We report that GCE modified with MWCNTs can be derivatized by the nitroaromatic drug nitrendipine (NTD) ((RS)-ethyl methyl 2,6-dimethyl-4-(3-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylate) simply by dipping the electrode in a solution of 0.1 M Britton-Robinson buffer containing 0.1 mM NTD (pH 2) for 4 min at open circuit. The derivatized electrode is thus reduced, producing the corresponding hydroxylamine derivative-modified electrode, which can be further oxidized to the nitroso derivative. A stable nitroso/hydroxylamine derivative couple appears if the modified electrode is conveniently cycled. With proper selection of the adequate potential, the derivatized electrode can be modified as nitroso or hydroxylamine derivatives. (C) 2011 Elsevier B.V. All rights reserved.