Three kinds of nanostructured resorcinol-formaldehyde (RF) carbonized polymers were prepared in different acidic solutions such as 0.2 M HCl, 02 M H2SO4 and 0.2 M HAc. Measurements of scanning electron microscopy and nitrogen adsorption-desorption isotherms indicated that the morphology and surface area of the prepared polymers were heavily dependent on the used reaction medium. The oxidation behaviors of amaranth revealed that the prepared polymers displayed different electrochemical reactivity toward the oxidation of amaranth. On the surface of RF carbonized polymers, the oxidation signals of amaranth enhanced obviously, and the prepared RE-1 carbonized polymer in 0.2 M HCl was more active for the oxidation of amaranth. As a result, a novel electrochemical sensor with high sensitivity was developed for amaranth. It was used in the drink sample analysis, and the detected results consist with the values that obtained by high-performance liquid chromatography. (C) 2016 Elsevier B.V. All rights reserved.