Biosensing for the environment and defence: aqueous uranyl detection using bacterial surface layer proteins.

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.