The Stability of Silver Nanoparticles For Time, Temperature, pH And Antibacterial activities against Gram-Negative Bacteria (Escherichia coli)

Abstract

In this study, silver nanoparticles were synthesized by chemical method (chemical reduction method) using AgNO3 and BH4as starting materials in the presente of Sodium dodecyl sulfate (SDS) as a stabilizer. The obtained Ag nanoparticles were characterized by UV/Vis absorption at about 400 nm. Ddifferent concentrations of silver nitrate (0.1 mM, 0 and 2 mM, 0.5 mM, 1 mM) were used as initial concentration. The stability of AgNPs was measured by UV up to 3 months. The intensities of the Surface Plasmon Resonance(SPRs) progressively increase with temperature, and the position of SPRs was red-shifted to longer wavelength. In addition The absorption was increased with an increase in pH and gives the narrow peak at pH 7-8. Hence, the neutral condition is favored for controlling the particle size. The results showed that, the AgNPs have antibacterial activity against E. coli (Gram negative bacteria).