A novel electrochemical dopamine sensor was fabricated based on a composite film solely consisting of kappa-carrageenan and hierarchical porous carbon drop-casted onto a glassy carbon electrode in a conventional three electrode system. Graphene oxide was synthesized in a one-step thermal conversion from base-catalyzed alkali lignin. Five ratios by mass of a novel hierarchical porous activated carbon and kappa-carrageenan were studied for dopamine quantification without synthetic binders such as polytetrafluoroethylene. Various tests were performed to explicate structure and electrochemical properties of the films. Utilizing differential pulse voltammetry for detection, the optimized 10:1 ratio system elicited a linear range of 1–250 μmol l−1 and a limit of detection of 0.14 μmol l−1 (S/N = 3). Results suggested an effective new combination of materials for non-enzymatic dopamine sensing.