Abstract

Biological processes using microorganisms for nanoparticle synthesis are appealing as eco-friendly nanofac-tories. The response of the photosynthetic bacterium Rhodobacter sphaeroides to gold exposure and its reducingcapability of Au(III) to produce stable gold nanoparticles (AuNPs), using metabolically active bacteria andquiescent biomass, is reported in this study.In the former case, bacterial cells were grown in presence of gold chloride at physiological pH. Gold exposurewas found to cause a significant increase of the lag-phase duration at concentrations higher than 10 ?M, sug-gesting the involvement of a resistance mechanism activated by Au(III). Transmission Electron Microscopy(TEM) and Scanning Electron Microscopy/Energy Dispersive X-ray Spectrometry (SEM/EDS) analysis of bac-terial cells confirmed the extracellular formation of AuNPs.Further studies were carried out on metabolically quiescent biomass incubated with gold chloride solution.The biosynthesized AuNPs were spherical in shape with an average size of 10 ± 3 nm, as analysed byTransmission Electron Microscopy (TEM). The nanoparticles were hydrophilic and stable against aggregation forseveral months.In order to identify the functional groups responsible for the reduction and stabilization of nanoparticles,AuNPs were analysed by Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FTIR) spectroscopy, X-ray Photoelectron Spectroscopy (XPS), X-ray Fluorescence Spectrometry (XRF) and X-ray AbsorptionSpectroscopy (XAS) measurements. The obtained results indicate that gold ions bind to functional groups of cellmembrane and are subsequently reduced by reducing sugars to gold nanoparticles and capped by a protein/peptide coat.Gold nanoparticles demonstrated to be efficient homogeneous catalysts in the degradation of nitroaromaticcompounds.

Autore Pugliese

• Carrozzini Benedetta , Trotta Massimo , Comparelli Roberto , Melillo Maria Teresa

Tutti gli autori

• F. Italiano; A. Agostiano ; B.D. Belviso; R. Caliandro;B. Carrozzini; R. Comparelli; M.T. Melillo; E. Mesto;G.Tempesta; M. Trotta

Titolo volume/Rivista

Colloids and surfaces. B, Biointerfaces

Anno di pubblicazione

2018

ISSN

0927-7765

ISBN

Non Disponibile

Numero di citazioni Wos

Nessuna citazione

Ultimo Aggiornamento Citazioni

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Numero di citazioni Scopus

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Ultimo Aggiornamento Citazioni

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Settori ERC

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Codici ASJC

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