Optimization and characterization of zinc oxide nanoparticles synthesized with the assistance of Bacillus tequilensis supernatant

Biogenic synthesis of metal oxide nanoparticles offers a novel and environmentally friendly alternative to conventional synthesis methods. The current study utilized the cell-free supernatant of Bacillus tequilensis to assist the biosynthesis of Zinc Oxide (ZnO) nanoparticles by employing zinc sulphate monohydrate as precursor. The conditions of the synthesis procedure, such as precursor concentration, pH, and temperature of the reaction mixture, were optimized to improve the nanoparticle yield, stability, and reproducibility. The formation of ZnO nanoparticles was assessed using UV-Vis spectroscopy. Fourier-transform infrared (FTIR) analysis demonstrated the presence of functional groups responsible for the reduction and stabilization of the nanoparticles. The crystalline wurtzite structure of ZnO was established using X-ray Diffraction (XRD). Field-emission scanning electron microscopy (FESEM) with energy dispersive X-ray spectroscopy established the shape of the particles and elemental composition corresponding to Zn and O. Zeta potential analysis indicated the moderate colloidal stability of the synthesized nanoparticles. The findings of the present study demonstrate the feasibility of using Bacillus tequilensis as a novel biological system for the controlled synthesis of ZnO nanoparticles using the cell-free supernatant method.