We report a sensor platform for the determination of L-tryptophane. It is based on a carbon paste electrode that was modified with LaCoO3 poriferous nanofibers that were synthesized by electrospinning and subsequent thermal treatment. The structures and morphologies of LaCoO3 poriferous nanofibers were characterized by X-ray diffraction spectrum and scanning electron microscopy. The electrochemical performance of the sensor was evaluated by cyclic voltammetry and amperometry, and the results demonstrated that it exhibits strong electrocatalytical activity towards the oxidation of L-tryptophan in 0.1 mol L-1 phosphate buffer solution (pH 3.0). The linear range of L-tyrosine was 5.0 x 10(-8) to 5.0 x 10(-6) mol L-1 with a low detection limit down to 1.0 x 10(-8) mol L-1. Moreover, the modified electrode exhibited high selectivity, long-term stability and fast current response, demonstrating its feasibility for the analytical purpose.