Biomimetic Selective Ion Transport through Graphene Oxide Membranes Functionalized with Ion Recognizing Peptides

Membranes that differentiate ions are being actively developed to meet the needs in separation, sensing, biomedical, and water treatment technologies. Biomimetic approaches that combine bioinspired functional molecules with solid state supports offer great potential for imitating the functions and principles of biological ion channels. Here we report the design and fabrication of biomimetic graphene oxide (GO) based membranes functionalized with a peptide motif that has the capabilities for selective recognition and transport. The peptide, which has ion binding affinity to Co2+ ions, was adopted to enable the ion selective filtration capability and was then anchored on a GO surface. The resulting GO-based membranes show remarkable ion selectivity toward the specific ion of interest, for the transport across the membranes as in the biological ion channels. Ion recognition capability of this peptide motif successfully translates into ion specificity for selective transport. This study provides a new avenue for developing artificial ion channels via a synergistic combination of biomimetic recognition chemistry, with a novel nanoplatform such as GO.