Two enantioselective, potentiometric membrane electrodes (EPMEs) based on carbon paste impregnated with [5-6] fullerene-C-70 (I) and diethyl (1,2-methanofullerene C-70)-71-71-dicarboxylate (II) for the enantioanalysis of S-clenbuterol are reported. The electrodes exhibited near-Nernstian (higher than 55.00 mV/decade of concentration) responses only over S-clenbuterol in the following concentration ranges: 10(-10) - 10(-5) and 10(-9) - 10(-4) mol/L, for (I) and (II), respectively. The limits of detection were of 10(-11) and 10(-10) mol/L magnitude order, for EPMEs based on (I) and (II), respectively. The proposed electrodes proved to be successful for the enantioanalysis of S-Clenbuterol as raw material and from serum samples: average recovery of S-Clen in serum samples being higher than 98.40%, with RSD values not exceeding 1.25%. (C) 2015 The Electrochemical Society. All rights reserved.