Biosynthesis of silver nanoparticle using citrus plants and its antimicrobial activity

Plant extract from C. aurantium and Punica granatum was used for the synthesis of silver nano-particles (AgNPs) from silver nitrate solution. AgNPs were characterized by UV–visible spectrophotometer, change in colour was visually observed in the silver nitrate solution added to the biological extracts. The bio reduction of precursor silver ions was monitored by sampling of aliquots (1ml) at different time intervals. Absorption measurements were carried out on UV–visible spectrophotometer at a resolution of 1 nm. UV Visible analysis of several weeks old samples was also carried out to check the stability of Silver nanoparticle. Among inorganic antibacterial agents, silver has been employed most extensively since ancient times to fight infections and control spoilage. The antibacterial activity of biologically produced was tested on different E.coli, P. aeruginosa, S. aureus, B. subtilis bacteria. The inhibition tests were carried out by the disc diffusion method. Growth inhibition of bacteria by AgNPs were compared with AgNO3 solution and found that AgNPs were competent enough with AgNO3 solution. The Ag NPs synthesized in this process has the efficient antimicrobial activity against pathogenic bacteria. Of these, silver nano-particles are playing a major role in the field of nanotechnology and nanomedicine.