A poly(5-hydroxytryptamine) (poly(5-HT)) modified electrode was fabricated by electropolymerization of 5-hydroxytryptamine (5-HT) on a glassy carbon electrode (GCE) by cyclic voltammetry (CV) in 0.05 M PBS (pH 7). The characterization of poly(5-HT)-modified electrode was carried out by atomic force microscopy (AFM), voltammetry and electrochemical impedance spectroscopy (EIS). Results showed that a brown and heterogeneous film was formed on the surface of the modified electrode. The mechanism of electro-deposition of 5-HT at GCE was discussed. The modified electrode showed good affinity and electrocatalytic properties to some species, such as norepinephrine (NE) and uric acid (UA). Furthermore, the poly(5-HT)-modified electrode could separately detect NE and UA, even in the presence of 10-fold concentration of ascorbic acid (AA). The modified electrode could be stored stable for at least 2 weeks in 0.05 M PBS (pH 4) at 4 degrees C. Owing to its favorable electroactivity, biocompatibility and stability, the prepared poly(5-HT) film could be considered as an immobilization matrix candidate for anchoring of interested biological molecules in the fabrication of biosensors. In addition, the poly(5-HT)-modified GCE was applied successfully to the analysis of NE preparations and healthy human urines. (C) 2013 Elsevier Ltd. All rights reserved.