Development of new nanoparticle compositions is of the greatest concern to derive alternative successful applications in different fields. Little is known, however, about the electrochemical characterization of the arsenic-doped cysteine-capped ceramic-based nanoparticles. In this work, several arsenic-doped cysteine-capped thoria-/zirconia-based nanoparticles were prepared for the first time and used as electrode material for its characterization by cyclic voltammetry. This approach takes advantage particularly of the quantitative oxidation of arsenic to arsenite, after previous reduction of arsenite to arsenic. Besides, electroanalytical sensing of cysteine, together with additional information about the cysteine and arsenic interactions were also clearly demonstrated. (C) 2013 Elsevier Ltd. All rights reserved.