This article reports the results of novel polyaniline material as gas sensor, capable of operating at room temperature for toxic gases. Polyaniline-maleicacid-dodecylhydrogensulfate salt (PANI-MA-DHS) was prepared by emulsion polymerization pathway, which is soluble in N, N-dimethyl formamide. PANI-MA-DHS was coated on a ceramic bead by simple brush coating method and used as sensor material. The resistance change of PANT-MA-DHS material for NH3, CO2, SO2, and H2S gases at different concentrations (10, 100, 1000, and 10,000 ppm level) was monitored for sensor characteristics. The stability of the polyaniline material under continuous exposure of gas level from 10 to 10,000 ppm was also studied. This novel gas sensor material has advantages such as excellent sensing ability, low cost, fast regeneration time (similar to 1-2 min), simple experimental setup, and operable at room temperature. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 118: 518-524, 2010