A microbial biosensor based on Gluconobacter oxydans cells immobilized on the conducting polymer of 4-(2,5-di(thiophen-2-yl)-1H-pyrrol-1-yl)benzenamine (SNS-NH2) coated onto the Surface of graphite electrode was constructed. The proposed biosensor was characterized using glucose as the Substrate. The linear relation was observed in the range of 0.1-2.5 mM and defined by the equation y = 0.415x + 0.377 (R-2 = 0.986). Analytical characterization, effects of electropolymerization time, pH, cell amount and the presence of gold nanoparticles (GNP) on the polymer surface together with the biological material were examined as well. Finally, the system was used for ethanol and glucose detection in real samples. (c) 2008 Elsevier B.V. All rights reserved.