NOVELTY - The sensor (10) has a substrate (20) e.g. glass substrate, provided with two electrodes e.g. platinum electrodes, that are placed on the substrate. A carbon nanotube-polyaniline (CNT/PANI) film is placed on the substrate and in contact with the two electrodes. The film comprises carbon nanotubes coated with a layer of polyaniline such that electron transportation is occurred along and between the carbon nanotubes. The layer is transparent to electron tunneling. Average thickness of polyaniline coating on a surface of CNTs e.g. nanowires, is less than average diameter of the nanotubes.    USE - Electrochemical sensor e.g. nanomaterial-based pristine CNT gas sensor such as single-walled nanotubes (SWNT) or multi-walled nanotubes (MWNT) sensor, sulfonated conducting polymer PANI sensor, and gas detection instrument, for detecting or sensing a gaseous analyte i.e. ammonia (claimed), for an application e.g. industrial health and safety application, environmental monitoring application and process controlling applications, chemical and petroleum refining application, rocket fuel production application, fuel cell manufacturing application, semiconductor processing application and biomedical application, utilized in a gaseous environment. Can also be used for detecting or sensing hydrogen, hydrogen sulfide, nitrogen dioxide, water vapor, oxygen and methane.    ADVANTAGE - The sensor does not require complex fabrication process or high operating temperatures. The sensor has better sensing properties such as high sensitivity, low resistivity, high resolution, low detection limits, fast response and recovery times, better reproducibility, better selectivity in the detection of gases and long term stability, at low analyte concentrations.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for a method for making an electrochemical sensor for sensing a gaseous analyte.    DESCRIPTION OF DRAWING(S) - The drawing shows a photograph of an electrochemical sensor.    Electrochemical sensor (10)    Substrate (20)    Contact areas (22)    Substrate holder (24)    Active area (30)