title: Bulk protonic conductivity in a cephalopod structural protein.
abstract: Proton-conducting materials play a central role in many renewable energy and bioelectronics technologies, including fuel cells, batteries and sensors. Thus, much research effort has been expended to develop improved proton-conducting materials, such as ceramic oxides, solid acids, polymers and metal-organic frameworks. Within this context, bulk proton conductors from naturally occurring proteins have received somewhat less attention than other materials, which is surprising given the potential modularity, tunability and processability of protein-based materials. Here, we report proton conductivity for thin films composed of reflectin, a cephalopod structural protein. Bulk reflectin has a proton conductivity of ~2.6 × 10(-3) S cm(-1) at 65 °C, a proton transport activation energy of ~0.2 eV and a proton mobility of ~7 × 10(-3) cm(2) V(-1) s(-1). These figures of merit are similar to those reported for state-of-the-art artificial proton conductors and make it possible to use reflectin in protein-based protonic transistors. Our findings may hold implications for the next generation of biocompatible proton-conducting materials and protonic devices.
authors.affiliation: Department of Chemical Engineering and Materials Science, University of California, Irvine, Irvine, California 92697, USA.
authors.forename: David D
authors.initials: DD
authors.lastname: Ordinario
authors.affiliation: Department of Chemical Engineering and Materials Science, University of California, Irvine, Irvine, California 92697, USA.
authors.forename: Long
authors.initials: L
authors.lastname: Phan
authors.affiliation: Department of Chemical Engineering and Materials Science, University of California, Irvine, Irvine, California 92697, USA.
authors.forename: Ward G
authors.initials: WG
authors.lastname: Walkup
authors.affiliation: Department of Chemical Engineering and Materials Science, University of California, Irvine, Irvine, California 92697, USA.
authors.forename: Jonah-Micah
authors.initials: JM
authors.lastname: Jocson
authors.affiliation: Department of Chemical Engineering and Materials Science, University of California, Irvine, Irvine, California 92697, USA.
authors.forename: Emil
authors.initials: E
authors.lastname: Karshalev
authors.affiliation: Department of Chemical Engineering and Materials Science, University of California, Irvine, Irvine, California 92697, USA.
authors.forename: Nina
authors.initials: N
authors.lastname: Hüsken
authors.affiliation: 1] Department of Chemical Engineering and Materials Science, University of California, Irvine, Irvine, California 92697, USA [2] Department of Chemistry, University of California, Irvine, Irvine, California 92697, USA.
authors.forename: Alon A
authors.initials: AA
authors.lastname: Gorodetsky
mesh_terms: D000818:Animals; D049830:Cephalopoda / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry*; D061766:Proton Therapy
chemical_list: D011108:Polymers