Biological Synthesis of Copper Oxide Nano Particles Using Escherichia coli

In this paper, we report a facile biological method for extracellular synthesis of copper oxide nanoparticles (CONPs) using Escherichia coli (E. coli). We report that trichloroacetic acid (TCA) precipitated protein fraction of E. coli has synthesized copper oxide nanoparticles (CONPs), under simple experimental conditions like aerobic environment, neutral pH and room temperature. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) results have shown that proteins of molecular weight ranging from 22 KDa, 52 KDa, and 25 KDa are not only involved in reduction of Cu (II) into CONPs, but also play a significant role in stabilization of formed nanoparticles at room temperature. Further, transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction measurements (XRD) and fourier transform infrared (FTIR) analysis have confirmed the synthesis of nanoparticles through microbial route. CONPs formed were of variable size and shapes.