Practical methods for oceanic uranium extraction have yet to be developed in order to tap into the vast uranium reserve in the ocean as an alternative energy. In the proposed research we aim to develop a reusable, economical protein hydrogel system to sequester large amounts of uranium from seawater efficiently. This hydrogel-based uranium adsorbent will contain a covalent network of super uranyl binding proteins (SUPs) with a strong affinity and excellent specificity toward uranyl ions. The protein network will be synthesized by either 1) reacting two cysteine residues of recombinant ELP-fusion SUP proteins with the chemical crosslinker 4-arm PEG-maleimide under mild conditions, or 2) SpyTag/SpyCatcher chemistry enabling spontaneous covalent bond formation between proteins. Both approaches are environmentally friendly in that the materials are produced mainly through bacterial cellular synthesis and that the two reactions for hydrogel assembly involve no organic solvents and chemical wastes. Microfluidic technologies will further be used to fabricate monodispersed SUP hydrogel microbeads featuring high efficiency, facile separation and reusability, thus greatly reducing the cost for oceanic uranium extraction. The proposed technology has the potential to not only revolutionize the uranium mining and nuclear power industry but also help reduce carbon emission and combat climate change around the globe.