Biological synthesis and characterization of gold nanoparticles from Enterococcus faecalis

Abstract

The present investigation discusses about extracellular synthesis of gold nanoparticles from standardized Enterococcus faecalis culture supernatant with 20 mM hydraulic chloride (v/v ratio) solution. The bacterial culture supernatant was able to produce gold nanoparticles with different sizes as confirmed by visual observation and UV-Vis spectroscopy. The appearance of dark ruby color indicated the synthesis of gold nanoparticles in the reaction mixture. UV-Vis spectrum of the aqueous medium containing gold nanoparticles showed a maximum absorbance peak around 590 nm. The Field Emission Scanning Electron Microscopy and Energy-dispersive X-ray (EDX) study reveals that the gold nanoparticles sizes ranges from 30-100 nm with spherical shape synthesized at 37 °C incubation for pH 7.4 with different elemental composition. Nanoparticle Tracking Analysis (NTA) studies also confirmed the concentration of the particles in the range of 6.05×1010 particles/ml. The crystalline nature of the particles was confirmed from an X-ray diffractometer. Fourier transform infrared spectroscopy revealed possible involvement of reductive groups on the surface of gold nanoparticles. Microbial Production method of gold nanoparticles is a low energy requirement, environmental compatibility, scalability, and nanoparticle stabilization compared with the chemical synthesis. © 2014 American Scientific Publishers. All rights reserved.