A method and reagent for detecting the presence or amount of an analyte by a redox reaction and a fluorimetric determination, is disclosed. The reagent comprises a compound of the general formula Q-F as a redox indicator, wherein Q is a quencher group and F is a fluorophore group. The quencher group Q or/and the fluorophore group F can be reduced or oxidized, and the fluorescence can change depending on the reduction or oxidation.