This work describes for the first time the modification of a glassy carbon electrode with a hybrid material formed by the dispersion of multi-walled carbon nanotubes in the metallopolymer P4VP-Fe(CN)5. The reversible redox couple of the material was formed at relatively low overpotential and showed a good electrocatalytic activity toward cysteine electrooxidation. The cathodic shift of the oxidation process for the modified electrode was 500 mV compared to the bare glassy carbon electrode. The rate constant (K-obs) for the chemical reaction between the redox mediator and cysteine was found to be 8.95 x 10(3) Lmol(-1) s(-1). The analytical curve was found to be linear from 20.5 up to 151 nmol L-1, with a sensitivity of 0.996 nA L nmo1(-1) and response time of 0.1 s. (C) 2013 Elsevier Ltd. All rights reserved.