The reduced graphene oxide was prepared at interface of Au electrode modified by positive charge bearing self-assembled monolayer of N-(6-mercapto)hexylpyridinium. Surface-enhanced Raman spectroscopy (SERS) was employed to probe in situ the potential induced changes in parameters of D- and G-bands. We demonstrated that both D- and G-band wavenumbers linearly depend on the potential with slopes of 4.7 +/- 0.3 and 5.9 +/- 0.3 cm(-1)/V, respectively. The decrease in width of both bands was detected at more positive potentials. The effect was explained in terms of changes in the C-C bond length induced by the electrochemical doping. (C) 2013 Elsevier B. V. All rights reserved.