▎ 摘　　要

NOVELTY - Graphene element comprises a coating layer comprising n-type doped polymer and hygroscopic polymer. USE - The element is useful to sense carbon dioxide (claimed) for portable electronic devices i.e. mobile phones. ADVANTAGE - The element has excellent reaction and recovery speed and electrical characteristics. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for producing graphene element, comprising (a) preparing first solution containing an n-type doped polymer, (b) preparing second solution containing hygroscopic polymer, (c) mixing the first solution and the second solution to prepare mixed solution, and (d) coating the mixed solution on top of graphene.