Ethanolic Extract of Guava Seed Leaves (Psidium guajava L.) as Media for Biosynthesis of ZnO Nanoparticles : Characterization and In Vitro Study to Escherichia coli Bacteria Ahmad Fatoni1,a), Ika Oktania2), Yopi Rikmasari1) and Nurlisa Hidayati3)
Sekolah Tinggi Ilmu Farmasi Bhakti Pertiwi
Abstract
The biosynthesis of ZnO nanoparticles 1 and 2 was researched. Biosynthesis of ZnO nanoparticles, their characterization, and, its application as an antibacterial agent of Escherichia coli was the goal of this research. ZnO nanoparticles 1 were biosynthesized by the media of ethanolic extract of guava seed leaves (Psidium guajava L.), zinc ion, and an alkaline solution. ZnO nanoparticles 2 were biosynthesized without an alkaline solution. FTIR spectroscopy and X-ray diffractions are the instruments to analyze functional groups and physical structure of ZnO nanoparticles 1 and 2. The suspension of ZnO nanoparticles 1 and 2 was used as an antibacterial agent with the well agar diffusion method. The Zn-O group at ZnO nanoparticles 1 and 2 has a wavenumber at 470.63 and 675.09-617.22 cm-1 respectively. The crystallite size of ZnO nanoparticles 1 and 2 was estimated at 7.01 and 14.14 nm respectively. At the concentration of 0.5 and 1 % (w/v), ZnO nanoparticles 1 and 2 have the same average diameter inhibition zone to Escherichia coli bacteria.
