Study on Bactericidal Effect of Biosynthesized Silver Nanoparticles in Combination with Gentamicin and Ampicillin on Pseudomonas aeruginosa

Abstract

Silver nanoparticles are the most promising nanomaterial with antibacterial properties. Recent study of resistance to most potential antibiotics promotes research in the bactericidal activity of the silver nanoparticles. In this work, the effect of biosynthesized silver nanoparticles, in combination with gentamicin and ampicillin, on Pseudomonas Aeruginosa bacteria has been studied. Pseudomonas Aeruginosa is a common bacterium that can cause infections which are generalized as inflammation and sepsis. The results show that the bactericidal properties of the nanoparticles depends on the size of the as-synthesized silver nanoparticles as nanoparticles of diameter ~120 nm only have a direct interaction with the bacteria. It is observed that the antibacterial activities of antibiotics increase in the presence of AgNPs against test strains. Silver nanoparticles were synthesized elctrolytically using silver wire of 99% purity as anode and carbon rod wrapped with LDPE as cathode. 0.01 N Silver nitrate was used as an electrolyte. The process is termed as biosynthesis, because tea extract was used used as the capping agent which is also a very mild reducing agent. The polyphenols theaflavins and thearubigins, present in tea perform the role of stabilizing or capping agents due to their bulky and steric nature. A brown colored colloidal solution of silver nanoparticles is obtained. The as-synthesized silver nanoparticles were characterized using XRD, TEM and UV-Vis spectroscopy.