title: Green synthesis of silver and gold nanoparticles employing levan, a biopolymer from Acetobacter xylinum NCIM 2526, as a reducing agent and capping agent.
abstract: With a vision of finding greener materials to synthesize nanoparticles, we report the production and isolation of levan, a polysaccharide with repeating units of fructose, from Acetobacter xylinum NCIM2526. The isolated levan were characterized using potassium ferricyanide reducing power assay, Fourier transform infra-red (FTIR) spectroscopy and (1)H nuclear magnetic resonance spectroscopy ((1)H NMR). To exploit levan in nanotechnology, we present a simple and greener method to synthesize silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs) using biopolymer, levan as both reducing and stabilizing agents. The morphology and stability of the AgNPs and AuNPs were examined by transmission electron microscopy (TEM) and UV-vis absorption (UV-vis) spectroscopy. The possible capping mechanism of the nanoparticles was postulated using FTIR studies. As synthesized biogenic nanoparticles showed excellent catalytic activity as evidenced from sodium borohydride mediated reduction of 4-nitro phenol and methylene blue.
authors.affiliation: Department of Chemistry, School of Chemical and Biotechnology, SASTRA University, Thanjavur, Tamil Nadu, India.
authors.forename: Khan Behlol Ayaz
authors.initials: KB
authors.lastname: Ahmed
authors.affiliation: Department of Biotechnology, School of Chemical and Biotechnology, SASTRA University, Thanjavur, Tamil Nadu, India.
authors.forename: Divya
authors.initials: D
authors.lastname: Kalla
authors.affiliation: Department of Biotechnology, School of Chemical and Biotechnology, SASTRA University, Thanjavur, Tamil Nadu, India. Electronic address: kiranbabu@scbt.sastra.edu.
authors.forename: Kiran Babu
authors.initials: KB
authors.lastname: Uppuluri
authors.affiliation: Department of Chemistry, School of Chemical and Biotechnology, SASTRA University, Thanjavur, Tamil Nadu, India. Electronic address: anbazhagan@scbt.sastra.edu.
authors.forename: Veerappan
authors.initials: V
authors.lastname: Anbazhagan
mesh_terms: D001704:Biopolymers / Q000737:chemistry; D002384:Catalysis; D005630:Fructans / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism; D041822:Gluconacetobacter xylinus / Q000737:chemistry* / Q000378:metabolism; D006046:Gold / Q000737:chemistry; D055772:Green Chemistry Technology / Q000379:methods*; D053768:Metal Nanoparticles / Q000737:chemistry*; D008751:Methylene Blue / Q000737:chemistry; D046529:Microscopy, Electron, Transmission; D009596:Nitrophenols / Q000737:chemistry; D019163:Reducing Agents / Q000737:chemistry; D012834:Silver / Q000737:chemistry; D013056:Spectrophotometry, Ultraviolet; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D001704:Biopolymers; D005630:Fructans; D009596:Nitrophenols; D019163:Reducing Agents; D012834:Silver; D006046:Gold; C072599:levan; D008751:Methylene Blue; C024836:4-nitrophenol
keywords: Acetobacter xylinum; Catalyst; Gold nanoparticles; Levan; Silver nanoparticles