Comparative antimicrobial activity of phytofabricated Ag and Au nanoparticles from ledebouria hydrabadensis rhizome using various methods

Abstract

The paper reports the comparative study, synthesis and evaluation of antimicrobial activity of silver (Ag) and gold (Au) nanoparticles. These are phytofabricated from root bulb extract of medicinal plant Ledebouria hyderabadensis using various methods such as stirring, sonication and autoclave. Synthesized Ag and Au nanoparticles characterized by multiple instrumental techniques such as the UV-Visible spectroscopy, the maximum absorption peak noted at 436 nm and 556 nm indicate the formation of metallic colloidal Ag and Au nanoparticles respectively. The Fourier transform infrared spectroscopy of Ag and Au nanoparticles indicates the phytochemicals proteins, alcohols and phenols present in the Ledebouria hyderabadensis rhizome extract involving in the reduction and stabilization by capping around the Ag and Au nanoparticles. The average particle size found to be below 50 nm in all the cases except Ag nanoparticles synthesized by the stirring method. The transmission electron microscopy images clearly indicating the nano-sized monoclinic, polyclinic, anisotropic, polydistributed, spherical shaped particles. These Ag and Au nanoparticles exhibited profound antimicrobial activity against harmful tested phytopathogenic fungi Sclerotium rolfsii, Rhizoctonia solani and human pathogenic fungi Aspergillus flavus as well as against human harmful bacteria Escherichia coli, Bacillus subtilis used in this experimentt.