title: Arsenate reductase from Thermus thermophilus conjugated to polyethylene glycol-stabilized gold nanospheres allow trace sensing and speciation of arsenic ions.
abstract: Water sources pollution by arsenic ions is a serious environmental problem all around the world. Arsenate reductase enzyme (TtArsC) from Thermus thermophilus extremophile bacterium, naturally binds arsenic ions, As(V) and As (III), in aqueous solutions. In this research, TtArsC enzyme adsorption onto hybrid polyethylene glycol-stabilized gold nanoparticles (AuNPs) was studied at different pH values as an innovative nanobiosystem for metal concentration monitoring. Characterizations were performed by UV/Vis and circular dichroism spectroscopies, TEM images and in terms of surface charge changes. The molecular interaction between arsenic ions and the TtArsC-AuNPs nanobiosystem was also monitored at all pH values considered by UV/Vis spectroscopy. Tests performed revealed high sensitivities and limits of detection equal to 10 ± 3 M-12and 7.7 ± 0.3 M-12for As(III) and As(V), respectively.
authors.affiliation: Institute for Microelectronics and Microsystems, Unit of Naples-National Research Council, via P. Castellino 111, 80127 Naples, Italy.
authors.forename: Jane
authors.initials: J
authors.lastname: Politi
authors.affiliation: Sorbonne Universités, UPMC Univ Paris VI, Laboratoire de Réactivité de Surface, 4 place Jussieu, 75005 Paris, France CNRS, UMR 7244, CSPBAT, Laboratoire de Chimie, Structures et Propriétés de Biomateriaux et d'Agents Therapeutiques Université Paris 13, Sorbonne Paris Cité, Bobigny, France CNRS, Paris, France.
authors.forename: Jolanda
authors.initials: J
authors.lastname: Spadavecchia
authors.affiliation: Department of Biology, University of Naples 'Federico II', Via Cynthia, 80126 Naples, Italy.
authors.forename: Gabriella
authors.initials: G
authors.lastname: Fiorentino
authors.affiliation: Department of Biology, University of Naples 'Federico II', Via Cynthia, 80126 Naples, Italy.
authors.forename: Immacolata
authors.initials: I
authors.lastname: Antonucci
authors.affiliation: Institute for Microelectronics and Microsystems, Unit of Naples-National Research Council, via P. Castellino 111, 80127 Naples, Italy luca.destefano@na.imm.cnr.it.
authors.forename: Luca
authors.identifier: 0000-0002-9442-4175
authors.initials: L
authors.lastname: De Stefano
mesh_terms: D053502:Arsenate Reductases / Q000737:chemistry*; D001151:Arsenic / Q000032:analysis*; D001426:Bacterial Proteins / Q000737:chemistry*; D015374:Biosensing Techniques / Q000379:methods*; D004800:Enzymes, Immobilized / Q000737:chemistry; D006046:Gold / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D011092:Polyethylene Glycols / Q000737:chemistry*; D016963:Thermus thermophilus / Q000201:enzymology*
chemical_list: D001426:Bacterial Proteins; D004800:Enzymes, Immobilized; D011092:Polyethylene Glycols; D006046:Gold; D053502:Arsenate Reductases; D001151:Arsenic; C000595209:polyethylene glycol 1000
keywords: arsenic pollution; enzyme; gold nanoparticles