Microbial Mediated Fabrication of Ag and TiO2 Nanoparticles for Bacterial Inhibition

Introduction: Microorganisms are world of their own multiplying in millions by reproduction and creating problems to human lives and environment. In this light, it is necessary to transform them into useful product to solving challenges by investigating their inhibition to bacterial growth.

Method: In the current study, Pseudomonas aeruginosa was applied for the synthesis of silver and titanium oxide nanoparticles (Ag NPs and TiO2 NPs). The nanoparticles were prepared from the supernatant solution of the cultured organism of Pseudomonas aeruginosa and the silver nitrate solution and titanium tetraisopropoxide solution. The microbial assisted synthesized nanoparticles were characterized for UV-Visible spectrophotometer, Fourier Transform Infrared (FTIR) spectrophotometer, Powder X-ray Diffraction (PXRD), Transmission Electron Microscope (TEM), Scanning Electron Microscope (SEM) and Energy Dispersive Spectrophotometer (EDS).

Results: UV–Visible spectra provided the absorption maxima at the wavelength of 414 nm for Ag NPs and 390 nm for TiO2 NPs. The FTIR spectra provided N–H stretch absorption for peptide linkages, O–H stretch of carboxylic acid, amide bend and –C––O stretch which may could have be linked to the micro-organism. The PXRD analysis of both Ag NPs and TiO2 NPs confirmed their crystallography structures. SEM results showed that both nanoparticles show true sphericity with porous surface. TEM analysis revealed that the particles were well dispersed without agglomeration with average particle size of 7.27 and 6.83 nm respectively. The EDS revealed elemental constituents showing Ag and Ti to be more dominant in their weight percentages. The antibacterial characterization using the biosynthesized nanoparticles provided a significant inhibition against disease causing microorganisms, and TiO2 NPs was found to be superior to Ag NPs and the control drugs.