title: Biosensing for the environment and defence: aqueous uranyl detection using bacterial surface layer proteins.
abstract: The fabrication of novel uranyl (UO(2)(2+)) binding protein based sensors is reported. The new biosensor responds to picomolar levels of aqueous uranyl ions within minutes using Lysinibacillus sphaericus JG-A12 S-layer protein tethered to gold electrodes. In comparison to traditional self assembled monolayer based biosensors the porous bioconjugated layer gave greater stability, longer electrode life span and a denser protein layer. Biosensors responded specifically to UO(2)(2+) ions and showed minor interference from Ni(2+), Cs(+), Cd(2+) and Co(2+). Chemical modification of JG-A12 protein phosphate and carboxyl groups prevented UO(2)(2+) binding, showing that both moieties are involved in the recognition to UO(2)(2+).
authors.affiliation: Biosensors and Biocatalysis Group, Institute of Membranes and Systems Biology, University of Leeds, Leeds, LS2 9JT, UK. sms4dc@leeds.ac
authors.forename: David J R
authors.initials: DJ
authors.lastname: Conroy
authors.forename: Paul A
authors.initials: PA
authors.lastname: Millner
authors.forename: Douglas I
authors.initials: DI
authors.lastname: Stewart
authors.forename: Katrin
authors.initials: K
authors.lastname: Pollmann
mesh_terms: D001407:Bacillus / Q000378:metabolism*; D015374:Biosensing Techniques / Q000379:methods*; D002959:Civil Defense / Q000379:methods*; D025802:Electric Capacitance; D004784:Environmental Monitoring / Q000379:methods*; D008562:Membrane Glycoproteins / Q000378:metabolism*; D008855:Microscopy, Electron, Scanning; D013499:Surface Properties; D017974:Uranium Compounds / Q000032:analysis*; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D008562:Membrane Glycoproteins; C055764:S-layer proteins; D017974:Uranium Compounds; D014874:Water Pollutants, Chemical