Ordered mesoporous carbon (OMC) functionalized with poly-azure B (denoted as PAB/OMC) composite-modified electrode was fabricated by electropolymerizing azure B (AB) on the surface of glassy carbon electrode (GCE). OMC provides a conductive network for the polymer immobilization. The new nanocomposite film was characterized by cyclic voltammetry (CV) and scanning electron microscopy (SEM). The results indicated that this poly nanocomposite modified electrode had strong electrocatalytic activity toward the oxidation of dihydronicotinamide adenine dinucleotide (NADH). NADH could effectively accumulate on the modified electrode and generate a sensitive anodic peak at 0.045 V (vs. Ag/AgCl) in pH 7.0 phosphate buffer solution. Under the selected conditions, the anodic peak current of NADH was linear with its concentration within the range from 3.0 to 1000 mu M, and the detection limit was 0.1 mu M (S/N = 3). The low detection potential of the nanocomposite film (0.045 V) also eliminated interferences from other redox-active molecules such as uric acid (UA), dopamine (DA) and ascorbic acid (AA). In comparison with the OMC/GCE or PAB/GCE electrode prepared in the similar way, this composite-modified electrode exhibited better catalytic activity, selectivity and linear range. (C) 2010 Elsevier B.V. All rights reserved.