Indole-3-carboxaldehyde (In3C) monomer was oxidized by electrochemical methods at the glassy carbon (GC) electrode in 0 05 M tetrabutylammonium tetrafluoroborate in acetonitrile with the aim to prepare a modified electrode Modification was performed using cyclic voltammetry (CV) scanning from 0 0 V to 2 0 V at a scan rate of 50 mV s(-1) for 10 cycles in 1 mM In3C monomer solution The modified GC surface (In3C-GC) was characterized by CV response of potassium ferricyanide and ferrocene redox probes as well as by the electrochemical impedance spectroscopy The modified surface was analyzed by reflection-absorption infrared spectroscopy and compared with the spectrum of the monomeric In3C Elemental composition of the surface was determined by X-ray photoelectron spectroscopy Contact angle measurements was also performed to check the changes in hydrophobic character of the bare GC and compared to that of In3C-GC surface Thickness of the oligomeric/polymeric film was investigated by ellipsometric measurements and a surface confined polymerization mechanism was proposed (c) 2010 Published by Elsevier B V