New sensing platform based on modified glassy carbon (GC) suitable for design of heavy metal-ion sensor is reported in this study. GC-based electrodes were electrochemically modified by poly-5-nitro-1,10-phenanthroline (poly-5NP) and poly-5-amino, 6-nitro-1,10-phenanthroline (poly-5A6NP) layers. Grafting of electrochemically formed poly-5NP and poly-5A6NP layers at the GC electrode surface was confirmed by electrochemical reduction of nitro groups into amine groups. Presence of grafted poly-5NP and poly-5A6NP layers and formation of their reduced forms on the GC electrode surface were verified by cyclic voltammetry, electrochemical impedance spectroscopy, contact angle measurements, ellipsometry and X-ray photoelectron spectroscopy. The applicability of poly-5NP- and poly-5A6NP-functionalized carbon surfaces for the determination of Cu(II) ions was demonstrated by formation of complexes between GC-grafted poly-5NP and poly-5A6NP layers and Cu(II) ions. © 2012 Elsevier B.V. All rights reserved.