Removing Metal Ions from Water with Graphene⁻Bovine Serum Albumin Hybrid Membrane.

Here we report the fabrication of graphene oxide (GO)-based membranes covalently combined with bovine serum albumin (BSA) for metal ions detection. In this system, BSA acts as a transporter protein in the membrane and endows the membrane with selective recognition of Co2+, Cu2+, AuCl₄-, and Fe2+. Combining the metal-binding ability of BSA and the large surface area of GO, the hybrid membrane can be used as a water purification strategy to selectively absorb a large amount of AuCl₄- from HAuCl₄ solution. Moreover, BSA could reduce the membrane-immobilized AuCl₄- by adding sodium borohydride (NaBH₄). Interestingly, adsorption experiments on three kinds of metal ions showed that the GO⁻BSA membrane had good selective adsorption of Co2+ compared with Cu2+ and Fe2+. The morphology and composition changes of the membrane were observed with atomic force microscopy (AFM) and Raman spectroscopy, respectively. It is expected that this facile strategy for fabricating large-scale graphene-biomolecule membranes will spark inspirations in the development of functional nanomaterials and wastewater purification.