Title
Arsenate reductase from Thermus thermophilus conjugated to polyethylene glycol-stabilized gold nanospheres allow trace sensing and speciation of arsenic ions
Author
Jane Politi, Jolanda Spadavecchia, Gabriella Fiorentino, Immacolata Antonucci, Luca De Stefano
Year
2016
Journal
Journal of the Royal Society
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, TtArsCenzyme 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−12 and 7.7 ± 0.3 M−12 for As(III) and As(V), respectively.
Instrument
J-815
Keywords
Circular dichroism, Secondary structure, Chemical stability, Nanostructures, Materials, Biochemistry