPs) against Gram-positive and Gram-negative bacteria was evaluated by an agar disc diffusion method. The SEM images showed that by applying pineapple peel aqueous extract, the pp-ZnO with an average size below 100 nm with a mixture of flakes and rod-like shapes were obtained. The XRD pattern confirmed the wurtzite phase of ZnO, while antibacterial assay results showed that the pp-ZnO actively inhibited B. subtilis and E.coli. at concentrations of 5 and 10 wt%. Therefore, phyto-assisted synthesis mediated by pineapple peel wastes is a promising green approach to preparing ZnO nanoparticles.