The problem of uranium contamination is a source of great concern. Uranium can have severe detrimental health effects (it is particularly harmful to the liver, kidney and bones) and lead to environment issues (chemical and radioactive hazards). Current treatment options available for uranium leaks in nuclear power plants or uranium pollution around ore-fields, such as ion exchange or flocculation-setting and phytoremediation, all have limitations including their high cost, low efficiency and the sheer complexity of the involved procedures.

To address these problems, the Peking iGEM team aims to construct a novel functional biomaterial consisting of multiple functional protein modules. This material is designed to be produced and secreted by bacteria, and automatically self-assemble to form a protein hydrogel. In combination with a specific uranium-binding protein module, it obtains the ability to adsorb uranyl ions. After very short contacting with polluted water, the uranyl-laden biomaterial, which also contains a monomeric streptavidin module, can be easily retrieved using biotinylated magnetic beads.

This uranyl-binding biomaterial shows many advantages, such as high specificity, high efficiency, self-assembly and renewability. Furthermore, the uranyl-binding module can be replaced or combined with modules that are capable of binding other heavy metal ions, as well as fluorescent proteins, obtaining multi-functionality. By taking advantage of modularization in the design, additional applications beyond uranium adsorption can be developed based on this material in the future.