We report a facile synthesis of electrospun RuO2-Co3O4 hybrid nanotubes as well as their enhanced electrochemical responses. Among all RuO2-Co3O4 hybrid nanotubes, the polycrystalline RuO2-Co3O4 hybrid nanotubes with optimum relative atomic ratios of Ru/Co=2.3:1.0 show the highly efficient catalytic activity for oxygen reduction reaction (ORR). Additionally, the nanotubes represent the favorable electrochemical sensing behavior for ascorbic acid, resulting in the high sensitivity of 204 mu AmM(-1)cm(-2), the low detection limit of 6.6 mu M, and the broad dynamic range without the interference from other biological relevant species. (C) 2014 Elsevier B.V. All rights reserved.