Extracellular biosynthesis and characterization of silver and zinc oxide nanoparticles using Pseudomonas aeruginosa and Escherichia coli

Abstract

Abstract Background: The development of dependable and environmentally friendly nanomaterial resources is an essential aspect of recent nanotechnology research and application. Microorganisms have recently been investigated as a potential biofactor for the synthesis of many nanoparticles (NPs). Objectives: The aim of this article is to evaluate the extracellular biosynthesis capabilities of metallic NPs such as silver (Ag) and zinc oxide (ZnO) by screening common bacteria. Materials and Methods: Silver nitrate and zinc nitrate were used as a source of Ag and ZnO NPs, by means of Escherichia coli and Pseudomonas aeruginosa as potential candidates for the rapid synthesis of NPs. Ag and ZnO NPs were synthesized using a reduction of aqueous solutions with cell-free filtrates of bacteria. Characterization of synthesized NPs was conducted by UV–Vis spectroscopy. Results: Transmission electron microscopy (TEM) was used to examine the particle size of (Ag, ZnO) NPs. The maximum absorbance was around (425, 450 nm) for Ag and (300, 380 nm) for ZnO by E. coli and P. aeruginosa, respectively. We found that particle size of Ag NP obtained from P. aeruginosa was smaller than that of NP obtained from E. coli. The range of particle size was 24–32 nm with an average of 29.5 nm for Ag P. aeruginosa and was 25–37 nm with an average of 32 nm for Ag E. coli. The particle size range of ZnO of P. aeruginosa was 23–28 nm with an average of 25 nm and was 25–34 nm with an average of 29.7 nm for E. coli. Conclusion: E. coli and P. aeruginosa are good candidates for biosynthesis of NPs. As a result, obliged characteristics and green synthesis and the potential issue for various environmental and health-related applications may exist.