In the present study, a novel electrode based on 2,9-dihydroxy-1,10-diphenoxy-4,7-dithiadecane (DHDPDTD) that is selective to cerium (III) cations was evaluated electrochemically, and a Nerenstian slope (19.3 +/- 1 mV decade(-1)) over a concentration range of 1.0 x 10(-8)-1.0 x 10(-1) M and a detection limit of 2.1 x 10(-9) M were observed. The proposed electrochemical sensor displayed a rapid response time of 10 s, improved selectivity towards Ce (III) cations in the presence of alkali, alkaline earth, transition and heavy metal cations, and could be used in a pH range of 5.0-8.0. Additionally, the proposed sensor was used as an indicator in the potentiometric titration of fluoride and the determination of F- ions in real samples. (C) 2011 Elsevier Ltd. All rights reserved.