This paper describes the development and utilization of a new nanocomposite consisting of benzofuran derivative-functionalized multiwalled carbon nanotubes and ionic liquid (IL) for glassy carbon electrode modification. A pair of well-defined redox peaks of benzofuran derivative was obtained at the glassy carbon (GC) electrode by direct electron transfer between the benzofuran derivative and the GC electrode. The novel sensor shows excellent electrocatalytic activities toward the oxidation of norepinephrine (NE) and serotonin (5-HT). Furthermore, no obvious interference was found for the detection of NE and 5-HT in the presence of common interferents such as ascorbic acid and uric acid that coexists compounds with NE and 5-HT in biological systems. Differential pulse voltammetry (DPV) exhibited two linear dynamic ranges of 0.1-30.0 mu M and 30.0-1000.0 mu M for NE and one linear dynamic ranges of 5.0-900.01 mu M for 5-HT. The detection limits for NE and 5-HT were found to be 49 nM and 2 mu M, respectively. The proposed sensor was successfully applied for the determination of NE and 5-HT in human serum. (c) 2014 Elsevier B.V. All rights reserved.