A novel ammonia sensor was fabricated based on silver sulfide film and its responses to seventeen gases were investigated. The sensor showed high response to NH3 at room temperature. The most sensitive sensor to NH3 was the sensor based on Ag2S prepared with H2S at 323 K. The response value reached 297 to 7.08% of NH3 at 2 V operating voltage. The linearity of the response in the NH3 gas concentration range from 0.084 to 6.08% at 5 V operating voltage suggests the sensor can be reliably used to monitor the concentration of NH3 gas in this range. The sensor for determination of unknown concentration of ammonia real sample had good consistency with the traditional Nessler's reagent spectrophotometry. (C) 2014 Elsevier Ltd. All rights reserved.