We report on the electrochemical behavior of chemically modified glassy carbon (GC) electrodes by using surfactant/hydrotalcite (HT) films, incorporating ferrocenedicarboxylic acid (FDC) as redox mediators for NADH. The FDC retained in the films displayed two well-defined voltammetric peaks. They correspond to the redox process ferrocene/ferrocenium. The type of surfactants adsorbed have a pronounced effect on the FDC adsorption on the HT. The modified electrodes are found to give stable and reproducible electrocatalytic response to NADH and axhibit good stability.